Downloads and Free Reading Options

A systematic review

Current therapies for invasive and metastatic prostate cancer are not curative and prolong survival by nearly a year even in patients with a metastatic disease. Metastasis is a multi-step process wherein tumor cells acquire properties that enable them to detach, migrate, gain access to conduits, and disseminate throughout the body. The dissemination of cancer from the primary carcinoma mass requires a loosening of the cell-cell bonds. Previous investigations have demonstrated that the epidermal growth factor receptor (EGFR) promotes tumor cell invasiveness and metastasis. However, the regulatory control of metastasis genes have not explored the key molecular events mediated by the EGFR induced responses. Recently, Kaiso a biomodal transcription factor, has been shown to be associated with, many cancer-related genes which function as tumor suppressor, such as cell cycle regulator CDKN2A (P16), TIMPS and E-cadherin. However, a direct link between Kaiso and metastasis as not been shown. Therefore, we hypothesized that Kaiso fits into the EGFR signaling cascade, and is associated with EGFR induced cell migration and metastasis.

This article is from Journal for Immunotherapy of Cancer , volume 1 . Abstract None

This article is from Journal for Immunotherapy of Cancer , volume 1 . Abstract None

Key webinar highlights: Recognizing the "friend or foe" relationship between (blood) cancer and immunity Leveraging on the immunotherapies for malignant and nonmalignant (hematological) tumors Need for next-generation immune monitoring

The reactive stroma microenvironment is important to prostate cancer, however specific mechanisms of its role in regulating prostate cancer progression are poorly understood. Human lung, breast, and colon carcinomas all exhibit alterations in the stromal compartment, yet the specific composition, the origin of reactive cells, and the factors that regulate this evolution are understudied. The myofibroblast appears to be a key component of carcinoma associated reactive stroma. This highly synthetic cell with a contractile phenotype is not observed in the normal human prostate and its appearance positively correlates with prostate cancer severity. Recent studies have suggested that myofibroblasts at sites of reactive stroma might originate from circulating fibrocytes linked to the hematopoietic lineage. CD34, a single chain transmembrane glycoprotein is important in homing and adhesion of hematopoietic progenitor cells. This cell surface marker is expressed by fibrocytes and is emerging as an important player in the normal wound repair response. Full thickness skin wounds showed robust recruitment of CD34+ to the dermis, with subsequent differentiation to myofibroblasts. Similarly, mouse lungs treated with allergen resulted in recruitment of circulating CD34+ progenitors to bronchial tissue where they subsequently differentiated to myofibroblasts. This study also showed allergic asthma patients had fibrocytes in bronchial mucosa that were positive for CD34, collagen I, and smooth muscle alpha actin, suggesting that progenitors were from circulating bone marrow derived cells.

This article is from Cell Communication and Signaling : CCS , volume 9 . Abstract Recent advances in tumor biology have revealed that a detailed analysis of the complex interactions of tumor cells with their adjacent microenvironment (tumor stroma) is mandatory in order to understand the various mechanisms involved in tumor growth and the development of metastasis. The mutual interactions between tumor cells and cellular and non-cellular components (extracellular matrix = ECM) of the tumor microenvironment will eventually lead to a loss of tissue homeostasis and promote tumor development and progression. Thus, interactions of genetically altered tumor cells and the ECM on the one hand and reactive non-neoplastic cells on the other hand essentially control most aspects of tumorigenesis such as epithelial-mesenchymal-transition (EMT), migration, invasion (i.e. migration through connective tissue), metastasis formation, neovascularisation, apoptosis and chemotherapeutic drug resistance. In this mini-review we will focus on these issues that were recently raised by two review articles in CCS.

This article is from Frontiers in Oncology , volume 4 . Abstract The immune system has a key role to play in controlling cancer initiation and progression. T cell activation, which is central to anti-tumor immune responses, coincides with changes in cellular metabolism. Naïve T cells predominantly require an ATP generating metabolic profile, whereas proliferating effector T cells require anabolic metabolic profiles that promote rapid growth and proliferation. Furthermore, specific T cell subsets require distinct energetic and biosynthetic pathways to match their functional requirements. The often hostile tumor microenvironment can affect T cell immune responses by altering the resulting cellular metabolism. Tailoring immune responses by manipulating cellular metabolic pathways may provide an exciting new option for cancer immunotherapy. T cell responses might also be skewed via metabolic manipulation to treat the complications of obesity-associated inflammation, which is a rapidly growing global health problem and a major risk factor for many malignancies. In this review, the diverse metabolic requirements of T cells in anti-tumor immunity are discussed, as well as the profound influence of the tumor microenvironment and the possible avenues for manipulation to enhance anti-tumor immunity.

This article is from Breast Cancer Research : BCR , volume 16 . Abstract Introduction: Although C-X-C motif chemokine 12 (CXCL12) has been shown to bind to C-X-C chemokine receptor type 7 (CXCR7), the exact molecular mechanism regulations by CXCL12/CXCR7 axis in breast tumor growth and metastasis are not well understood. CXCR7 expression has been shown to be upregulated during pathological processes such as inflammation and cancer. Methods: Breast cancer cell lines were genetically silenced or pharmacologically inhibited for CXCR7 and/or its downstream target signal transducer and activator of transcription 3 (STAT3). 4T1 or 4T1 downregulated for CXCR7 and 4T1.2 breast cancer cell lines were injected in mammary gland of BALB/c mice to form tumors, and the molecular pathways regulating tumor growth and metastasis were assessed. Results: In this study, we observed that CXCL12 enhances CXCR7-mediated breast cancer migration. Furthermore, genetic silencing or pharmacologic inhibition of CXCR7 reduced breast tumor growth and metastasis. Further elucidation of mechanisms revealed that CXCR7 mediates tumor growth and metastasis by activating proinflammatory STAT3 signaling and angiogenic markers. Furthermore, enhanced breast tumorigenicity and invasiveness were associated with macrophage infiltration. CXCR7 recruits tumor-promoting macrophages (M2) to the tumor site through regulation of the macrophage colony-stimulating factor (M-CSF)/macrophage colony-stimulating factor receptor (MCSF-R) signaling pathway. In addition, CXCR7 regulated breast cancer metastasis by enhancing expression of metalloproteinases (MMP-9, MMP-2) and vascular cell-adhesion molecule-1 (VCAM-1). We also observed that CXCR7 is highly expressed in invasive ductal carcinoma (IDC) and metastatic breast tissue in human patient samples. In addition, high CXCR7 expression in tumors correlates with worse prognosis for both overall survival and lung metastasis-free survival in IDC patients. Conclusion: These observations reveal that CXCR7 enhances breast cancer growth and metastasis via a novel pathway by modulating the tumor microenvironment. These findings identify CXCR7-mediated STAT3 activation and modulation of the tumor microenvironment as novel regulation of breast cancer growth and metastasis. These studies indicate that new strategies using CXCR7 inhibitors could be developed for antimetastatic therapy.

3D Bioprinting

Recent scientific advances have revealed that a malignant tumor can be viewed as an organ consisting of different types of interacting cells. Different tumor cell types play different roles in the growth and development of the tumor and thus in the end, all cells within the tumor may help pave the way for further tumor growth in a patient with cancer. Current work in the field indicates that fibroblasts surrounding breast cancers are particularly important for cancer progression, but no one knows why. Our experimental approach to this problem is a direct one; we target the mutation of genes in stromal fibroblasts surrounding the tumor in order to learn whether these genes are important for cancer progression. Using this approach we have shown that the Pten gene in fibroblasts is a major gene involved in suppressing epithelial breast cancers. In order to understand how Pten works in fibroblasts we will measure the immediate and long-term consequences of Pten mutation on the biology of all the cells surrounding the tumor, including the tumor cells themselves, as well as the matrix that holds these cells together. Because the entire system is so complex, we plan to study how the Pten gene behaves as a tumor suppressor by developing extremely detailed three-dimensional images of tumors where each image is annotated with detailed cancer related molecular information. This will allow us to use bioinformatics (computer assisted methods) to understand the molecular basis for how fibroblasts promote breast cancer. This information will lead to the design of novel therapeutic strategies that target fibroblasts and that could be used in combination with current therapies that target epithelial cells, to stop tumor growth and prevent reoccurrence or metastasis.

A major impediment to effective prostate cancer treatment involves the acquired resistance to cytotoxic therapies. Components of the tissue microenvironment are increasingly recognized to profoundly influence tumor cell phenotypes that include susceptibilities to toxic insults. Using a genome-wide analysis of transcriptional responses to genotoxic stress induced by cancer therapeutics, we have identified a spectrum of secreted proteins derived from the tumor microenvironment (TME) that have the potential to modify tumor growth and enhance resistance to DNA-damaging cancer therapeutics. These results suggest a mechanism by which genotoxic therapies given in a cyclical fashion can enhance subsequent treatment resistance through cell non-autonomous effects contributed by the TME. To date, the contributions of individual members of this DNA Damage-associated Secretory Program (DDSP) have not been defined, nor have the signaling mechanisms responsible for propagating the DNA-damage signal(s) been determined. Our objective during this grant period is to test whether treatment-associated DNA damage responses in cells comprising the prostate TME promote tumor growth and subsequent therapy resistance. During this funding period we have: (1) Generated a prostate fibroblast cell line stably expressing SPINK1; (2) Evaluated the impact which SPINK1 activation has upon the growth characteristics of prostate cancer cells lines; (3) Examined how SPINK1 secretion from the microenvironment modulates the response of prostate cancer cells to chemotherapeutics: (4) Begun the evaluation of SPINK1 regulatory pathway; (5) Evaluated the impact of SPINK1 overexpression on tumor growth in-vivo.

The Purpose of this proposal is to examine how senescence in the prostate may be caused by medical treatments for prostate cancer, and to identify senescence-associated factors which may mediate resistance of neoplastic epithelium. The effects of standard and targeted therapeutics on senescence-mediated resistance will be determined. To date, our major findings present a mixed picture of chemotherapy-induced senescence. Senescence-associated -galactosidase staining has not identified significant chemotherapy-induced senescence, but quantitation of gene expression changes reveal a pervasive pattern of senescence changes. Correlation of chronological aging and senescence is seen. Detailed investigations into a putative secreted marker of senescence, STC1 find significant decreases in cancer compared to benign prostate glands and possible links to hepatocyte growth factor in the prostate microenvironment. Finally, our clinical trial of neoadjuvant anti-IGF-1R antibody therapy with combined androgen deprivation prior to prostatectomy will examine the clinical effects of abrogating a pathway which is altered in senescence.

Hypoxia is a potent microenvironmental factor promoting metastatic progression. A critical step in metastatic tumor progression is the ability of tumor cells to evade immune attack. Tumor cells utilize a complex set of mechanisms that prevent the immune system from mounting effective anti-tumor responses. Moreover, the hypoxic tumor microenvironment plays an important role in immune escape by favoring immune suppression and tumor resistance. Tumor hypoxia is thought to promote the immunosuppressive phenotypes of both tumor cells as well as infiltrating immune cells. However, the mechanisms by which hypoxia promotes immunosuppression in ovarian cancer remains to be elucidated and may have important therapeutic implications in the treatment of metastatic ovarian cancer. We hypothesize that hypoxia through HIF-1 signaling in regulatory T cells promotes angiogenic and immunosuppressive phenotypes, each contributing to metastatic ovarian cancer tumor growth. Here we generated mice to directly assess the functional role of HIF-1 in Treg cells in ovarian cancer metastatic tumor growth, angiogenesis, and immunosuppression.

Most therapeutic approaches have focused on the tumor cell and its genetic alterations. However, it is becoming clear that the microenvironment plays an important role in tumor evolution. We hypothesized that conventional chemotherapy for ovarian cancer will be more effective if the microenvironment that harbors the resistant cancer cells is simultaneously targeted. Since activated carcinoma-associated fibroblasts (CAFs) have a prominent role in most aspects of tumor progression, including responses to anticancer agents by forming a physical barrier that prevents chemotherapy access and promotes resistance, we predicted that targeting CAFs will inhibit tumor progression and/or increase chemotherapeutic efficacy. We used three different approaches to target CAFs in an immunocompetent mouse model of ovarian cancer that was developed in our laboratory. In this first funding period, we have optimized the preclinical trial design and developed an efficient pipeline for the collection of tissues from tumors and major organs that may be affected by CAF-targeted therapies. We have tested three drugs that target different molecular aspects of CAF activation. Although the tested drugs did not have significant effects on disease onset or survival in mice, the pending analyses of the collected tissues will provide key information about the possible cellular and molecular effects of these drugs on the tumor microenvironment.

In this work we have set out to answer the question of whether tissue transglutaminase is one of the enzymes that is responsible for extracellular matrix changes that correlate with tumor metastatic activity. However there is a lack of analytical tools to study and characterize what TG is doing at the molecular level. To date we have developed the necessary tools to begin to characterize TG mediated crosslinks in the extracellular environment of complex in vitro and in vivo biological systems. Future work is focus on defining how TG crosslinked matrix influences breast cancer cell lines phenotype to determine the therapeutic potential of this enzyme.

In this work we have set out to answer the question of whether tissue transglutaminase is one of the enzymes that is responsible for extracellular matrix changes that correlate with tumor metastatic activity. However there is a lack of analytical tools to study and characterize what TG is doing at the molecular level. To date we have developed the necessary tools to begin to characterize TG mediated crosslinks in the extracellular environment of complex in vitro and in vivo biological systems. Future work is focus on defining how TG crosslinked matrix influences breast cancer cell lines phenotype to determine the therapeutic potential of this enzyme.

This article is from Journal for Immunotherapy of Cancer , volume 1 . Abstract The Workshop associated with the 27th Annual Meeting of the Society for Immunotherapy of Cancer (SITC), North Bethesda, MD, October 24-25, 2012 focused on targeting the tumor microenvironment as part of an integrative approach to immune-based cancer therapy.

We identified a tumor microenvironment-based activated fibroblast gene signature that correlates with poor survival in ovarian cancer patients. We are refining this gene signature to develop biomarkers for the identification of patients with adverse outcomes on standard treatment. In the first part of this project, we have analyzed a gene signature for the identification of patients who are unlikely to benefit from standard surgery and/or chemotherapy and should be considered for clinical trials targeting specific pathways in the tumor microenvironment. Specifically, we found that suboptimal surgical outcome is associated with a molecularly aggressive subtype of ovarian cancer characterized by the presence of activated fibroblasts, which likely contributes to chemotherapy resistance. In the current part of the project, we focused on the molecular characterization of activated cancer fibroblasts. First, we defined COL11A1 as a highly specific biomarker of activated fibroblasts. Second, using COL11A1 as a seed to identify coexpressed genes, we demonstrated that activated fibroblasts express a highly conserved gene signature across genetically different epithelial cancer types. In the last part of the project (no-cost extension), we will validate the gene signature in patient samples and develop a preliminary quantitative assay for use in the clinical setting.

This article is from Frontiers in Physiology , volume 4 . Abstract Radiotherapy is an important modality used in the treatment of more than 50% of cancer patients in the US. However, despite sophisticated techniques for radiation delivery as well as the combination of radiation with chemotherapy, tumors can recur. Thus, any method of improving the local control of the primary tumor by radiotherapy would produce a major improvement in the curability of cancer patients. One of the challenges in the field is to understand how the tumor vasculature can regrow after radiation in order to support tumor recurrence, as it is unlikely that any of the endothelial cells within the tumor could survive the doses given in a typical radiotherapy regimen. There is now considerable evidence from both preclinical and clinical studies that the tumor vasculature can be restored following radiotherapy from an influx of circulating cells consisting primarily of bone marrow derived monocytes and macrophages. The radiation-induced influx of bone marrow derived cells (BMDCs) into tumors can be prevented through the blockade of various cytokine pathways and such strategies can inhibit tumor recurrence. However, the post-radiation interactions between surviving tumor cells, recruited immune cells, and the remaining stroma remain poorly defined. While prior studies have described the monocyte/macrophage inflammatory response within normal tissues and in the tumor microenvironment, less is known about this response with respect to a tumor after radiation therapy. The goal of this review is to summarize existing research studies to provide an understanding of how the myelomonocytic lineage may influence vascular recovery within the irradiated tumor microenvironment.

This article is from Oncoimmunology , volume 2 . Abstract There is much promise in the use of immunotherapy for the treatment of cancer. Approaches such as those using antibodies or adoptive cell transfer can mediate complete tumor regression in a proportion of patients. However, the tumor microenvironment can inhibit immune responses leading to ineffective or suboptimal responses of tumors to immunotherapy in the majority of cases. As our knowledge of the tumor microenvironment increases, many strategies are emerging for changing the immunosuppressive nature of the tumor toward a microenvironment able to support immunity. These strategies aim to enhance the ability of immunotherapies to initiate effective immune responses able to destroy tumors. In this article, we review approaches that use immunomodulators specifically to modify the tumor microenvironment, and their use in combination with other immune-based strategies for cancer therapy.

This article is from BMC Medical Genomics , volume 4 . Abstract Background -: Traditional Chinese Medicine (TCM) has been used for thousands of years to treat or prevent diseases, including cancer. Good manufacturing practices (GMP) and sophisticated product analysis (PhytomicsQC) to ensure consistency are now available allowing the assessment of its utility. Polychemical Medicines, like TCM, include chemicals with distinct tissue-dependent pharmacodynamic properties that result in tissue-specific bioactivity. Determining the mode of action of these mixtures was previously unsatisfactory; however, information rich RNA microarray technologies now allow for thorough mechanistic studies of the effects complex mixtures. PHY906 is a long used four herb TCM formula employed as an adjuvant to relieve the side effects associated with chemotherapy. Animal studies documented a decrease in global toxicity and an increase in therapeutic effectiveness of chemotherapy when combined with PHY906. Methods -: Using a systems biology approach, we studied tumor tissue to identify reasons for the enhancement of the antitumor effect of CPT-11 (CPT-11) by PHY906 in a well-characterized pre-clinical model; the administration of PHY906 and CPT-11 to female BDF-1 mice bearing subcutaneous Colon 38 tumors. Results -: We observed that 1) individually PHY906 and CPT-11 induce distinct alterations in tumor, liver and spleen; 2) PHY906 alone predominantly induces repression of transcription and immune-suppression in tumors; 3) these effects are reverted in the presence of CPT-11, with prevalent induction of pro-apoptotic and pro-inflammatory pathways that may favor tumor rejection. Conclusions -: PHY906 together with CPT-11 triggers unique changes not activated by each one alone suggesting that the combination creates a unique tissue-specific response.

This article is from Cancers , volume 4 . Abstract In addition to malignant cancer cells, tumors contain a variety of different stromal cells that constitute the tumor microenvironment. Some of these cell types provide crucial support for tumor growth, while others have been suggested to actually inhibit tumor progression. The composition of tumor microenvironment varies depending on the tumor site. The brain in particular consists of numerous specialized cell types such as microglia, astrocytes, and brain endothelial cells. In addition to these brain-resident cells, primary and metastatic brain tumors have also been shown to be infiltrated by different populations of bone marrow-derived cells. The role of different cell types that constitute tumor microenvironment in the progression of brain malignancies is only poorly understood. Tumor microenvironment has been shown to be a promising therapeutic target and diagnostic marker in extracranial malignancies. A better understanding of tumor microenvironment in the brain would therefore be expected to contribute to the development of improved therapies for brain tumors that are urgently required due to a poor availability of treatments for these malignancies. This review summarizes some of the known interactions between brain tumors and different stromal cells, and also discusses potential therapeutic approaches within this context.

This article is from Disease Models & Mechanisms , volume 5 . Abstract Obesity and concomitant comorbidities have emerged as public health problems of the first order. For instance, obese individuals have an increased risk for kidney cancer. However, direct mechanisms linking obesity with kidney cancer remain elusive. We hypothesized that diet-induced obesity (DIO) promotes renal carcinogenesis by inducing an inflammatory and tumor-promoting microenvironment. We compared chow-fed lean Wistar rats with those that were sensitive (DIOsens) or partially resistant (DIOres) to DIO to investigate the impact of body adiposity versus dietary nutrient overload in the development of renal preneoplasia and activation of tumor-promoting signaling pathways. Our data clearly show a correlation between body adiposity, the severity of nephropathy, and the total number and incidence of preneoplastic renal lesions. However, similar plasma triglyceride, plasma free fatty acid and renal triglyceride levels were found in chow-fed, DIOres and DIOsens rats, suggesting that lipotoxicity is not a critical contributor to the renal pathology. Obesity-related nephropathy was further associated with regenerative cell proliferation, monocyte infiltration and higher renal expression of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-6, IL-6 receptor and leptin receptor. Accordingly, we observed increased signal transducer and activator of transcription 3 (STAT3) and mammalian target of rapamycin (mTOR) phosphorylation in tubules with preneoplastic phenotypes. In summary, our results demonstrate that high body adiposity induces an inflammatory and proliferative microenvironment in rat kidneys that promotes the development of preneoplastic lesions, potentially via activation of the STAT3 and mTOR signaling pathways.

The role of innate immunity in prostate cancer tumorigenesis is unclear. Toll-like receptors (TLRs) are key signaling molecules that regulate innate and adaptive immune responses in the presence of pathogens and endogenous ligands. We have generated and begun to characterize TRAMP Tg(exp +/-) x MyD88' mice. Initial results reveal that de novo prostate cancers in absence of MyD88 develop higher grade adenocarcinomas than wild-type controls at 30 weeks of age. Analysis of tumor infiltrating cells at 24 and 30 weeks of age already reveal increased infiltration of macrophage lineage cells, decreased CD8 T lymphocytes, NK cells, as well as decreased activation of canonical NF- B levels and increased non-canonical NF- B levels in the MyD88-deficient TRAMP Tg(exp +/-) mice. We have also observed decreased splenocytic NK cells in MyD88(exp -/-) animals with and without the presence of prostate cancer. From these data, we will determine the role of the MyD88 pathway of innate immunity in prostate cancer tumorigenesis. However, we have noted several limitations of our current system in achieving our initial aims. Thus, we have also proposed and now have been approved a revised SOW.

This article is from Journal for Immunotherapy of Cancer , volume 1 . Abstract None

This article is from Journal for Immunotherapy of Cancer , volume 1 . Abstract None

This article is from Cancer Cell International , volume 14 . Abstract Background: The role of the microenvironment during the initiation and progression of carcinogenesis is thought to be of critical importance, both for the enhanced understanding of fundamental cancer biology as well as for improving molecular diagnostics and therapeutics. The aim of this study was to establish an in vitro model based on a co-culture of healthy human fibroblasts (HFs) and human osteosarcoma cells (MG-63s) to simulate the microenvironment including tumor and healthy cells. Methods: The HFs and MG-63s were in vitro co-cultured for a period of time ranging from 24 h to 7 days. Cell morphology and organization were studied using phase contrast microscopy while the expression of Human Cartilage Glycoprotein 39 (YKL-40), Vascular Endothelial Growth Factor (VEGF) and Matrix Metalloprotease 1 (MMP1) was investigated by Real Time PCR and Western Blotting. Results: The results showed a characteristic disposition of tumor and healthy co-cultured cells in columns which are not visible in tumor and healthy cells grown singularly. The expression of YKL-40, VEGF and MMP1 significantly changed in co-cultured cells compared to HFs and MG-63s separately cultured. Conclusions: We concluded that the tumor microenvironment has an influence on the protein expression of the healthy surrounding tissues and the process of tumorigenicity.

T-cell redirecting therapies with gene-engineered CAR T-cells and T-cell engaging bispecific antibodies ( bsAb ) are showing promising results in clinical trials. To guide precision immunotherapy, other factors should also be taken into consideration, including greater availability of immune targets and compounds with different modes of action during the development of new biomarkers, and determinants of response and resistance to a specific regimen.

Ductal carcinoma in situ (DCIS) makes up 18% of all new breast cancer diagnoses, and is considered a precursor to invasive breast cancer even though the majority of cases almost 70% may never progress to invasive disease. Markers that identify which patients are most likely to experience progression are critically needed so that fewer patients are over-treated. This study is evaluating two novel tumor markers that may indicate greater risk of tumor progression based on recent work that suggests that stromal syndecan-1 expression induces an extracellular matrix with an aligned collagen fiber architecture, and that this collagen alignment in turn facilitates malignant cell invasion. We are using archived tumor tissue from 267 cases of DCIS of the breast to evaluate syndecan-1 expression and collagen alignment. These DCIS cases, diagnosed between 1995 and 1999, have been followed for breast cancer outcomes; to-date, 12.5% of cases have experienced a second breast cancer diagnosis. Analysis of syndecan-1 expression and collagen alignment patterns is on-going. Data analysis will ensue upon completion of tumor markers. No scientific knowledge has yet been produced.

This article is from Cancers , volume 4 . Abstract Rationale: The tumor microenvironment (TME) is heterogeneous including both malignant and host cell components as well as regions of hypoxia, elevated interstitial fluid pressure (IFP) and poor nutrient supply. The quantitative extent to which the microenvironmental properties of primary tumors are recapitulated in xenograft models is not well characterized. Methods: Xenografts were generated by implanting tumor biopsies directly into the cervix of mice to create a panel of orthotopically-passaged xenografts (OCICx). Tumors were grown to ~1 cm (diameter) and IFP measurements recorded prior to sacrifice. Enlarged para-aortic lymph nodes (>1–2 mm) were excised for histologic confirmation of metastatic disease. Quantitative histological analysis was used to evaluate hypoxia, proliferation, lymphatic and blood vessels in the epithelial and stromal regions of the xenografts and original patient tumour. Results: IFP and nodal disease were not correlated with tumor engraftment. IFP measurements in the xenografts were generally lower than those in the patient’s tumor. Lymphatic metastasis increased with passage number as did levels of hypoxia in the epithelial component of the xenografts. The blood vessel density in the stromal component of the xenografts increased in parallel. When all the markers were compared between the biopsy and the respective 3rd generation xenograft 10 of 11 tumors showed a good correlation. Conclusions: This ongoing study provides characterization about tumoral and stromal heterogeneity in a unique orthotopic xenograft model.

A major impediment to effective prostate cancer treatment involves the acquired resistance to cytotoxic therapies. Components of the tissue microenvironment are increasingly recognized to profoundly influence tumor cell phenotypes that include susceptibilities to toxic insults. Using a genome-wide analysis of transcriptional responses to genotoxic stress induced by cancer therapeutics, we have identified a spectrum of secreted proteins derived from the tumor microenvironment (TME) that have the potential to modify tumor growth and enhance resistance to DNA-damaging cancer therapeutics. These results suggest a mechanism by which genotoxic therapies given in a cyclical fashion can enhance subsequent treatment resistance through cell non-autonomous effects contributed by the TME. To date, the contributions of individual members of this DNA Damage-associated Secretory Program (DDSP) have not been defined, nor have the signaling mechanisms responsible for propagating the DNA-damage signal(s) been determined. Our objective during this grant period is to test whether treatment-associated DNA damage responses in cells comprising the prostate TME promote tumor growth and subsequent therapy resistance. During this funding period we have: (1) Generated a prostate fibroblast cell line stably expressing SPINK1; (2) Evaluated the impact which SPINK1 activation has upon the growth characteristics of prostate cancer cells lines; (3) Examined how SPINK1 secretion from the microenvironment modulates the response of prostate cancer cells to chemotherapeutics: (4) Begun the evaluation of SPINK1 regulatory pathway.

The focus of this project is to evaluate the effects of calcitriol (1,25-dihydroxycholecalciferol), the active form of vitamin D and/or dexamethasone on endothelial cells found in both tumor and non-tumor or normal microenvironments. Calcitriol has significant anti-tumor effects in LNCaP, PC-3, and MLL Dunning rat prostate models. Dexamethasone potentiates the antitumor effects of calcitriol. In mice, we have demonstrated that calcitriol s effect in vivo could contribute to its action on the endothelial cells (EC) found in the tumor (tumor-derived endothelial cells, TDEC). Preclinical data indicate that these effects were more profound in TDEC when compared to the endothelial cells isolated from matrigel plugs implanted in normal animals (matrigel-derived endothelial cells, MDEC). The differential effects observed could be due to differences in the availability of vitamin D receptor (VDR) to interact with the transcription machinery.

This article is from Frontiers in Oncology , volume 4 . Abstract Heparan sulfate proteoglycans (HSPGs) are an integral and dynamic part of normal tissue architecture at the cell surface and within the extracellular matrix. The modification of HSPGs in the tumor microenvironment is known to result not just in structural but also functional consequences, which significantly impact cancer progression. As substrates for the key enzymes sulfatases and heparanase, the modification of HSPGs is typically characterized by the degradation of heparan sulfate (HS) chains/sulfation patterns via the endo-6-O-sulfatases (Sulf1 and Sulf2) or by heparanase, an endo-glycosidase that cleaves the HS polymers releasing smaller fragments from HSPG complexes. Numerous studies have demonstrated how these enzymes actively influence cancer cell proliferation, signaling, invasion, and metastasis. The activity or expression of these enzymes has been reported to be modified in a variety of cancers. Such observations are consistent with the degradation of normal architecture and basement membranes, which are typically compromised in metastatic disease. Moreover, recent studies elucidating the requirements for these proteins in tumor initiation and progression exemplify their importance in the development and progression of cancer. Thus, as the influence of the tumor microenvironment in cancer progression becomes more apparent, the focus on targeting enzymes that degrade HSPGs highlights one approach to maintain normal tissue architecture, inhibit tumor progression, and block metastasis. This review discusses the role of these enzymes in the context of the tumor microenvironment and their promise as therapeutic targets for the treatment of cancer.

This article is from Frontiers in Oncology , volume 4 . Abstract The majority of women who are diagnosed with epithelial ovarian cancer present with extensive peritoneal carcinomatosis and are rarely cured by conventional chemotherapy. Ovarian cancer cells typically disseminate by shedding into the peritoneal fluid and implant on the mesothelium-lined peritoneal surfaces that overlie connective and white adipose tissues. Emerging evidence indicates that ovarian tumor progression is orchestrated by dynamic interplay between tumor cells and a variety of stromal cells such as adipocytes, endothelial cells, fibroblasts, mesenchymal stem cells, macrophages, and other immune cells. This mini-review discusses the biological significance of the heterotypic cellular interactions in the ovarian tumor microenvironment and the therapeutic implications of targeting these interactions.

This article is from Journal of Experimental & Clinical Cancer Research : CR , volume 32 . Abstract Background: Toll-like receptor (TLR) agonists have important properties that can be exploited for immunotherapy against tumors. Locally injected immunostimulatory oligodeoxynucleotides containing CpG motifs (CpG-ODNs), which are TLR9 agonists, have shown promise in cancer models. Several studies have demonstrated that these motifs have immunologic effects similar to those of bacterial DNA and can stimulate monocytes, macrophages, dendritic, and B cells, which then produce several proinflammatory cytokines. However, these CpG-ODNs appear to produce opposite effects on tumor B cells. Methods: In this study, we investigated the direct effects of a murine class B CpG (1826) ODNs on lymphoma B cells in vitro and in vivo, using mouse models of non-Hodgkin B lymphomas developing in immunoprivileged sites, specifically the brain and the eye, and in subcutaneous sites. Results: In vitro, CpG-ODNs produced antiproliferative and proapoptotic effects on lymphoma B cells. In vivo, it had an antitumor effect when injected into tumors in murine models of subcutaneous lymphoma (SCL) and primary cerebral lymphoma (PCL). However, its intravitreal administration into a primary intraocular lymphoma (PIOL) mouse model did not produce an antitumor effect. In vitro experiments using supernatant from mouse PIOL samples demonstrated that the PIOL molecular microenvironment inhibits the antiproliferative effect of CpG-ODNs on lymphoma B-cells. Conclusions: Responsiveness to CpG stimulation differs in subcutaneous, cerebral, and ocular tumors, according to the tumoral and molecular microenvironment, and this should be considered for further therapeutic approaches.

This article is from Frontiers in Physiology , volume 4 . Abstract The tumor microenvironment is acidic due to glycolytic cancer cell metabolism, hypoxia, and deficient blood perfusion. It is proposed that acidosis in the tumor microenvironment is an important stress factor and selection force for cancer cell somatic evolution. Acidic pH has pleiotropic effects on the proliferation, migration, invasion, metastasis, and therapeutic response of cancer cells and the function of immune cells, vascular cells, and other stromal cells. However, the molecular mechanisms by which cancer cells and stromal cells sense and respond to acidic pH in the tumor microenvironment are poorly understood. In this article the role of a family of pH-sensing G protein-coupled receptors (GPCRs) in tumor biology is reviewed. Recent studies show that the pH-sensing GPCRs, including GPR4, GPR65 (TDAG8), GPR68 (OGR1), and GPR132 (G2A), regulate cancer cell metastasis and proliferation, immune cell function, inflammation, and blood vessel formation. Activation of the proton-sensing GPCRs by acidosis transduces multiple downstream G protein signaling pathways. Since GPCRs are major drug targets, small molecule modulators of the pH-sensing GPCRs are being actively developed and evaluated. Research on the pH-sensing GPCRs will continue to provide important insights into the molecular interaction between tumor and its acidic microenvironment and may identify new targets for cancer therapy and chemoprevention.

T-cell redirecting therapies with gene-engineered CAR T-cells and T-cell engaging bispecific antibodies ( bsAb ) are showing promising results in clinical trials. To guide precision immunotherapy, other factors should also be taken into consideration, including greater availability of immune targets and compounds with different modes of action during the development of new biomarkers, and determinants of response and resistance to a specific regimen.

Overcoming tumor resistance to platinum chemotherapy is critical for prolonging life in women with advanced ovarian cancer. The nuclear factor-kappaB (NF- B) signaling pathway is a key mediator of tumorigenesis by linking inflammatory pathways to cancer. Inhibitors of NF- B such as thymoquinone (TQ) potentiate the effects of cytotoxic agents, including cisplatin, in ovarian cancer cells. Equally relevant are the potential effects of NF- B inhibition in host cells such as peritoneal macrophages, thought to play pro-tumor (M2-like) or anti-tumor (M1-like) roles during ovarian cancer progression. We defined patterns of NF- B activity in (i) ID8 tumor cells stably expressing the NGL NF- B reporter plasmid, and (ii) in host cells in ID8-injected NGL reporter mice. We showed increased NF- B reporter activity in tumor cells and in host macrophages during progression, and increased markers of M2 macrophages in ascites fluid. Reducing NF- B activity in tumor cells with TQ treatment elevated expression of M1 macrophage markers, while longer-term TQ treatment lead to increased ascites, elevated NF- B signaling and elevated expression of M2 markers. Combined TQ and cisplatin treatment lead to synergistic anti-tumor effects in vitro, reduced tumor burden and apoptotic marks in tumors to a greater extent than treatment with cisplatin alone, reduced M2 and induced M1 macrophage markers, and decreased levels of known pro-tumorigenic cytokines in ascites fluid.

Outcome predictors based on gene signatures have been successfully applied in breast cancer but similar predictors have not been developed for ovarian cancer. We identified a tumor microenvironment-based gene signature that correlates with poor survival in ovarian cancer patients. We are refining this gene signature to develop biomarkers for the identification of patients with adverse outcomes on standard treatment. In the first part of this project, we have analyzed a gene signature for the identification of patients who are unlikely to benefit from standard surgery and/or chemotherapy and should be considered for clinical trials targeting specific pathways in the tumor microenvironment. Specifically, we found that suboptimal surgical outcome is associated with a molecularly aggressive subtype of ovarian cancer characterized by the presence of reactive tumor stroma, which likely contributes to chemotherapy resistance. In the second part of the project, we will validate the gene signature in patient samples and develop a preliminary quantitative assay for use in the clinical setting. A validated gene signature to identify patients with adverse outcomes has the potential to reduce both the human and financial costs of ineffective therapies and associated toxicities. This will facilitate more individualized treatment decisions and improve the quality of care for patients with ovarian cancer.

This article is from Journal of Translational Medicine , volume 11 . Abstract Background: Tissue microarray (TMA) technology revolutionized the investigation of potential biomarkers from paraffin-embedded tissues. However, conventional TMA construction is laborious, time-consuming and imprecise. Next-generation tissue microarrays (ngTMA) combine histological expertise with digital pathology and automated tissue microarraying. The aim of this study was to test the feasibility of ngTMA for the investigation of biomarkers within the tumor microenvironment (tumor center and invasion front) of six tumor types, using CD3, CD8 and CD45RO as an example. Methods: Ten cases each of malignant melanoma, lung, breast, gastric, prostate and colorectal cancers were reviewed. The most representative H&E slide was scanned and uploaded onto a digital slide management platform. Slides were viewed and seven TMA annotations of 1 mm in diameter were placed directly onto the digital slide. Different colors were used to identify the exact regions in normal tissue (n = 1), tumor center (n = 2), tumor front (n = 2), and tumor microenvironment at invasion front (n = 2) for subsequent punching. Donor blocks were loaded into an automated tissue microarrayer. Images of the donor block were superimposed with annotated digital slides. Exact annotated regions were punched out of each donor block and transferred into a TMA block. 420 tissue cores created two ngTMA blocks. H&E staining and immunohistochemistry for CD3, CD8 and CD45RO were performed. Results: All 60 slides were scanned automatically (total time 

Deaths due to prostate cancer- the second leading cause of cancer death in men in the United States - could be prevented with more effective treatments. Overcoming tumor cell resistance to the effects of androgen deprivation and chemotherapies would significantly improve the morbidity and mortality of prostate cancer. We hypothesize that the induction of cellular senescence in the tumor microenvironment by androgen deprivation and cytotoxic chemotherapy promotes the resistance and survival of carcinoma cells. We further hypothesize that targeting senescence associated pro-survival paracrine factors will enhance the effects of these therapies and enhance response rates. To address these hypotheses, we have three aims: First, to identify senescence changes in prostate tissue induced by androgen deprivation and chemotherapy, specifically focusing on identifying factors with the potential to influence the survival/resistance of neoplastic epithelium via paracrine mechanisms. Second, to evaluate the effects of inhibiting specific senescence associated pro-survival factors using in vivo models. Third, to develop and execute clinical trials designed to inhibit senescence-associated paracrine survival mechanisms and determine if enhanced tumor responses can be achieved.

This article is from PLoS ONE , volume 9 . Abstract Aims: Cancer development and progression is not only associated with the tumor cell proliferation but also depends on the interaction between tumor cells and the stromal microenvironment. A new understanding of the role of the tumor microenvironment suggests that the loss of stromal caveolin-1 (Cav-1) as a key regulator may become a potential therapy target. This study aims to elucidate whether stromal Cav-1 expression in pancreatic cancer can be a strong prognosis biomarker. Methods: Tissue samples from 45 pancreatic cancer patients were studied. Parenchyma and stroma were separated and purified using laser capture microdissection. Stromal Cav-1 expression was measured from pancreatic cancer, paraneoplastic, and normal tissue using immunohistochemistry. We analyzed the correlation of stromal Cav-1 expression with clinicopathologic features and prognostic indicators, such as tumor marker HER-2/neu gene. Results: Specimens from six patients (13.3%) showed high levels of stromal Cav-1 staining, those from eight patients (17.8%) showed a lower, intermediate level of staining, whereas those from 31 patients (68.9%) showed an absence of staining. Cav-1 expression in cancer-associated fibroblasts was lower than that in paracancer-associated and in normal fibroblasts. Stromal Cav-1 loss was associated with TNM stage (P = 0.018), lymph node metastasis (P = 0.014), distant metastasis (P = 0.027), and HER-2/neu amplification (P = 0.007). The relationships of age, sex, histological grade, and tumor size with stromal Cav-1 expression were not significant (P>0.05). A negative correlation was found between circulating tumor cells and stromal Cav-1 expression (P

This study describes a new mechanism of intercellular communication originating from extracellular vesicles (EVs). We demonstrate that in the context of prostate cancer, EV populations isolated from human patients harbor AKT1 and that AKT1 kinase activity is sustained in these particles, nominating them as active signaling platforms. Consistently, active AKT1 in circulating EVs from the plasma of metastatic prostate cancer patients is detected predominantly in large, tumor-derived EVs,termed large oncosomes (LO). LO internalization induces reprogramming of human normal prostate fibroblasts, as reflected by high levels of -SMA, IL6, and MMP9. In turn, LO reprogrammed normal prostate fibroblasts stimulate endothelial tube formation in vitro.

The role of innate immunity in prostate cancer tumorigenesis is unclear. We hypothesis that innate immune pathways contribute to programming the inflammatory component of the tumor microenvironment and that activation of these pathways may selectively skew this immune composition and alter tumor growth. Pattern recognition receptors such as Toll-like receptors (TLRs) are key signaling molecules that regulate innate and adaptive immune responses in the presence of pathogens and endogenous ligands. We have generated and characterized TRAMP Tg +/- x MyD88-/- mice. We showed that de novo prostate cancers in absence of MyD88 develop higher grade adenocarcinomas than wild-type controls at 30 weeks of age. Analysis of tumor infiltrating cells revealed increased infiltration of macrophage lineage cells, characterized as myeloid-derived suppressor cells (MDSCs), and decreased CD8 T lymphocytes and NK cells. We have shown that MyD88plays in intrinsic role in the differentiation of MDSCs, with the absence of MyD88 biasing development towards the granulocytic subtype. MyD88-deficient MDSCs have an increased migration in response to the endogenous ligand S100A9, suggesting a role of MyD88 in governing MDSC homeostasis that can be leveraged as an anti-tumor therapy.

The purpose of this study is to identify the mechanisms whereby the bone marrow microenvironment is involved in regulation of tumor dormancy. Aim1 will identify and explore how DTCs stay dormant for long periods of time. We postulate that DTCs drive the bone marrow niche into dormancy through the GAS6 pathway. Aim2 will determine how DTCs escape dormancy, consequently rendering them more susceptible to the chemotherapy. As a major accomplishment of this study during this period is that the PI, Dr. Yusuke Shiozawa, accepted a position as an Assistant Professor at Wake Forest School of Medicine as of 03/01/15. The PI obtained the necessary institutional approvals (IACUC, IRB, IBC) and submitted the grant transfer request (06/11/2015) to gain approval from the Department of Defense for a transfer of the award from the University of Michigan to Wake Forest School of Medicine. As a result, the progress of this award was suspended at Wake Forest School of Medicine during this period of time. Once the PI obtains the grant transfer approval from the Department of Defense, he will initiate the proposed research as soon as possible.

The purpose of this study is to identify the mechanisms whereby the bone marrow microenvironment is involved in regulation of tumor dormancy. Aim1 will identify and explore how DTCs stay dormant for long periods of time. We postulate that DTCs drive the bone marrow niche into dormancy through the GAS6 pathway. Aim2 will determine how DTCs escape dormancy, consequently rendering them more susceptible to the chemotherapy. As a major accomplishment of this study during this period is that the PI, Dr. Yusuke Shiozawa, accepted a position as an Assistant Professor at Wake Forest School of Medicine as of 03/01/15. The PI obtained the necessary institutional approvals (IACUC, IRB, IBC) and submitted the grant transfer request (06/11/2015) to gain approval from the Department of Defense for a transfer of the award from the University of Michigan to Wake Forest School of Medicine. As a result, the progress of this award was suspended at Wake Forest School of Medicine during this period of time. Once the PI obtains the grant transfer approval from the Department of Defense, he will initiate the proposed research as soon as possible.

This article is from Oncoimmunology , volume 2 . Abstract Tumor-infiltrating immune cells play important roles in metastasis. We have recently revealed the recruitment of a specific myeloid cell subset (CD11b/Gr1mid) to hepatic metastases. Such a recruitment relies on CCL2/CCR2 signaling and acts to sustain metastatic growth. A similar cell subset was identified in patients bearing hepatic metastases of colorectal cancer, highlighting the potential therapeutic relevance of our findings.

This article is from Scientific Reports , volume 3 . Abstract Oncolytic viruses obliterate tumor cells in tissue culture but not against the same tumors in vivo. We report that macrophages can induce a powerfully protective antiviral state in ovarian and breast tumors, rendering them resistant to oncolytic virotherapy. These tumors have activated JAK/STAT pathways and expression of interferon-stimulated genes (ISGs) is upregulated. Gene expression profiling (GEP) of human primary ovarian and breast tumors confirmed constitutive activation of ISGs. The tumors were heavily infiltrated with CD68+ macrophages. Exposure of OV-susceptible tumor cell lines to conditioned media from RAW264.7 or primary macrophages activated antiviral ISGs, JAK/STAT signaling and an antiviral state. Anti-IFN antibodies and shRNA knockdown studies show that this effect is mediated by an extremely low concentration of macrophage-derived IFNβ. JAK inhibitors reversed the macrophage-induced antiviral state. This study points to a new role for tumor-associated macrophages in the induction of a constitutive antiviral state that shields tumors from viral attack.

Tamoxifen and parity induce ECM remodeling resulting in microenvironments that are anticipated to be inhibitory to breast cancer progression. Given the technical difficulties in studying tumor cell dormancy in the context of secondary lesions, we propose to use suppression at the primary site as a model for breast cancer dormancy. Aims: 1) Identify ECM proteins of the quiescent mammary gland. 2) Determine whether a reconstituted tumor suppressive ECM causes tumor cells to enter a quiescent/dormant-like state in vitro. 3) Validate the tumor suppressive rat ECM signature in breast tissue of parous women and in women with anti-estrogen treatment compared to controls using IHC assays. Results: Mammary ECM isolated from parous rats suppressed tumor progression in in vitro and in vivo assays, and supported adherens junction formation. Mass spec-based proteomics and label-free quantitative analysis identified an increase in collagen I in parous compared to nulliparous rat mammary glands; data that contradicts the paradigm that higher fibrillar collagen density is tumor promotional. Analysis of collagen architecture revealed an increased amount of anisotropic collagen fibers in parous glands relative to nulliparous glands, suggesting reduced tensional properties with parity. Impact on Breast Cancer Research/ Patients: Objective: identify ECM proteins that support tumor cell dormancy for the purpose of developing cell culture conditions suitable for screening drugs targeting dormancy. This work has the potential to yield high impact data and open new avenues of investigation into mechanisms and targeting of tumor dormancy.