Signaling In Cancer-associated Fibroblasts Research Articles

Abstract LB-268: Androgen signaling in cancer-associated fibroblasts contributes to progression of prostate cancer

Abstract Interactions between epithelial and stromal cells are important in the development of prostate cancer (PCa). Cancer-associated fibroblasts (CAFs) have been to support tumor progression, metastasis, and differentiation. Androgen receptor (AR) and related pathways are known to support the growth and survival of prostate epithelial cancer cells, the roles of AR-dependent processes in cancerous stroma are less clear. We sought to investigate if AR-dependent pathways present in CAF cells influence the growth and tumorogencity of epithelial cancer cells in relation to androgen-deprivation therapy in prostate cancer. Murine CAFs were isolated from a well-described PTEN-dependent cancer mouse model. A co-culture system was developed based on multiple lines of murine CAFs grown along with human prostate cancer epithelial cells, and a murine-specific anti-sense oligonucleotide (ASO) against murine AR was used to specifically suppress AR expression in murine CAFs in this system. Using this co-culture system, we found that murine CAFs promoted cell proliferation and colony formation in several human prostate cancer cell lines. Further, these processes were decreased by suppression of AR-expression in CAFs. Expression of genes related to tumorogenicity in epithelial cells were investigated by real-time quantitative PCR. Markers associated with epithelial-mesenchymal transition (EMT) and stemness were increased in human prostate cancer cells grown with low-AR CAFs. Our data indicates that suppression of AR in CAFs results in down-regulation in the growth and tumorogenecity of prostate cancer cells through pathways related to EMT and “cell reprograming”. As such, development of therapies which inhibit the tumor-promoting pathways present in stromal cells may be one approach to improve the treatment of prostate cancer. Citation Format: Chun-Peng Liao, Leng-Ying Chen, Andrea Luethy, Youngsoo Kim, Robert MacLeod, Mitchell Gross. Androgen signaling in cancer-associated fibroblasts contributes to progression of prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-268.

FAP Promotes Immunosuppression by Cancer-Associated Fibroblasts in the Tumor Microenvironment via STAT3-CCL2 Signaling.

Cancer-associated fibroblasts (CAF) are components of the tumor microenvironment whose contributions to malignant progression are not fully understood. Here, we show that the fibroblast activation protein (FAP) triggers induction of a CAF subset with an inflammatory phenotype directed by STAT3 activation and inflammation-associated expression signature marked by CCL2 upregulation. Enforcing FAP expression in normal fibroblasts was sufficient to endow them with an inflammatory phenotype similar to FAP(+)CAFs. We identified FAP as a persistent activator of fibroblastic STAT3 through a uPAR-dependent FAK-Src-JAK2 signaling pathway. In a murine liver tumor model, we found that FAP(+)CAFs were a major source of CCL2 and that fibroblastic STAT3-CCL2 signaling in this setting promoted tumor growth by enhancing recruitment of myeloid-derived suppressor cells (MDSC). The CCL2 receptor CCR2 was expressed on circulating MDSCs in tumor-bearing subjects and FAP(+)CAF-mediated tumor promotion and MDSC recruitment was abrogated in Ccr2-deficient mice. Clinically, we observed a positive correlation between stromal expression of FAP, p-STAT3, and CCL2 in human intrahepatic cholangiocarcinoma, a highly aggressive liver cancer with dense desmoplastic stroma, where elevated levels of stromal FAP predicted a poor survival outcome. Taken together, our results showed how FAP-STAT3-CCL2 signaling in CAFs was sufficient to program an inflammatory component of the tumor microenvironment, which may have particular significance in desmoplasia-associated cancers. Cancer Res; 76(14); 4124-35. ©2016 AACR.

NOTCH3 Is Induced in Cancer-Associated Fibroblasts and Promotes Angiogenesis in Oral Squamous Cell Carcinoma.

Recent studies have shown that Notch signaling is involved in many types of cancers, including oral squamous cell carcinomas (OSCCs). However, the role of Notch signaling in the tumor microenvironment is not yet fully understood. In this study, we investigated the roles of NOTCH3 signaling in cancer associated fibroblasts (CAFs) in OSCCs. Immunohistochemical study of 93 human tongue OSCC cases indicated that about one third of OSCCs showed NOTCH3 expression in CAFs, and that this expression significantly correlated with tumor-size. In vitro study showed that OSCC cell lines, especially HO1-N-1 cells stimulated NOTCH3 expression in normal human dermal fibroblasts (NHDFs) through direct cell-to-cell contact. Immunohistochemical and morphometric analysis using human OSCC samples demonstrated that NOTCH3 expression in CAFs significantly correlated with micro-vessel density in cancer stroma. In vitro angiogenesis assays involving co-culture of NHDFs with HO1-N-1 and human umbilical endothelial cells (HUVECs), and NOTCH3 knockdown in NHDFs using siRNA, demonstrated that HO1-N-1 cells significantly promoted tube formation dependent on NOTCH3-expression in NHDFs. Moreover, NOTCH3 expression in CAFs was related to poor prognosis of the OSCC patients. This work provides a new insight into the role of Notch signaling in CAFs associated with tumor angiogenesis and the possibility of NOTCH3-targeted molecular therapy in OSCCs.

Role of estrogen receptor alpha in human cervical cancer-associated fibroblasts: a transcriptomic study.

Cancer-Associated Fibroblasts (CAFs) are crucial in genesis and progression of tumors; however, cervical CAFs (C-CAFs) are not well characterized. Estradiol (E2) has been implicated as a cofactor in human papillomavirus (HPV)-mediated cervical cancer (CxCa), both in animal models and in women using oral contraceptives; however, the exact role of the hormone is unclear. Human C-CAFs have recently been shown to express estrogen receptor alpha (ER-α). We investigated gene expression patterns in ex vivo cultured early and late stage C-CAFs in the context of E2. CAFs were isolated from four patients with early and two patients with late stage CxCa. ER-α expression in CxCa tissues was localized to stromal fibroblast-like cells and confirmed in ex vivo cultured C-CAFs. Two ER antagonists (ICI 182,780 and Methyl Piperidino Pyrazole) were used to unravel ER signaling in CAFs. Microarray technology was used for expression profiling and validated by quantitative reverse transcription PCR. The transcriptomes of C-CAFs across stages indicated their activated state. C-CAFs had gene expression patterns associated with both pro-tumorigenic and pro-inflammatory signaling. Late-stage C-CAFs compared to those of early stage appeared to be more actively metabolizing and cycling but expressed fewer genes related to immune function. We report differential expression profiles between C-CAFs: early vs. late stage and in the presence of ER antagonists. Both ER antagonists seemed to modulate C-CAF function by downregulating genes associated with cell cycle and metabolism, affecting angiogenesis and cancer progression. This study characterized C-CAFs from early and late stage disease, and experiments with ER inhibitors emphasized the probable importance of canonical ER-α signaling. Interfering with paracrine signaling through fibroblast ER-α is worth exploiting as a targeted therapy in CxCa management.

Abstract 5066: Reprogramming the TGF-beta signaling in cancer-associated fibroblasts inhibits ovarian cancer progression

Abstract Ovarian cancer is the most lethal gynecologic malignancy in the US. While major research efforts have been dedicated to identify disease related genes and mutations in cancer cells, the role of the stromal tumor microenvironment in disease progression is relatively unexplored. We previously reported that while ovarian cancer cells have minimal response to TGF-beta, TGF-beta induced secretory proteins from cancer associated fibroblasts (CAFs) promote ovarian cancer motility and invasion potential. The present study seeks to further evaluate the involvement of TGF-beta signaling in CAFs in the progression of ovarian cancer and the therapeutic potential of targeting such signaling in cancer treatment. By comparing the gene expression profiles of laser-microdissected ovarian tumor stromal tissues from high-grade serous ovarian cancer (HGSOC) patients with short and long survival, a differentially expressed gene signature was identified. Using the IPA platform, signaling pathways and upstream regulators activated in CAFs from patients with short survival were identified. TGF-beta signaling was found to be significantly activated (p = 2.47E-03), while the ligand TGF-beta 1 was identified as the most significant upstream regulator (Z-score = 5.189, p = 8.85E-29), suggested the involvement of CAF TGF-beta signaling in poor patient survival. Further immunohistochemistry and survival analyses revealed the clinical relevance of multiple TGF-beta regulated stromal genes, including VCAN, MFAP5 and COMP in poor disease prognosis. Subsequently, cell culture studies were performed to evaluate the effects of TGF-beta in ovarian cancer progression. While exogenous TGF-beta did not affect proliferation, motility and invasion potential of ovarian cancer cells directly, TGF-beta promoted ovarian cancer cells motility and invasion potential in a co-culture system of cancer cells and CAFs. Similarly, treatment of exogenous TGF-beta-induced CAF secretory proteins promoted ovarian cancer progression, suggested the presence of CAFs is required for TGF-beta mediated ovarian cancer progression and targeting such TGF-beta signaling in CAFs could be a novel modality of ovarian cancer treatment. To reprogram CAFs by targeting its TGF-beta signaling, multiple approaches were tested in co-culture systems. Using either siRNAs or small molecule inhibitors, TGF-beta signaling in CAFs was effectively suppressed and inhibited ovarian cancer progression was observed. Based on our current findings, animal studies will be performed to further evaluate the efficacy of targeting the CAF TGF-beta signaling pathway in ovarian cancer treatment. This study presents the paradigm which activation of TGF-beta signaling in ovarian CAFs is significantly associated to the poor clinical outcomes. Targeting such pathway activation in CAFs could effectively suppress tumor progression and thereby presented a novel approach in cancer treatment. Citation Format: Tsz-Lun Yeung, Cecilia S. Leung, Kwong-Kwok Wong, Samuel C. Mok. Reprogramming the TGF-beta signaling in cancer-associated fibroblasts inhibits ovarian cancer progression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5066. doi:10.1158/1538-7445.AM2015-5066

Akt-Girdin signaling in cancer-associated fibroblasts contributes to tumor progression.

PI3K-Akt signaling is critical for the development, progression, and metastasis of malignant tumors, but its role in the tumor microenvironment has been relatively little studied. Here, we report that the Akt substrate Girdin, an actin-binding protein that regulates cell migration, is expressed and activated by Akt phosphorylation in cancer-associated fibroblasts (CAF) and blood vessels within the tumor microenvironment. Lewis lung tumors grafted into mice defective in Akt-mediated Girdin phosphorylation (SA transgenic mice) exhibited a decrease in both CAF infiltration and tumor growth, compared with wild-type (WT) host control animals. Contrasting with the findings of other studies, we found that Akt-dependent phosphorylation of Girdin was not a rate-limiting step in the growth of endothelial cells. In addition, Lewis lung tumors displayed limited outgrowth when cotransplanted with CAF derived from tumor-bearing SA transgenic mice, compared with CAF derived from tumor-bearing WT mice. Collectively, our results revealed a role for Akt-mediated Girdin phosphorylation in CAF during tumor progression, highlighting the need to inhibit Akt function in both tumor cells and cells that comprise the tumor microenvironment.

PDGF/PDGFR Signaling and Targeting in Cancer Growth and Progression: Focus on Tumor Microenvironment and Cancer-associated Fibroblasts

Traditionally, the studies on cancer growth and progression have been focused on the transformed, malignant cells. However, it is now well recognized that the tumour stroma represents a crucial parameter in tumour development, growth and progression. Indeed, several cancers are characterized by a prominent stromal compartment and it is the interactions between cancer cells, stromal cells and extracellular matrix (ECM) components that control the overall tumour growth. Among stromal cells, fibroblasts represent the most important type. They are responsible for deposition and remodeling of ECM components, as well as for the release of cytokines and growth factors, including platelet-derived growth factor (PDGF), acting in a paracrine manner on cancer cells. In this review we elucidate the role of tumor stroma interactions, the roles of PDGF receptor signaling in cancer-associated fibroblasts via alteration of stromal matrix composition and the mitogenic effects of cancer-derived PDGFs. Focus on the targeting of tumor microenvironment at the level of PDGF/PDGF receptor (PDGFR) is also presented as to stimulate further studies for designing and development of novel pharmaceutical agents and combined pharmaceutical interventions. Conclusively, PDGF/PDGFR axis is of paramount importance in the tumour microenvironment context and the inhibition of PDGF receptors' activation represents a major target for future anticancer therapies.

MP52-13 ESTROGEN RECEPTOR α IN CANCER ASSOCIATED FIBROBLASTS SUPPRESSES PROSTATE CANCER INVASION VIA MODULATION OF THROMBOSPONDIN-2 AND MATRIX METALLOPROTEINASE 3

You have accessJournal of UrologyProstate Cancer: Basic Research V1 Apr 2014MP52-13 ESTROGEN RECEPTOR α IN CANCER ASSOCIATED FIBROBLASTS SUPPRESSES PROSTATE CANCER INVASION VIA MODULATION OF THROMBOSPONDIN-2 AND MATRIX METALLOPROTEINASE 3 Chiuan-Ren Yeh, Spencer Slavin, Jun Da, Chawnshang Chang, Edward M. Messing, Hiroshi Miyamoto, and Shuyuan Yeh Chiuan-Ren YehChiuan-Ren Yeh More articles by this author , Spencer SlavinSpencer Slavin More articles by this author , Jun DaJun Da More articles by this author , Chawnshang ChangChawnshang Chang More articles by this author , Edward M. MessingEdward M. Messing More articles by this author , Hiroshi MiyamotoHiroshi Miyamoto More articles by this author , and Shuyuan YehShuyuan Yeh More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1623AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives The prostate cancer (PCa) microenvironment contains active stromal cells known as cancer associated fibroblasts (CAF) that may play important roles in influencing tumor progression. Here we studied the CAF Estrogen receptor α (ERα)’s role and found it could protect against PCa invasion. Methods (1) Human tissue sample IHC staining to analyze the correlation of ERα expression and recurrent free survival in PCa. (2) Lentiviral ERα transduction of CAF cells and firefly luciferase infection of 22Rv1. (3) Zymography was used to determine MMP3 and MMP2 activities.(4) Chromatin immunoprecipitation (ChIP) assay was used to determine the ERα binding to target gene (5) Q-PCR analysis was performedto detect mRNA expression. Results Immunohistochemistry on prostatectomy specimens showed that PCa patients with ERα-positive stroma had a significantly lower risk for biochemical recurrence. In vitro invasion assays further confirmed that the stromal ERα was able to reduce PCa cell invasion. Dissection of the molecular mechanism revealed that the CAF ERα could function through a CAF-epithelial interaction via selectively up-regulating thrombospondin-2 (Thbs2) and down-regulating matrix metalloproteinase 3 (MMP3) at the protein and mRNA levels. Chromatin Immunoprecipitation assays further showed that ERα could bind to an estrogen response element (ERE) on the promoter of Thbs2. Importantly, knockdown of Thbs2 led to increased MMP3 expression and interruption of the ERα mediated invasion suppression providing further evidence of an ERα-Thbs2-MMP3 axis in CAF. In vivo studies using athymic nude mice injected with 22Rv1 PCa epithelial cells and CAF cells ± ERα also confirmed that mice co-implanted with PCa cells and CAF ERα+ cells had less tumor foci in the pelvic lymph nodes, less metastasis, and tumors showed less angiogenesis, MMP3, and MMP9 (an MMP3 downstream target) positive staining. Conclusions Together, these data suggest that CAF ERα could play protective roles in suppressing PCa metastasis. Our results may lead to developing new and alternative therapeutic approaches to battle PCa via controlling ERα signaling in CAF. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e584 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Chiuan-Ren Yeh More articles by this author Spencer Slavin More articles by this author Jun Da More articles by this author Chawnshang Chang More articles by this author Edward M. Messing More articles by this author Hiroshi Miyamoto More articles by this author Shuyuan Yeh More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Estrogen receptor α in cancer-associated fibroblasts suppresses prostate cancer invasion via modulation of thrombospondin 2 and matrix metalloproteinase 3

The prostate cancer (PCa) microenvironment contains active stromal cells known as cancer-associated fibroblasts (CAF) that may play important roles in influencing tumor progression. Here we studied the role of CAF estrogen receptor alpha (ERα) and found that it could protect against PCa invasion. Immunohistochemistry on prostatectomy specimens showed that PCa patients with ERα-positive stroma had a significantly lower risk for biochemical recurrence. In vitro invasion assays further confirmed that the stromal ERα was able to reduce PCa cell invasion. Dissection of the molecular mechanism revealed that the CAF ERα could function through a CAF-epithelial interaction via selectively upregulating thrombospondin 2 (Thbs2) and downregulating matrix metalloproteinase 3 (MMP3) at the protein and messenger RNA levels. Chromatin immunoprecipitation assays further showed that ERα could bind to an estrogen response element on the promoter of Thbs2. Importantly, knockdown of Thbs2 led to increased MMP3 expression and interruption of the ERα mediated invasion suppression, providing further evidence of an ERα-Thbs2-MMP3 axis in CAF. In vivo studies using athymic nude mice injected with CWR22Rv1 (22Rv1) PCa epithelial cells and CAF cells ± ERα also confirmed that mice coimplanted with PCa cells and CAF ERα+ cells had less tumor foci in the pelvic lymph nodes, less metastases, and tumors showed less angiogenesis, MMP3, and MMP9 (an MMP3 downstream target) positive staining. Together, these data suggest that CAF ERα could play protective roles in suppressing PCa metastasis. Our results may lead to developing new and alternative therapeutic approaches to battle PCa via controlling ERα signaling in CAF.

Interaction with colon cancer cells hyperactivates TGF-β signaling in cancer-associated fibroblasts

The interaction between epithelial cancer cells and cancer-associated fibroblasts (CAFs) has a major role in cancer progression and eventually in metastasis. In colorectal cancer (CRC), CAFs are present in high abundance, but their origin and functional interaction with epithelial tumor cells has not been elucidated. In this study we observed strong activation of the transforming growth factor-β (TGF-β)/Smad signaling pathway in CRC CAFs, accompanied by decreased signaling in epithelial tumor cells. We evaluated the TGF-β1 response and the expression of target genes including matrix metalloproteinases (MMPs) and plasminogen activator inhibitor (PAI)-1 of various epithelial CRC cell lines and primary CAFs in vitro. TGF-β1 stimulation caused high upregulation of MMPs, PAI-1 and TGF-β1 itself. Next we showed that incubation of CAFs with conditioned medium (CM) from epithelial cancer cells led to hyperactivation of the TGF-β signaling pathway, enhanced expression of target genes like PAI-1, and the expression of α-smooth muscle actin (α-SMA). We propose that the interaction of tumor cells with resident fibroblasts results in hyperactivated TGF-β1 signaling and subsequent transdifferentiation of the fibroblasts into α-SMA-positive CAFs. In turn this leads to cumulative production of TGF-β and proteinases within the tumor microenvironment, creating a cancer-promoting feedback loop.

Functions of Paracrine PDGF Signaling in the Proangiogenic Tumor Stroma Revealed by Pharmacological Targeting

BackgroundImportant support functions, including promotion of tumor growth, angiogenesis, and invasion, have been attributed to the different cell types populating the tumor stroma, i.e., endothelial cells, cancer-associated fibroblasts, pericytes, and infiltrating inflammatory cells. Fibroblasts have long been recognized inside carcinomas and are increasingly implicated as functional participants. The stroma is prominent in cervical carcinoma, and distinguishable from nonmalignant tissue, suggestive of altered (tumor-promoting) functions. We postulated that pharmacological targeting of putative stromal support functions, in particular those of cancer-associated fibroblasts, could have therapeutic utility, and sought to assess the possibility in a pre-clinical setting.Methods and FindingsWe used a genetically engineered mouse model of cervical carcinogenesis to investigate platelet-derived growth factor (PDGF) receptor signaling in cancer-associated fibroblasts and pericytes. Pharmacological blockade of PDGF receptor signaling with the clinically approved kinase inhibitor imatinib slowed progression of premalignant cervical lesions in this model, and impaired the growth of preexisting invasive carcinomas. Inhibition of stromal PDGF receptors reduced proliferation and angiogenesis in cervical lesions through a mechanism involving suppression of expression of the angiogenic factor fibroblast growth factor 2 (FGF-2) and the epithelial cell growth factor FGF-7 by cancer-associated fibroblasts. Treatment with neutralizing antibodies to the PDGF receptors recapitulated these effects. A ligand trap for the FGFs impaired the angiogenic phenotype similarly to imatinib. Thus PDGF ligands expressed by cancerous epithelia evidently stimulate PDGFR-expressing stroma to up-regulate FGFs, promoting angiogenesis and epithelial proliferation, elements of a multicellular signaling network that elicits functional capabilities in the tumor microenvironment.ConclusionsThis study illustrates the therapeutic benefits in a mouse model of human cervical cancer of mechanism-based targeting of the stroma, in particular cancer-associated fibroblasts. Drugs aimed at stromal fibroblast signals and effector functions may prove complementary to conventional treatments targeting the overt cancer cells for a range of solid tumors, possibly including cervical carcinoma, the second most common lethal malignancy in women worldwide, for which management remains poor.