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

Periostin+ cancer-associated fibroblasts promote lymph node metastasis by impairing the lymphatic endothelial barriers in cervical squamous cell carcinoma

Lymph node metastasis (LNM), a critical prognostic determinant in cancer patients, is critically influenced by the presence of numerous heterogeneous cancer‐associated fibroblasts (CAFs) in the tumor microenvironment. However, the phenotypes and characteristics of the various pro‐metastatic CAF subsets in cervical squamous cell carcinoma (CSCC) remain unknown. Here, we describe a CAF subpopulation with elevated periostin expression (periostin⁺CAFs), located in the primary tumor sites and metastatic lymph nodes, that positively correlated with LNM and poor survival in CSCC patients. Mechanistically, periostin⁺CAFs impaired lymphatic endothelial barriers by activating the integrin‐FAK/Src‐VE‐cadherin signaling pathway in lymphatic endothelial cells and consequently enhanced metastatic dissemination. In contrast, inhibition of the FAK/Src signaling pathway alleviated periostin‐induced lymphatic endothelial barrier dysfunction and its related effects. Notably, periostin^‐CAFs were incapable of impairing endothelial barrier integrity, which may explain the occurrence of CAF‐enriched cases without LNM. In conclusion, we identified a specific periostin⁺CAF subset that promotes LNM in CSCC, mainly by impairing the lymphatic endothelial barriers, thus providing the basis for potential stromal fibroblast‐targeted interventions that block CAF‐dependent metastasis.

Stromal microenvironment promoted infiltration in esophageal adenocarcinoma and squamous cell carcinoma: a multi-cohort gene-based analysis

The stromal microenvironment has been shown to affect the infiltration of esophageal carcinoma (ESCA), which is linked to prognosis. However, the complicated mechanism of how infiltration is influenced by the stromal microenvironment is not well-defined. In this study, a stromal activation classifier was established with ridge cox regression to calculate stroma scores for training (n = 182) and validation cohorts (n = 227) based on the stroma-related 32 hub genes identified by sequential bioinformatics algorithms. Patients with high stromal activation were associated with high T stage and poor prognosis in both esophagus adenocarcinoma and esophagus squamous cell carcinoma. Besides, comprehensive multi-omics analysis was used to outline stromal characterizations of 2 distinct stromal groups. Patients with activated tumor stoma showed high stromal cell infiltration (fibroblasts, endothelial cells, and monocyte macrophages), epithelial-mesenchymal transition, tumor angiogenesis and M2 macrophage polarization (CD163 and CD206). Tumor mutation burden of differential stromal groups was also depicted. In addition, a total of 6 stromal activation markers in ESCA were defined and involved in the function of carcinoma-associated fibroblasts that were crucial in the differentiation of distinct stromal characterizations. Based on these studies, a practical classifier for the stromal microenvironment was successfully proposed to predict the prognosis of ESCA patients.

Towards screening Barrett's oesophagus: current guidelines, imaging modalities and future developments

Barrett's oesophagus is the only known precursor to oesophageal adenocarcinoma (OAC). Although guidelines on the screening and surveillance exist in Barrett's oesophagus, the current strategies are inadequate. Oesophagogastroduodenoscopy (OGD) is the gold standard method in screening for Barrett's oesophagus. This invasive method is expensive with associated risks negating its use as a current screening tool for Barrett's oesophagus. This review explores current definitions, epidemiology, biomarkers, surveillance, and screening in Barrett's oesophagus. Imaging modalities applicable to this condition are discussed, in addition to future developments. There is an urgent need for an alternative non-invasive method of screening and/or surveillance which could be highly beneficial towards reducing waiting times, alleviating patient fears and reducing future costs in current healthcare services. Vibrational spectroscopy has been shown to be promising in categorising Barrett's oesophagus through to high-grade dysplasia (HGD) and OAC. These techniques need further validation through multicentre trials.

Periostin regulates autophagy through integrin α5β1 or α6β4 and an AKT-dependent pathway in colorectal cancer cell migration

Colorectal cancer (CRC) is one of the most fatal cancers with highly invasive properties. The progression of CRC is determined by the driving force of periostin (PN) from cancer‐associated fibroblasts (CAFs) in the tumour microenvironment. This present work aims to investigate autophagy‐mediated CRC invasion via the receptor integrin (ITG) by PN. The level of PN in 410 clinical CRC tissues was found increased and was an independent poor prognosis marker (HR = 2.578, 95% CI = 1.218‐5.457, P‐value = .013) with a significant correlation with overall survival time (P‐value < .001). PN activated proliferation, migration and invasion of CRC cells, but with reduced autophagy. Interestingly, the reduction of LC3 autophagic protein corresponded to the increased ability of CRC cell migration. The siITGα5‐treated HT‐29 and siITGβ4‐treated HCT‐116 CRC cells attenuated epithelial‐to‐mesenchymal transitions (EMT)‐related genes and pAKT compared with those in siITG‐untreated cells. The reduction of pAKT by a PI3K inhibitor significantly restored autophagy in CRC cells. These evidences confirmed the effect of PN through either ITGα5β1 or ITGα6β4 and the AKT‐dependent pathway to control autophagy‐regulated cell migration. In conclusion, these results exhibited the impact of PN activation of ITGα5β1 or ITGα6β4 through pAKT in autophagy‐mediated EMT and migration in CRC cells.

Prognostic Significance of Stromal Periostin Expression in Non-Small Cell Lung Cancer

Background: The microenvironment of solid tumours is significant in cancer development and progression. The aim of this study was to determine periostin (POSTN) expression by cancer-associated fibroblasts (CAFs) in non-small-cell lung cancer (NSCLC), as well as to assess associations with clinicopathological factors and prognosis. Materials and Methods: Immunohistochemical analysis of POSTN expression was performed on NSCLC (N = 700) and non-malignant lung tissue (NMLT) (N = 110) using tissue microarrays. Laser capture microdissection (LCM) for isolation of stromal and cancer cells of NSCLC was employed, and subsequently, POSTN mRNA expression was detected by real-time PCR. Immunofluorescence reaction and colocalisation analysis were performed by confocal microscopy. Results: Expression of POSTN in CAFs was significantly higher in NSCLC and in the adenocarcinoma (AC) and squamous cell carcinoma (SCC) subtypes compared to NMLT. POSTN expression in CAFs increased with clinical cancer stage, grades (G) of malignancy, and lymph node involvement in NSCLC. Higher POSTN expression in CAFs was an independent prognostic factor for overall survival (OS). LCM confirmed significantly higher POSTN mRNA expression in the stromal cells (CAFs) compared to the lung cancer cells. Conclusions: POSTN produced by CAFs might be crucial for NSCLC progression and can be an independent negative prognostic factor in NSCLC.

Cancer-Associated Fibroblasts Provide a Stromal Niche for Liver Cancer Organoids That Confers Trophic Effects and Therapy Resistance

BACKGROUND & AIMS

Cancer-associated fibroblasts (CAFs) play a key role in the cancer process, but the research progress is hampered by the paucity of preclinical models that are essential for mechanistic dissection of cancer cell-CAF interactions. Here, we aimed to establish 3-dimensional (3D) organotypic co-cultures of primary liver tumor-derived organoids with CAFs, and to understand their interactions and the response to treatment.

METHODS

Liver tumor organoids and CAFs were cultured from murine and human primary liver tumors. 3D co-culture models of tumor organoids with CAFs and Transwell culture systems were established in vitro. A xenograft model was used to investigate the cell-cell interactions in vivo. Gene expression analysis of CAF markers in our hepatocellular carcinoma cohort and an online liver cancer database indicated the clinical relevance of CAFs.

RESULTS

To functionally investigate the interactions of liver cancer cells with CAFs, we successfully established murine and human 3D co-culture models of liver tumor organoids with CAFs. CAFs promoted tumor organoid growth in co-culture with direct cell-cell contact and in a Transwell system via paracrine signaling. Vice versa, cancer cells secrete paracrine factors regulating CAF physiology. Co-transplantation of CAFs with liver tumor organoids of mouse or human origin promoted tumor growth in xenograft models. Moreover, tumor organoids conferred resistance to clinically used anticancer drugs including sorafenib, regorafenib, and 5-fluorouracil in the presence of CAFs, or the conditioned medium of CAFs.

CONCLUSIONS

We successfully established murine and human 3D co-culture models and have shown robust effects of CAFs in liver cancer nurturing and treatment resistance.

Cancer associated fibroblast mediated chemoresistance: A paradigm shift in understanding the mechanism of tumor progression

One of the undeniable issues with cancer eradication is the evolution of chemoresistance in due course of treatment, and the mechanisms of chemoresistance have been the subject of extensive research for several years. The efficacy of chemotherapy is hindered by cancer epithelium, mostly in a cell-autonomous mechanism. However, recently the valid experimental evidence showed that the surrounding tumor microenvironment (TME) is equivalently responsible for the induction of chemoresistance. Of the verities of cells in the tumor microenvironment, cancer-associated fibroblasts (CAFs) are the major cellular component of TME and act as a key regulator in the acquisition of cancer chemoresistance by providing a protective niche to the cancer cells against the anti-cancer drugs. Moreover, the symbiotic relationship between the tumor and CAFs to obtain key resources such as growth factors and nutrients for optimal tumor growth and proliferation favors the chemoresistance phenotype. Here, in this review, we provide an up-to-date overview of our knowledge of the role of the CAFs in inducing chemoresistance and tumor progression. We also further delineated the emerging events leading to the CAF origins and activation of normal fibroblasts to CAFs. Along with this, we also discuss the novel area of research confined to the CAF targeted therapies of cancer. The identification of CAF-specific markers may allow unveiling new targets and avenues for blunting or reverting the detrimental pro-tumorigenic potential of CAFs in the foreseeable future.

Connective tissue growth factor produced by cancer‑associated fibroblasts correlates with poor prognosis in epithelioid malignant pleural mesothelioma

Malignant mesothelioma is an aggressive neoplasm for which effective treatments are lacking. We often encounter mesothelioma cases with a profound desmoplastic reaction, suggesting the involvement of cancer-associated fibroblasts (CAFs) in mesothelioma progression. While the roles of CAFs have been extensively studied in other tumors and have led to the view that the cancer stroma contains heterogeneous populations of CAFs, their roles in mesothelioma remain unknown. We previously showed that connective tissue growth factor (CTGF), a secreted protein, is produced by both mesothelioma cells and fibroblasts and promotes the invasion of mesothelioma cells in vitro. In this study, we examined the clinical relevance of CAFs in mesothelioma. Using surgical specimens of epithelioid malignant pleural mesothelioma, we evaluated the clinicopathological significance of the expression of α-smooth muscle actin (αSMA), the most widely used marker of CAFs, the expression of CTGF, and the extent of fibrosis by immunohistochemistry and Elastica-Masson staining. We also analyzed the expression of mesenchymal stromal cell- and fibroblast-expressing Linx paralogue (Meflin; ISLR), a recently reported CAF marker that labels cancer-restraining CAFs and differ from αSMA-positive CAFs, by in situ hybridization. The extent of fibrosis and CTGF expression in mesothelioma cells did not correlate with patient prognosis. However, the expression of αSMA and CTGF, but not Meflin, in CAFs correlated with poor prognosis. The data suggest that CTGF⁺ CAFs are involved in mesothelioma progression and represent a potential molecular target for mesothelioma therapy.

Correlation Between Immunoinflammatory Measures and Periostin Expression in Esophageal Squamous Cell Carcinoma: A Single-Center, Retrospective Cohort Study

BACKGROUND

Immunoinflammatory measures such as the neutrophil-lymphocyte ratio (NLR), the platelet-lymphocyte ratio (PLR), and the C-reactive protein (CRP)-albumin ratio (CAR) are useful prognostic measures in various malignancies. However, no study has investigated the correlation of these measures with microenvironmental inflammation. Periostin (POSTN), a small extracellular matrix protein, strongly associates with cancer microenvironmental inflammation. The current study investigated the correlation of NLR, PLR, and CAR with periostin expression in esophageal squamous cell carcinoma (ESCC).

METHODS

The study retrospectively evaluated preoperative NLR, PLR, and CAR hematologically and POSTN immunohistochemically in 171 patients. The correlation of immunoinflammatory measures, POSTN expression, and survival outcomes was measured.

RESULTS

The study showed a significant correlation of POSTN-positive expression with poor overall survival (OS) (P < 0.0001) and recurrence-free survival (RFS) (P = 0.03). The POSTN-positive group had higher PLR (189.6 ± 8 vs. 159.3 ± 12; P = 0.04) and CAR (0.36 ± 0.06 vs. 0.14 ± 0.09; P < 0.05) than the POSTN-negative group, whereas NLR did not differ between the two groups (3.27 ± 0.19 vs. 2.65 ± 0.28; P = 0.07). The uni- and multivariate analyses showed that POSTN-positive expression (hazard ratio [HR], 1.595; 95% confidence interval [CI], 0.770-3.031; P = 0.03), CAR (HR, 1.663; 95% CI, 1.016-2.764; P = 0.03), gender (HR, 2.303; 95% CI, 1.067-6.019; P = 0.03), and tumor depth (HR, 1.957; 95% CI, 1.122-3.526; P = 0.01) were independent prognostic factors.

CONCLUSIONS

Because POSTN-positive expression strongly correlates with immunoinflammatory measures, especially PLR and CAR, it is an independent prognostic factor in ESCC.

The Cancer-Immune Set Point in Oesophageal Cancer

Immunotherapy has achieved long-term disease control in a proportion of cancer patients, but determinants of clinical benefit remain unclear. A greater understanding of antitumor immunity on an individual basis is needed to facilitate a precision oncology approach. A conceptual framework called the "cancer-immune set point" has been proposed to describe the equilibrium between factors that promote or suppress anticancer immunity and can serve as a basis to understand the variability in clinical response to immune checkpoint blockade. Oesophageal cancer has a high mutational burden, develops from pre-existing chronic inflammatory lesions and is therefore anticipated to be sensitive to immune checkpoint inhibition. However, both tumour- and patient-specific factors including the immune microenvironment, the microbiome, obesity, and host genetics contribute to an immune set point that confers a lower-than-expected response to checkpoint blockade. Immunotherapy is therefore currently confined to latter lines of treatment of advanced disease, with no reliable predictive biomarker of response. In this review, we examine oesophageal cancer in the context of the cancer-immune set point, discuss factors that contribute to response to immunotherapeutic intervention, and propose areas requiring further investigation to improve treatment response.

NOX4 Inhibition Potentiates Immunotherapy by Overcoming Cancer-Associated Fibroblast-Mediated CD8 T-cell Exclusion from Tumors

Determining mechanisms of resistance to αPD-1/PD-L1 immune-checkpoint immunotherapy is key to developing new treatment strategies. Cancer-associated fibroblasts (CAF) have many tumor-promoting functions and promote immune evasion through multiple mechanisms, but as yet, no CAF-specific inhibitors are clinically available. Here we generated CAF-rich murine tumor models (TC1, MC38, and 4T1) to investigate how CAFs influence the immune microenvironment and affect response to different immunotherapy modalities [anticancer vaccination, TC1 (HPV E7 DNA vaccine), αPD-1, and MC38] and found that CAFs broadly suppressed response by specifically excluding CD8+ T cells from tumors (not CD4+ T cells or macrophages); CD8+ T-cell exclusion was similarly present in CAF-rich human tumors. RNA sequencing of CD8+ T cells from CAF-rich murine tumors and immunochemistry analysis of human tumors identified significant upregulation of CTLA-4 in the absence of other exhaustion markers; inhibiting CTLA-4 with a nondepleting antibody overcame the CD8+ T-cell exclusion effect without affecting Tregs. We then examined the potential for CAF targeting, focusing on the ROS-producing enzyme NOX4, which is upregulated by CAF in many human cancers, and compared this with TGFβ1 inhibition, a key regulator of the CAF phenotype. siRNA knockdown or pharmacologic inhibition [GKT137831 (Setanaxib)] of NOX4 "normalized" CAF to a quiescent phenotype and promoted intratumoral CD8+ T-cell infiltration, overcoming the exclusion effect; TGFβ1 inhibition could prevent, but not reverse, CAF differentiation. Finally, NOX4 inhibition restored immunotherapy response in CAF-rich tumors. These findings demonstrate that CAF-mediated immunotherapy resistance can be effectively overcome through NOX4 inhibition and could improve outcome in a broad range of cancers. SIGNIFICANCE: NOX4 is critical for maintaining the immune-suppressive CAF phenotype in tumors. Pharmacologic inhibition of NOX4 potentiates immunotherapy by overcoming CAF-mediated CD8+ T-cell exclusion. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/9/1846/F1.large.jpg.See related commentary by Hayward, p. 1799.

LTBP1 promotes esophageal squamous cell carcinoma progression through epithelial-mesenchymal transition and cancer-associated fibroblasts transformation

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent cancers worldwide. Due to its high morbidity and mortality rates, it is urgent to find a molecular target that contributes to esophageal carcinogenesis and progression. In this research, we aimed to investigate the functions of Latent transforming growth factor β binding protein 1(LTBP1) in ESCC progression and elucidate the underlying mechanisms.

METHODS

The tandem mass tag-based quantitative proteomic approach was applied to screen the differentially expressed proteins (DEPs) between 3 cases of ESCC tumor samples and paired normal tissues. Then the DEPs were validated in human ESCC tissues using western blot assays and GEPIA database respectively. The expression level of LTBP1 was detected in 152 cases of ESCC tissues and paired normal tissues. Loss-of-function assays were performed to detect the function of LTBP1 in vivo and in vitro. Immunofluorescence and Western blot assays were used to detect the expression of apoptosis, epithelial-mesenchymal transition (EMT) and cancer-associated fibroblasts (CAFs) markers.

RESULTS

A total of 39 proteins were screened to be up-regulated (ratio > 2.0) in all three ESCC tissues. The results of immunohistochemistry assays indicated that the expression level of LTBP1 was higher in ESCC tissues than that in paired normal tissues (p < 0.001). Overexpression of LTBP1 was positively associated with lymphatic metastasis in ESCC (p = 0.002). Down-regulation of LTBP1 inhibited the invasion and migration as well as metastatic abilities in vitro and in vivo. It was also observed the down-regulation of LTBP1 not only decreased the mesenchymal phenotypes but also inhibited TGFβ-induced EMT in ESCC cells. We further found that down-regulation of LTBP1 enhanced ESCC cells' sensitivity to 5-FU treatment. Inhibition of LTBP1 expression could also attenuate induction of CAFs transformation and restrain fibroblast express fibronectin (FN1) in ESCC cells.

CONCLUSION

Overexpression of LTBP1 was associated with lymph node metastasis in ESCC. Our results indicated that LTBP1 not only increased the malignant behaviors of ESCC cells but also induced EMT and CAFs transformation. Our studies suggested an oncogenic role of LTBP1 in ESCC progression and it may serve as a potential therapeutic target for ESCC patients.

Cancer-associated fibroblasts that restrain cancer progression: Hypotheses and perspectives

The roles of cancer‐associated fibroblasts (CAF) in the progression of various types of cancers are well established. CAF promote cancer progression through pleiotropic mechanisms, including the secretion of soluble factors and extracellular matrix, physical interactions with cancer cells, and the regulation of angiogenesis, immunity and metabolism. Their contribution to therapeutic resistance is also well appreciated. Therefore, CAF have been considered as a therapeutic target in cancer. However, recent studies in autochthonous pancreatic cancer models suggest that specific subset(s) of CAF exhibit cancer‐restraining roles, indicating that CAF are functionally and molecularly heterogeneous, which is supported by recent single‐cell transcriptome analyses. While cancer‐promoting CAF (pCAF) have been extensively studied, the nature and specific marker(s) of cancer‐restraining CAF (rCAF) have remained uncharacterized. Interestingly, a recent study provided insight into the nature of rCAF and suggested that they may share molecular properties with pancreatic stellate cells (PSC) and mesenchymal stem/stromal cells (MSC). Complicating this finding is that PSC and MSC have been shown to promote the formation of a tumor‐permissive and tumor‐promoting environment in xenograft tumor models. However, these cells undergo significant transcriptional and epigenetic changes during ex vivo culture, which confounds the interpretation of experimental results based on the use of cultured cells. In this short review, we describe recent studies and hypotheses on the identity of rCAF and discuss their analogy to fibroblasts that suppress fibrosis in fibrotic diseases. Finally, we discuss how these findings can be exploited to develop novel anticancer therapies in the future.

Cancer-associated fibroblasts that restrain cancer progression: Hypotheses and perspectives

The roles of cancer-associated fibroblasts (CAF) in the progression of various types of cancers are well established. CAF promote cancer progression through pleiotropic mechanisms, including the secretion of soluble factors and extracellular matrix, physical interactions with cancer cells, and the regulation of angiogenesis, immunity and metabolism. Their contribution to therapeutic resistance is also well appreciated. Therefore, CAF have been considered as a therapeutic target in cancer. However, recent studies in autochthonous pancreatic cancer models suggest that specific subset(s) of CAF exhibit cancer-restraining roles, indicating that CAF are functionally and molecularly heterogeneous, which is supported by recent single-cell transcriptome analyses. While cancer-promoting CAF (pCAF) have been extensively studied, the nature and specific marker(s) of cancer-restraining CAF (rCAF) have remained uncharacterized. Interestingly, a recent study provided insight into the nature of rCAF and suggested that they may share molecular properties with pancreatic stellate cells (PSC) and mesenchymal stem/stromal cells (MSC). Complicating this finding is that PSC and MSC have been shown to promote the formation of a tumor-permissive and tumor-promoting environment in xenograft tumor models. However, these cells undergo significant transcriptional and epigenetic changes during ex vivo culture, which confounds the interpretation of experimental results based on the use of cultured cells. In this short review, we describe recent studies and hypotheses on the identity of rCAF and discuss their analogy to fibroblasts that suppress fibrosis in fibrotic diseases. Finally, we discuss how these findings can be exploited to develop novel anticancer therapies in the future.

Immunohistochemical analysis of the expression of cancer-associated fibroblast markers in esophageal cancer with and without neoadjuvant therapy

Esophageal carcinoma (EC) is one of the most aggressive human malignancies with high rates of resistance to conventional anticancer treatment. Cancer-associated fibroblasts (CAFs) are an important part of the tumor microenvironment and associated with tumor progression. COL11A1, SPARC, and CD90 have been identified as rather specific CAF markers, with COL11A1 expression particularly shown to influence response to chemotherapy. We investigated the impact of CAFs in esophageal cancer with a special focus on response to neoadjuvant treatment (nTX). Two collections of esophageal carcinomas were investigated: 164 cases treated with primary resection and 256 cases receiving nTX before resection. The expression of CAF markers was determined using next-generation tissue microarray (ngTMA®) technology and immunohistochemistry. The presence of COL11A1 and SPARC in fibroblasts within both primary resected cases and nTX-treated cases was associated with unfavorable clinicopathological variables such as higher (y)pT category and lymphatic invasion (p<0.001 each). The presence of COL11A1-positive CAFs was associated with worse overall survival in primary resected cases (HR: 2.162, p = 0.004, CI 95% 1.275-3.686). While in tumors showing regression after nTX, COL11A1-positive CAFs were detected less frequently, SPARC-positive CAFs were enriched after nTX, in both responding and non-responding patients (p < 0.001). Our results support the concept of CAFs as an important factor of tumor promotion and maintenance in EC. The population of CAFs increases with tumor progression and decreases, partly depending on the subtype, after regression following nTX. CAFs may serve as potential target for future therapeutic approaches for these highly aggressive tumors.

Latest Advances in Targeting the Tumor Microenvironment for Tumor Suppression

The tumor bulk is composed of a highly heterogeneous population of cancer cells, as well as a large variety of resident and infiltrating host cells, extracellular matrix proteins, and secreted proteins, collectively known as the tumor microenvironment (TME). The TME is essential for driving tumor development by promoting cancer cell survival, migration, metastasis, chemoresistance, and the ability to evade the immune system responses. Therapeutically targeting tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), regulatory T-cells (T-regs), and mesenchymal stromal/stem cells (MSCs) is likely to have an impact in cancer treatment. In this review, we focus on describing the normal physiological functions of each of these cell types and their behavior in the cancer setting. Relying on the specific surface markers and secreted molecules in this context, we review the potential targeting of these cells inducing their depletion, reprogramming, or differentiation, or inhibiting their pro-tumor functions or recruitment. Different approaches were developed for this targeting, namely, immunotherapies, vaccines, small interfering RNA, or small molecules.

Meflin-Positive Cancer-Associated Fibroblasts Inhibit Pancreatic Carcinogenesis

Cancer-associated fibroblasts (CAF) constitute a major component of the tumor microenvironment. Recent observations in genetically engineered mouse models and clinical studies have suggested that there may exist at least two functionally different populations of CAFs, that is, cancer-promoting CAFs (pCAF) and cancer-restraining CAFs (rCAF). Although various pCAF markers have been identified, the identity of rCAFs remains unknown because of the lack of rCAF-specific marker(s). In this study, we found that Meflin, a glycosylphosphatidylinositol-anchored protein that is a marker of mesenchymal stromal/stem cells and maintains their undifferentiated state, is expressed by pancreatic stellate cells that are a source of CAFs in pancreatic ductal adenocarcinoma (PDAC). In situ hybridization analysis of 71 human PDAC tissues revealed that the infiltration of Meflin-positive CAFs correlated with favorable patient outcome. Consistent herewith, Meflin deficiency led to significant tumor progression with poorly differentiated histology in a PDAC mouse model. Similarly, genetic ablation of Meflin-positive CAFs resulted in poor differentiation of tumors in a syngeneic transplantation model. Conversely, delivery of a Meflin-expressing lentivirus into the tumor stroma or overexpression of Meflin in CAFs suppressed the growth of xenograft tumors. Lineage tracing revealed that Meflin-positive cells gave rise to α-smooth muscle actin-positive CAFs that are positive or negative for Meflin, suggesting a mechanism for generating CAF heterogeneity. Meflin deficiency or low expression resulted in straightened stromal collagen fibers, which represent a signature for aggressive tumors, in mouse or human PDAC tissues, respectively. Together, the data suggest that Meflin is a marker of rCAFs that suppress PDAC progression. SIGNIFICANCE: Meflin marks and functionally contributes to a subset of cancer-associated fibroblasts that exert antitumoral effects.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5367/F1.large.jpg.

Breast cancer in patients with germline TP53 pathogenic variants have typical tumour characteristics: the Cohort study of TP53 carrier early onset breast cancer (COPE study)

Germline TP53 pathogenic variants are rare but associated with a high risk of cancer; they are often identified in the context of clinically diagnosed Li-Fraumeni syndrome predisposing to a range of young onset cancers including sarcomas and breast cancer. The study aim was to conduct a detailed morphological review and immuno-phenotyping of breast cancer arising in carriers of a germline TP53 pathogenic variant. We compared breast cancers from five defined groups: (1) TP53 carriers with breast cancer (n = 59), (2) early onset HER2-amplified breast cancer, no germline pathogenic variant in BRCA1/2 or TP53 (n = 55), (3) BRCA1 pathogenic variant carriers (n = 60); (4) BRCA2 pathogenic variant carriers (n = 61) and (5) young onset breast cancer with no known germline pathogenic variant (n = 98). Pathologists assessed a pre-agreed set of morphological characteristics using light microscopy. Immunohistochemistry (IHC) for HER2, ER, PR, p53, integrin alpha v beta 6 (αvβ6) integrin, α-smooth muscle actin (α-SMA) and pSMAD2/3 was performed on tissue microarrays of invasive carcinoma. We confirmed a previously reported high prevalence of HER2-amplified, ductal no special type invasive breast carcinoma amongst known TP53 germline pathogenic variant carriers 20 of 36 (56%). Furthermore we observed a high frequency of densely sclerotic tumour stroma in cancers from TP53 carriers (29/36, 80.6%) when compared with non-carriers, 50.9% (28/55), 34.7% (50/144), 41.4% (65/157), 43.8% (95/217) in groups 2-5 respectively. The majority of germline TP53 gene carrier breast tumours had a high intensity of integrin αvβ6, α-SMA and pSMAD2/3 expression in the majority of cancer cells. In conclusion, aggressive HER2 positive breast cancers with densely sclerotic stroma are common in germline TP53 carriers. High levels of αvβ6 integrin, α-SMA and pSMAD2/3 expression suggest that the dense stromal phenotype may be driven by upregulated transforming growth factor beta signalling.

Epiregulin reprograms cancer-associated fibroblasts and facilitates oral squamous cell carcinoma invasion via JAK2-STAT3 pathway

Background

Local resident normal fibroblasts (NFs) are the major source of cancer-associated fibroblasts (CAFs), which are distinguishable from NFs by their tumor-supportive properties. However, the mechanism and the effects underlying the transition of NFs to CAFs in oral squamous cell carcinoma (OSCC) remain unclear.

Methods

Five pairs of matching primary NFs and CAFs derived from OSCC patients were sent for RNA sequencing. Epiregulin (EREG) expression was analyzed by IHC in fibroblasts from OSCC patients. The role of EREG in the NF-CAF transition and the consequential effects on OSCC progression were examined by upregulation/downregulation of EREG in NFs/CAFs both in vitro and in vivo.

Results

Here, we identified epiregulin (EREG) as the most remarkably upregulated gene in CAFs. High EREG expression in CAFs correlated with higher T stage, deeper invasion and inferior worst pattern of invasion (WPOI) in OSCC patients and predicted shorter overall survival. Overexpression of EREG in NFs activated the CAF phenotype. Mechanistically, the JAK2/STAT3 pathway was enhanced by EREG in parallel with increased IL-6 expression, which could be inhibited by the JAK2 inhibitor AG490. Recombinant IL-6 upregulated the JAK2/STAT3/EREG pathway in a feedback loop. Moreover, EREG-induced CAF activation promoted the epithelial-mesenchymal transition (EMT) necessary for migration and invasion, which was dependent on JAK2/STAT3 signaling and IL-6. In vivo, EREG expression in stroma fibroblasts promoted tumor growth with high stromal α-SMA, phospho-JAK2/STAT3, and IL-6 expression and upregulated EMT in HSC3 cells.

Conclusions

EREG is essential for the NF-CAF transformation needed to induce EMT of tumor cells in a JAK2-STAT3- and IL-6-dependent manner in OSCC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1277-x) contains supplementary material, which is available to authorized users.

Short-term RANKL exposure initiates a neoplastic transcriptional program in the basal epithelium of the murine salivary gland

Although salivary gland cancers comprise only ∼3-6% of head and neck cancers, treatment options for patients with advanced-stage disease are limited. Because of their rarity, salivary gland malignancies are understudied compared to other exocrine tissue cancers. The comparative lack of progress in this cancer field is particularly evident when it comes to our incomplete understanding of the key molecular signals that are causal for the development and/or progression of salivary gland cancers. Using a novel conditional transgenic mouse (K5:RANKL), we demonstrate that Receptor Activator of NFkB Ligand (RANKL) targeted to cytokeratin 5-positive basal epithelial cells of the salivary gland causes aggressive tumorigenesis within a short period of RANKL exposure. Genome-wide transcriptomic analysis reveals that RANKL markedly increases the expression levels of numerous gene families involved in cellular proliferation, migration, and intra- and extra-tumoral communication. Importantly, cross-species comparison of the K5:RANKL transcriptomic dataset with The Cancer Genome Atlas cancer signatures reveals the strongest molecular similarity with cancer subtypes of the human head and neck squamous cell carcinoma. These studies not only provide a much needed transcriptomic resource to mine for novel molecular targets for therapy and/or diagnosis but validates the K5:RANKL transgenic as a preclinical model to further investigate the in vivo oncogenic role of RANKL signaling in salivary gland tumorigenesis.

Phase I Dose Escalation Study with Expansion Cohort of the Addition of Nab-Paclitaxel to Capecitabine and Oxaliplatin (CapOx) as First-Line Treatment of Metastatic Esophagogastric Adenocarcinoma (ACTION Study)

First-line triplet chemotherapy including a taxane may prolong survival in patients with metastatic esophagogastric cancer. The added toxicity of the taxane might be minimized by using nab-paclitaxel. The aim of this phase I study was to determine the feasibility of combining nab-paclitaxel with the standard of care in the Netherlands, capecitabine and oxaliplatin (CapOx). Patients with metastatic esophagogastric adenocarcinoma received oxaliplatin 65 mg/m² on days 1 and 8, and capecitabine 1000 mg/m² bid on days 1-14 in a 21-day cycle, with nab-paclitaxel on days 1 and 8 at four dose levels (60, 80, 100, and 120 mg/m², respectively), using a standard 3 + 3 dose escalation phase, followed by a safety expansion cohort. Baseline tissue and serum markers for activated tumor stroma were assessed as biomarkers for response and survival. Twenty-six patients were included. The first two dose-limiting toxicities (i.e., diarrhea and dehydration) occurred at dose level 3. The resulting maximum tolerable dose (MTD) of 80 mg/m² was used in the expansion cohort, but was reduced to 60 mg/m² after three out of eight patients experienced diarrhea grade 3. The objective response rate was 54%. The median progression-free (PFS) and overall survival were 8.0 and 12.8 months, respectively. High baseline serum ADAM12 was associated with a significantly shorter PFS (p = 0.011). In conclusion, albeit that the addition of nab-paclitaxel 60 mg/m² to CapOx may be better tolerated than other taxane triplets, relevant toxicity was observed. There is a rationale for preserving taxanes for later-line treatment. ADAM12 is a potential biomarker to predict survival, and warrants further investigation.

Photoimmunotherapy for cancer-associated fibroblasts targeting fibroblast activation protein in human esophageal squamous cell carcinoma

Cancer-associated fibroblasts (CAFs) are strongly implicated in tumor progression, including in the processes of tumorigenesis, invasion, and metastasis. The targeting of CAFs using various therapeutic approaches is a novel treatment strategy; however, the efficacy of such therapies remains limited. Recently, near-infrared photoimmunotherapy (NIR-PIT), which is a novel targeted therapy employing a cell-specific mAb conjugated to a photosensitizer, has been introduced as a new type of phototherapy. In this study, we have developed a novel NIR-PIT technique to target CAFs, by focusing on fibroblast activation protein (FAP), and we evaluate the treatment efficacy in vitro and in vivo. Esophageal carcinoma cells exhibited enhanced activation of fibroblasts, with FAP over-expressed in the cytoplasm and on the cell surface. FAP-IR700-mediated PIT showed induced rapid cell death specifically for those cells in vitro and in vivo, without adverse effects. This novel therapy for CAFs, designed as local control phototherapy, was safe and showed a promising inhibitory effect on FAP⁺ CAFs. PIT targeting CAFs via the specific marker FAP may be a therapeutic option for CAFs in the tumor microenvironment in the future.

Integrins, CAFs and Mechanical Forces in the Progression of Cancer

Cells respond to both chemical and mechanical cues present within their microenvironment. Various mechanical signals are detected by and transmitted to the cells through mechanoreceptors. These receptors often contact with the extracellular matrix (ECM), where the external signals are converted into a physiological response. Integrins are well-defined mechanoreceptors that physically connect the actomyosin cytoskeleton to the surrounding matrix and transduce signals. Families of α and β subunits can form a variety of heterodimers that have been implicated in cancer progression and differ among types of cancer. These heterodimers serve as the nexus of communication between the cells and the tumor microenvironment (TME). The TME is dynamic and composed of stromal cells, ECM and associated soluble factors. The most abundant stromal cells within the TME are cancer-associated fibroblasts (CAFs). Accumulating studies implicate CAFs in cancer development and metastasis through their remodeling of the ECM and release of large amounts of ECM proteins and soluble factors. Considering that the communication between cancer cells and CAFs, in large part, takes place through the ECM, the involvement of integrins in the crosstalk is significant. This review discusses the role of integrins, as the primary cell-ECM mechanoreceptors, in cancer progression, highlighting integrin-mediated mechanical communication between cancer cells and CAFs.

Cancer-associated fibroblasts: how do they contribute to metastasis?

Cancer-associated fibroblasts (CAFs) are activated fibroblasts in the tumor microenvironment. They are one of the most prominent cell types in the stroma and produce large amounts of extracellular matrix molecules, chemokines, cytokines and growth factors. Importantly, CAFs promote cancer progression and metastasis by multiple pathways. This, together with their genetic stability, makes them an interesting target for cancer therapy. However, CAF heterogeneity and limited knowledge about the function of the different CAF subpopulations in vivo, are currently major obstacles for identifying specific molecular targets that are of value for cancer treatment. In this review, we discuss recent major findings on CAF development and their metastasis-promoting functions, as well as open questions to be addressed in order to establish successful cancer therapies targeting CAFs.

Whole Genome Methylation Analysis of Nondysplastic Barrett Esophagus that Progresses to Invasive Cancer

OBJECTIVE

To investigate differences in methylation between patients with nondysplastic Barrett esophagus who progress to invasive adenocarcinoma and those who do not.

BACKGROUND

Identifying patients with nondysplastic Barrett esophagus who progress to invasive adenocarcinoma remains a challenge. Previous studies have demonstrated the potential utility of epigenetic markers for identifying this group.

METHODS

A whole genome methylation interrogation using the Illumina HumanMethylation 450 array of patients with nondysplastic Barrett esophagus who either develop adenocarcinoma or remain static, with validation of findings by bisulfite pyrosequencing.

RESULTS

In all, 12 patients with "progressive" versus 12 with "nonprogressive" nondysplastic Barrett esophagus were analyzed via methylation array. Forty-four methylation markers were identified that may be able to discriminate between nondysplastic Barrett esophagus that either progress to adenocarcinoma or remain static. Hypomethylation of the recently identified tumor suppressor OR3A4 (probe cg09890332) validated in a separate cohort of samples (median methylation in progressors 67.8% vs 96.7% in nonprogressors; P = 0.0001, z = 3.85, Wilcoxon rank-sum test) and was associated with the progression to adenocarcinoma. There were no differences in copy number between the 2 groups, but a global trend towards hypomethylation in the progressor group was observed.

CONCLUSION

Hypomethylation of OR3A4 has the ability to risk stratify the patient with nondysplastic Barrett esophagus and may form the basis of a future surveillance program.

Stromal-derived interleukin 6 drives epithelial-to-mesenchymal transition and therapy resistance in esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) has a dismal prognosis, and survival benefits of recent multimodality treatments remain small. Cancer-associated fibroblasts (CAFs) are known to contribute to poor outcome by conferring therapy resistance to various cancer types, but this has not been explored in EAC. Importantly, a targeted strategy to circumvent CAF-induced resistance has yet to be identified. By using EAC patient-derived CAFs, organoid cultures, and xenograft models we identified IL-6 as the stromal driver of therapy resistance in EAC. IL-6 activated epithelial-to-mesenchymal transition in cancer cells, which was accompanied by enhanced treatment resistance, migratory capacity, and clonogenicity. Inhibition of IL-6 restored drug sensitivity in patient-derived organoid cultures and cell lines. Analysis of patient gene expression profiles identified ADAM12 as a noninflammation-related serum-borne marker for IL-6-producing CAFs, and serum levels of this marker predicted unfavorable responses to neoadjuvant chemoradiation in EAC patients. These results demonstrate a stromal contribution to therapy resistance in EAC. This signaling can be targeted to resensitize EAC to therapy, and its activity can be measured using serum-borne markers.

Dual role of twist1 in cancer-associated fibroblasts and tumor cells promoted epithelial-mesenchymal transition of esophageal cancer

Cancer-associated fibroblasts (CAFs) play critical roles in tumor progression. However, the role and mechanism underlying CAFs in esophageal cancer (EC) remain unclear. In this study, primary CAFs and normal esophageal fibroblasts (NOFs) were isolated and characterized by immunofluorescence, qRT-PCR and western blot. Clinical significance of twist1 in CAFs were evaluated by immunohistochemistry assay. Conditioned medium (CM) was collected from CAFs to evaluate the influence on epithelial-mesenchymal transition (EMT) of EC cells. EC cells were mixed with CAFs and subcutaneously injected into nude mice to assess the in vivo tumor growth. As the result, twist1 was overexpressed in CAFs compared with NOFs and exhibited adverse prognostic significance. In CAFs, twist1 promoted the expression and secretion of CXCL12. In EC cells, activated CXCL12/CXCR4 signaling promoted the EMT process through ERK/AKT - twist1 - MMP1/E-cadherin pathway. In addition, knockdown of twist1 in CAFs also suppressed in vivo tumor growth. In conclusion, our results revealed a dual role of twist1 in CAFs and EC cells to promote the EMT process.

Practical Application of Periostin as a Biomarker for Pathological Conditions

In physiological condition, periostin is expressed in limited tissues such as periodontal ligament, periosteum, and heart valves. Periostin protein is mainly localized on extracellular collagen bundles and in matricellular space. On the other hand, in pathological condition, expression of periostin is induced in disordered tissues of human patients. In tumor development and progression, periostin is elevated mainly in its microenvironment and stromal tissue rich in extracellular matrix. Tumor stromal fibroblasts highly express periostin and organize the tumor-surrounding extracellular matrix architecture. In fibrosis in lung, liver, and kidney, proliferating activated fibroblasts express periostin and replace normal functional tissues with dense connective tissues. In inflammation and allergy, inflammatory cytokines such as IL-4 and IL-13 induce expression of periostin that plays important roles in pathogenesis of these diseases. The elevated levels of periostin in human patients could be detected not only in tissue biopsy samples but also in peripheral bloods using specific antibodies against periostin, because periostin secreted from the disordered tissues is transported into blood vessels and circulates in the cardiovascular system. In this chapter, I introduce the elevated expression of periostin in pathological conditions, and discuss how periostin could be utilized as a biomarker in disease diagnosis.

ColXα1 is a stromal component that colocalizes with elastin in the breast tumor extracellular matrix

The tumor microenvironment regulates tissue development and homeostasis, and its dysregulation contributes to neoplastic progression. Increased expression of type X collagen α-1 (ColXα1) in tumor-associated stroma correlates with poor pathologic response to neoadjuvant chemotherapy in estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2)-positive breast cancers. Evaluation of ColXα1 expression patterns suggests a potential connection with elastin fibers. To investigate the possible interaction between ColXα1 and elastin, we evaluated the expression of ColXα1 in relation to elastin fibers in normal breast tissue, ductal carcinoma in situ, and invasive breast carcinomas at cellular and subcellular levels. Our findings demonstrate that ColXα1 colocalizes with elastin in invasive breast cancer-associated stroma by immunohistochemistry, immunofluorescence, and electron microscopy. In 212 invasive breast carcinomas, this complex was aberrantly and selectively expressed in tumor extracellular matrix in 79% of ER+/HER2-, 80% of ER+/HER2+, 76% of ER-/HER2+, and 58% of triple negative breast cancers. In contrast, ColXα1 was generally absent, while elastin was present perivascularly in normal breast tissue. ColXα1 and elastin were coexpressed in 58% of ductal carcinoma in situ (DCIS) in periductal areas. In mass-forming DCIS with desmoplastic stroma, the complex was intensely expressed in periductal areas as well as within the tumor-associated stroma in all cases. Our data suggest that the breast carcinoma neoplastic process may involve aberrant expression of ColXα1 and elastin in the tumor microenvironment emerging early at the DCIS stage. Enrichment of these complexes in tumor-associated stroma may represent a stromal signature indicative of intrinsic differences between breast cancers. These findings shed light on investigation into the role of aberrant collagen complex expression in tumorigenesis and tumor progression which may be leveraged in therapeutic and theranostic applications.

Periostin induces kidney fibrosis after acute kidney injury via the p38 MAPK pathway

Periostin plays a crucial role in fibrosis, and acute kidney injury results in a high risk of progression to chronic kidney disease. Therefore, we hypothesized that periostin was involved in the progression of acute kidney injury to kidney fibrosis. Unilateral ischemia-reperfusion injury (UIRI) was induced in 7- to 8-wk-old male wild-type and periostin-null mice, and the animals were observed for 6 wk. In vitro, human kidney-2 cells and primary-cultured human tubular epithelial cells were incubated under hypoxic conditions (5% O₂, 5% CO₂, and 90% N₂) for 5 days. The cells were also cultured with recombinant periostin (rPeriostin) and a p38 mitogen-activated protein kinase (MAPK) inhibitor in a hypoxic incubator. At 6 wk after UIRI, interstitial fibrosis/tubular atrophy was significantly alleviated in periostin-null mice compared with wild-type controls. In addition, periostin-null mice had attenuated expression of fibrosis/apoptosis markers and phosphorylated-p38 MAPK compared with wild-type controls. In vitro, hypoxic injury increased the expression of fibrosis markers, periostin, and phosphorylated-p38 MAPK, which was comparable to or substantially greater than their expression levels following treatment with recombinant transforming growth factor-β1 under normoxic conditions. Furthermore, rPeriostin treatment under hypoxic conditions enhanced fibrosis/apoptosis markers and phosphorylated-p38 MAPK. In contrast, p38 MAPK inhibition ameliorated hypoxia-induced fibrosis, and the addition of the p38 MAPK inhibitor to rPeriostin significantly ameliorated the changes induced by rPeriostin. In conclusion, periostin promotes kidney fibrosis via the p38 MAPK pathway following acute kidney injury triggered by a hypoxic or ischemic insult. Periostin ablation may protect against chronic kidney disease progression.

Cancer-associated fibroblasts (CAFs) promote the lymph node metastasis of esophageal squamous cell carcinoma

Lymph node metastasis is a pathognomonic feature of spreading tumors, and overcoming metastasis is a challenge in attaining more favorable clinical outcomes. Esophageal cancer is an aggressive tumor for which lymph node metastasis is a strong poor prognostic factor, and the tumor microenvironment (TME), and cancer-associated fibroblasts (CAFs) in particular, has been implicated in esophageal cancer progression. CAFs play a central role in the TME and have been reported to provide suitable conditions for the progression of esophageal cancer, similar to their role in other malignancies. However, little is known concerning the relevance of CAFs to the lymph node metastasis of esophageal cancer. Here, we used clinical samples of esophageal cancer to reveal that CAFs promote lymph node metastasis and subsequently verified the intercellular relationships in vitro and in vivo using an orthotopic metastatic mouse model. In the analysis of clinical samples, FAP⁺ CAFs were strongly associated with lymph node metastasis rather than with other prognostic factors. Furthermore, CAFs affected the ability of esophageal cancer cells to acquire metastatic phenotypes in vitro; this finding was confirmed by data from an in vivo orthotopic metastatic mouse model showing that the number of lymph node metastases increased upon injection of cocultured cancer cells and CAFs. In summary, we verified in vitro and in vivo that the accumulation of CAFs enhances the lymph node metastasis of ESCC. Our data suggest that CAF targeted therapy can reduce lymph node metastasis and improve the prognosis of patients with esophageal cancer in the future.

Chemoresistance and the Self-Maintaining Tumor Microenvironment

The progression of cancer is associated with alterations in the tumor microenvironment, including changes in extracellular matrix (ECM) composition, matrix rigidity, hypervascularization, hypoxia, and paracrine factors. One key malignant phenotype of cancer cells is their ability to resist chemotherapeutics, and elements of the ECM can promote chemoresistance in cancer cells through a variety of signaling pathways, inducing changes in gene expression and protein activity that allow resistance. Furthermore, the ECM is maintained as an environment that facilitates chemoresistance, since its constitution modulates the phenotype of cancer-associated cells, which themselves affect the microenvironment. In this review, we discuss how the properties of the tumor microenvironment promote chemoresistance in cancer cells, and the interplay between these external stimuli. We focus on both the response of cancer cells to the external environment, as well as the maintenance of the external environment, and how a chemoresistant phenotype emerges from the complex signaling network present.

The Precise Diagnosis of Cancer Invasion/Metastasis via 2D Laser Ablation Mass Mapping of Metalloproteinase in Primary Cancer Tissue

Cancer invasion and metastasis remain the major causes of over 90% of patient deaths. Molecular imaging methods such as computed tomography (CT)/magnetic resonance imaging (MRI) can precisely assess primary regional lymph node invasion and distant organ metastasis via body scanning; however, such diagnostic methods are often utilized too late for cancer therapy. To date, pathologic methods mainly provide information on differentiation/proliferation and potential drug therapy biomarkers of primary tumors rather than precisely reveal tumor regional invasion and distant metastasis in the body. We hypothesized that quantification of membrane type-1 matrix metalloproteinase (MT1-MMP) levels in primary tumor tissue will provide a precise assessment of tumor regional lymph node invasion and remote organ metastasis. In this work, we developed peptide-coated Au clusters with intrinsic red fluorescence and a specific mass signal. When these clusters labeled MT1-MMP in tumor tissue sections derived from the xenograft lung carcinoma model, human lung carcinoma and human renal carcinoma, we could directly observe MT1-MMP via optical fluorescence microscopy and quantitatively detect the MT1-MMP expression level via laser ablation inductively coupled plasma mass spectrometry 2D mapping (2D-LA-Mass Mapping). By observing and quantifying the MT1-MMP expression level in primary human lung carcinoma and human renal carcinoma tissue sections, we precisely assessed the risk of primary tumor invasion/metastasis. Importantly, the accuracy of this pathologic method was verified by CT/MRI molecular imaging of cancer patients and traditional hematoxylin and eosin (H&E) staining/immunohistochemistry (IHC)/immunofluorescence (IF) pathologic studies of primary tumor tissues.

Obesity and gastrointestinal cancer: the interrelationship of adipose and tumour microenvironments

Increasing recognition of an association between obesity and many cancer types exists, but how the myriad of local and systemic effects of obesity affect key cellular and non-cellular processes within the tumour microenvironment (TME) relevant to carcinogenesis, tumour progression and response to therapies remains poorly understood. The TME is a complex cellular environment in which the tumour exists along with blood vessels, immune cells, fibroblasts, bone marrow-derived inflammatory cells, signalling molecules and the extracellular matrix. Obesity, in particular visceral obesity, might fuel the dysregulation of key pathways relevant to both the adipose microenvironment and the TME, which interact to promote carcinogenesis in at-risk epithelium. The tumour-promoting effects of obesity can occur at the local level as well as systemically via circulating inflammatory, growth factor and metabolic mediators associated with adipose tissue inflammation, as well as paracrine and autocrine effects. This Review explores key pathways linking visceral obesity and gastrointestinal cancer, including inflammation, hypoxia, altered stromal and immune cell function, energy metabolism and angiogenesis.

The Role of Tumor Microenvironment in Chemoresistance: 3D Extracellular Matrices as Accomplices

BACKGROUND

The functional interplay between tumor cells and their adjacent stroma has been suggested to play crucial roles in the initiation and progression of tumors and the effectiveness of chemotherapy. The extracellular matrix (ECM), a complex network of extracellular proteins, provides both physical and chemicals cues necessary for cell proliferation, survival, and migration. Understanding how ECM composition and biomechanical properties affect cancer progression and response to chemotherapeutic drugs is vital to the development of targeted treatments.

METHODS

3D cell-derived-ECMs and esophageal cancer cell lines were used as a model to investigate the effect of ECM proteins on esophageal cancer cell lines response to chemotherapeutics. Immunohistochemical and qRT-PCR evaluation of ECM proteins and integrin gene expression was done on clinical esophageal squamous cell carcinoma biopsies. Esophageal cancer cell lines (WHCO1, WHCO5, WHCO6, KYSE180, KYSE 450 and KYSE 520) were cultured on decellularised ECMs (fibroblasts-derived ECM; cancer cell-derived ECM; combinatorial-ECM) and treated with 0.1% Dimethyl sulfoxide (DMSO), 4.2 µM cisplatin, 3.5 µM 5-fluorouracil and 2.5 µM epirubicin for 24 h. Cell proliferation, cell cycle progression, colony formation, apoptosis, migration and activation of signaling pathways were used as our study endpoints.

RESULTS

The expression of collagens, fibronectin and laminins was significantly increased in esophageal squamous cell carcinomas (ESCC) tumor samples compared to the corresponding normal tissue. Decellularised ECMs abrogated the effect of drugs on cancer cell cycling, proliferation and reduced drug induced apoptosis by 20⁻60% that of those plated on plastic. The mitogen-activated protein kinase-extracellular signal-regulated kinase (MEK-ERK) and phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) signaling pathways were upregulated in the presence of the ECMs. Furthermore, our data show that concomitant addition of chemotherapeutic drugs and the use of collagen- and fibronectin-deficient ECMs through siRNA inhibition synergistically increased cancer cell sensitivity to drugs by 30⁻50%, and reduced colony formation and cancer cell migration.

CONCLUSION

Our study shows that ECM proteins play a key role in the response of cancer cells to chemotherapy and suggest that targeting ECM proteins can be an effective therapeutic strategy against chemoresistant tumors.

A systematic review and meta-analysis of prognostic biomarkers in resectable esophageal adenocarcinomas

Targeted therapy is lagging behind in esophageal adenocarcinoma (EAC). To guide the development of new treatment strategies, we provide an overview of the prognostic biomarkers in resectable EAC treated with curative intent. The Medline, Cochrane and EMBASE databases were systematically searched, focusing on overall survival (OS). The quality of the studies was assessed using a scoring system ranging from 0-7 points based on modified REMARK criteria. To evaluate all identified prognostic biomarkers, the hallmarks of cancer were adapted to fit all biomarkers based on their biological function in EAC, resulting in the features angiogenesis, cell adhesion and extra-cellular matrix remodeling, cell cycle, immune, invasion and metastasis, proliferation, and self-renewal. Pooled hazard ratios (HR) and 95% confidence intervals (CI) were derived by random effects meta-analyses performed on each hallmarks of cancer feature. Of the 3298 unique articles identified, 84 were included, with a mean quality of 5.9 points (range 3.5-7). The hallmarks of cancer feature 'immune' was most significantly associated with worse OS (HR 1.88, (95%CI 1.20-2.93)). Of the 82 unique prognostic biomarkers identified, meta-analyses showed prominent biomarkers, including COX-2, PAK-1, p14ARF, PD-L1, MET, LC3B, IGFBP7 and LGR5, associated to each hallmark of cancer.

Preclinical models for the study of Barrett's carcinogenesis

Barrett's esophagus (BE) is clinically significant, as it is the only known precursor lesion for esophageal adenocarcinoma. To develop improved therapies for the treatment of BE, a greater understanding of the disease process at the molecular genetic level is needed. However, achieving a greater understanding will require improved preclinical models so that the disease process can be more closely studied and novel therapies can be tested. Our concise review highlights progress in the development of preclinical models for the study of BE and identifies the most suitable model in which to test novel therapies.

Analysis of the expression of cancer-associated fibroblast- and EMT-related proteins in submucosal invasive colorectal cancer

Objective: Recent studies have shown that cancer-associated fibroblasts (CAFs) and the epithelial-mesenchymal transition (EMT) play important roles in the progression and metastasis of CRC. Although prediction of lymph node metastasis in submucosal invasive colorectal cancer (SiCRC) is important, the relationships of CAF and EMT with lymph node metastasis of SiCRC have not yet been examined. Here, we aimed to analyze the expression patterns of CAF- and EMT-related proteins in SiCRC.

Materials and Methods: The expression of CAF-related markers, including α-smooth muscle actin, CD10, podoplanin, fibroblast specific protein 1, and adipocyte enhancer-binding protein 1, and EMT-related proteins [zinc finger protein SNAI2 (ZEB1) and twist-related protein 1 (TWIST1) in SiCRC with (n = 29) or without (n = 80) lymph node metastasis was examined by immunohistochemistry. We examined the expression patterns of biomarkers using hierarchical cluster analysis. Consequently, four subgroups were established based on the expression patterns of CAF- and EMT-related markers, and the associations of these subgroups with clinicopathological variables.

Results: In multivariate analysis, subgroup 2, which was characterized by high expression of all markers, was correlated with lymph node metastasis (p < 0.01). Next, we examined the associations of individual biomarkers with lymph node metastasis. Multivariate analysis showed that moderately differentiated adenocarcinoma was significantly associated with lymph node metastasis (p < 0.05).

Conclusions: Our findings showed that expression patterns of CAF markers and EMT-related proteins may allow for stratification of patients into risk categories for lymph node metastasis in SiCRC.

Quantitative proteomic profiling of primary cancer-associated fibroblasts in oesophageal adenocarcinoma

BACKGROUND

Cancer-associated fibroblasts (CAFs) form the major stromal component of the tumour microenvironment (TME). The present study aimed to examine the proteomic profiles of CAFs vs. normal fibroblasts (NOFs) from patients with oesophageal adenocarcinoma to gain insight into their pro-oncogenic phenotype.

METHODS

CAFs/NOFs from four patients were sub-cultured and analysed using quantitative proteomics. Differentially expressed proteins (DEPs) were subjected to bioinformatics and compared with published proteomics and transcriptomics  datasets.

RESULTS

Principal component analysis of all profiled proteins showed that CAFs had high heterogeneity and clustered separately from NOFs. Bioinformatics interrogation of the DEPs demonstrated inhibition of adhesion of epithelial cells, adhesion of connective tissue cells and cell death of fibroblast cell lines in CAFs vs. NOFs (p < 0.0001). KEGG pathway analysis showed a significant enrichment of the insulin-signalling pathway (p = 0.03). Gene ontology terms related with myofibroblast phenotype, metabolism, cell adhesion/migration, hypoxia/oxidative stress, angiogenesis, immune/inflammatory response were enriched in CAFs vs. NOFs. Nestin, a stem-cell marker up-regulated in CAFs vs. NOFs, was confirmed to be expressed in the TME with immunohistochemistry.

CONCLUSIONS

The identified pathways and participating proteins may provide novel insight on the tumour-promoting properties of CAFs and unravel novel adjuvant therapeutic targets in the TME.

Periostin attenuates tumor growth by inducing apoptosis in colitis-related colorectal cancer

Inflammatory bowel diseases, which are multifactorial autoimmune colitis diseases, are occurring with increasing prevalence. One of the most serious complications of these diseases is colorectal cancer. Here we investigated the role of periostin (Postn), a matricellular protein that interacts with various integrin molecules on the cell surface, in colitis-induced colorectal cancer. Immunohistochemistry of mouse and human colorectal cancer samples revealed that Postn was expressed in the stroma and was upregulated in close proximity to the cancer cells. The colonic tumorigenesis in an inflammation-related colon carcinogenesis mouse model was increased in Postn knock-out (Postn^−/−) mice compared to Postn^+/+ mice. Although no difference was found in the degree of colitis between Postn^+/+ and Postn^−/− mice, Postn inhibited tumor growth and induced the apoptosis of mouse rectal cancer cells in vitro. Furthermore, fewer apoptotic colorectal cancer cells were observed in Postn^−/− than in Postn^+/+ mice. These data suggested that Postn has an anti-tumor effect on colitis-induced colorectal cancer.

Urokinase plasminogen activator secreted by cancer-associated fibroblasts induces tumor progression via PI3K/AKT and ERK signaling in esophageal squamous cell carcinoma

Cancer-associated fibroblasts (CAFs) are believed to influence tumor behavior and clinical outcomes. We previously showed that conditioned medium (CM) from CAFs induces proliferation and motility of esophageal squamous cell carcinoma (ESCC) cells. Here, we investigated the molecular mechanisms by which the CAF-secreted proteins induce ESCC development and progression. Using antibody arrays, we identified urokinase plasminogen activator (uPA) as one of the main proteins whose release was increased in CAFs compared to normal fibroblasts (NFs). Immunohistochemical analysis of pathological sections showed that uPA-positive cells were localized at the boundaries of tumor and stroma tissues, in stroma between tumor nests, and within the tumors. Increased stromal uPA levels (132/146 cases) correlated with tumor invasion (p < 0.05) and overall survival of ESCC patients (p < 0.05). In vitro assays showed that uPA promotes ESCC cell proliferation, migration, and invasion via PI3K/AKT and ERK signaling pathways. In vivo, anti-uPA antibody suppressed tumor growth in ESCC xenografts. These results suggest that uPA released from stroma, and especially from CAFs, might be a predictive marker for ESCC diagnosis and prognosis, as well as an effective therapeutic target.

Individual patient oesophageal cancer 3D models for tailored treatment

Background

A model to predict chemotherapy response would provide a marked clinical benefit, enabling tailored treatment of oesophageal cancer, where less than half of patients respond to the routinely administered chemotherapy.

Methods

Cancer cells were established from tumour biopsies taken from individual patients about to undergo neoadjuvant chemotherapy. A 3D-tumour growth assay (3D-TGA) was developed, in which cancer cells were grown with or without supporting mesenchymal cells, then subjected to chemo-sensitivity testing using the standard chemotherapy administered in clinic, and a novel emerging HDAC inhibitor, Panobinostat.

RESULTS

Individual patients cancer cells could be expanded and screened within a clinically applicable timescale of 3 weeks. Incorporating mesenchymal support within the 3D-TGA significantly enhanced both the growth and drug resistance profiles of the patients cancer cells. The ex vivo drug response in the presence, but not absence, of mesenchymal cells accurately reflected clinical chemo-sensitivity, as measured by tumour regression grade. Combination with Panobinostat enhanced response and proved efficacious in otherwise chemo-resistant tumours.

Conclusions

This novel method of establishing individual patient oesophageal cancers in the laboratory, from small endoscopic biopsies, enables clinically-relevant chemo-sensitivity testing, and reduces use of animals by providing more refined in vitro models for pre-screening of drugs. The 3D-TGA accurately predicted chemo-sensitivity in patients, and could be developed to guide tailored patient treatment. The incorporation of mesenchymal cells as the stromal cell component of the tumour micro-environment had a significant effect upon enhancing chemotherapy drug resistance in oesophageal cancer, and could prove a useful target for future drug development.

Polyphyllin I inhibits gastric cancer cell proliferation by downregulating the expression of fibroblast activation protein alpha (FAP) and hepatocyte growth factor (HGF) in cancer-associated fibroblasts

The aim of this study was to identify the anti-cancer mechanism of Polyphyllin I (PPI) on gastric cancer cells via its activity on cancer-associated fibroblasts (CAFs). We cultured purified gastric CAFs obtained from fresh human gastric cancer tissue and examined the effect of Polyphyllin I on CAF proliferation using a colorimetric viability assay. In addition, we established a nude mouse xenograft model to examine the effect of Polyphyllin I administration on tumorigenesis. Using Western analysis, we quantified protein expression of the CAF-derived cytokines fibroblast activation protein alpha (FAP), secreted protein acidic and cysteine rich (SPARC), stromal cell-derived factor 1 (SDF-1), hepatocyte growth factor tenascin-C (TNC), and hepatocyte growth factor (HGF) in both in vitro and in vivo models. We found that Polyphyllin I inhibits the proliferation of CAFs in a concentration-dependent manner. Following treatment with 2 μg/ml PPI for 24 h in vitro, the expression of FAP, SDF-1 and HGF protein in CAFs was significantly lower than that in the control group, but there was no significant difference in SPARC and TNC protein expression between the two groups. In the nude mouse xenograft model, the tumor inhibition rate was 45.5% when PPI was administered early and 29.4% with administration in the third week. The expression of FAP and HGF in the xenografts was significantly decreased, while the expression of SPARC, SDF-1, and TNC was largely unaltered. Altogether, these data suggest that Polyphyllin I can inhibit the proliferation of gastric cancer cells by downregulating the expression of FAP and HGF in CAFs in vivo.