Carcinoma-associated Fibroblasts Research Articles

Heterogeneity in Cancer Metabolism: New Concepts in an Old Field.

Significance: In the last years, metabolic reprogramming, fluctuations in bioenergetic fuels, and modulation of oxidative stress became new key hallmarks of tumor development. In cancer, elevated glucose uptake and high glycolytic rate, as a source of adenosine triphosphate, constitute a growth advantage for tumors. This represents the universally known Warburg effect, which gave rise to one major clinical application for detecting cancer cells using glucose analogs: the positron emission tomography scan imaging.Recent Advances: Glucose utilization and carbon sources in tumors are much more heterogeneous than initially thought. Indeed, new studies emerged and revealed a dual capacity of tumor cells for glycolytic and oxidative phosphorylation (OXPHOS) metabolism. OXPHOS metabolism, which relies predominantly on mitochondrial respiration, exhibits fine-tuned regulation of respiratory chain complexes and enhanced antioxidant response or detoxification capacity.Critical Issues: OXPHOS-dependent cancer cells use alternative oxidizable substrates, such as glutamine and fatty acids. The diversity of carbon substrates fueling neoplastic cells is indicative of metabolic heterogeneity, even within tumors sharing the same clinical diagnosis. Metabolic switch supports cancer cell stemness and their bioenergy-consuming functions, such as proliferation, survival, migration, and invasion. Moreover, reactive oxygen species-induced mitochondrial metabolism and nutrient availability are important for interaction with tumor microenvironment components. Carcinoma-associated fibroblasts and immune cells participate in the metabolic interplay with neoplastic cells. They collectively adapt in a dynamic manner to the metabolic needs of cancer cells, thus participating in tumorigenesis and resistance to treatments.Future Directions: Characterizing the reciprocal metabolic interplay between stromal, immune, and neoplastic cells will provide a better understanding of treatment resistance. Antioxid. Redox Signal. 26, 462–485.

Analysis of gene expression changes associated with human carcinoma-associated fibroblasts in non-small cell lung carcinoma

BackgroundThis study aimed to investigate the gene expression changes associated with carcinoma-associated fibroblasts (CAFs) involving in non-small cell lung carcinoma (NSCLC).MethodsWe downloaded the GEO series GSE22862, which contained matched gene expression values for 15 CAF and normal fibroblasts samples, and series GSE27289 containing SNP genotyping for four matched NSCLC samples. The differentially expressed genes in CAF samples were identified using the limma package in R. Then we performed gene ontology (GO) and pathway enrichment analysis and protein–protein interaction (PPI) network construction using the identified DEGs. Moreover, aberrant cell fraction, ploidy, allele-specific copy number, and loss of heterozygosity (LOH) within CAF cells were analyzed using the allele-specific copy number analysis.ResultsWe obtained 545 differentially expressed genes between CAF and normal fibroblasts samples. The up-regulated genes are mainly involved in GO terms such as positive regulation of cell migration and extracellular region, while the down-regulated genes participate in the lung development and extracellular region. Multiple genes including bone morphogenetic protein 4 (BMP4) and transforming growth factor, beta 3 (TGFB3) are involved in the TGF-β signaling pathway. Genes including BMP4, TGFBI and matrix Gla protein (MGP) were hub genes. Moreover, no LOH event for BMP4 and MGP was found, that for sphingosine kinase 1 (SPHK1) was 70%, and for TGFBI was 40%.ConclusionOur data suggested that BMP4, MGP, TGFBI, and SPHK1 may be important in CAFs-associated NSCLC, and the abnormal expression and high LOH frequency of them may be used as the diagnosis targets of CAFs in NSCLC.

Malignant ascites-derived exosomes promote proliferation and induce carcinoma-associated fibroblasts transition in peritoneal mesothelial cells.

Malignant ascites-derived exosomes have been demonstrated to participate in tumor metastasis. In peritoneal metastasis, normal mesothelial cells (MCs) can be converted into carcinoma-associated fibroblasts (CAFs) by mesothelial-mesenchymal transition (MMT). Herein, we evaluated the effect of malignant ascites-derived exosomes on peritoneal MCs in vitro and in vivo experiments to determine whether exosomes could educate MCs and contribute to peritoneal metastasis.Under the treatment of ascites-derived exosomes, peritoneal MCs showed increased ability to proliferate and migrate. Expression of CAFs specific proteins markers in MCs, including fibroblast activation protein (FAP), alpha-smooth muscle actin (α-SMA), and fibronectin, were increased after treatment of exosomes. In clinical samples test, TGF-β1 was found to be overexpressed in both malignant ascites and malignant ascites-derived exosomes, and the high volume of TGF-β1 may be responsible for peritoneum fibrosis. In addition, exosomes can increase xenograft tumor growth by suppressing the inhibitive ability on tumor cells by MCs. Besides, CAFs specific proteins markers including FAP, α-SMA, and vimentin were increased in clinical peritoneal biopsies. The immunohistochemical staining for mice tumor biopsies also revealed increased expression of fibronectin and FAP, along with decreased expression of E-cadherin and VCAM-1 after exosomes treatment.Thus, malignant ascites-derived exosomes may be of importance in the development of peritoneal metastasis by facilitating MCs to proliferate and convert into CAFs by TGF-β1 induced MMT.

Tumor stroma interaction is mediated by monocarboxylate metabolism

Human breast tumors contain significant amounts of stromal cells. There exists strong evidence that these stromal cells support cancer development and progression by altering various pathways (e.g. downregulation of tumor suppressor genes or autocrine signaling loops). Here, we suggest that stromal carcinoma-associated fibroblasts (CAFs), shown to be generated from bone marrow-derived mesenchymal stem cells, may (i) recycle tumor-derived lactate for their own energetic requirements, thereby sparing glucose for neighboring glycolytic tumor cells, and (ii) subsequently secrete surplus energetically and biosynthetically valuable metabolites of lactate oxidation, such as pyruvate, to support tumor growth. Lactate, taken up by stromal CAFs, is converted to pyruvate, which is then utilized by CAFs for energy needs as well as excreted and shared with tumor cells. We have interrogated lactate oxidation in CAFs to determine what metabolites may be secreted, and how they may affect the metabolism and growth of MDA-MB-231 breast cancer cells. We found that CAFs secrete pyruvate as a metabolite of lactate oxidation. Further, we show that pyruvate is converted to lactate to promote glycolysis in MDA-MB-231 cells and helps to control elevated ROS levels in these tumor cells. Finally, we found that inhibiting or interfering with ROS management, using the naturally occurring flavonoid phloretin (found in apple tree leaves), adds to the cytotoxicity of the conventional chemotherapeutic agent doxorubicin. Our work demonstrates that a lactate-pyruvate, reciprocally-supportive metabolic relationship may be operative within the tumor microenvironment (TME) to support tumor growth, and may be a useful drug target.

Taxotere-induced elevated expression of IL8 in carcinoma-associated fibroblasts of breast invasive ductal cancer.

Breast cancer is the most common malignant tumor in women worldwide, and accounts for an estimated 29% of new cases and 15% of cancer-associated mortalities each year. Invasive ductal carcinoma represents 70-80% of all breast cancer cases, which are responsible for the majority of breast cancer fatalities. Though great progress has been made in understanding the tumorigenesis and development of breast cancer, problems surrounding treatment persist. It was previously reported that carcinoma-associated fibroblasts (CAFs) may be closely associated with chemotherapy resistance. In the present study, primary-cultured CAFs from surgically resected breast invasive ductal cancer tissues were prepared and tested to clarify the change of gene expression profile following treatment with 20 ng/ml Taxotere® for 24 h through microarray analysis. In addition, quantitative polymerase chain reaction and western blotting were performed to compare the gene and protein expression of the candidate gene in CAFs prior to and following Taxotere treatment. Based on the obtained data, 35 differentially expressed genes were identified, including ACTA2, ACTC1, ACTG, ALDH1B1, AMY1A, C5orf13, CNN1, CXCR7, DDAH1, FGF1, PDLIM3, MAMLD1, MYH11, OXTR, PDLIM5, RARRES1, SERPINA3, TRIL, C14orf43, C1orf51, CXCL12, CXCL2, EGR2, EGR3, IER3, interleukin (IL)8, IRF1, JUNB, MMP1, NAV2, NFKBIA, NFKBIZ, TRIB1, WNT16 and ZC3H12A. It was observed that the expression of the candidate gene IL8 in the CAFs of breast invasive cancer following treatment with Taxotere was increased (P<0.05). Overall, elevated expression of IL8 induced by Taxotere in CAFs potentially supports the association between IL8 and chemotherapy response.

Protein Nanocage Mediated Fibroblast-Activation Protein Targeted Photoimmunotherapy To Enhance Cytotoxic T Cell Infiltration and Tumor Control.

Carcinoma-associated fibroblasts (CAFs) are found in many types of cancer and play an important role in tumor growth and metastasis. Fibroblast-activation protein (FAP), which is overexpressed on the surface of CAFs, has been proposed as a universal tumor targeting antigen. However, recent studies show that FAP is also expressed on multipotent bone marrow stem cells. A systematic anti-FAP therapy may lead to severe side effects and even death. Hence, there is an urgent need of a therapy that can selectively kill CAFs without causing systemic toxicity. Herein we report a nanoparticle-based photoimmunotherapy (nano-PIT) approach that addresses the need. Specifically, we exploit ferritin, a compact nanoparticle protein cage, as a photosensitizer carrier, and we conjugate to the surface of ferritin a FAP-specific single chain variable fragment (scFv). With photoirradiation, the enabled nano-PIT efficiently eliminates CAFs in tumors but causes little damage to healthy tissues due to the localized nature of the treatment. Interestingly, while not directly killing cancer cells, the nano-PIT caused efficient tumor suppression in tumor-bearing immunocompetent mice. Further investigations found that the nano-PIT led to suppressed C-X-C motif chemokine ligand 12 (CXCL12) secretion and extracellular matrix (ECM) deposition, both of which are regulated by CAFs in untreated tumors and mediate T cell exclusion that prevents physical contact between T cells and cancer cells. By selective killing of CAFs, the nano-PIT reversed the effect, leading to significantly enhanced T cell infiltration, followed by efficient tumor suppression. Our study suggests a new and safe CAF-targeted therapy and a novel strategy to modulate tumor microenvironment (TME) for enhanced immunity against cancer.

Evaluation of carcinoma-associated fibroblasts in oral squamous cell carcinoma: a potential role for cathepsin K

Aim The aim of this work was to identify carcinoma-associated fibroblasts (CAFs) in the stroma of oral squamous cell carcinoma (OSCC), through examining α-smooth muscle actin (α-SMA) expression immunohistochemically. Also, to investigate the immunohistochemical expression pattern of cathepsin K (CTSK) in CAFs as well as to assess the expression level of CTSK mRNA in CAFs, by real-time reverse transcription PCR (RT-PCR) technique. Furthermore, to correlate CTSK expression in different histopathological grades of OSCC, in order to identify its potential role in tumor progression and aggressiveness. Materials and methods Paraffin-embedded OSCC specimens were stained immunohistochemically using antibodies against α-SMA and CTSK. At the same time, level of CTSK mRNA expression was evaluated in fibroblasts indirectly cocultured with OSCC cells by means of real-time RT-PCR technique. Results In addition to CTSK coimmunolocalization with α-SMA in stromal CAFs, its expression by OSCC cells was significantly correlated with increased malignant criteria. Stromal CAFs showed upregulated CTSK expression in poorly differentiated OSCC. Real-time RT-PCR results revealed enhanced CTSK mRNA expression by fibroblasts in indirect coculture. Conclusion Collectively, the results propose an evolving role for CTSK in OSCC progression.

Obesity Enhances the Conversion of Adipose-Derived Stromal/Stem Cells into Carcinoma-Associated Fibroblast Leading to Cancer Cell Proliferation and Progression to an Invasive Phenotype.

Obesity is associated with enhanced tumor growth and progression. Within the adipose tissue are adipose-derived stromal/stem cells (ASCs) that have been shown to convert into carcinoma-associated fibroblast (CAFs) in the presence of tumor-derived factors. However, the impact of obesity on the ASCs and on the conversion of ASCs into CAFs has not been demonstrated. In the current study, ASCs isolated from lean donors (BMI < 25; lnASCs) were compared with ASCs isolated from obese donors (BMI > 30, obASCs). The contribution of tumor-derived factors on the conversion of ASCs to CAFs was investigated. Following exposure to cancer cells, obASCs expressed higher levels of CAF markers, including NG2, alpha-SMA, VEGF, FAP, and FSP, compared to lnASCs. To investigate the crosstalk between ASCs and breast cancer cells, MCF7 cells were serially cocultured with lnASCs or obASCs. After coculture with lnASCs and obASCs, MCF7 cells demonstrated enhanced proliferation and expressed an invasive phenotype morphologically, with more pronounced effects following exposure to obASCs. Long-term exposure to obASCs also enhanced the expression of protumorgenic factors. Together, these results suggest that obesity alters ASCs to favor their rapid conversion into CAFs, which in turn enhances the proliferative rate, the phenotype, and gene expression profile of breast cancer cells.

Inhibition of Bone Marrow-Derived Mesenchymal Stem Cells Homing Towards Triple-Negative Breast Cancer Microenvironment Using an Anti-PDGFRβ Aptamer.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are shown to participate in tumor progression by establishing a favorable tumor microenvironment (TME) that promote metastasis through a cytokine networks. However, the mechanism of homing and recruitment of BM-MSCs into tumors and their potential role in malignant tissue progression is poorly understood and controversial. Here we show that BM-MSCs increase aggressiveness of triple-negative breast cancer (TNBC) cell lines evaluated as capability to migrate, invade and acquire stemness markers. Importantly, we demonstrate that the treatment of BM-MSCs with a nuclease-resistant RNA aptamer against platelet-derived growth factor receptor β (PDGFRβ) causes the inhibition of receptor-dependent signaling pathways thus drastically hampering BM-MSC recruitment towards TNBC cell lines and BM-MSCs trans-differentiation into carcinoma-associated fibroblast (CAF)-like cells. Moreover, in vivo molecular imaging analysis demonstrated the aptamer ability to prevent BM-MSCs homing to TNBC xenografts. Collectively, our results indicate the anti-PDGFRβ aptamer as a novel therapeutic tool to interfere with BM-MSCs attraction to TNBC providing the rationale to further explore the aptamer in more complex pre-clinical settings.

Role of Carcinoma Associated Fibroblasts in Anoikis Resistance in Oral Squamous Cell Carcinoma –need of the hour

Role of Carcinoma Associated Fibroblasts in Anoikis Resistance in Oral Squamous Cell Carcinoma –need of the hour

P3.01-019 Desmoplasia is Associated with Poor Prognosis and Carcinoma-Associated Fibroblast Heterogeneity in Non-Small Cell Lung Cancer: Topic: Morphology

Cancer-associated fibroblasts (CAFs) are known to influence tumor development, progression and metastasis. Their characteristics and prognostic role in non-small cell lung cancer (NSCLC) patients have been recognized. However, the functional heterogeneity of CAFs between patients and its genetic basis is less understood. Two pathologists scored for desmoplasia on Hematoxylin-Eosin stained sections of resected lung tumors from two patient cohorts: one consisting of 171 NSCLC patients (128 adenocarcinoma, 43 squamous carcinoma) and the second of 24 primary cultures of CAFs. Percent area of desmoplasia among total tumor stroma was used to define high desmoplasia (HD) versus low desmoplasia (LD). The desmoplasia and survival analysis were assessed for 171 NSCLC patients. Gene expression data on RNA extracted from CAFs in contracted gels following 24 hours incubation was obtained using Illumina Human HT-12v4 Bead Chips array and was preprocessed and normalized using RMA and values were log2 transformed. Significant genes whose expression is strongly correlated (Spearman correlation coefficient and p value) with percent of desmoplasia were identified in both cohorts. The gene set enrichment analysis (GSEA) was applied to test for the enrichment of CAF cohort significant genes in 171 NSCLC cohort. Additionally, CAF significant genes were subjected to pathway enrichment analysis using Pathway Data Integration Portal ver. 2.5 (http://ophid.utoronto.ca/pahtDIP). The prognosis of adenocarcinoma patients with HD had poorer outcome in comparison to the patients with LD (disease free survival at 3 years 34% vs. 75% p=0.00045 and relapse rate 41% vs. 14%, p=0.0051). In the CAF cohort, the number of genes that are significantly associated with desmoplasia for enrichment are 356. Using GSEA, these genes were enriched in 171 NSCLC cohort (with a p value of 0.045). Protein-protein interaction (PPI) partners of these 356 genes were acquired using Integrated Interaction Database – IID (version 2016-03, http://dcv.uhnres.utoronto.ca/iid/). Obtained genes were then ranked according to their degree, i.e., number of PPIs. Top 44 (top 1%) of the genes were then selected to pathway enrichment analysis using pathDIP version 2.5. 245 pathways that significantly enriched by these 44 genes (FDR < 0.01) were obtained. Many of these pathways are known to be involved in lung cancer. We demonstrated that the prognosis of lung adenocarcinoma patients with HD had poorer outcome in comparison to the patients with LD. Furthermore, PPI analysis of CAF genes associated with HD reveals enrichment of many cancer-related pathways, suggesting their high relevance to lung cancer.

P38MAPK builds a hyaluronan cancer niche to drive lung tumorigenesis.

Expansion of neoplastic lesions generates the initial signal that instigates the creation of a tumor niche. Nontransformed cell types within the microenvironment continuously coevolve with tumor cells to promote tumorigenesis. Here, we identify p38MAPK as a key component of human lung cancer, and specifically stromal interactomes, which provides an early, protumorigenic signal in the tissue microenvironment. We found that lung cancer growth depends on short-distance cues produced by the cancer niche in a p38-dependent manner. We identified fibroblast-specific hyaluronan synthesis at the center of p38-driven tumorigenesis, which regulates early stromal fibroblast activation, the conversion to carcinoma-associated fibroblasts (CAFs), and cancer cell proliferation. Systemic down-regulation of p38MAPK signaling in a knock-in model with substitution of activating Tyr182 to phenylalanine or conditional ablation of p38 in fibroblasts has a significant tumor-suppressive effect on K-ras lung tumorigenesis. Furthermore, both Kras-driven mouse lung tumors and orthotopically grown primary human lung cancers show a significant sensitivity to both a chemical p38 inhibitor and an over-the-counter inhibitor of hyaluronan synthesis. We propose that p38MAPK-hyaluronan-dependent reprogramming of the tumor microenvironment plays a critical role in driving lung tumorigenesis, while blocking this process could have far-reaching therapeutic implications.

Membrane-bound ICAM-1 contributes to the onset of proinvasive tumor stroma by controlling acto-myosin contractility in carcinoma-associated fibroblasts.

Acto-myosin contractility in carcinoma-associated fibroblasts leads to 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 the glycoprotein ICAM-1 as a crucial regulator of stroma fibroblast proinvasive matrix remodeling. We demonstrate that the membrane-bound ICAM-1 isoform is necessary and sufficient to promote inflammation-dependent extracellular matrix contraction, which favors cancer cell invasion. Indeed, ICAM-1 mediates generation of acto-myosin contractility downstream of the Src kinases in stromal fibroblasts. Moreover, acto-myosin contractility regulates ICAM-1 expression by establishing a positive feedback signaling. Thus, targeting stromal ICAM-1 might constitute a possible therapeutic mean to counteract tumor cell invasion and dissemination.

Metronomic chemotherapy prevents therapy-induced stromal activation and induction of tumor-initiating cells.

Although traditional chemotherapy kills a fraction of tumor cells, it also activates the stroma and can promote the growth and survival of residual cancer cells to foster tumor recurrence and metastasis. Accordingly, overcoming the host response induced by chemotherapy could substantially improve therapeutic outcome and patient survival. In this study, resistance to treatment and metastasis has been attributed to expansion of stem-like tumor-initiating cells (TICs). Molecular analysis of the tumor stroma in neoadjuvant chemotherapy-treated human desmoplastic cancers and orthotopic tumor xenografts revealed that traditional maximum-tolerated dose chemotherapy, regardless of the agents used, induces persistent STAT-1 and NF-κB activity in carcinoma-associated fibroblasts. This induction results in the expression and secretion of ELR motif-positive (ELR+) chemokines, which signal through CXCR-2 on carcinoma cells to trigger their phenotypic conversion into TICs and promote their invasive behaviors, leading to paradoxical tumor aggression after therapy. In contrast, the same overall dose administered as a low-dose metronomic chemotherapy regimen largely prevented therapy-induced stromal ELR+ chemokine paracrine signaling, thus enhancing treatment response and extending survival of mice carrying desmoplastic cancers. These experiments illustrate the importance of stroma in cancer therapy and how its impact on treatment resistance could be tempered by altering the dosing schedule of systemic chemotherapy.

The CCL2-CCR2 Axis in Lymph Node Metastasis From Oral Squamous Cell Carcinoma: An Immunohistochemical Study

Cytokine or chemokine networks involve lymphatic and distant metastasis of various malignancies, including oral squamous cell carcinoma (OSCC). Immunohistochemical analysis was used to investigate the contribution of the axis of the CC chemokine receptor-2 (CCR2) and the CC chemokine receptor-2 ligand (CCL2) to lymphatic metastasis, particularly the relation between primary OSCC and marginal sinus histiocytosis in regional lymph nodes. Thirteen metastasis-free cases, 15 metastatic cases at resection of primary tumor resection, and 13 postresection metastasis cases were examined. No patient was treated with radiotherapy or chemotherapy before neck dissection. Samples were fixed in formalin, embedded inparaffin, and subjected to immunohistochemical analysis using antibodies against CCL2, CCR2, podoplanin, and α-smooth muscle actin (α-SMA). Marginal sinus histiocytosis was frequently observed in metastatic cases. CCL2 was expressed in tumor-associated neutrophils (TANs) and moderately or poorly differentiated SCC was detected atprimary tumor sites. TANs expressing CCL2 flowed into the marginal sinus in the lymph nodes. CCR2-positive macrophages and mesenchymal cells infiltrated the tumor stroma and were seen within the carcinoma nests. They were predominantly present in the marginal sinus of metastatic cases. In small metastatic foci, α-SMA-positive spindle cells resembling carcinoma-associated fibroblasts (CAFs) were observed adjacent to the macrophages. The CCL2-CCR2 axis is associated with lymphatic metastasis. To clarify the mechanism of lymphatic metastasis from OSCC, further functional analyses of the CCL2-positive TANs, CCR2-positive macrophages, and CAF-like cells detected in this study are recommended.

Senescent Carcinoma-Associated Fibroblasts Upregulate IL8 to Enhance Prometastatic Phenotypes.

Findings show that senescent cancer-associated fibroblasts secret excess IL8 to promote pancreatic cancer invasion and metastasis; thus, senescent CAFs represent a phenotypic subtype, challenging conventional assumptions that CAFs are a homogeneous population. Mol Cancer Res; 15(1); 3-14. ©2016 AACR.

Hepatic carcinoma-associated fibroblasts enhance immune suppression by facilitating the generation of myeloid-derived suppressor cells.

A major barrier to effective cancer immunotherapy is immune suppression in favor of tumor progression. Additionally, the accumulation of myeloid-derived suppressor cells (MDSCs) has recently been recognized as a major mechanism of the promotion of immune suppression. However, how MDSCs are induced and the cells from which they arise remains unknown. Although studies have demonstrated that tumor-derived cytokines promote MDSC accumulation and activation, little is known regarding the role of the tumor stroma in MDSC accumulation and activation. In this study, we identified a novel mechanism of MDSC differentiation. Tumor-associated fibroblasts (TAFs) attracted monocytes by the stromal cell-derived factor (SDF)-1a/CXCR4 pathway and induced their differentiation into MDSCs through interleukin (IL)-6-mediated STAT3 activation. TAF-treated monocytes (T-MDSCs) then impaired T-cell proliferation and altered the phenotype and/or function of T-cells in an STAT3-dependent manner. CD11b+ myeloid cells, which resembled T-MDSCs both phenotypically and functionally, were primarily in the peritumoral stroma and a positive association with TAFs in vivo. Additionally, a negative association between CD11b+ myeloid cell densities and overall survival was observed. An increased number of stromal CD11b+ myeloid cells was correlated with Hepatocellular Carcinoma (HCC) progression. Together, our results are the first to show that TAF-derived cytokines, such as IL-6 and SDF-1a, can induce MDSC generation and activation and then impair human anti-tumor immune responses, which create favorable conditions for HCC progression. These data also suggest an important role for STAT3 activation in TAF-mediated MDSC generation and MDSC-mediated immune suppression. Consequently, methods in which immunotherapy is combined with IL-6, SDF-1a or STAT3 inhibition may offer an improved option to eliminate suppressive CD11b+ myeloid cells in HCC patients.

Prunella vulgaris Polysaccharide Inhibits Growth and Migration of Breast Carcinoma-Associated Fibroblasts by Suppressing Expression of Basic Fibroblast Growth Factor.

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 (P <0.01) and arresting cell cycle (P <0.01). It also inhibited the migration of CAFs (P <0.01). bFGF promoted CAFs proliferation (P <0.01) and migration (P <0.01), protected CAFs from apoptosis (P <0.05) and reduced G0 phase to 49.06% (P <0.01). However, these effects of bFGF on CAFs could be abrogated by PVP. Culturing SKBr-3 with CAFs-CM, PVP could inhibit the viability of breast cancer SKBr-3 cells indirectly. Moreover, PVP reduced the mRNA expression (P <0.01) and protein secretion of bFGF (P <0.01) in CAFs. PVP could exert an anti-cancer effect on breast CAFs by inhibiting bFGF expression, thus inhibiting the growth of breast cancer SKBr-3 cells indirectly.

The hallmarks of CAFs in cancer invasion

The ability of cancer cells to move out of the primary tumor and disseminate through the circulation to form metastases is one of the main contributors to poor patient outcome. The tumor microenvironment provides a niche that supports cancer cell invasion and proliferation. Carcinoma-associated fibroblasts (CAFs) are a highly enriched cell population in the tumor microenvironment that plays an important role in cancer invasion. However, it remains unclear whether CAFs directly stimulate cancer cell invasion or they remodel the extracellular matrix to make it more permissive for invasion. Here we discuss paracrine communication between cancer cells and CAFs that promotes tumor invasion but also stimulates CAFs to remodel the matrix increasing cancer dissemination.

Analysis of Axin2 expression and function in murine models for pancreatic cancer.

BackgroundThe involvement of Wnt in carcinogenesis and progression of pancreatic cancer is currently intensely discussed. We evaluated activation of the Wnt signaling pathway by using a Wnt reporter mouse strain expressing β-galactosidase under the control of the Axin2 promotor during pancreatitis induced formation of precancerous lesions. We also evaluated activation of Wnt signaling during interaction of pancreatic cancer with the tumor stroma.ResultsActivation of Wnt signaling was observed during acinar-to-ductal metaplasia after chronic as well as acute pancreatitis. Activation of Wnt signaling was also noticed during growth of pancreatic cancer in an orthotopic syngeneic pancreas cancer model. Activation of Wnt signaling was, however, not observed in carcinoma associated fibroblasts, but was detected in few cell clusters inside the tumor. Genetic ablation of Axin2 significantly reduced body weight without having a major impact on blood glucose concentration. However, ablation of Axin2 had no influence on the observed β-galactosidase positive cell clusters or on tumor weight.ConclusionThese data demonstrate that the Wnt signaling pathway is activated during acinar-to-ductal metaplasia after injury to the pancreas. However these data do not support a major role of Wnt signaling or of Axin2 in carcinoma associated fibroblasts and tumor growth.Electronic supplementary materialThe online version of this article (doi:10.1186/s13578-016-0116-4) contains supplementary material, which is available to authorized users.