Cancer-associated fibroblasts predict poor outcome and promote periostin-dependent invasion in oesophageal adenocarcinoma

Cancer-associated fibroblasts in tumor microenvironment - Accomplices in tumor malignancy

There is much cellular heterogeneity in the tumor microenvironment. The tumor epithelia and stromal cells co-evolve, and this reciprocal relationship dictates almost every step of cancer development and progression. Despite this, many anticancer therapies are designed around druggable features of tumor epithelia, ignoring the supportive role of stromal cells. Cancer-associated fibroblasts (CAFs) are the dominant cell type within the reactive stroma of many tumor types. Numerous previous studies have highlighted a pro-tumorigenic role for CAFs via secretion of various growth factors, cytokines, chemokines, and the degradation of extracellular matrix. Recent works showed that CAFs secrete H₂O₂ to effect stromal-mediated field cancerization, transform primary epithelial cells, and aggravate cancer cell aggressiveness, in addition to inflammatory and mitogenic factors. Molecular characterization of CAFs also underscores the importance of Notch and specific nuclear receptor signaling in the activation of CAFs. This review consolidates recent findings of CAFs and highlights areas for future investigations.

Cancer-associated fibroblasts enhance tumor 18F-FDG uptake and contribute to the intratumor heterogeneity of PET-CT

Purpose: Elevated glucose uptake is a hallmark of cancer. Fluorodeoxyglucose (FDG) uptake was believed to indicate the aggressiveness of tumors and the standardized uptake value (SUV) is a well-known measurement for FDG uptake in positron emission tomography-computed tomography (PET/CT). However, the SUV is variable due to the heterogeneity of tumors. Methods: 126 patients with colorectal cancer underwent ¹⁸F-FDG PET/CT scanning before surgery between Jan 2011 and April 2016. Cancer-associated fibroblast (CAF) densities were calculated with the inForm Advanced image analysis software and were comparatively analyzed between patients with high and low maximum SUV (SUVmax-high and SUVmax-low). Glucose uptake was evaluated in induced and isolated CAFs and CAF-cocultured colon cancer HCT116 cells. Moreover, micro-PET/CT was performed on xenografted tumors and autoradiography was performed in the AOM/DSS induced colon cancer model. Results: CAFs were glycolytic, evidenced by glucose uptake and upregulated HK2 expression. Compared to non-activated fibroblasts (NAFs), CAFs were more dependent on glucose and sensitive to a glycolysis inhibitor. CAFs increased the SUVmax in xenograft tumors and spontaneous colon cancers. Moreover, multivariate analysis revealed that the SUVmax was only associated with tumor size among conventional parameters in colon cancer patients (126 cases, p = 0.009). Besides tumor size, the CAF density was the critical factor associated with SUVmax and outcome, which was 2.27 ± 0.74 and 1.68 ± 0.45 in the SUVmax-high and the SUVmax-low groups, respectively (p = 0.014). Conclusion: CAFs promote tumor progression and increase SUVmax of ¹⁸F-FDG, suggesting CAFs lead to the intratumor heterogeneity of the SUV and the SUVmax is a prognostic marker for cancer patients.

Esophageal 3D Culture Systems as Modeling Tools in Esophageal Epithelial Pathobiology and Personalized Medicine

The stratified squamous epithelium of the esophagus shows a proliferative basal layer of keratinocytes that undergo terminal differentiation in overlying suprabasal layers. Esophageal pathologies, including eosinophilic esophagitis, gastroesophageal reflux disease, Barrett's esophagus, squamous cell carcinoma, and adenocarcinoma, cause perturbations in the esophageal epithelial proliferation-differentiation gradient. Three-dimensional (3D) culture platforms mimicking in vivo esophageal epithelial tissue architecture ex vivo have emerged as powerful experimental tools for the investigation of esophageal biology in the context of homeostasis and pathology. Herein, we describe types of 3D culture that are used to model the esophagus, including organotypic, organoid, and spheroid culture systems. We discuss the development and optimization of various esophageal 3D culture models; highlight the applications, strengths, and limitations of each method; and summarize how these models have been used to evaluate the esophagus under homeostatic conditions as well as under the duress of inflammation and precancerous/cancerous conditions. Finally, we present future perspectives regarding the use of esophageal 3D models in basic science research as well as translational studies with the potential for personalized medicine.

Targeting the Myofibroblastic Cancer-Associated Fibroblast Phenotype Through Inhibition of NOX4

Background

Cancer-associated fibroblasts (CAFs) are tumor-promoting and correlate with poor survival in many cancers, which has led to their emergence as potential therapeutic targets. However, effective methods to manipulate these cells clinically have yet to be developed.

Methods

CAF accumulation and prognostic significance in head and neck cancer (oral, n = 260; oropharyngeal, n = 271), and colorectal cancer (n = 56) was analyzed using immunohistochemistry. Mechanisms regulating fibroblast-to-myofibroblast transdifferentiation were investigated in vitro using RNA interference/pharmacological inhibitors followed by polymerase chain reaction (PCR), immunoblotting, immunofluorescence, and functional assays. RNA sequencing/bioinformatics and immunohistochemistry were used to analyze NAD(P)H Oxidase-4 (NOX4) expression in different human tumors. NOX4's role in CAF-mediated tumor progression was assessed in vitro, using CAFs from multiple tissues in Transwell and organotypic culture assays, and in vivo, using xenograft (n = 9-15 per group) and isograft (n = 6 per group) tumor models. All statistical tests were two-sided.

Results

Patients with moderate/high levels of myofibroblastic-CAF had a statistically significant decrease in cancer-specific survival rates in each cancer type analyzed (hazard ratios [HRs] = 1.69-7.25, 95% confidence intervals [CIs] = 1.11 to 31.30, log-rank P ≤ .01). Fibroblast-to-myofibroblast transdifferentiation was dependent on a delayed phase of intracellular reactive oxygen species, generated by NOX4, across different anatomical sites and differentiation stimuli. A statistically significant upregulation of NOX4 expression was found in multiple human cancers (P < .001), strongly correlating with myofibroblastic-CAFs (r = 0.65-0.91, adjusted P < .001). Genetic/pharmacological inhibition of NOX4 was found to revert the myofibroblastic-CAF phenotype ex vivo (54.3% decrease in α-smooth muscle actin [α-SMA], 95% CI = 10.6% to 80.9%, P = .009), prevent myofibroblastic-CAF accumulation in vivo (53.2%-79.0% decrease in α-SMA across different models, P ≤ .02) and slow tumor growth (30.6%-64.0% decrease across different models, P ≤ .04).

Conclusions

These data suggest that pharmacological inhibition of NOX4 may have broad applicability for stromal targeting across cancer types.

Periostin and its interacting proteins in the construction of extracellular architectures

Periostin is a matricellular protein that is composed of a multi-domain structure with an amino-terminal EMI domain, a tandem repeat of four FAS 1 domains, and a carboxyl-terminal domain. These distinct domains have been demonstrated to bind to many proteins including extracellular matrix proteins (Collagen type I and V, fibronectin, tenascin, and laminin), matricellular proteins (CCN3 and βig-h3), and enzymes that catalyze covalent crosslinking between extracellular matrix proteins (lysyl oxidase and BMP-1). Adjacent binding sites on periostin have been suggested to put the interacting proteins in close proximity, promoting intermolecular interactions between each protein, and leading to their assembly into extracellular architectures. These extracellular architectures determine the mechanochemical properties of connective tissues, in which periostin plays an important role in physiological homeostasis and disease progression. In this review, we introduce the proteins that interact with periostin, and discuss how the multi-domain structure of periostin functions as a scaffold for the assembly of interacting proteins, and how it underlies construction of highly sophisticated extracellular architectures.

Midkine derived from cancer-associated fibroblasts promotes cisplatin-resistance via up-regulation of the expression of lncRNA ANRIL in tumour cells

Midkine (MK) is a heparin-binding growth factor that promotes carcinogenesis and chemoresistance. The tumour microenvironment (TME) can affect chemotherapy sensitivity. However, the role of stromal-derived MK, especially in cancer-associated fibroblasts (CAFs), is unclear. Here, we confirmed that MK decreased cisplatin-induced cell death in oral squamous cell carcinoma (OSCC) cells, ovarian cancer cells and lung cancer cells. We also isolated primary CAFs (n = 3) from OSCC patients and found that CAFs secreted increased levels of MK, which abrogated cisplatin-induced cell death. Moreover, MK increased the expression of lncRNA ANRIL in the tumour cells. Normal tissues, matched tumour-adjacent tissues and OSCC tissues were analysed (n = 60) and showed that lncRNA ANRIL was indeed overexpressed during carcinogenesis and correlated with both high TNM stage and lymph node metastasis (LNM). Furthermore, lncRNA ANRIL knockdown in tumour cells inhibited proliferation, induced apoptosis and increased cisplatin cytotoxicity of the tumour cells via impairment of the drug transporters MRP1 and ABCC2, which could be restored by treatment with human MK in a caspase-3/BCL-2-dependent manner. In conclusion, we firstly describe that CAFs in the TME contribute to the high level of MK in tumours and that CAF-derived MK can promote cisplatin resistance via the elevated expression of lncRNA ANRIL.

Drug targeting to myofibroblasts: Implications for fibrosis and cancer

Myofibroblasts are the key players in extracellular matrix remodeling, a core phenomenon in numerous devastating fibrotic diseases. Not only in organ fibrosis, but also the pivotal role of myofibroblasts in tumor progression, invasion and metastasis has recently been highlighted. Myofibroblast targeting has gained tremendous attention in order to inhibit the progression of incurable fibrotic diseases, or to limit the myofibroblast-induced tumor progression and metastasis. In this review, we outline the origin of myofibroblasts, their general characteristics and functions during fibrosis progression in three major organs: liver, kidneys and lungs as well as in cancer. We will then discuss the state-of-the art drug targeting technologies to myofibroblasts in context of the above-mentioned organs and tumor microenvironment. The overall objective of this review is therefore to advance our understanding in drug targeting to myofibroblasts, and concurrently identify opportunities and challenges for designing new strategies to develop novel diagnostics and therapeutics against fibrosis and cancer.

Periostin function in communication with extracellular matrices

Periostin is a secretory protein with a multi-domain structure, comprising an amino-terminal cysteine-rich EMI domain, four internal FAS 1 domains, and a carboxyl-terminal hydrophilic domain. These adjacent domains bind to extracellular matrix proteins (type I collagen, fibronectin, tenascin-C, and laminin γ2), and BMP-1 that catalyzes crosslinking of type I collagen, and proteoglycans, which play a role in cell adhesion. The binding sites on periostin have been demonstrated to contribute to the mechanical strength of connective tissues, enhancing intermolecular interactions in close proximity and their assembly into extracellular matrix architectures, where periostin plays further essential roles in physiological maintenance and pathological progression. Furthermore, periostin also binds to Notch 1 and CCN3, which have functions in maintenance of stemness, thus opening up a new field of periostin action.

The Role of Tumor Microenvironment in Chemoresistance: To Survive, Keep Your Enemies Closer

Chemoresistance is a leading cause of morbidity and mortality in cancer and it continues to be a challenge in cancer treatment. Chemoresistance is influenced by genetic and epigenetic alterations which affect drug uptake, metabolism and export of drugs at the cellular levels. While most research has focused on tumor cell autonomous mechanisms of chemoresistance, the tumor microenvironment has emerged as a key player in the development of chemoresistance and in malignant progression, thereby influencing the development of novel therapies in clinical oncology. It is not surprising that the study of the tumor microenvironment is now considered to be as important as the study of tumor cells. Recent advances in technological and analytical methods, especially ‘omics’ technologies, has made it possible to identify specific targets in tumor cells and within the tumor microenvironment to eradicate cancer. Tumors need constant support from previously ‘unsupportive’ microenvironments. Novel therapeutic strategies that inhibit such microenvironmental support to tumor cells would reduce chemoresistance and tumor relapse. Such strategies can target stromal cells, proteins released by stromal cells and non-cellular components such as the extracellular matrix (ECM) within the tumor microenvironment. Novel in vitro tumor biology models that recapitulate the in vivo tumor microenvironment such as multicellular tumor spheroids, biomimetic scaffolds and tumor organoids are being developed and are increasing our understanding of cancer cell-microenvironment interactions. This review offers an analysis of recent developments on the role of the tumor microenvironment in the development of chemoresistance and the strategies to overcome microenvironment-mediated chemoresistance. We propose a systematic analysis of the relationship between tumor cells and their respective tumor microenvironments and our data show that, to survive, cancer cells interact closely with tumor microenvironment components such as mesenchymal stem cells and the extracellular matrix.

Filaggrin and Periostin Expression Is Altered in Eosinophilic Esophagitis and Normalized With Treatment

OBJECTIVES

Previous data have suggested that filaggrin (FLG) and periostin (POSTN) genes may be dysregulated in eosinophilic esophagitis (EoE). We aimed to further evaluate the expression patterns of FLG and POSTN proteins in esophageal tissue samples of patients with EoE, as compared to those of patients with gastroesophageal reflux disease (GERD) and normal controls.

METHODS

A total of 61 prospectively collected cases, including 40 children with EoE and 21 children with GERD, and a control group of 14 sex- and age-matched healthy children were enrolled. Patients with EoE were treated with skin testing-driven elimination diet and/or corticosteroids. The immunohistochemical expression of FLG and POSTN was evaluated in esophageal biopsies obtained from patients and controls, and the results were correlated with EoE-related clinicopathological parameters.

RESULTS

Positive FLG and negative POSTN staining were observed in all esophageal biopsies from normal controls. In contrast, FLG and POSTN stained negative and positive, respectively, in all pretreatment biopsies obtained from patients with EoE, whereas FLG and POSTN stained positive in 57.1% and 95.2% of GERD cases, respectively (P < 0.001). A statistically significant decrease of the proportion of cases with negative FLG and positive POSTN staining was observed from the first (pretreatment) to the second (post-treatment) biopsy in the subgroup of patients with EoE (P < 0.001 in both correlations).

CONCLUSIONS

FLG and POSTN expression may be downregulated and upregulated, respectively, in the esophageal mucosa of patients with active EoE, and these changes may be restored with treatment in a significant percentage of cases.

Prognostic Significance of Periostin and Mammalian Target of Rapamycin (mTOR) in Locally Advanced Esophageal Squamous Cell Carcinoma

Background

Periostin and the mammalian target of rapamycin (mTOR) are involved in several cancers. This study aimed to evaluate the expression level of periostin and mTOR in locally advanced esophageal squamous cell carcinoma (ESCC) and to analyze their correlations with prognostic value.

Material/Methods

Expression levels of periostin and mTOR were examined by immunohistochemistry in locally advanced ESCC and corresponding adjacent normal tissue of 71 patients. The expression of periostin and mTOR were correlated with clinicopathologic characteristics by χ² test or Kruskal-Wallis analysis. The prognostic factors of periostin and mTOR on overall survival (OS) and disease-free survival (DFS) were assessed using Kaplan-Meier and Cox regression methods, respectively.

Results

The high expression of periostin was significantly correlated to tumor stage (P=0.000), vascular invasion (P=0.027), differentiation (P=0.002), invasion depth (P=0.023), and lymph node metastasis (P=0.017). The high expression of mTOR was associated with tumor stage (P=0.001), lymphatic metastasis (P=0.014), and differentiation (P=0.036). Expression levels of periostin and mTOR was positively correlated (r=0.416, P=0.000). The OS and DFS in patients in the high-periostin group were significantly shorter than those in the low-periostin group, (both P<0.001). Similar results were found in mTOR analysis. Moreover, Cox regression analysis showed that the expressions of periostin and mTOR, along with tumor stage, were the independent factors affecting the survival time of ESCC patients.

Conclusions

Expressions of periostin and mTOR are related to multiple clinicopathologic features. High expression of periostin and mTOR were independent risk factors of ESCC patients, which might offer a potential target strategy for ESCC treatment in the future.

Fibroblasts derived from oesophageal adenocarcinoma differ in DNA methylation profile from normal oesophageal fibroblasts

Oesophageal adenocarcinoma (OAC) is increasing in incidence and has a poor prognosis. Tumour derived fibroblasts (TDFs) differ functionally from normal fibroblasts (NDFs), and play a pivotal role in cancer. Many of the differences persist through subculture. We measured the DNA methylation profiles of 10 TDFs from OAC with 12 NDF from normal oesophageal mucosa using Infinium HumanMethylation450 Beadchips and found they differed in multidimensional scaling analysis. We identified 4,856 differentially methylated CpGs (DMCs, adjusted p < 0.01 and absolute difference in average β-value > 0.15), of which 3,243 (66.8%) were hypomethylated in TDFs compared to NDFs. Hypermethylated DMCs were enriched at transcription start sites (TSSs) and in CpG islands, and depleted in transcriptional enhancers. Gene ontology analysis of genes with DMCs at TSSs revealed an enrichment of genes involved in development, morphogenesis, migration, adhesion, regulation of processes and response to stimuli. Alpha-smooth muscle actin (α-SMA) is a marker of activated fibroblasts and a poor prognostic indicator in OAC. Hypomethylated DMCs were observed at the TSS of transcript variant 2 of α-SMA, which correlated with an increase in α-SMA protein expression. These data suggest that DNA methylation may contribute to the maintenance of the TDF phenotype.

Association between periostin and epithelial-mesenchymal transition in esophageal squamous cell carcinoma and its clinical significance

The present study aimed to investigate the association between periostin (POSTN), epithelial cadherin (E-cad) and vimentin (Vim) expression levels in esophageal squamous cell carcinoma (ESCC) tissues, and its clinicopathological significance. A total of 58 patients with esophageal cancer were enrolled. Immunohistochemistry was performed to quantify the expression levels of POSTN, E-cad and Vim. E-cad expression was reduced in ESCC tissue, which was associated with severe tumor node metastasis (TNM) stage (P<0.001), lymphatic metastasis (P<0.001) and vascular invasion (P=0.026). Conversely, Vim expression was found to be increased in ESCC tissues, and had associations with TNM stage (P=0.039) and lymphatic metastasis (P=0.039). POSTN overexpression observed in ESCC cells was associated with attenuation of E-cad expression (P<0.001) and elevated expression levels of Vim (P<0.001). Additionally, significant correlations between the overexpression of POSTN in ESCC cells and clinicopathological variables including TNM staging (P=0.009), degree of differentiation (P<0.001), lymphatic metastasis (P=0.009) and vascular invasion (P=0.002) were verified. Multivariate analysis revealed that overexpression of POSTN in ESCC cancer cells is able to predict the poor prognosis of patients independently of overall survival (P=0.022) and disease free survival (P=0.019). The preliminary findings of the present study demonstrate that POSTN is involved in the epithelial-mesenchymal transition of ESCC cells, and may therefore be a predictive factor for tumor invasion and metastasis, as well as an indicator of poor prognosis for patients with ESCC.

Overexpression of POSTN in Tumor Stroma Is a Poor Prognostic Indicator of Colorectal Cancer

BACKGROUND

Tumor microenvironment has recently drawn attention in that it is related with tumor prognosis. Cancer-associated fibroblast also plays a critical role in cancer invasiveness and progression in colorectal cancers. Periostin (POSTN), originally identified to be expressed in osteoblasts and osteoblast-derived cells, is expressed in cancer-associated fibroblasts in several tissue types of cancer. Recent studies suggest an association between stromal overexpression of POSTN and poor prognosis of cancer patients.

METHODS

We analyzed colorectal cancer cases for their expression status of POSTN in tumor stroma using immunohistochemistry and correlated the expression status with clinicopathological and molecular features.

RESULTS

High level of POSTN expression in tumor stroma was closely associated with tumor location in proximal colon, infiltrative growth pattern, undifferentiated histology, tumor budding, luminal necrosis, and higher TNM stage. High expression status of POSTN in tumor stroma was found to be an independent prognostic parameter implicating poor 5-year cancer-specific survival and 5-year progression-free survival.

CONCLUSIONS

Our findings suggest that POSTN overexpression in tumor stroma of colorectal cancers could be a possible candidate marker for predicting poor prognosis in patients with colorectal cancers.

A minimum core outcome dataset for the reporting of preclinical chemotherapeutic drug studies: Lessons learned from multiple discordant methodologies in the setting of colorectal cancer

In vivo studies in animal models are critical tools necessary to study the fundamental complexity of carcinogenesis. A constant strive to improve animal models in cancer exists, especially those investigating the use of chemotherapeutic effectiveness. In the present systematic review, colorectal cancer (CRC) is used as an example to highlight and critically evaluate the range of reporting strategies used when investigating chemotherapeutic agents in the preclinical setting. A systematic review examining the methodology and reporting of preclinical chemotherapeutic drug studies using CRC murine models was conducted. A total of 45 studies were included in this systematic review. The literature was found to be highly heterogeneous with various cell lines, animal strains, animal ages and chemotherapeutic compounds/regimens tested, proving difficult to compare outcomes between similar studies or indeed gain any significant insight into which chemotherapeutic regimen caused adverse events. From this analysis we propose a minimum core outcome dataset that could be regarded as a standardised way of reporting results from in vivo experimentation.

The mechanisms of radioresistance in esophageal squamous cell carcinoma and current strategies in radiosensitivity

Esophageal cancer is the eighth most common cancer and the sixth leading cause of cancer-related death worldwide. Surgery is the primary form of treatment, but the survival is poor, especially for patients with locally advanced esophageal cancer. Radiotherapy has been a critical treatment option that may be combined with chemotherapy in patients with unresectable esophageal cancer. However, resistance to chemoradiotherapy might result in treatment failures and cancer relapse. This review will mainly focus on the possible cellular mechanisms and tumor-associated microenvironmental (TAM) factors that result in radioresistance in patients with esophageal cancer. In addition, current strategies to increase radiosensitivity, including targeted therapy and the use of radiosensitive biomarkers in clinical treatment, are discussed in this review.

Emerging treatment approaches for myeloma-related bone disease

INTRODUCTION

Multiple myeloma is characterized by the presence of osteolytic lesions that leads to devastating skeletal-related events in the majority of patients. Myeloma bone disease is attributed to increased osteoclastic and suppressed osteoblastic activity. Areas covered: Bisphosphonates remain the main treatment option, however they have limitations on their own. Understanding the pathogenesis of myeloma bone disease may provide a roadmap for new therapeutic approaches. The pathway of RANKRANKLOPG pathway has revealed denosumab, a monoclonal antibody targeting RANKL as a novel emerging therapy for myeloma-related bone disease. Furthermore, the Wnt signaling inhibitors dicckopf-1 and sclerostin that are implicated in the pathogenesis of bone destruction of myeloma are now targeted by novel monoclonal antibodies. Activin-A is a TGF-beta superfamily member which increases osteoclast activity and inhibits osteoblast function in myeloma; sotatercept and other molecules targeting activin-A have entered into clinical development. Several other molecules and pathways that play an important role in the pathogenesis of bone destruction in myeloma, such as periostin, adiponectin, Notch and BTK signaling are also targeted in an attempt to develop novel therapies for myeloma-related bone disease. Expert commentary: We summarize the current advances in the biology of myeloma bone disease and the potential therapeutic targets.

A subset of myofibroblastic cancer-associated fibroblasts regulate collagen fiber elongation, which is prognostic in multiple cancers

Collagen structure has been shown to influence tumor cell invasion, metastasis and clinical outcome in breast cancer. However, it remains unclear how it affects other solid cancers. Here we utilized multi-photon laser scanning microscopy and Second Harmonic Generation to identify alterations to collagen fiber structure within the tumor stroma of head & neck, esophageal and colorectal cancers. Image segmentation algorithms were then applied to quantitatively characterize these morphological changes, showing that elongated collagen fibers significantly correlated with poor clinical outcome (Log Rank p < 0.05). We used TGF-β treatment to model fibroblast conversion to smooth muscle actin SMA-positive cancer associated fibroblasts (CAFs) and found that these cells induce the formation of elongated collagen fibers in vivo. However, proteomic/transcriptomic analysis of SMA-positive CAFs cultured ex-vivo showed significant heterogeneity in the expression of genes with collagen fibril organizing gene ontology. Notably, stratifying patients according to stromal SMA-positivity and collagen fiber elongation was found to provide a highly significant correlation with poor survival in all 3 cancer types (Log Rank p ≤ 0.003). In summary, we show that increased collagen fiber length correlates with poor patient survival in multiple tumor types and that only a sub-set of SMA-positive CAFs can mediate the formation of this collagen structure.

Induction of fibroblast senescence generates a non-fibrogenic myofibroblast phenotype that differentially impacts on cancer prognosis

Cancer-associated fibroblasts (CAF) remain a poorly characterized, heterogeneous cell population. Here we characterized two previously described tumor-promoting CAF sub-types, smooth muscle actin (SMA)-positive myofibroblasts and senescent fibroblasts, identifying a novel link between the two. Analysis of CAF cultured ex vivo, showed that senescent CAF are predominantly SMA-positive; this was confirmed by immunochemistry in head & neck (HNSCC) and esophageal (EAC) cancers. In vitro, we found that fibroblasts induced to senesce develop molecular, ultrastructural and contractile features typical of myofibroblasts and this is dependent on canonical TGF-β signaling. Similar to TGF-β1-generated myofibroblasts, these cells secrete soluble factors that promote tumor cell motility. However, RNA-sequencing revealed significant transcriptomic differences between the two SMA-positive CAF groups, particularly in genes associated with extracellular matrix (ECM) deposition and organization, which differentially promote tumor cell invasion. Notably, second harmonic generation imaging and bioinformatic analysis of SMA-positive human HNSCC and EAC showed that collagen fiber organization correlates with poor prognosis, indicating that heterogeneity within the SMA-positive CAF population differentially impacts on survival. These results show that non-fibrogenic, SMA-positive myofibroblasts can be directly generated through induction of fibroblast senescence and suggest that senescence and myofibroblast differentiation are closely linked processes.

Periostin expression in intra-tumoral stromal cells is prognostic and predictive for colorectal carcinoma via creating a cancer-supportive niche

Periostin (POSTN) expression in cancer cells and circulation has been related to poor prognosis of colorectal carcinoma (CRC). However, the role of POSTN expressed in intra-tumoral stroma on CRC progression remains largely unknown. This study enrolled 1098 CRC patients who received surgical treatment in Shanghai and Guangzhou, Mainland China. In Shanghai cohort, immunohistochemistry score of stromal POSTN expression increased consecutively from adjacent mucosa, primary CRC tissues, to metastatic CRC tissues (P < 0.001), while medium- and high-stromal POSTN expression, rather than epithelial POSTN expression, independently predicted unfavorable prognoses of CRC, adjusted for covariates including TNM stage and postoperative chemotherapy in multivariate Cox models. The results in Shanghai cohort were faithfully replicated in Guangzhou cohort. Stromal POSTN expression dose-dependently predicted an unfavorable prognosis of stage III CRC patients with postoperative chemotherapy in both cohorts. POSTN derived from colonic fibroblasts or recombinant POSTN significantly promoted proliferation, anchorage independent growth, invasion, and chemo-resistance of CRC cells; whereas these effects were counteracted via targeting to PI3K/Akt or Wnt/β-catenin signaling pathway. CRC cell RKO-derived factor(s) significantly induced POSTN production in colonic fibroblasts and autocrine POSTN promoted proliferation, migration, and anchorage independent growth of fibroblasts. Conclusively, stromal POSTN is prognostic and predictive for CRC via creating a niche to facilitate cancer progression. Targeting POSTN-induced signaling pathways may be therapeutic options for metastatic or chemoresistant CRC.

High levels of periostin correlate with increased fracture rate, diffuse MRI pattern, abnormal bone remodeling and advanced disease stage in patients with newly diagnosed symptomatic multiple myeloma

Periostin is an extracellular matrix protein that is implicated in the biology of normal bone remodeling and in different cancer cell growth and metastasis. However, there is no information on the role of periostin in multiple myeloma (MM). Thus, we evaluated periostin in six myeloma cell lines in vitro; in the bone marrow plasma and serum of 105 newly diagnosed symptomatic MM (NDMM) patients and in the serum of 23 monoclonal gammopathy of undetermined significance (MGUS), 33 smoldering MM (SMM) patients, 30 patients at the plateau phase post-first-line therapy, 30 patients at first relapse and 30 healthy controls. We found high levels of periostin in the supernatants of myeloma cell lines compared with ovarian cancer cell lines that were not influenced by the incubation with the stromal cell line HS5. In NDMM patients the bone marrow plasma periostin was almost fourfold higher compared with the serum levels of periostin and correlated with the presence of fractures and of diffuse magnetic resonance imaging pattern of marrow infiltration. Serum periostin was elevated in NDMM patients compared with healthy controls, MGUS and SMM patients and correlated with advanced disease stage, high lactate dehydrogenase, increased activin-A, increased bone resorption and reduced bone formation. Patients at first relapse had also elevated periostin compared with healthy controls, MGUS and SMM patients, while even patients at the plateau phase had elevated serum periostin compared with healthy controls. These results support an important role of periostin in the biology of myeloma and reveal periostin as a possible target for the development of antimyeloma drugs.

Vascular mimicry formation is promoted by paracrine TGF-β and SDF1 of cancer-associated fibroblasts and inhibited by miR-101 in hepatocellular carcinoma

Vascular mimicry (VM) describes the phenomenon that tumor cells but not endothelial cells form vascular-like channels, which provide blood perfusion for tumor tissues. VM is associated with tumor growth, metastasis and worse survival of different cancers. The mechanisms of VM formation remain largely unknown. We showed that the conditioned medium of cancer-associated fibroblast (CM-CAF) promoted tumor cells to form capillary-like structure in vitro. Consistently, co-implantation of CAFs with tumor cells significantly enhanced VM formation in mouse xenografts, and higher amount of CAFs was found in VM⁺ human HCC tissues compared to VM^- ones. However, the CM-CAF-promoted VM formation was attenuated when TGF-β or SDF1 signaling was abrogated. Similar to CM-CAF, recombinant TGF-β1 and SDF1 induced VM formation. We further disclosed that the CAF-secreted TGF-β and SDF1 enhanced the expression of VE-cadherin, MMP2 and laminin5γ2 via TGF-βR1 and CXCR4 in tumor cells, thereby promoted VM formation. Moreover, tumor cells with high activity of self-sustaining TGF-β signaling displayed strong capability of VM formation. Subsequent investigations showed that miR-101, which was down-regulated in both tumor cells and CAFs, suppressed the CAF-promoted VM formation in vitro and in vivo. Gain- and loss-of-function analyses revealed that miR-101 attenuated TGF-β signaling transduction by targeting TGF-βR1 and Smad2 in tumor cells, and simultaneously abrogated SDF1 signaling by suppressing SDF1 expression in CAFs and inhibiting VE-cadherin expression in tumor cells. Our findings suggest that the miR-101-TGF-β/SDF1-VE-cadherin/MMP2/LAMC2 networks regulate VM formation and represent the potential targets for cancer therapy.

Periostin expression in cancer-associated fibroblasts of invasive ductal breast carcinoma

Periostin (POSTN) is a secreted cell adhesion glycoprotein that plays an important role in proliferation, adhesion and migration processes, as well as in regulation of mechanisms related to epithelial-mesenchymal transition (EMT). It also plays a key role in angio- and lymphangiogenesis and in formation of distant metastases. The aim of this work was to determine expression of POSTN in invasive ductal breast carcinoma (IDC) and in non-invasive ductal carcinoma in situ (DCIS) and to correlate its expression with clinicopathological parameters. Material for immunohistochemical studies (IHC) comprise of 70 IDC cases, 44 DCIS cases and 21 cases of fibrocystic change (FC). Frozen (-80˚C) fragments of tumours taken from 41 patients with IDC were used for molecular studies (real-time PCR), including 11 cases of IDC subjected to laser capture microdissection (LCM). POSTN expression was shown mainly in tumour stromal cells, i.e. cancer-associated fibroblasts (CAFs). Statistically significant higher level of POSTN expression in CAFs in IDC as compared to FC (p<0.0001) was observed. Additionally, statistically elevated expression level of POSTN in CAFs in IDC relative to DCIS (p<0.0001) and significantly increased expression of POSTN in CAFs in DCIS in comparison to FC (p=0.0158) was also shown. High level of POSTN expression in CAFs in IDC (>8 IRS points) was significantly correlated with tumour malignancy grade (G) (p=0.0070). Moreover, higher POSTN expression by CAFs was associated with patient shorter overall survival. Significant increase of POSTN expression on mRNA and protein level in CAFs in IDC with the growing malignancy grade of the tumours (G) was shown. Furthermore, with the use of LCM method, statistically significant higher expression of mRNA POSTN in stromal cells relative to cancer cells (p<0.001) was noted. POSTN might be a factor playing an important role in the mechanism of IDC progression.

Authentication and characterisation of a new oesophageal adenocarcinoma cell line: MFD-1

New biological tools are required to understand the functional significance of genetic events revealed by whole genome sequencing (WGS) studies in oesophageal adenocarcinoma (OAC). The MFD-1 cell line was isolated from a 55-year-old male with OAC without recombinant-DNA transformation. Somatic genetic variations from MFD-1, tumour, normal oesophagus, and leucocytes were analysed with SNP6. WGS was performed in tumour and leucocytes. RNAseq was performed in MFD-1, and two classic OAC cell lines FLO1 and OE33. Transposase-accessible chromatin sequencing (ATAC-seq) was performed in MFD-1, OE33, and non-neoplastic HET1A cells. Functional studies were performed. MFD-1 had a high SNP genotype concordance with matched germline/tumour. Parental tumour and MFD-1 carried four somatically acquired mutations in three recurrent mutated genes in OAC: TP53, ABCB1 and SEMA5A, not present in FLO-1 or OE33. MFD-1 displayed high expression of epithelial and glandular markers and a unique fingerprint of open chromatin. MFD-1 was tumorigenic in SCID mouse and proliferative and invasive in 3D cultures. The clinical utility of whole genome sequencing projects will be delivered using accurate model systems to develop molecular-phenotype therapeutics. We have described the first such system to arise from the oesophageal International Cancer Genome Consortium project.

The role of integrins in TGFβ activation in the tumour stroma

TGFβ1 is the most pleiotropic of all known cytokines and thus, to avoid uncontrolled TGFβ-activated processes, its activity is tightly regulated. Studies in fibrosis have led to the discovery that αv integrins are the major regulators of the local activation of latent TGFβ in our tissues. Since all cells can express one or more types of αv integrins, this raises the possibility that, in the complex milieu of a developing cancer, multiple cell types including both cancer cells and stromal cells activate TGFβ. In normal tissues, TGFβ1 is a tumour suppressor through its ability to suppress epithelial cell division, whereas in cancer, in which tumour cells develop genetic escape mechanisms to become resistant to TGFβ growth suppression, TGFβ signalling creates a tumour-permissive environment by activating fibroblast-to-myofibroblast transition, by promoting angiogenesis, by suppressing immune cell populations and by promoting the secretion of both matrix proteins and proteases. In addition, TGFβ drives epithelial-to-mesenchymal transition (EMT) increasing the potential for metastasis. Since αv integrins activate TGFβ, they almost certainly drive TGFβ-dependent cancer progression. In this review, we discuss the data that are helping to develop this hypothesis and describe the evidence that αv integrins regulate the TGFβ promotion of cancer. Graphical Abstract Mechanisms of integrin-mediated transforming growth factor beta (TGFβ) activation and its effect on stromal processes. 1 Matrix-bound latent LAP-TGFβ1 binds αv integrins expressed by epithelial cells or fibroblasts (LAP latency-associated peptide). TGFβ1 becomes exposed. 2 Active TGFβ1 binds the TGFβ receptor in an autocrine or paracrine fashion. 3 TGFβ1 signalling increases integrin expression, LAP-TGFβ1 secretion and trans-differentiation of fibroblasts into contractile cells that secrete collagens and collagen cross-linking proteins. By contracting the matrix, latent TGFβ1 is stretched making the activation of latent TGFβ1 easier and creating a continuous cycle of TGFβ1 signalling. TGFβ1 promotes cancer progression by promoting angiogenesis, immune suppression and epithelial-to-mesenchymal transition (EMT).

Genetic progression of Barrett's oesophagus to oesophageal adenocarcinoma

Barrett's oesophagus (BE) is the premalignant condition associated with the development of oesophageal adenocarcinoma (OAC). Diagnostically, p53 immunohistochemistry remains the only biomarker recommended clinically to aid histopathological diagnosis. The emerging mutational profile of BE is one of highly heterogeneous lesions at the genomic level with many mutations already occurring in non-dysplastic tissue. As well as point mutations, larger scale copy-number changes appear to have a key role in the progression to OAC and clinically applicable assays for the reliable detection of aneuploidy will be important to incorporate into future clinical management of patients. For some patients, the transition to malignancy may occur rapidly through a genome-doubling event or chromosomal catastrophe, termed chromothripsis, and detecting these patients may prove especially difficult. Given the heterogeneous nature of this disease, sampling methods to overcome inherent bias from endoscopic biopsies coupled with the development of more objective biomarkers than the current reliance on histopathology will be required for risk stratification. The aim of this approach will be to spare low-risk patients unnecessary procedures, as well as to provide endoscopic therapy to the patients at highest risk, thereby avoiding the burden of incurable metastatic disease.

Periostin promotes immunosuppressive premetastatic niche formation to facilitate breast tumour metastasis

Periostin (POSTN) is a limiting factor in the metastatic colonization of disseminated tumour cells. However, the role of POSTN in regulating the immunosuppressive function of immature myeloid cells in tumour metastasis has not been documented. Here, we demonstrate that POSTN promotes the pulmonary accumulation of myeloid-derived suppressor cells (MDSCs) during the early stage of breast tumour metastasis. Postn deletion decreases neutrophil and monocytic cell populations in the bone marrow of mice and suppresses the accumulation of MDSCs to premetastatic sites. We also found that POSTN-deficient MDSCs display reduced activation of ERK, AKT and STAT3 and that POSTN deficiency decreases the immunosuppressive functions of MDSCs during tumour progression. Moreover, the pro-metastatic role of POSTN is largely limited to ER-negative breast cancer patients. Lysyl oxidase contributes to POSTN-promoted premetastatic niche formation and tumour metastasis. Our findings indicate that POSTN is essential for immunosuppressive premetastatic niche formation in the lungs during breast tumour metastasis and is a potential target for the prevention and treatment of breast tumour metastasis. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Role of periostin in esophageal, gastric and colon cancer

Periostin, also known as osteoblast-specific factor 2, is a cell-adhesion protein with pleiotropic properties. The protein serves a vital role in the maintenance and development of tooth and bone tissue, in addition to cardiac development and healing. Periostin levels are increased in several forms of cancer, including pancreatic, ovarian, colon, lung, breast, gastric, thyroid, and esophageal head and neck carcinomas. The present review highlights the key role of periostin in tumorigenesis, particularly in increasing cell survival, invasion, angiogenesis, epithelial-mesenchymal transition and metastasis of carcinoma cells by interacting with numerous cell-surface receptors, including integrins, in the phosphoinositide 3-kinase-Akt pathway. In addition, periostin actively affects the canonical Wnt signaling pathway of colorectal tumorigenesis. The current review focused on the involvement of periostin in the development of colorectal, esophageal and gastric cancer.

Tumor-associated fibroblasts promote the proliferation and decrease the doxorubicin sensitivity of liposarcoma cells

The reasons for the distinct chemoresistance of liposarcomas and their high risk of local recurrence still remain unclear. Depending on the histological subtype of liposarcoma, first-line therapy with the cytostatic agent, doxorubicin, only achieves response rates of approximately 36%. Approximatley 70% of all local recurrences develop in spite of complete surgical resection of the primary tumor with microscopically negative margins. In this study, we aimed to assess the influence of tumor-associated fibroblasts (TAFs) obtained from surgically removed liposarcomas on the well-established human liposarcoma SW872 cell line. Intratumoral TAFs were isolated from intermediate- and high-grade liposarcoma samples. The human liposarcoma cell line, SW872, was co-cultured with the corresponding TAFs or with dermal fibroblasts as a control. The proliferation (by BrdU assay), cell viability (by MTT assay) and sensitivity to doxorubicin (using the iCELLigence system) of the co-cultured SW872 cells were examined. The SW872 cells exhibited a significant increase in proliferation and viability when co-cultured with the TAFs. As detected by real-time cell analysis, the SW872 cells co-cultured with the TAFs exhibited a diminished response towards doxorubicin. Notably, co-culture with TAFs obtained from high-grade liposarcoma samples resulted in higher proliferation and increased chemoresistance than co-culture with TAFs obtained from intermediate-grade liposarcoma samples. The findings of the present study thus indicate that TAFs from liposarcomas enhance the proliferation and decrease the chemosensitivity of SW872 liposarcoma cells significantly compared with normal fibroblasts from the dermis. TAFs from more malignant liposarcomas promoted tumor cell proliferation and chemoresistance more strikingly than TAFs from less malignant liposarcomas. These data provide evidence for the influence of the tumor microenvironment on liposarcoma and support for further investigations in patients with different liposarcoma subentities, assessing the influence of TAFs on tumor progression.

Beneficial effects of the naturally occurring flavonoid silibinin on the prostate cancer microenvironment: role of monocyte chemotactic protein-1 and immune cell recruitment

Tumor microenvironment plays an essential role in prostate carcinogenesis and offers novel opportunities to prevent and treat prostate cancer (PCA). Here, we investigated the ability of cancer-associated fibroblasts (CAFs) to promote PCA progression, and silibinin efficacy to target this response. We collected conditioned media from CAFs treated with vehicle or silibinin, and labeled as control conditioned media (CCM) or silibinin-treatment conditioned media (SBCM), respectively. Next, we characterized the effect of CCM and SBCM treatment in several PCA cell lines (RWPE-1, WPE-1 NA-22, WPE-1 NB-14 and PC3). Result showed that compared with SBCM, CCM significantly reduces E-cadherin expression and increases invasiveness and clonogenicity in PCA cells. Further molecular studies identified monocyte chemotactic protein-1 (MCP-1) as the key component of CCM that promotes PCA invasiveness, whereas silibinin treatment strongly reduced MCP-1 expression in CAFs by inhibiting the DNA-binding activity of MCP-1 transcriptional regulators-nuclear factor-kappaB and AP-1. In vivo, silibinin feeding (200mg/kg body weight) strongly reduced TRAMPC1 allografts growth (by 68%) in syngeneic C57Bl/6 mice. TRAMPC1 tumor analysis showed that silibinin reduced MCP-1 and CAFs' biomarkers (fibroblast activation protein, α-smooth muscle actin, transforming growth factor beta 2, vimentin etc.) and significantly modulated the recruitment of immune cells in the tumor microenvironment. Similar inhibitory effects of silibinin on MCP-1 and immune cells recruitment were also observed in TRAMP PCA tissues with reported silibinin efficacy. Overall, our data suggest that silibinin can target CAF-mediated invasiveness in PCA by inhibiting MCP-1 secretion. This, in turn, was associated with a reduction in immune cell recruitment in vivo along with a marked reduction in tumor growth.

The emerging roles of exosomes in tumor-stroma interaction

PURPOSE

The tumor-stroma interaction is critical for the development and progression of cancer. Cancer-associated fibroblasts (CAFs), one of the major components of the tumor stroma, can promote tumor growth and metastasis. Exosomes are secreted microvesicles that mediate cell-to-cell communication. Exosomal contents, including proteins, nucleic acids, and lipids, can be shuttled from donor cells to target cells. Recent studies suggest that exosomes play important roles in the tumor-stroma interaction. Herein, we review the multifaceted roles of exosomes in the tumor-stroma interaction and the underlying molecular mechanisms.

METHODS

Literature search for all relevant publications was performed on PubMed databases. The keywords of exosomes, tumor, stroma, CAFs, mesenchymal stem cells (MSCs) and other closely related terms were used for searching.

RESULTS

Tumor cell-derived exosomes induce the differentiation of fibroblasts and MSCs into CAFs. In turn, exosomes secreted by CAFs promote tumor growth, metastasis, and drug resistance through distinct mechanisms. Moreover, exosomes from stromal cells can be used as therapeutic vehicles for the delivery of anticancer drugs.

CONCLUSIONS

Tumor cells communicate with CAFs through exosomes, which establishes a bidirectional cross talk to promote tumor growth, metastasis, and drug resistance. Targeting exosomes in tumor-stroma interaction may have important implications for anticancer therapy.

The tumor microenvironment in esophageal cancer

Esophageal cancer is a deadly disease, ranking sixth among all cancers in mortality. Despite incremental advances in diagnostics and therapeutics, esophageal cancer still carries a poor prognosis, and thus there remains a need to elucidate the molecular mechanisms underlying this disease. There is accumulating evidence that a comprehensive understanding of the molecular composition of esophageal cancer requires attention to not only tumor cells but also the tumor microenvironment, which contains diverse cell populations, signaling factors, and structural molecules that interact with tumor cells and support all stages of tumorigenesis. In esophageal cancer, environmental exposures can trigger chronic inflammation, which leads to constitutive activation of pro-inflammatory signaling pathways that promote survival and proliferation. Anti-tumor immunity is attenuated by cell populations such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), as well as immune checkpoints like programmed death-1 (PD-1). Other immune cells such as tumor-associated macrophages can have other pro-tumorigenic functions, including the induction of angiogenesis and tumor cell invasion. Cancer-associated fibroblasts secrete growth factors and alter the extracellular matrix (ECM) to create a tumor niche and enhance tumor cell migration and metastasis. Further study of how these TME components relate to the different stages of tumor progression in each esophageal cancer subtype will lead to development of novel and specific TME-targeting therapeutic strategies, which offer considerable potential especially in the setting of combination therapy.

In Vitro Tumor Models: Advantages, Disadvantages, Variables, and Selecting the Right Platform

In vitro tumor models have provided important tools for cancer research and serve as low-cost screening platforms for drug therapies; however, cancer recurrence remains largely unchecked due to metastasis, which is the cause of the majority of cancer-related deaths. The need for an improved understanding of the progression and treatment of cancer has pushed for increased accuracy and physiological relevance of in vitro tumor models. As a result, in vitro tumor models have concurrently increased in complexity and their output parameters further diversified, since these models have progressed beyond simple proliferation, invasion, and cytotoxicity screens and have begun recapitulating critical steps in the metastatic cascade, such as intravasation, extravasation, angiogenesis, matrix remodeling, and tumor cell dormancy. Advances in tumor cell biology, 3D cell culture, tissue engineering, biomaterials, microfabrication, and microfluidics have enabled rapid development of new in vitro tumor models that often incorporate multiple cell types, extracellular matrix materials, and spatial and temporal introduction of soluble factors. Other innovations include the incorporation of perfusable microvessels to simulate the tumor vasculature and model intravasation and extravasation. The drive toward precision medicine has increased interest in adapting in vitro tumor models for patient-specific therapies, clinical management, and assessment of metastatic potential. Here, we review the wide range of current in vitro tumor models and summarize their advantages, disadvantages, and suitability in modeling specific aspects of the metastatic cascade and drug treatment.

The role of cancer-associated fibroblasts in esophageal cancer

Fibroblasts are known as critical stromal cells in wound healing by synthesizing extracellular matrix and collagen. A subpopulation of them is called cancer-associated fibroblasts (CAFs), because their production of proteins participated in various biological activities including tumor cell proliferation, invasion and metastasis. Currently some studies shed light on their role in esophageal cancer which was an aggressive cancer with a dismal survival and high rate of metastasis. Thus, to find cures for it relies on elucidating the epithelial-fibroblasts crosstalk. Herein, we reviewed the present knowledge of the CAFs’ role in esophageal premalignant condition, cancer initiation, progression, metastasis and prognosis prediction and further provided some insights into its clinical application.

The prognostic role of desmoplastic stroma in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant desmoplastic stroma. We examined the prognostic value of stroma density and activity in patients with resectable PDAC treated with surgery and adjuvant gemcitabine-based chemotherapy. FFPE-tissue from the pancreatectomy of 145 patients was immunohistochemically stained for haematoxylin-eosin and Masson's trichrome to assess stroma density, and alpha-smooth muscle actin (αSMA) expression for activated pancreatic stellate cells. Their expression was correlated with clinicopathological characteristics as well as overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS) and distant metastases free-survival (DMFS). After a mean follow-up of 20 months (range, 2-69 months), the median OS was 21 months and the 3-year OS was 35.7%. In multivariate analysis, highly-dense stroma was an independent prognostic parameter for OS (p = 0.001), PFS (p = 0.007), LPFS (p = 0.001) and DMFS (p = 0.002), while αSMA expression lacked significance. Interestingly, highly-dense stroma retained significance for the four clinical endpoints only in early (pT1-2) but not late (pT3-4) stage tumors. Additionally, late pT-stage (pT3-4), the presence of lymph node metastases (pN+ vs pN0), perineural/neural invasion and administration of adjuvant chemotherapy also correlated with prognosis in multivariate analysis. Altogether, stroma density constitutes an independent prognostic marker in PDAC patients treated with adjuvant chemotherapy. Our findings highlight the dynamic complexity of desmoplasia and indicate that highly-dense stroma is correlated with better outcome. Further validation of the prognostic value of stroma as a biomarker and its role in PDAC patients after adjuvant chemotherapy is warranted and will be performed in a prospective study.

Altered expression of epithelial-to-mesenchymal transition proteins in extraprostatic prostate cancer

Epithelial to mesenchymal transition (EMT) of cancer cells involves loss of epithelial polarity and adhesiveness, and gain of invasive and migratory mesenchymal behaviours. EMT occurs in prostate cancer (PCa) but it is unknown whether this is in specific areas of primary tumours. We examined whether any of eleven EMT-related proteins have altered expression or subcellular localisation within the extraprostatic extension component of locally advanced PCa compared with other localisations, and whether similar changes may occur in in vitro organotypic PCa cell cultures and in vivo PCa models. Expression profiles of three proteins (E-cadherin, Snail, and α-smooth muscle actin) were significantly different in extraprostatic extension PCa compared with intra-prostatic tumour, and 18/27 cases had an expression change of at least one of these three proteins. Of the three significantly altered EMT proteins in pT3 samples, one showed similar significantly altered expression patterns in in vitro organotypic culture models, and two in in vivo Pten-/- model samples. These results suggest that changes in EMT protein expression can be observed in the extraprostatic extension component of locally invasive PCa. The biology of some of these changes in protein expression may be studied in certain in vitro and in vivo PCa models.

Wharton's Jelly-Derived Mesenchymal Stromal Cells and Fibroblast-Derived Extracellular Matrix Synergistically Activate Apoptosis in a p21-Dependent Mechanism in WHCO1 and MDA MB 231 Cancer Cells In Vitro

The tumour microenvironment plays a crucial role in tumour progression and comprises tumour stroma which is made up of different cell types and the extracellular matrix (ECM). Mesenchymal stromal cells (MSCs) are part of the tumour stroma and may have conflicting effects on tumour growth. In this study we investigated the effect of Wharton's Jelly-derived MSCs (WJ-MSCs) and a fibroblast-derived ECM (fd-ECM) on esophageal (WHCO1) and breast (MDA MB 231) cancer cells in vitro. Both WJ-MSCs and the fd-ECM, alone or in combination, downregulate PCNA, cyclin D1, Bcl-2, Bcl-xL, and MMPs and upregulate p53 and p21. p21 induction resulted in G2 phase cell cycle arrest and induced apoptosis in vitro. Our data suggest that p21 induction is via p53-dependent and p53-independent mechanisms in WHCO1 and MDA MB 231 cells, respectively. Vascular endothelial growth factor, Akt, and Nodal pathways were downregulated in cancer cells cocultured with WJ-MSCs. We also demonstrate that WJ-MSCs effects on cancer cells appear to be short-lived whilst the fd-ECM effect is long-lived. This study shows the influence of tumour microenvironment on cancer cell behaviour and provides alternative therapeutic targets for potential regulation of tumour cells.

Translational aspects in targeting the stromal tumour microenvironment: from bench to bedside

Solid tumours comprise, not only malignant cells but also a variety of stromal cells and extracellular matrix proteins. These components interact via an array of signalling pathways to create an adaptable network that may act to promote or suppress cancer progression. To date, the majority of anti-tumour chemotherapeutic agents have principally sought to target the cancer cell. Consequently, resistance develops because of clonal evolution, as a result of selection pressure during tumour expansion. The concept of activating or inhibiting other cell types within the tumour microenvironment is relatively novel and has the advantage of targeting cells which are genetically stable and less likely to develop resistance. This review outlines key players in the stromal tumour microenvironment and discusses potential targeting strategies that may offer therapeutic benefit.

Periductal stromal collagen topology of pancreatic ductal adenocarcinoma differs from that of normal and chronic pancreatitis

Pancreatic ductal adenocarcinoma continues to be one of the most difficult diseases to manage with one of the highest cancer mortality rates. This is due to several factors including nonspecific symptomatology and subsequent diagnosis at an advanced stage, aggressive metastatic behavior that is incompletely understood, and limited response to current therapeutic regimens. As in other cancers, there is great interest in studying the role of the tumor microenvironment in pancreatic ductal adenocarcinoma and whether components of this environment could serve as research and therapeutic targets. In particular, attention has turned toward the desmoplastic collagen-rich pancreatic ductal adenocarcinoma stroma for both biological and clinical insight. In this study, we used quantitative second harmonic generation microscopy to investigate stromal collagen organization and structure in human pancreatic ductal adenocarcinoma pathology tissues compared with non-neoplastic tissues. Collagen topology was characterized in whole-tissue microarray cores and at specific pathology-annotated epithelial-stroma interfaces representing 241 and 117 patients, respectively. We quantitatively demonstrate that a unique collagen topology exists in the periductal pancreatic ductal adenocarcinoma stroma. Specifically, collagen around malignant ducts shows increased alignment, length, and width compared with normal ducts and benign ducts in a chronic pancreatitis background. These findings indicate that second harmonic generation imaging can provide quantitative information about fibrosis that complements traditional histopathologic insights and can serve as a rich field for investigation into pathogenic and clinical implications of reorganized collagen as a pancreatic ductal adenocarcinoma disease marker.

Cancer-associated fibroblasts as target and tool in cancer therapeutics and diagnostics

Cancer-associated fibroblasts (CAFs) are drivers of tumour progression and are considered as a target and a tool in cancer diagnostic and therapeutic applications. An increased abundance of CAFs or CAF signatures are recognized as a bad prognostic marker in several cancer types. Tumour-environment biomimetics strongly improve our understanding of the communication between CAFs, cancer cells and other host cells. Several experimental drugs targeting CAFs are in clinical trials for multiple tumour entities; alternatively, CAFs can be exploited as a tool to characterize the functionality of circulating tumour cells or to capture them as a tool to prevent metastasis. The continuous interaction between tissue engineers, biomaterial experts and cancer researchers creates the possibility to biomimic the tumour-environment and provides new opportunities in cancer diagnostics and management.

Molecular mechanism underlying the tumor-promoting functions of carcinoma-associated fibroblasts

Tumor microenvironment is composed of all the untransformed elements in the vicinity of tumor, mainly including a large number of stromal cells and extracellular matrix proteins, which play an active role in most solid tumor initiation and progression. Carcinoma-associated fibroblasts (CAFs), one of the most common stromal cell types in the tumor microenvironment, have been demonstrated to be involved in tumor growth, invasion, and metastasis. Therefore, they are becoming a promising target for anti-cancer therapies. In this review, we firstly summarize the current understandings of CAFs' molecular biology, including the heterogeneous cellular origins and molecular markers, and then, we focus on reviewing their various tumor-promoting phenotypes involved in complex mechanisms, which can be summarized to the CAF-conveyed paracrine signals in tumor cells, cancer stem cells, and metastasis-initiating cancer cells, as well as the CAF-enhanced extrinsic tumor-promoting processes including angiogenesis, extracellular matrix remodeling, and tumor-related inflammation; finally, we describe the available directions of CAF-based target therapy and suggest research areas which need to be further explored so as to deepen the understanding of tumor evolution and provide new therapeutic targets for cancer treatment.