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Carcinoma-associated fibroblasts (CAFs) are a component of the cancer microenvironment. CAF influence the recruitment of leukocytes to the tumor and contribute to the regulation of tumor cell growth and migration. Details of the origins of CAF and the extent of their heterogeneity and function are not fully defined, especially in human cancer. Human prostatic CAF are heterogeneous and can induce malignant transformation in genetically initiated epithelial cells in vivo. CAF appear to be genomically normal, although the expression of some genes may be fixed by epigenetic mechanisms. The cells nevertheless represent a stable target for therapy development. Studies to define the heterogeneity and interactions of human prostate CAF are incomplete and will yield a fuller understanding of their nature and role in cancer initiation and progression.

Background: Tumor microenvironment (TME) is a crucial part of tumor hallmarks. Mesenchymal stem cells (MSCs), important components of TME, are the main source of Carcinoma-associated fibroblasts (CAFs), but the mechanism of transformation regulation is still unclear. Transforming growth factor-β1 (TGF-β1), chemokine Stromal cell-derived factor-1 (SDF-1) and its endogenous receptor CXCR4 may play important roles during this process. Methods: Co-culture technique was used to explore the effects of MSCs on the proliferation, migration and invasion of colorectal carcinoma (CRC) cells and how they induced MSCs to differentiate into CAFs. The expression of α-SMA, Vimentin, S100A4 and FAP were detected as CAFs markers. Inhibitors AMD3100 and cyclophosphamide (Cy) were pre-treated in MSCs to verify the functions of CXCR4/TGF-β1. Finally, the xenograft models in nude mice were generated to further verify this process in vivo. Results: MSCs promoted the CRCs proliferation, invasion and migration, and induced SDF-1 expression and secretion, which dramatically up-regulated CXCR4 and TGF-β1 expression in MSCs. The levels of CAFs markers elevated in MSCs, indicating CAFs differentiation occurred in MSCs. AMD3100 and Cy treatment significantly blocked this differentiation process of MSCs by suppressing CXCR4 expression and TGF-β1 secretion. In vivo xenograft experiments also demonstrated that MSCs promoted differentiation into CAFs through CXCR4/TGF-β1 signaling in either primary tumor tissues or hepatic metastatic tissues of CRC. Conclusion: Our studies have revealed the essential role of CXCR4/TGF-β1 axis playing in the transformation of tumor microenvironment by mediating MSCs differentiation into CAFs, promoting CRCs growth and metastasis.

Fibroblasts play an important role in cancer development and progression. Small extracellular vesicles (sEVs) are one type of extracellular vesicles, which mediate the interaction between cancer-associated fibroblasts and cancer cells by transferring their contents. However, the roles of sEVs from cancer-associated fibroblasts on breast cancer stem cell properties are largely unraveled. The purpose of this study was to explore the roles of sEVs from cancer-associated fibroblasts on breast cancer progression. The miRNA array data showed a different miRNA profile between CAFs sEVs and normal fibroblasts sEVs. By verification using real-time RT-PCR, the data analysis indicated that miR-7641 levels were lower in sEVs from CAFs compared with NFs. The cellular functions were assayed and the results indicated that CAFs derived sEVs with low miR-7641 levels suppressed breast cancer cell survival, glycolysis, and stem cell properties via the HIF-1α pathway. Collectively, these findings indicated that sEVs from CAFs promoted breast cancer stem cell properties and glycolysis via miR-7641/HIF-1α, which was a possible new way for targeting breast cancer.

Prostate cancer (PCa) is a multifocal neoplasm in which different cancer foci can be found within a single organ. This feature represents a technical difficulty when obtaining highly-enriched primary cultures of human prostate stroma cells (HPSCs), since their isolation involves enzymatic digestion of large pieces of tissue, resulting in an unknown proportion of benign- (BAF) and carcinoma-associated fibroblasts (CAF). Here we report an efficient tissue explant methodology to obtain highly-enriched populations of BAFs or CAFs from benign and malignant human prostate specimens, including needle biopsies. Also, we investigated whether different histological/pathological origins of the prostate tissue determine the activation of distinct transcription programs in HPSCs. Analysis of gene expression profiles revealed that CAFs exhibited a unique transcriptional program characterized by up-regulation of genes involved in proliferation, migration and cell adhesion. CAFs, but not BAFs, expressed typical activation markers such as α-smooth muscle actin, tenascin C and collagen 1 and stimulated tumor growth of PCa cells in vivo. Our study indicated that gene expression profile of HPSCs was determined mostly by the zone rather than the pathological state of the prostate tissue and that tissue explants from needle biopsies provide a valuable tool to obtain highly enriched primary cultures of HPSCs.

Carcinoma-associated fibroblasts (CAFs), one of the most important components of a tumor microenvironment (TME), play a significant role in the complex tumorigenesis process. Herein, the evolution of CAFs in TME is elaborately investigated by surface-enhanced Raman spectroscopy (SERS), a molecular fingerprint technique. Two-dimensional (2D) nanocomposites consisting of gold nanoparticles and a supramolecular "PCsheet" self-assembled between 2D nanosheets and oxidized phosphatidylcholine (PC) are fabricated as SERS-active probes to specifically recognize the CD36 receptor on the cytomembrane of the fibroblasts, a reliable landmark of CAF development. The 2D SERS substrates can also illuminate the fingerprint information around the CD36 protein with high detection sensitivity, which helps elucidate the biochemical component transition in the protein mini-domain during carcinoma progression. Visualized data are then supplied by label-free SERS imaging to exploit the distribution of biomolecules on the plasma membrane. In addition, the repressed expression of CD36 in TME is detected in lung metastasis tumor-bearing mice. This study based on the 2D SERS technique opens up an alternative avenue for unveiling carcinoma-associated molecular events.

Fibroblasts at the pre-metastatic site exhibited characteristic trait for creation of metastatic milieu which aid in the formation of distant metastasis, and are called as metastasis associated fibroblasts (MAFs).Array of studies showed that MAF bears similar attributes as that of carcinoma associated fibroblasts present in primary tumor. MAFs showed expression of specific type of molecules and pathways to form required pre-metastatic microenvironment at the distant site. It will be important to unrevealed characteristics features in OSCC so as to help in implicating the new therapeutic strategies.

Anoikis resistance (AR) is a favorable attribute exhibited by cancer cells for metastasis. Carcinoma associated Fibroblasts (CAFs) plays a crucial role in AR in various cancers. It was proved in array of studies in different cancers that there was definite interrelationship between CAFs and AR. But its role in OSCC is ambiguous. It is the need of the time to reveal the correlation of CAF and oral squamous cell carcinoma (OSCC) in relation with anoikis. Molecular pathways which affects the AR via CAFs in various cancers has been highlighted in this communication. Divulging the importance of CAF in cancer will aid in designing customized novel chemoprevention therapy and thus will help in enhancing the prognosis of patient in OSCC.

To study the effects of Prunella vulgaris polysaccharide (PVP) on human breast carcinoma-associated fibroblasts (CAFs).Cell viability was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5-(3-carboxymethoxyphenyl)-2-4-sulfophenyl)-2H-tetrazolium (MTS) assay. Wound healing experiment and transwell migration assay were used to investigate the anti-migration effects. Flow cytometry was applied to detect cell apoptosis and cell cycle distribution. Reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were used to detect the expression of basic fibroblast growth factor (bFGF) in CAFs. Culture SKBr-3 with CAFs conditioned medium (CAFs-CM) to evaluate the indirect function on the proliferation of breast cancer SKBr-3 cells.PVP inhibited the viability of CAFs by inducing apoptosis (P0.01) and arresting cell cycle (P0.01). It also inhibited the migration of CAFs (P0.01). bFGF promoted CAFs proliferation (P0.01) and migration (P0.01), protected CAFs from apoptosis (P0.05) and reduced GPVP could exert an anti-cancer effect on breast CAFs by inhibiting bFGF expression, thus inhibiting the growth of breast cancer SKBr-3 cells indirectly.

Experimental evidence indicates that mesenchymal stromal cells (MSCs) may regulate tumor microenvironment (TME). It is conceivable that the interaction with MSC can influence neoplastic cell functional behavior, remodeling TME and generating a tumor cell niche that supports tissue neovascularization, tumor invasion and metastasization. In addition, MSC can release transforming growth factor-beta that is involved in the epithelial–mesenchymal transition of carcinoma cells; this transition is essential to give rise to aggressive tumor cells and favor cancer progression. Also, MSC can both affect the anti-tumor immune response and limit drug availability surrounding tumor cells, thus creating a sort of barrier. This mechanism, in principle, should limit tumor expansion but, on the contrary, often leads to the impairment of the immune system-mediated recognition of tumor cells. Furthermore, the cross-talk between MSC and anti-tumor lymphocytes of the innate and adaptive arms of the immune system strongly drives TME to become immunosuppressive. Indeed, MSC can trigger the generation of several types of regulatory cells which block immune response and eventually impair the elimination of tumor cells. Based on these considerations, it should be possible to favor the anti-tumor immune response acting on TME. First, we will review the molecular mechanisms involved in MSC-mediated regulation of immune response. Second, we will focus on the experimental data supporting that it is possible to convert TME from immunosuppressive to immunostimulant, specifically targeting MSC.

Carcinoma-associated fibroblasts (CAFs) are activated fibroblasts during development of several cancer types, and therefore emerge as an attractive therapeutic target for cancer therapy. Drugs such as PT-100 and sibrotuzumab that block the functions of CAFs have already been in clinical trials. However, these drugs exhibit limited efficacy in patients, partially due to the fact that currently used biomarkers for determining efficacy are not CAF-specific. Furthermore, depletion of CAFs may promote carcinogenesis and accelerate cancer progression by inducing immunosuppression and hypoxia, leading to reduced survival. Accumulating evidence demonstrates that restoring the expression of key microRNA induces the functional conversion of CAFs into normal fibroblasts by targeting different signaling pathways and metabolic mechanisms. Therefore, reprograming CAFs into normal fibroblasts by altering specific expression of microRNAs, rather than targeted ablation, may be an effective, novel strategy for cancer treatment. This review focuses on specific microRNAs involved in the transformation of CAFs as well as their multiple roles during tumorigenesis and chemo-resistance.

// Manisha Tripathi 1, * , Srinivas Nandana 1, * , Sandrine Billet 1 , Karen A. Cavassani 1 , Rajeev Mishra 1 , Leland W.K. Chung 1 , Edwin M. Posadas 1 and Neil A. Bhowmick 1, 2 1 Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA 2 Department of Research, Greater Los Angeles Veterans Administration, Los Angeles, California 90048, USA * These authors have contributed equally to this work Correspondence to: Neil A. Bhowmick, email: neil.bhowmick@cshs.org Edwin M. Posadas, email: Edwin.Posadas@cshs.org Keywords: carcinoma associated fibroblasts, cabozantinib, metastasis, prostate cancer Received: May 30, 2017 Accepted: August 15, 2017 Published: September 23, 2017 ABSTRACT The tumor microenvironment (TME) is increasingly recognized as the arbiter of metastatic progression and drug resistance in advanced prostate cancer (PCa). Cabozantinib is a potent tyrosine kinase inhibitor (TKI) with reported biological activity in the PCa epithelia, but failed to provide an overall survival benefit in phase 3 clinical trials. However, the promising biologic efficacy of the drug in early trials warranted a better understanding of the mechanism of action, with the goal of improving patient selection for TKI-based therapy such as cabozantinib. We found a 100-fold lower cabozantinib IC 50 in macrophages, PCa associated fibroblasts, and bone marrow fibroblasts compared to PCa epithelia. In PCa mouse models, pre-treatment with cabozantinib potentiated osseous and visceral tumor engraftment, suggesting a pro-tumorigenic host response to the drug. We further found that the host effects of cabozantinib impacted bone turnover, but not necessarily tumor expansion. Cabozantinib affected M1 macrophage polarization in mice. Analogously, circulating monocytes from PCa patients treated with cabozantinib, demonstrated a striking correlation of monocyte reprograming with therapeutic bone responsivity, to support patient selection at early stages of treatment. Thus, a re-evaluation of TKI-based therapeutic strategies in PCa can be considered for suitable patient populations based on TME responses.

Carcinoma-associated fibroblast (CAF) as prominent cell type of the tumour microenvironment has complex interaction with both the cancer cells and other non-neoplastic surrounding cells. The CAF-derived regulators and extracellular matrix proteins can support cancer progression by providing a protective microenvironment for the cancer cells via reduction of chemotherapy sensitivity. On the other hand, these proteins may act as powerful prognostic markers as well as potential targets of anticancer therapy. In this review, we summarise the clinical importance of the major CAF-derived signals influencing tumour behaviour and determining the outcome of chemotherapy.

SummaryPancreatic ductal adenocarcinoma (PDAC) is associated with marked fibrosis and stromal myofibroblasts, but their functional contribution remains unknown. Transgenic mice with the ability to delete αSMA+ myofibroblasts in pancreatic cancer were generated. Depletion starting at either noninvasive precursor (pancreatic intraepithelial neoplasia) or the PDAC stage led to invasive, undifferentiated tumors with enhanced hypoxia, epithelial-to-mesenchymal transition, and cancer stem cells, with diminished animal survival. In PDAC patients, fewer myofibroblasts in their tumors also correlated with reduced survival. Suppressed immune surveillance with increased CD4+Foxp3+ Tregs was observed in myofibroblast-depleted mouse tumors. Although myofibroblast-depleted tumors did not respond to gemcitabine, anti-CTLA4 immunotherapy reversed disease acceleration and prolonged animal survival. This study underscores the need for caution in targeting carcinoma-associated fibroblasts in PDAC.

Background Carcinoma-associated fibroblasts (CAFs) contribute to carcinogenesis and cancer progression, although their origin and role remain unclear. We recently identified and investigated the in situ identity and implications of gastric submucosa-resident mesenchymal stem cells (GS-MSCs) in the progression of gastric carcinogenesis. Methods We isolated GS-MSCs from gastric submucosa using hydrogel-supported organ culture and defined their identity. Isolated cells were assessed in vitro by immunophenotype and mesengenic multipotency. Reciprocal interactions between GS-MSCs and gastric cancer cells were evaluated. To determine the role of GS-MSCs, xenografts were constructed of gastric cancer cells admixed with or without GS-MSCs. Results Isolated cells fulfilled MSCs requirements in regard to plastic adherence, stromal cell immunophenotype, and multipotency. We demonstrated a paracrine loop that gastric cancer cells enhanced the migration, proliferation, and differentiation of GS-MSCs; additionally, GS-MSCs promoted the proliferation of gastric cancer cell in vitro. Xenograft experiments showed that GS-MSCs significantly promoted cancer growth and angiogenesis. GS-MSCs that integrated into gastric cancer became not only CAFs but also rarely endothelial cells which contributed to the formation of cellular and vascular cancer stroma. Conclusions Endogenous GS-MSCs play an important role in gastric cancer progression.

Acto-myosin contractility in carcinoma-associated fibroblasts leads to the assembly of the tumor extracellular matrix. The pro-inflammatory cytokine LIF governs fibroblast activation in cancer by regulating the myosin light chain 2 activity. So far, however, how LIF mediates cytoskeleton contractility remains unknown. Using phenotypic screening assays based on knock down of LIF-dependent genes in fibroblasts, we identified ICAM1 as a crucial regulator of stroma fibroblast proinvasive matrix remodeling. We demonstrate that ICAM1 is necessary and sufficient to promote inflammation-dependent extracellular matrix organization, which leads to cancer cell invasion. Indeed, ICAM1 mediates generation of acto-myosin contractility downstream of the Src kinases in stromal fibroblasts. Moreover, acto-myosin contractility regulates ICAM1 expression, establishing a positive feedback signaling. Thus, targeting stromal ICAM1 might constitute a possible therapeutic mean to counteract tumor cell invasion and dissemination.; Les carcinomes évoluent dans un microenvironnement inflammatoire composé de cellules stromales (fibroblastes, cellules endothéliales et immunitaires) immergées dans une matrice extracellulaire (MEC). Les fibroblastes associés aux carcinomes (FACs) déposent et remodèlent la MEC dans le but de la rendre permissive à la croissance et l’invasion tumorale. Parmi les facteurs pro-inflammatoires responsables de l’activation des fibroblastes résidents, la cytokine Leukemia Inhibitory Factor (LIF) détient un rôle capital. En régulant l’activité de la chaîne légère de la myosine II (MLC-II), LIF induit la contractilité du cytosquelette d’actomyosine, générant des forces de tension et le remodelage de la MEC par les FACs. En revanche, les gènes régulés par LIF impliqués dans le phénotype pro-invasif des FACs ne sont pas connus. A l’aide d’un criblage phénotypique en trois dimensions, nous avons identifiés ICAM-1 comme régulateur majeur du remodelage de la MEC par les FACs. Nous démontrons qu’ICAM-1 est nécessaire et suffisant pour induire la réorganisation de la MEC indispensable à l’invasion collective des cellules de carcinome squameux. En effet, ICAM-1 est un régulateur de la contractilité cellulaire dépendante de la voie de signalisation RhoA-ROCK et de la kinase Src. De plus, la contractilité cellulaire régule l’expression d’ICAM-1, menant ainsi à une boucle de régulation positive. Nous proposons alors qu’ICAM-1 représente une cible thérapeutique afin de lutter contre l’invasion tumorale et la dissémination métastatique.

The tumor stroma is no longer seen solely as physical support for mutated epithelial cells but as an important modulator and even a driver of tumorigenicity. Within the tumor stromal milieu, heterogeneous populations of fibroblast-like cells, collectively termed carcinoma-associated fibroblasts (CAFs), are key players in the multicellular, stromal-dependent alterations that contribute to malignant initiation and progression. This review focuses on novel insights into the contributions of CAFs to disease progression, emergent events leading to the generation of CAFs, identification of CAF-specific biomarkers predictive of disease outcome, and recent therapeutic approaches aimed at blunting or reverting detrimental protumorigenic phenotypes associated with CAFs.

Carcinoma-associated fibroblasts (CAFs) have been confirmed to play an important role in the occurrence and development of many kinds of tumors. Regarding proliferation as one manifestation of malignance, the objective was to observe the effects of oral CAFs on the proliferation of oral squamous carcinoma cells (OSCC) and to explore the role of keratinocyte growth factor (KGF) in this process. The results showed that oral CAFs secreted a higher level of KGF than oral normal fibroblasts (NFs), and the conditioned medium of CAFs could increase the viability of carcinoma cells and promote more of them into G2 and S phase. However, after blocking with KGF antibody, the viability and cell cycle of Tca8113 cultured with CAFs conditioned medium changed to be similar with NFs control groups. It was concluded that CAFs could promote the proliferation of OSCC through secreting high levels of KGF. These findings support the use of carcinoma-associated fibroblasts as a novel target in anticancer therapy.

Rationale: In previous studies, it has been found that cancer-associated fibroblasts (CAFs) interaction with carcinoma cells and helped cancer cell grow which contributed to cancer progression and aggressiveness. However, how CAFs helped cancer cells grow, specifically what nutrition CAFs provides to tumors has not yet been fully understood. Objectives: We are studying cancer metabolism to identify pathways to target for cancer therapy. Therefore, in this study, we sought to determine which key metabolites in glucose metabolism, specifically glycolysis and the tricarboxylic acid (TCA) cycle metabolites that CAFs feed cancer cells in order for pancreatic cancer cells (P198), to grow better. Measurement Methods and Main Results: We first assessed pancreatic cancer cell proliferation (P198 cells) with and without the presence of CAFs through the co-culture technique. We assessed P198 cell number after the co-culture. We found that P198 cells grew better when co-cultured with CAFs as compared to P198 that was grown alone. We next investigated which metabolites produced from the CAFs cells are feeding P198 cells. In order to determine which metabolites from glucose were provided from CAFs to P198 cells, we first grew CAFs in 13C6-labeled glucose, removed the labeling medium, then co-cultured P198 with CAFs. The collected metabolites were assessed using Agilent 6520 Quadrupole-Time-of-Flight (Q-TOF) mass spectrometer with Agilent 1260 HPLC and a 6490 triple-quadrupole (QQQ) mass spectrometer. Metabolites were identified by retention time using in-house compound standard databases. In parallel, metabolites were identified using MS/MS fragmentation data under identical conditions. Metabolic pathways were reconstructed and analyzed in three categories: bioenergetics, biosynthesis and redox homeostasis of glucose metabolism to study these metabolic pathways exchanged between CAF and P198. Metabolite peak intensities were normalized to the protein concentration and cell number. We observed an increase in intensities of metabolites in the TCA cycle and glycolysis in P198 after co-culture with CAFs. Conclusion: These data supports growth benefits of pancreatic cancer in the presence of CAFs. We also found evidence of the metabolic exchange between CAFs and pancreatic cancer cells, which potentially explains the growth benefit. Citation Format: Tu Nguyen, Jimmy Kirsch, Karim Nabi, Christos Sazeides, Addison Quinones, Jessica Tan, Marjorie Antonio, Felipe Camelo, Jin Jung, Anne Le. Effects of carcinoma-associated fibroblasts on cancer metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2401.

Carcinoma-associated fibroblast (CAF) as prominent cell type of the tumour microenvironment has complex interaction with both the cancer cells and other non-neoplastic surrounding cells. The CAF-derived regulators and extracellular matrix proteins can support cancer progression by providing a protective microenvironment for the cancer cells via reduction of chemotherapy sensitivity. On the other hand, these proteins may act as powerful prognostic markers as well as potential targets of anticancer therapy. In this review, we summarise the clinical importance of the major CAF-derived signals influencing tumour behaviour and determining the outcome of chemotherapy.

Background & Aims: Activated fibroblasts in the tumor stroma, also termed carcinoma-associated fibroblasts (CAFs), play a critical role in the progression of cancer. In our previous studies, we identified CAFs as playing an important role in cancer progression in the development of gastric cancer. However, it remains unclear which factor recruit and promote CAFs. The aim of this study is to clarify from where CAFs originate and which factor recruits them into the gastric cancer microenvironment. Methods: In vitro study analyzed the chemotaxis-stimulating factor from gastric cancer cells using bone marrow-derived mesenchymal cells (BM-MCs). The nude mice with bone marrow transplantation from CAG-EGFP mice were used for the in vivo gastric cancer experiments. The influences of chemokine (C-X-C motif) receptor 2 (CXCR2) inhibitor on the migration of BM-MCs were examined in vitro and in vivo. Results: BM-MCs migrated into tumor stroma of in vivo gastric cancer. The number of BM-MCs was much greater in the gastric tumor than in normal tissue from three days after inoculation of cancer cells. C-X-C motif ligand 1 (CXCL1) from gastric cancer cells significantly (p Conclusions: BM-MSCs recruit into gastric tumor and differentiate into CAFs. CXCL1 from gastric cancer cells stimulates the recruitment of BM-MCs into gastric cancer locus via CXCR2 signalling. Inhibition of BM-MCs’ recruitment appears a promising therapy for gastric cancer. Citation Format: Masakazu Yashiro, Tomohisa Okuno, Hiroaki Kasashima, Yuichiro Miki, Hirohisa Nakamae, Kisyu Kitayama, Toshiyuki Kawashima, Takaharu Hatano, Heishiro Fujikawa, Tsuyoshi Hasegawa, Takahiko Nakane, Masayuki Hino, Kosei Hirakawa, Masaichi Ohira. CXCL1-CXCR2 signaling might recruit the bone marrow-derived mesenchymal cells to the carcinoma-associated fibroblasts of gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 941. doi:10.1158/1538-7445.AM2017-941

Introduction: Progression of prostate cancer (CaP) is modulated by the carcinoma-associated fibroblasts (CAFs) within the tumor microenvironment. However, little is known about the specific mechanisms involved in the activation of the benign prostate fibroblasts (BAFs) to CAFs in CaP and the specific signaling altered in CAFs that are needed to maintain its activated phenotype. Vascular endothelial growth factor-A (VEGF-A) is overexpressed in CaP and, additionally to the angiogenic effect, a non-angiogenic effects of VEGF-A on cancer cells have been recently reported. This study seeks to evaluate the potential role of VEGF-A signaling in the activation of BAFs and/or in the maintenance of the activated phenotype presented in CAFs. Material and Methods: Primary cultures of BAFs and CAFs were characterized by gene expression profile, qPCR, WB and ELISA for the expression and/or secretion of VEGF-A and its receptors. Dose-response and time course analysis for the effect of exogenous VEGF-A, TGF-β1 and conditioned medium from CAFs (CM-CAFs) were analyzed by RT-qPCR, immunocytochemistry and WB for the stroma cell markers: Vimentin, Pro-collagen, α-SMA, Tenascin, Fibronectin and FSP-1. The contribution of VEGF-A signaling to the pgenotype of CAFs was determined by siRNA assays for the VEGFRs and the functional effect of CAFs on cancer progression was studied using CM-CAFs or CM from VEGFR siRNA-CAFs over PC3 cancer cells growth in vitro and in vivo. Results: Exposure of primary cultures of BAFs to exogenous VEGF-A, TGF-β1 and CM-CAFs upregulate stroma cell markers associated with the appearance of CAFs phenotype and it is reversed with the pre-treatment of the VEGF-A antibody Bevacizumab. Furthermore, CAFs, but not BAFs, produced massive levels of VEGF-A and overexpress its cognate receptors. siRNA studies demonstrated that knock down VEGFRs in CAFs reverse the activated phenotype and CM from VEGFRsiRNA-CAFs failed to increase the migration and invasion potential of PC3 cells in vitro and tumor growth in vivo. Discussion: Our data indicate that VEGF-A signaling plays a key role in the activation of human prostate fibroblasts. Furthermore, VEGF-A and TGF-β1 interactions may cooperatively regulate activation of fibroblasts within the tumor microenvironment in CaP. These findings also suggest that blockade of this signaling cascade in the activated fibroblasts could be a potential therapeutic target designed to prevent disease progression. Citation Format: Javier Cerda Infante, Marianela Sanchez, Paola Conejeros, Alejandra Alarcón, Alejandro Godoy, Enrique Brandan, Viviana P. Montecinos. Involvement of VEGF-A signaling in the acquisition and maintenance of human prostate carcinoma-associated fibroblast phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5901. doi:10.1158/1538-7445.AM2017-5901

Epithelial to mesenchymal transitions (EMT) have been suggested to be crucial during epithelial cancer cell invasion. However, in a three-dimensional "organotypic" invasion assay squamous cell carcinoma (SCC) cells that retain epithelial characteristics "hitch a ride" with carcinoma associated fibroblasts (CAFs) in order to collectively invade. Thus epithelial cancer cells can utilise the mesenchymal characteristics of CAFs without the need to undergo EMT themselves. This work provides new insight in cancer cell invasion and shows a new role for CAFs as a target for an anti-invasive therapy.

Carcinoma-associated fibroblasts (CAFs) can influence the biological characteristics of a laryngeal carcinoma cell line. These results could lay the foundation for further studies on the role of CAFs in the laryngeal tumor-host microenvironment.CAFs are important contributors to the microenvironment in determining the fate of tumors. The aim of this study was to separate, culture, and identify laryngeal CAFs and investigate their biological influence on the laryngeal carcinoma cell line.The primary CAFs and normal fibroblasts (NFs) of the larynx were obtained by tissue culture. The cells were verified according to immunohistochemical and immunofluorescence staining of certain proteins. Conditioned medium (CM) from CAFs and NFs was obtained. Functional assays were performed to test the influence of each CM on laryngeal carcinoma cell lines.Third-passage purified laryngeal CAFs and NFs were successfully attained. The CAFs showed positive staining for vimentin, α-smooth muscle actin (α-SMA), and fibroblast activation protein (FAP). The migration ability of the CAFs increased significantly compared with that of NFs (p0.05). CM from CAFs (compared with CM from NFs) stimulated proliferation, migration, and invasion to a greater extent.

In recent years, a variety of experimental evidence has convincingly shown that progression of malignant tumors does not depend exclusively on cell-autonomous properties of the cancer cells, but can also be influenced by the tumor stroma. The concept that cancer cells are subjected to microenvironmental control has thus emerged as an important chapter in cancer biology. Recent findings have suggested an important role, in particular, for macrophages, endothelial cells, and cancer-associated fibroblasts (CAFs) in tumor growth and progression. Numerous lines of evidence indicate that the bone marrow is the source, at least in part, of these cells. This chapter summarizes our current knowledge of how bone marrow contributes to the tumor stroma, with particular emphasis on CAFs. The potential role of hypoxia in modulating the differentiation and activity of CAFs, and the therapeutical implications of targeting CAFs for anticancer therapy are discussed.

Malignancy is considered as a pathological imbalance of tissue-cell societies, a state that emerges from tumor-host microenvironment in which host participates in induction, selection and expansion of the neoplastic cells. Invasion of these malignancies can be viewed as a derangement in the proper sorting of cell populations, causing a violation of normal tissue boundaries. This violation is carried out by certain stromal cells like carcinoma associated fibroblasts (CAFs), tumor associated macrophage (TAMs), endothelial cells (ECs) leucocytes, bone marrow derived cells, etc. Tumor cells may alter the surrounding stroma and in turn, stromal cells may promote cancer progression and invasion. Thus, this review compares the role of CAFs, TAMs and ECs in tumor microenvironment towards tumor progression. This compilation aims to collate existing literature on stromal cell with particular emphasis on their role in tumor invasiveness and summarize experimental studies, trials and literature of last 10 years collected from pubmed central indexed journals.