Cancer-associated fibroblasts and epithelial-mesenchymal transition in metastatic oral tongue squamous cell carcinoma

Extracellular vesicles in the pathogenesis and future diagnostics of oral squamous cell carcinoma

Extracellular vesicles are a group of heterogeneous particles secreted during both physiological and pathological conditions which serve in intercellular communication and play a role in the development and progression of oral squamous cell carcinoma, the most common malignant tumor of the head and neck with a high mortality rate. Extensive research is being conducted in order to determine the precise role of extracellular vesicles in oncogenic processes and to explore the possible application of extracellular vesicles as early tumor biomarkers. In this review, we aimed to systematize observed roles extracellular vesicles might play in organizing of tumor microenvironment, tumor invasion and metastasis, as well as the impact of extracellular vesicles on immune dysregulation and development of resistance to chemotherapeutics. Additionally, we summarized findings involving the potential use of extracellular vesicles cargo proteins as early disease biomarkers.

Cancer-associated fibroblasts, tumor and radiotherapy: interactions in the tumor micro-environment

Cancer-associated fibroblasts (CAFs) represent a group of genotypically non-malignant stromal cells in the tumor micro-environment (TME) of solid tumors that encompasses up to 80% of the tumor volume. Even though the phenotypic diversity and plasticity of CAFs complicates research, it is well-established that CAFs can affect many aspects of tumor progression, including growth, invasion and therapy resistance. Although anti-tumorigenic properties of CAFs have been reported, the majority of research demonstrates a pro-tumorigenic role for CAFs via (in)direct signaling to cancer cells, immunomodulation and extracellular matrix (ECM) remodeling. Following harsh therapeutic approaches such as radio- and/or chemotherapy, CAFs do not die but rather become senescent. Upon conversion towards senescence, many pro-tumorigenic characteristics of CAFs are preserved or even amplified. Senescent CAFs continue to promote tumor cell therapy resistance, modulate the ECM, stimulate epithelial-to-mesenchymal transition (EMT) and induce immunosuppression. Consequently, CAFs play a significant role in tumor cell survival, relapse and potentially malignant transformation of surviving cancer cells following therapy. Modulating CAF functioning in the TME therefore is a critical area of research. Proposed strategies to enhance therapeutic efficacy include reverting senescent CAFs towards a quiescent phenotype or selectively targeting (non-)senescent CAFs. In this review, we discuss CAF functioning in the TME before and during therapy, with a strong focus on radiotherapy. In the future, CAF functioning in the therapeutic TME should be taken into account when designing treatment plans and new therapeutic approaches.

Biomolecular alterations temporally anticipate microarchitectural modifications of collagen in oral tongue squamous cell carcinoma

High resolution analysis of collagen bundles could provide information on tumor onset and evolution. This study was focused on the microarchitecture and biomolecular organization of collagen bundles in oral tongue squamous cell carcinoma (OTSCC). Thirty-five OTSCC biopsy samples were analyzed by synchrotron-based phase-contrast microcomputed tomography and Fourier transform infrared imaging (FTIRI) spectroscopy. PhC-microCT evidenced the presence of reduced and disorganized collagen in the tumor area compared to the extratumoral (ExtraT) one. FTIRI also revealed a reduction of folded secondary structures in the tumor area, and highlighted differences in the peritumoral (PeriT) areas in relation with the OTSCC stage, whereby a significantly lower amount of collagen with less organized fibers was found in the PeriT stroma of advanced-OTSCC stages. Interestingly, no significant morphometrical mismatches were detected in the same region by PhC-microCT analysis. These results suggest that biomolecular alterations in the OTSCC stroma temporally anticipate structural modifications of collagen bundle microarchitecture.

Evaluation of BH3 mimetics as a combination therapy with irradiation in head and neck squamous cell carcinoma

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) is a common cancer with a five-year survival rate around 60%, indicating a need for new treatments. BH3 mimetics are small molecules that inhibit anti-apoptotic Bcl-2 family proteins, resulting in apoptosis induction.

METHODS

We performed a high-throughput screen using a Myogel matrix to identify the synergy between irradiation and the novel BH3 mimetics A-1155463, A-1331852, and navitoclax in 12 HNSCC cell lines, normal (NOF) and cancer-associated fibroblasts (CAF), and dysplastic keratinocytes (ODA). Next, we examined synergy in an apoptosis assay, followed by a clonogenic assay and a Myogel spheroid on selected HNSCC cell lines. Finally, we applied zebrafish larvae xenograft to validate the effects of navitoclax and A-1331852.

RESULTS

All three BH3 mimetics exhibited a strong synergy with irradiation in eight HNSCC cell lines and ODAs, but not in NOFs and CAFs. A-1155463 and A-1331852 induced apoptosis and reduced proliferation, and together with irradiation, significantly increased apoptosis and arrested proliferation. A-1331852 and navitoclax significantly decreased the clonogenicity compared with the control, and combination treatment led to a decreased clonogenicity compared with monotherapy or irradiation. However, unlike navitoclax or A-1155463, only A-1331852 significantly reduced cancer cell invasion. Furthermore, in spheroid and zebrafish, irradiation appeared ineffective and failed to significantly increase the drug effect. In the zebrafish, A-1331852 and navitoclax significantly reduced the tumor area and metastasis.

CONCLUSIONS

Our findings encourage the further preclinical investigation of BH3 mimetics, particularly A-1331852, as a single agent or combined with irradiation as a treatment for HNSCC.

Heterogeneity of cancer-associated fibroblasts in head and neck squamous cell carcinoma: opportunities and challenges

Head and neck squamous cell carcinoma (HNSCC) is among the most severe and complex malignant diseases with a high level of heterogeneity and, as a result, a wide range of therapeutic responses, regardless of clinical stage. Tumor progression depends on ongoing co-evolution and cross-talk with the tumor microenvironment (TME). In particular, cancer-associated fibroblasts (CAFs), embedded in the extracellular matrix (ECM), induce tumor growth and survival by interacting with tumor cells. Origin of CAFs is quite varied, and the activation patterns of CAFs are also heterogeneous. Crucially, the heterogeneity of CAFs appears to play a key role in ongoing tumor expansion, including facilitating proliferation, enhancing angiogenesis and invasion, and promoting therapy resistance, through the production of cytokines, chemokines, and other tumor-promotive molecules in the TME. This review describes the various origin and heterogeneous activation mechanisms of CAFs, and biological heterogeneity of CAFs in HNSCC is also included. Moreover, we have highlighted versatility of CAFs heterogeneity in HNSCC progression, and have discussed different tumor-promotive functions of CAFs respectively. In the future, it is a promising strategy for the therapy of HNSCC that specifically targeting tumor-promoting CAF subsets or the tumor-promoting functional targets of CAFs.

Tumour-stroma ratio is a valuable prognostic factor for oral tongue squamous cell carcinoma

OBJECTIVE

The objectives of this study were to estimate the prognostic value of the tumour-stroma ratio (TSR) and tumour budding (TB) in oral tongue squamous cell carcinoma (OTSCC) and to establish a reliable model to predict the outcome of OTSCC patients.

METHODS

A total of 103 patients surgically treated at our hospital were enrolled in this study. Chi-square tests, Kaplan-Meier analyses and Cox proportional hazards regression models were performed for statistical analysis.

RESULTS

Fifty-six patients were categorized as stroma-rich, and 47 patients were categorized as stroma-poor. Only pathological grade was associated with the TSR (p = 0.017). Kaplan-Meier analysis showed that stroma-rich, high-intensity budding and high risk groups were associated with worse prognosis. The Cox regression model showed that the TSR was an independent risk factor for OTSCC patients prognosis, and the high risk group was also related to poor prognosis (p < 0.05). TB was significantly associated with poor prognosis but was not an independent risk factor.

CONCLUSIONS

We found that patients in the stroma-rich group had a worse long-term prognosis. The TSR is an independent risk factor for OTSCC patients' outcome. In addition, a risk model that combined the TSR and TB proved to be valuable for predicting OTSCC patients' outcome.

Resveratrol Loaded Liposomes Disrupt Cancer Associated Fibroblast Communications within the Tumor Microenvironment to Inhibit Colorectal Cancer Aggressiveness

Colorectal cancer (CRC) is a cancer-associated fibroblast, CAF-rich tumor. CAF promotes cancer cell proliferation, metastasis, drug resistance via secretes soluble factors, and extracellular matrices which leads to dense stroma, a major barrier for drug delivery. Resveratrol (RES) is a polyphenolic compound, has several pharmacologic functions including anti-inflammation and anticancer effects. Considering tumor microenvironment of CRC, resveratrol-loaded liposome (L-RES) was synthesized and employed to inhibit CAF functions. The L-RES was synthesized by thin-film hydration method. The cytotoxicity of L-RES was evaluated using MTT assay. Effect of L-RES treated CAF on tumor spheroid growth was performed. Cell invasion was determined using spheroid invasion assay. The effect of L-RES on 5-fluorouracil (5-FU) sensitivity of CRC cells was determined in co-cultured tumor spheroids. Subtoxic dose of L-RES was selected to study possible inhibiting CAF functions. Decreased CAF markers, α-SMA and IL-6 levels, were observed in L-RES treated activated fibroblast. Interestingly, the activated fibroblast promoted invasive ability and drug resistance of CRC cells in co-culture condition of both 2D and 3D cultures and was attenuated by L-RES treatment in the activated fibroblast. Therefore, L-RES provides a promising drug delivery strategy for CRC treatment by disrupting the crosstalk between CRC cells and CAF.

Cancer-associated fibroblasts and their role in tumor progression

The stromal elements of a malignant tumor can promote cancer progression and metastasis. The structure of the tumor stroma includes connective tissue elements, blood vessels, nerves, and extracellular matrix (ECM). Some of the cellular elements of the tumor stroma are cancer-associated fibroblasts (CAFs). The origin and function of CAFs have been actively studied over the past thirty years. CAFs produce collagen, the main scaffold protein of the extracellular matrix. Collagen in the tumor stroma stimulates fibrosis, enhances the rigidity of tumor tissue, and disrupts the transmission of proliferation and differentiation signaling pathways. CAFs control tumor angiogenesis, cell motility, tumor immunogenic properties, and the development of resistance to chemo- and immunotherapy. As a result of metabolic adaptation of rapidly growing tumor tissue to the nutrients and oxygen deprivation, the main type of energy production in cells changes from oxidative phosphorylation to anaerobic glycolysis. These changes lead to sequential molecular alterations, including the induction of specified transcriptional factors that result in the CAFs activation. The molecular phenotype of activated CAFs is similar to fibroblasts activated during inflammation. In activated CAFs, alpha-smooth muscle actin (α-SMA) is synthetized de novo and various proteases and fibronectin are produced. Since CAFs are found in all types of carcinomas, these cells are potential targets for the development of new approaches for anticancer therapy. Some CAFs originate from resident fibroblasts of the organs invaded by the tumor, while others originate from epithelial tumor cells, which are undergoing an epithelial-mesenchymal transition (EMT). To date, many molecular and metabolic inducers of the EMT have been discovered including the transforming growth factor-beta (TGF-β), hypoxia, and inflammation. This review classifies modern concepts of molecular markers of CAFs, their functional features, and discusses the stages of epithelial-mesenchymal transition, and the potential of CAFs as a target for antitumor therapy.

Small interfering RNA targeting N-cadherin regulates cell proliferation and migration in enzalutamide-resistant prostate cancer

Enzalutamide is one of the options for treating patients with castration-resistant or metastatic prostate cancer. However, a substantial proportion of patients become resistant to enzalutamide after a period of treatment. Cells in these tumors typically exhibit increased proliferative and migratory capabilities, in which N-cadherin (CDH2) appear to serve an important role. In the present study, by up- and downregulating the expression of CDH2, the possible effects of CDH2 on the prostate cancer cell line LNCaP were investigated. Male sex hormone-sensitive LNCaP cells treated with 10 µM enzalutamide were named LNCaP enzalutamide-resistant (EnzaR) cells. Reverse transcription-PCR, western blotting and immunofluorescence staining were used to measure CDH2, E-cadherin, α-SMA, Snail and Slug expression. Transfection with the pCMV-CDH2 plasmid was performed for CDH2 upregulation, whilst transfection with small interfering RNA (siRNA)-CDH2 was performed for CDH2 downregulation. MTT and Cell Counting Kit-4 assays were used to evaluate the proportion of viable cancer cells. Subsequently, gap closure assay was performed to evaluate the migratory capability of both LNCaP and LNCaP EnzaR cell lines. CDH2 expression was found to be increased in LNCaP EnzaR cells compared with that in LNCaP cells. CDH2 overexpression increased cell viability and migration in both LNCaP and LNCaP EnzaR cell lines. By contrast, the opposite trend was observed after CDH2 expression was knocked down. CDH2 expression also showed a high association with that of four epithelial-mesenchymal transition markers, which was confirmed by western blotting. Based on these results, it was concluded that knocking down CDH2 expression using siRNA transfection mediated significant influence on LNCaP EnzaR cell physiology, which may be a potential therapeutic option for prostate cancer treatment.

Overexpression of Nicotinamide N-methyltransferase mainly covers stroma of colorectal cancer and correlates with unfavorable survival by its product 1-MNA

Background: Accumulating evidence indicates that Nicotinamide N-methyltransferase (NNMT) is abnormally expressed in tumor tissues of several cancers including colorectal cancer (CRC) and associated with cancer progression. However, the distribution characteristics and the clinical value of each part of NNMT expression in CRC are still not fully understood. The purpose of this study is to determine the distribution of NNMT expression and its association with survival in CRC. Methods: By using the cancer genome atlas (TCGA) and clinical proteomic tumor analysis consortium (CPTAC), we firstly analyzed the difference of gene and protein levels of NNMT between CRC and normal colorectal tissue. Then, NNMT protein expressions were detected in 18 intraepithelial neoplastic samples and 177 CRC tumor samples through immunohistochemistry in our study cohort. Furthermore, the relationship between NNMT expression and clinicopathological characteristics, overall survival (OS) and disease-free survival (DFS) of CRC patients were analyzed by Pearson χ2 test and log-rank test, respectively, in public datasets and our study cohort. Lastly, the function of NNMT and its product 1-methyl-nicotinamide (1-MNA) on migration and invasion in colorectal cancer cells was analyzed by wound healing assay and transwell assay. Results: We determined that higher NNMT expression in CRC tissues than normal tissues in both gene and protein level in TCGA and CPTAC datasets (all p < 0.05). In addition, the strong relationships of NNMT expression with stromal cells were found in the TCGA cohort. Fortunately, our cohort could validate that the expression of NNMT in tumor stroma cell was significantly higher than that in tumor cell (p < 0.0001), and both of them were significantly higher than that in adjacent normal tissue (ANT) (p < 0.0001 and p < 0.0001, respectively). Furthermore, the positive NNMT expression in tumor cell and stromal cell were associated with series of unfavorable clinical characteristics, including advanced TNM stage, lymph node metastasis, distant metastasis (all p < 0.05). Also, higher NNMT was associated with unfavorable survival both in our study and public datasets, including TCGA and two Gene Expression Omnibus (GEO) datasets (GSE33113 and GSE17538). Moreover, the functional experiments showed that stromal cells with high NNMT expression can secret 1-MAN to promote migration and invasion of CRC cells in vitro. Conclusions: In CRC, NNMT is overexpressed in tumor cells and stroma cells, and then mainly expressed in tumor stroma cells. Overexpression of NNMT in tumor cell and stroma cell both are associated with metastasis and unfavorable survival. Besides, stromal cells with high NNMT expression secrets 1-MAN to promote migration and invasion of CRC cells. Therefore, NNMT may be a potential prognostic indicator in CRC patients.

Current Study of RhoA and Associated Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth-most common cancer in the world, with an estimated 1.034 million new cases in 2015, and the third-highest cause of cancer deaths, estimated at 785,558, in 2014. Early diagnosis and treatment greatly affect the survival rate in patients with GC: the 5-year survival rate of early GC reaches 90%-95%, while the mortality rate significantly increases if GC develops to the late stage. Recently, studies for the role of RhoA in the diseases have become a hot topic, especially in the development of tumors. A study found that RhoA can regulate actin polymerization, cell adhesion, motor-myosin, cell transformation, and the ability to participate in the activities of cell movement, proliferation, migration, which are closely related to the invasion and metastasis of tumor cells. However, the specific role of RhoA in tumor cells remains to be studied. Therefore, our current study aimed to briefly review the role of RhoA in GC, especially for its associated signaling pathways involved in the GC progression.

Functions of Matricellular Proteins in Dental Tissues and Their Emerging Roles in Orofacial Tissue Development, Maintenance, and Disease

Matricellular proteins (MCPs) are defined as extracellular matrix (ECM) associated proteins that are important regulators and integrators of microenvironmental signals, contributing to the dynamic nature of ECM signalling. There is a growing understanding of the role of matricellular proteins in cellular processes governing tissue development as well as in disease pathogenesis. In this review, the expression and functions of different MP family members (periostin, CCNs, TSPs, SIBLINGs and others) are presented, specifically in relation to craniofacial development and the maintenance of orofacial tissues, including bone, gingiva, oral mucosa, palate and the dental pulp. As will be discussed, each MP family member has been shown to have non-redundant roles in development, tissue homeostasis, wound healing, pathology and tumorigenesis of orofacial and dental tissues.

Platelet-derived growth factor-B signalling might promote epithelial-mesenchymal transition in gastric carcinoma cells through activation of the MAPK/ERK pathway

Introduction

Epithelial-mesenchymal transition (EMT) is important in the metastasis of tumours and is triggered by several key growth factors, including platelet-derived growth factor-B (PDGF-B). But, whether PDGF-B signalling promotes EMT in gastric carcinoma cells is still unknown.

Material and methods

We established 2 gastric carcinoma cell lines (MKN28 and MKN45) to stably overexpress PDGF-B by lentiviral vectors, and expression of E-cadherin, N-cadherin, and ERK-1 were detected by western blot assay. Then, PDGF-B overexpression and normal MKN28 and MKN45 cells were cocultured with PDGFR-b positive fibroblast (hs738) and MAPK inhibitors were added; also, the expressions of ERK-1, E-cadherin, and N-cadherin were detected by western blot assay.

Results

After being cocultured with hs738 cells, expressions of ERK-1 and N-cadherin protein in PDGF-B overexpression MKN28 and MKN45 cells were much higher than normal MKN28 and MKN45 cells (p < 0.05), and those could be decreased by MAPK inhibitor. Also, expressions of E-cadherin protein in PDGF-B overexpression MKN28 and MKN45 cells were much lower than normal MKN28 and MKN45 cells (p < 0.05), and they could be increased by MAPK inhibitor.

Conclusions

Our data indicate that PDGF-B signalling can induce EMT in gastric carcinoma cells. Thr tumour microenvironment is imperative in the process of PDGF-B signalling inducing EMT in gastric carcinoma cells. Also, activation of MAPK/ERK pathway, which is a downstream pathway of PDGF-B signalling, might participate in this process.

The selective toxicity of superparamagnetic iron oxide nanoparticles (SPIONs) on oral squamous cell carcinoma (OSCC) by targeting their mitochondria

In recent years, many researchers have made tremendous efforts into using nanotechnology in biomedical applications and science, such as magnetic resonance imaging, drug delivery, and in particular, oncological therapeutic via superparamagnetic iron oxide nanoparticles (SPIONs). Head and neck squamous cell carcinoma (HNSCC) and especially oral squamous cell carcinoma (OSCC) have been a serious and ongoing concern. There are many strong emphases on the importance of toxic mechanisms due to oxidative stress and specifically, the changed cellular response. Therefore, our study was designed to evaluate the effects of SPIONs on OSCC mitochondria because of the usefulness of the application of these nanoparticles in cancer treatment and diagnosis. An increased level of reactive oxygen species (ROS) is one of the substantial mechanisms found for SPIONs in this study, and initially originated from disruption of the electron transfer chain shown by a decrease in mitochondrial succinate dehydrogenase activity. Increased ROS formation subsequently followed a decline of mitochondrial membrane potential, the release of mitochondrial cytochrome complex, and mitochondrial swelling in the OSCC mitochondria compared with almost no effect in normal mitochondria. In addition, the SPIONs decreased cell viability and increased lipid peroxidation level and caspase-3 activity in OSCC cells. The results represented that the exposure to the SPIONs induced selective toxicity only on the OSCC but not normal mitochondria. Based on our findings, we finally concluded that the SPIONs may be considered as a potential therapeutic candidate for the treatment of OSCC.

Cancer-associated fibroblasts promote tumor progression by lncRNA-mediated RUNX2/GDF10 signaling in oral squamous cell carcinoma

Cancer-associated fibroblasts (CAF) are the most abundant stromal cells in tumor and exert a pro-tumoral effect in cancer progression. Numerous evidence shows long non-coding RNA (lncRNA) abnormally regulates gene expression in various cancers. However, little is known about the role of lncRNA in the interaction between CAF and cancer cells. Here, we first identify an uncharacterized lncRNA, LOC100506114, which is significantly upregulated in CAF and is involved in the functional transformation of normal fibroblasts (NF) and CAF. Expression of LOC100506114 enhances the expression of fibroblast activation protein alpha and α-smooth muscle actin in NF and promotes malignant characteristics of NF and CAF in vivo and in vitro. The profile of gene co-expression analysis shows that growth differentiation factor 10 (GDF10) is positively correlated with the expression of LOC100506114. CAF promote stromal fibroblast activation and the proliferation and migration of tumor cells by secreting GDF10. Our data demonstrate that lncRNA plays a critical role in the interplay of stromal fibroblasts and tumor cells in oral squamous cell carcinoma.

WNT4 secreted by tumor tissues promotes tumor progression in colorectal cancer by activation of the Wnt/β-catenin signalling pathway

BACKGROUND

Wingless and Int-related protein (Wnt) ligands are aberrantly expressed in patients with colorectal cancer (CRC). However, the aberrant level of Wnt ligands in serum have not been explored. Here, we aimed to identify the levels of WNT4 in serum and explored its oncogenic role in CRC.

METHODS

The Oncomine database was used to analyze the relationship between WNT4 and the prognosis of CRC. ELISA was performed to measure WNT4 levels in serum and conditioned medium from fresh CRC tissues and adjacent normal tissues. Western blot and immunohistochemistry were carried out to measure the expression of WNT4 in human CRC tissues and adjacent normal tissues. The migration and invasion of CRC cells were determined by trans-well assay, and the effects of WNT4 on CRC invasion and metastasis in vivo were verified by tumor xenograft in nude mice. Cancer-associated fibroblasts (CAFs) and angiogenesis in subcutaneous nodules were detected by immunofluorescence (IF). In addition, the suspended spheres formation and tube formation assay were performed to explore the effects of WNT4 on CAFs and angiogenesis respectively.

RESULTS

WNT4 was significantly upregulated in serum of CRC patients, and CRC tissues were identified as an important source of elevated WNT4 levels in CRC patients. Interestingly, elevated levels of WNT4 in serum were downregulated after tumor resection. Furthermore, we found that WNT4 contributed to epithelial-to-mesenchymal transition (EMT) and activated fibroblasts by activating the WNT4/β-catenin pathway in vitro and in vivo. Moreover, angiogenesis was induced via the WNT4/β-catenin/Ang2 pathway. Those effects could be reversed by ICG-001, a β-catenin/TCF inhibitor.

CONCLUSION

Our findings indicated that serum levels of WNT4 may be a potential biomarker for CRC. WNT4 secreted by colorectal cancer tissues promote the progression of CRC by inducing EMT, activate fibroblasts and promote angiogenesis through the canonical Wnt/β-catenin signalling pathway.

Neuroendocrine tumours and their microenvironment

Tumours can escape the immune system by expressing programmed death-ligand-1 (PD-L1), which allows them to bind to PD-1 on T-cells and avoid recognition by the immune system. Regulatory T-cells (Tregs), indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) also play a role in immune suppression. Knowledge about the interaction of neuroendocrine tumours (NETs) with their immune microenvironment and the role of immunotherapy in patients with NET is scarce. Here, we investigated the immune microenvironment of serotonin-producing (SP) and non-serotonin-producing NETs (NSP-NETs). Tumours of 33 patients with SP-NET and 18 patients with NSP-NET were studied. Immunohistochemical analyses were performed for PD-L1, T-cells, IDO, TDO, mismatch repair proteins (MMRp) and activated fibroblasts. PD-L1 expression was seen in < 1% of tumour and T-cells. T-cells were present in 33% of NETs, varying between 1 and 10% T-cells per high power field. IDO was expressed in tumour cells in 55% of SP-NETs and 22% of NSP-NETs (p = 0.039). TDO was expressed in stromal cells in 64% of SP-NETs and 13% of NSP-NETs (p = 0.001). No tumours had loss of MMRp. TDO-expressing stromal cells also strongly expressed α-SMA and were identified as cancer-associated fibroblasts (CAFs). Factors that are associated with a response to checkpoint inhibitor treatment were absent or only present to a limited extent in the tumour microenvironment of NETs. The expression of IDO and TDO in a substantial part of NETs and the presence of CAFs suggest two mechanisms that could be responsible for the cold immune microenvironment, which should be explored to enhance anti-tumour immunity and clinical responses.

Cancer-associated Fibroblasts induce epithelial-mesenchymal transition via the Transglutaminase 2-dependent IL-6/IL6R/STAT3 axis in Hepatocellular Carcinoma

Cancer-associated fibroblasts (CAFs) play crucial roles in enhancing cell survival, proliferation, invasion, and metastasis. We previously showed that hepatocellular carcinoma-derived CAFs (H-CAFs) promoted proliferation of hepatocellular carcinoma (HCC) cells. This study aimed to further explore the role of CAFs in HCC epithelial-mesenchymal transition (EMT) and the underlying mechanism. High CAF density was significantly associated with liver cirrhosis, inferior clinicopathologic characteristics, elevated EMT-associated markers, and poorer survival in human HCC. Within HCC cells, EMT was induced after co-culture with H-CAFs. Secretomic analysis showed that IL-6 and HGF were the key EMT-stimulating cytokines secreted by H-CAFs. Proteomic analysis revealed that TG2 was significantly upregulated in HCC cells with EMT phenotypes. Overexpression of TG2 promoted EMT of HCC cells, and knockdown of TG2 remarkably attenuated the H-CAF-induced EMT. Furthermore, during EMT, TG2 expression was enhanced after HCC cells were stimulated by IL-6, but not HGF. Inhibition of the IL-6/STAT3 signaling decreased TG2 expression. The principal TG2 transcription control element and a potential STAT3 binding site were identified using promoter analysis. Hence, H-CAFs facilitates HCC cells EMT mediated by IL-6, which in turn activates IL-6/IL6R/STAT3 axis to promote TG2 expression.

Selective anticancer activity of superparamagnetic iron oxide nanoparticles (SPIONs) against oral tongue cancer using in vitro methods: The key role of oxidative stress on cancerous mitochondria

Today, it has been proven that the nanoparticles such as superparamagnetic iron oxide nanoparticles (SPIONs) have widespread use in biomedical applications, for instance, in magnetic resonance imaging and targeted delivery of drugs. Despite many studies on SPIONs in diagnosing some diseases like cancer, it has not been investigated on the oral tongue squamous cell carcinoma (OTSCC) detection by the NPs. Hence, the present study has been designed to assess the in vitro cytotoxicity of SPIONs on the isolated mitochondria of OTSCC by mitochondrial tests. Isolated mitochondria were removed from the separated cancer and control tissues from the squamous cells of tango in male Wistar rats (6 or 8 weeks) and exposed to the different concentrations of SPIONs (30, 60, and 120 nM). A rise in the production of reactive oxygen species is one of the significant mechanisms of this study, followed by a collapse of mitochondrial membrane potential, the escape of mitochondrial cytochrome c, and mitochondrial swelling in the exposed isolated mitochondria of OTSCC with SPIONs. Furthermore, our results indicated that the exposure to the SPIONs reduced the activity of succinate dehydrogenase in complex II of the mitochondria obtained from cancerous oral tongue squamous. So the SPIONs can induce selective cytotoxicity on the OTSCC mitochondria without significant effects on the control mitochondria. Based on the results and further studies about in vivo experiments in this regard, it is concluded the SPIONs may be a hopeful therapeutic candidate for the treatment of OTSCC.

Circulating syndecan-1 as a novel biomarker relates to lung function, systemic inflammation, and exacerbation in COPD

Introduction

Patients with COPD often show increased systemic inflammation which is associated with lower functional status, greater exacerbation risk, and worse clinical outcomes. Syndecans (SDCs), a family of transmembrane heparan sulfate proteoglycans (HSPGs), have been found to involve in inflammatory processes in many chronic inflammatory diseases. The aim of this preliminary clinical study was to investigate the possible association between two SDCs, SDC-1 and SDC-4, with lung function, systemic inflammation, and risk of exacerbations in COPD patients.

Method

Serum SDC-1 and SDC-4 levels were measured in 101 COPD patients and 57 health controls. Correlations between SDCs and other parameters were analyzed using Spearsman’s rho. Receiver operating curve (ROC) analysis was used to evaluate the threshold value in differentiating disease status.

Results

Although both serum SDC-1 and SDC-4 showed a downward trend in COPD patients, only SDC-1 levels were correlated positively with the ratio of FEV1/FVC and parameters of small airway obstruction. Besides, SDC-1 but not SDC-4, was negatively correlated with C-reactive protein (CRP) in COPD patients and downregulated in frequent exacerbators (FEs) of COPD. Using a cutoff value of 2.08 ng/mL, the sensitivity and specificity of SDC-1 to differentiate FE were 44% and 93.4%, respectively.

Conclusion

In conclusion, circulating SDC-1 may be a novel inflammatory biomarker associated with lung function and systemic inflammation in patients with COPD, which could also be useful to identify the risk of COPD exacerbation. Further studies should be performed to clarify the influences of SDC-1 on the pathogenesis and outcomes of COPD.

Curcumin: a potent agent to reverse epithelial-to-mesenchymal transition

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is involved in tumor progression, invasion, migration and metastasis. EMT is a process by which polarized epithelial cells acquire motile mesothelial phenotypic features. This process is initiated by disassembly of cell-cell contacts through the loss of epithelial markers and replacement of these markers by mesenchymal markers. Reconstruction of the cytoskeleton and degradation of the tumor basement membrane ensures the spread of invasive malignant tumor cells to distant locations. Accumulating evidence indicates that curcumin, as a well-known phytochemical, can inhibit EMT/metastasis through various mechanisms and pathways in human tumors.

CONCLUSIONS

In this review, we summarize the mechanisms by which curcumin may affect EMT in cells under pathological conditions to understand its potential as a novel anti-tumor agent. Curcumin can exert chemo-preventive effects by inhibition and reversal of the EMT process through both TGF-β-dependent (e.g. in hepatoma and retinal pigment epithelial cancer) and -independent (e.g. in oral cancer, colorectal cancer, pancreatic cancer, hepatocellular carcinoma, breast cancer, melanoma, prostate cancer, bladder cancer, thyroid cancer and lung cancer) pathways. Curcumin can also mitigate chemoresistance through EMT suppression and promotion of the antiproliferative effects of conventional chemotherapeutics. Therefore, curcumin has the potential to be used as a novel adjunctive agent to prevent tumor metastasis, which may at least partly be attributed to its hampering of the EMT process.

Oral cancer-associated fibroblasts predict poor survival: Systematic review and meta-analysis

OBJECTIVES

To perform systematic review and meta-analysis on correlations between cancer-associated fibroblasts (CAFs) and the risk of death for patients with oral squamous cell carcinoma.

SUBJECTS AND METHODS

English literature (1966-2018) was systematically analyzed for studies that immunohistochemically assessed CAF density by alpha-smooth muscle actin and presented 5 year survival rates by Kaplan-Meier plots. Mean age of patients, proportion of male/female patients, and male/female majority (>50% male/female patients) per study were also collected. Significance level for statistical models was p < 0.05.

RESULTS

Meta-analysis comprised 11 studies/1,040 patients. Univariate Cox regressions showed that high CAF density was a negative prognostic factor in studies with female and male majority [OR 5.329 (95% CI 3.223-8.811), p < 0.001, and OR 2.208 (95% CI 1.717-2.839), p < 0.001, respectively]. High CAF density with male majority was associated with a more favorable prognosis [OR 0.996 (95% CI 0.979-1.013), p < 0.001]. Multivariate Cox regressions showed that death risk was significantly higher among patients with high CAF density compared to low CAF [OR 2.741 (95% CI 2.220-3.384) p < 0.001]. High mean age and male proportion were significantly protective [OR 0.940 (95% CI 0.925-9.955), p < 0.001, OR 0.125 (95% CI 0.018-0.867), p = 0.035), respectively].

CONCLUSIONS

CAFs increased death risk, male majority, and higher mean age were protective. A clinically validated cutoff for CAF density could serve as a reliable prognostic tool.

Epithelial-mesenchymal transition markers screened in a cell-based model and validated in lung adenocarcinoma

Background

Re-capture of the differences between tumor and normal tissues observed at the patient level in cell cultures and animal models is critical for applications of these cancer-related differences. The epithelial-mesenchymal transition (EMT) process is essential for tumor migratory and invasive capabilities. Although plenty of EMT markers are revealed, molecular features during the early stages of EMT are poorly understood.

Methods

A cell-based model to induce lung cell (A549) EMT using conditioned medium of in vitro cancer activated fibroblast (WI38) was established. High-throughput sequencing methods, including RNA-seq and miRNA-seq, and advanced bioinformatics methods were used to explore the transcriptome profile transitions accompanying the progression of EMT. We validated our findings with experimental techniques including transwell and immunofluorescence assay, as well as the TCGA data.

Results

We have constructed an in vitro cell model to mimic the EMT in patients. We discovered that several new transcription factors were among the early genes (3 h) to respond to cancer micro-environmental cues which could play critical roles in triggering further EMT signals. The early EMT markers also included genes encoding membrane transporters and blood coagulation function. Three of the nine-examined early EMT hallmark genes, GALNT6, SPARC and HES7, were up-regulated specifically in the early stages of lung adenocarcinoma (LUAD) and confirmed by TCGA patient transcriptome data. In addition, we showed that miR-3613, a regulator of EGFR pathway genes, was constantly repressed during EMT progress and indicative of an epithelial miRNA marker.

Conclusions

The CAF-stimulated EMT cell model may recapture some of the molecular changes during EMT progression in clinical patients. The identified early EMT hallmark genes GALNT6, SPARC and HES7and miR-3613 provide new markers and therapeutic targets for LUAD for the further clinical diagnosis and drug screening.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5885-9) contains supplementary material, which is available to authorized users.

Activated Fibroblast Program Orchestrates Tumor Initiation and Progression; Molecular Mechanisms and the Associated Therapeutic Strategies

: Neoplastic epithelial cells coexist in carcinomas with various non-neoplastic stromal cells, together creating the tumor microenvironment. There is a growing interest in the cross-talk between tumor cells and stromal fibroblasts referred to as carcinoma-associated fibroblasts (CAFs), which are frequently present in human carcinomas. CAF populations extracted from different human carcinomas have been shown to possess the ability to influence the hallmarks of cancer. Indeed, several mechanisms underlying CAF-promoted tumorigenesis are elucidated. Activated fibroblasts in CAFs are characterized as alpha-smooth muscle actin-positive myofibroblasts and actin-negative fibroblasts, both of which are competent to support tumor growth and progression. There are, however, heterogeneous CAF populations presumably due to the diverse sources of their progenitors in the tumor-associated stroma. Thus, molecular markers allowing identification of bona fide CAF populations with tumor-promoting traits remain under investigation. CAFs and myofibroblasts in wound healing and fibrosis share biological properties and support epithelial cell growth, not only by remodeling the extracellular matrix, but also by producing numerous growth factors and inflammatory cytokines. Notably, accumulating evidence strongly suggests that anti-fibrosis agents suppress tumor development and progression. In this review, we highlight important tumor-promoting roles of CAFs based on their analogies with wound-derived myofibroblasts and discuss the potential therapeutic strategy targeting CAFs.

Cancer-Associated Fibroblasts Induce Epithelial-Mesenchymal Transition in Endometrial Cancer Cells by Regulating Pituitary Tumor Transforming Gene

Cancer-associated fibroblasts (CAFs) play an important role in the development and progression of cancer by inducing epithelial-mesenchymal transition (EMT). In this study, we investigated the role of CAFs in endometrial cancer (EC) cells. We found that the pituitary tumor transforming gene (PTTG) expression was significantly increased in EC cell lines compared to normal human endometrial epithelial cells. Furthermore, CAFs could induce PTTG over-expression and increase EC cell invasion and migration in vitro. In addition, CAFs also induced EMT in EC cells. This study demonstrated that CAFs induced EMT in endometrial cancer cells by regulating PTTG.

Effect of tumor microenvironment on pathogenesis of the head and neck squamous cell carcinoma: a systematic review

The tumor microenvironment (TME) is comprised of many different cell populations, such as cancer-associated fibroblasts and various infiltrating immune cells, and non-cell components of extracellular matrix. These crucial parts of the surrounding stroma can function as both positive and negative regulators of all hallmarks of cancer development, including evasion of apoptosis, induction of angiogenesis, deregulation of the energy metabolism, resistance to the immune detection and destruction, and activation of invasion and metastasis. This review represents a summary of recent studies focusing on describing these effects of microenvironment on initiation and progression of the head and neck squamous cell carcinoma, focusing on oral squamous cell carcinoma, since it is becoming clear that an investigation of differences in stromal composition of the head and neck squamous cell carcinoma microenvironment and their impact on cancer development and progression may help better understand the mechanisms behind different responses to therapy and help define possible targets for clinical intervention.

Biological heterogeneity and versatility of cancer-associated fibroblasts in the tumor microenvironment

Increasing lines of evidence show that the malignant behavior of cancer is not exclusively attributable to cancer cells but also radically influenced by cancerous stroma activity and controlled through various mechanisms by the microenvironment. In addition to structural components, such as the extracellular matrix, stromal cells, such as macrophages, endothelial cells, and specifically cancer-associated fibroblasts (CAFs), have attracted substantial attention over recent decades. CAFs provide routes for aggressive carcinomas and contribute to invasion and metastasis through the biochemical alteration and regulation of cancer-related pathways. However, another facet of CAFs that has been neglected by numerous studies is that CAFs might serve as a negative regulator of cancer progression under certain circumstances. The various origins of CAFs, the diverse tissues in which they reside and their interactions with different cancer cells appear to be responsible for this inconsistency. This review summarizes the latest knowledge regarding CAF heterogeneity and offers a novel perspective and a beneficial approach for obtaining an improved understanding of CAFs.

Twist and E-cadherin deregulation might predict poor prognosis in lower lip squamous cell carcinoma

OBJECTIVE

The aim of this study was to evaluate the expression of Twist and E-cadherin in lower lip squamous cell carcinoma (LLSCC) and their association with clinicopathologic parameters.

STUDY DESIGN

Fifty-nine cases of LLSCC were analyzed by applying immunohistochemistry techniques in a semiquantitative manner. The systems proposed by Bryne etal., Brandwein-Gensler etal., and Almangush etal. were applied for analysis of the histopathologic malignancy grading system.

RESULTS

Higher E-cadherin expression (general and membrane) was observed in cases presenting with disease-free survival after 5years of follow-up (P < .05). Higher Twist expression was observed in lesions classified as being in advanced stages, displaying recurrence, and having a high degree of malignancy. A significant negative correlation was detected between cytoplasmic Twist expression and membrane E-cadherin expression (P = .028). A statistically significant relationship was detected between high total Twist expression in tumors classified as high risk by Brandwein-Gensler etal., and no significant difference was observed among total, membrane, and cytoplasmic E-cadherin expressions in LLSCC cases and the 3 applied grading systems (P > .05).

CONCLUSIONS

The results of the present study suggest the potential involvement of Twist and E-cadherin in the modulation of events related to worse prognoses in LLSCC cases.

Anaplastic transition within the cancer microenvironment in early-stage oral tongue squamous cell carcinoma is associated with local recurrence

The cancer microenvironment (CME) promotes malignant progression of cancer cells by stimulating cell growth, migration and invasion. Cancer-associated fibroblasts (CAFs), prominent features of the CME, interact directly with cancer cells and facilitate epithelial-mesenchymal transition (EMT). The present study examined the spatial distribution of CAFs and EMT on cancer cells in patients with early-stage tongue squamous cell carcinoma (TSCC) and their association with local recurrence. The present study included 14 patients with early-stage TSCC who had undergone glossectomy between 2006 and 2015, of which 7 experienced local recurrence (LR group) and 7 did not (control group). Multiple immunofluorescent analysis (MIA) of PCNA, αSMA, vimentin, E-cadherin and cytokeratin 14 (CK14) was performed on slides obtained from surgical specimens to identify the expression of various cell-specific markers. The number of CAFs in the CME was significantly increased in the LR group (P=0.001). Furthermore, the neighbouring cancer cells were positive for vimentin expression, indicating EMT. However, the present study also identified concurrent expression of CK14 in all vimentin-positive cancer cells, whilst epithelial markers, including E-cadherin, were expressed in certain vimentin-positive cancer cells. Concurrent expression of CK14 and vimentin is not defined as EMT or partial EMT. Therefore, the present study proposed a novel mechanism of anaplastic transition (APT), in which epithelial cancer cells concurrently develop mesenchymal features, which is achieved by pathways other than EMT. APT is characterized such that epithelial cancer cells differentiate into more primitive states, which is different from EMT or partial EMT, and it may be associated with LR. The concept aids in improving knowledge regarding tumor recurrence in patients with early-stage TSCC.

Patient derived xenografts as models for head and neck cancer

Translational cancer research has benefitted significantly from the generation of preclinical models that recapitulate the native tumour environment. While conventional cell models have contributed substantially to the current understanding of cancer biology and therapeutic development, a missing link between cell culture and their clinical applications is evident. Patient derived xenograft (PDX) models represent this missing link as they enable the examination of patient tumour tissue in a native environment without significantly affecting the cellular complexity, genomics, and stromal architecture of the neoplasms. The use of PDXs to model head and neck cancer (HNC) begets the development of novel therapeutics, increased understanding of tumorigenesis and the advent of personalised treatments cancer patients. There has been an increase in attempts to generate viable PDXs for HNCs in recent years. This concise review summarizes the current developments in the field of PDXs for HNCs.

Desmoglein 3 - Influence on oral carcinoma cell migration and invasion

Desmoglein 3 (Dsg3) is an adhesion receptor in desmosomes, but its role in carcinoma cell migration and invasion is mostly unknown. Our aim was to quantitatively analyse the motion of Dsg3-modified carcinoma cells in 2D settings and in 3D within tumour microenvironment mimicking (TMEM) matrices. We tested mutant constructs of C-terminally truncated Dsg3 (∆238 and ∆560), overexpressed full-length (FL) Dsg3, and empty vector control (Ct) of buccal mucosa squamous cell carcinoma (SqCC/Y1) cells. We captured live cell images and analysed migration velocities and accumulated and Euclidean distances. We compared rodent collagen and Matrigel^® with human Myogel TMEM matrices for these parameters in 3D sandwich, in which we also tested the effects of monoclonal antibody AK23, which targets the EC1 domain of Dsg3. In monolayer culture, FL and both truncated constructs migrated faster and had higher accumulated distances than Ct cells. However, in the 3D assays, only the mutants invaded faster relative to Ct cells. Of the mutants, the shorter form (Δ238) exhibited faster migration and invasion than Δ560 cells. In the Transwell, all of the cells invaded faster through Myogel than Matrigel^® coated wells. In 3D sandwich, AK23 antibody inhibited only the invasion of FL cells. We conclude that different experimental 2D and 3D settings can markedly influence the movement of oral carcinoma cells with various Dsg3 modifications.

Organotypic three-dimensional assays based on human leiomyoma-derived matrices

Alongside cancer cells, tumours exhibit a complex stroma containing a repertoire of cells, matrix molecules and soluble factors that actively crosstalk between each other. Recognition of this multifaceted concept of the tumour microenvironment (TME) calls for authentic TME mimetics to study cancer in vitro. Traditionally, tumourigenesis has been investigated in non-human, three-dimensional rat type I collagen containing organotypic discs or by means of mouse sarcoma-derived gel, such as Matrigel^®. However, the molecular compositions of these simplified assays do not properly simulate human TME. Here, we review the main properties and benefits of using human leiomyoma discs and their matrix Myogel for in vitro assays. Myoma discs are practical for investigating the invasion of cancer cells, as are cocultures of cancer and stromal cells in a stiff, hypoxic TME mimetic. Myoma discs contain soluble factors and matrix molecules commonly present in neoplastic stroma. In Transwell, IncuCyte, spheroid and sandwich assays, cancer cells move faster and form larger colonies in Myogel than in Matrigel^®. Additionally, Myogel can replace Matrigel^® in hanging-drop and tube-formation assays. Myogel also suits three-dimensional drug testing and extracellular vesicle interactions. To conclude, we describe the application of our myoma-derived matrices in 3D in vitro cancer assays.

This article is part of the discussion meeting issue ‘Extracellular vesicles and the tumour microenvironment’.

Prognostic impact of tumour-stroma ratio in early-stage oral tongue cancers

AIMS

Oral tongue squamous cell carcinoma (OTSCC) has a relatively poor outcome, and there is a need to identify better prognostic factors. Recently, tumour-stroma ratio (TSR) has been associated with prognosis in several cancers. The aim of this multi-institutional study was to evaluate the prognostic value of TSR from original haematoxylin and eosin (HE)-stained tumour-resection slides in a series of early-stage (cT1-2N0) OTSCC patients.

METHODS AND RESULTS

A TSR cutoff value of 50% was used to divide the patients into stroma-rich (≥50%) and stroma-poor (<50%) groups. The relationships between TSR and clinicopathological characteristics of 311 early-stage OTSCC cases were analysed. The prognostic value of TSR in OTSCC was calculated separately and in combination with a previously published cancer cell budding and depth of invasion (BD) prognostic model. A total of 89 cases (28.6%) belonged to the stroma-rich group. In a multivariate analysis, the stroma-rich group had worse disease-free survival, with a hazard ratio (HR) of 1.81 [95% confidence interval (CI) 1.17-2.79, P = 0.008], and higher cancer-related mortality (HR 1.71, 95% CI 1.02-2.86, P = 0.03). The combination of the highest-risk parameter scores of TSR and the BD model showed significant correlations with recurrence rate (HR 3.42, 95% CI 1.71-6.82, P = 0.004) and cancer-related mortality (HR 11.63, 95% CI 3.83-35.31, P < 0.001).

CONCLUSIONS

We conclude that TSR is a simple histopathological feature that is useful for prognostication of early-stage OTSCC, and suggest that TSR analyses in association with BD score could be included in routine clinical pathology reports for HE-stained slides.

Cell Migration Related to MDR-Another Impediment to Effective Chemotherapy?

Multidrug resistance, mediated by members of the ATP-binding cassette (ABC) proteins superfamily, has become one of the biggest obstacles in conquering tumour progression. If the chemotherapy outcome is considered successful, when the primary tumour volume is decreased or completely abolished, modulation of ABC proteins activity is one of the best methods to overcome drug resistance. However, if a positive outcome is represented by no metastasis or, at least, elongation of remission-free time, then the positive effect of ABC proteins inhibition should be compared with the several side effects it causes, which may inflict cancer progression and decrease overall patient health. Clinical trials conducted thus far have shown that the tested ABC modulators add limited or no benefits to cancer patients, as some of them are merely toxic and others induce unwanted drug–drug interactions. Moreover, the inhibition of certain ABC members has been recently indicated as potentially responsible for increased fibroblasts migration. A better understanding of the complex role of ABC proteins in relation to cancer progression may offer novel strategies in cancer therapy.

Cancer-associated fibroblasts promote non-small cell lung cancer cell invasion by upregulation of glucose-regulated protein 78 (GRP78) expression in an integrated bionic microfluidic device

The tumor microenvironment is comprised of cancer cells and various stromal cells and their respective cellular components. Cancer-associated fibroblasts (CAFs), a major part of the stromal cells, are a key determinant in tumor progression, while glucose-regulated protein (GRP)78 is overexpressed in many human cancers and is involved in tumor invasion and metastasis. This study developed a microfluidic-based three dimension (3D) co-culture device to mimic an in vitro tumor microenvironment in order to investigate tumor cell invasion in real-time. This bionic chip provided significant information regarding the role of GRP78, which may be stimulated by CAFs, to promote non-small cell lung cancer cell invasion in vitro. The data showed that CAF induced migration of NSCLC A549 and SPCA-1 cells in this three-dimensional invasion microdevice, which is confirmed by using the traditional Transwell system. Furthermore, CAF induced GRP78 expression in A549 and SPCA-1 cells to facilitate NSCLC cell migration and invasion, whereas knockdown of GRP78 expression blocked A549 and SPCA-1 cell migration and invasion capacity. In conclusion, these data indicated that CAFs might promote NSCLC cell invasion by up-regulation of GRP78 expression and this bionic chip microdevice is a robust platform to assess the interaction of cancer and stromal cells in tumor environment study.

Inhibition of cancer cell epithelial mesenchymal transition by normal fibroblasts via production of 5-methoxytryptophan

We reported previously that human fibroblasts release 5-methoxytryptophan (5-MTP) which inhibits cancer cell COX-2 overexpression and suppresses cancer cell migration and metastasis. To determine whether fibroblasts block cancer cell epithelial mesenchymal transition (EMT) via 5-MTP, we evaluated the effect of Hs68 fibroblasts (HsFb) on A549 cancer cell EMT in a two-chamber system. Co-incubation of A549 with HsFb prevented TGF-β1-induced reduction of E-cadherin and increase in Snail and N-cadherin. Transfection of HsFb with tryptophan hydroxylase-1 siRNA, which inhibited tryptophan hydroxylase-1 protein expression and 5-MTP release in HsFb abrogated the effect of HsFb on A549 EMT. Direct addition of pure 5-MTP to cultured A549 cells followed by TGF-β1 prevented TGF-β1-induced reduction of E-cadherin, and elevation of Snail, vimentin and matrix metalloproteinase 9. Administration of 5-MTP to a murine xenograft tumor model reduced vimentin protein expression in the tumor tissues compared to vehicle control which was correlated with reduction of metastasis in the 5-MTP treated mice. Our experimental data suggest that 5-MTP exerted its anti-EMT actions through inhibition of p38 MAPK activation, p65/p50 NF-κB nuclear translocation and transactivation without the involvement of COX-2 or p300 histone acetyltransferase. Our findings indicate that fibroblasts release a tryptophan metabolite, 5-MTP, to reduce cancer cell EMT, migration, invasion and metastasis.

Role of the extracellular matrix in cancer-associated epithelial to mesenchymal transition phenomenon

The epithelial to mesenchymal transition (EMT) program is a crucial component in the processes of morphogenesis and embryonic development. The transition of epithelial to mesenchymal phenotype is associated with numerous structural and functional changes, including loss of cell polarity and tight cell-cell junctions, the acquisition of invasive abilities, and the expression of mesenchymal proteins. The switch between the two phenotypes is involved in human pathology and is crucial for cancer progression. Extracellular matrices (ECMs) are multi-component networks that surround cells in tissues. These networks are obligatory for cell survival, growth, and differentiation as well as tissue organization. Indeed, the ECM suprastructure, in addition to its supportive role, can process and deliver a plethora of signals to cells, which ultimately regulate their behavior. Importantly, the ECM derived signals are critically involved in the process of EMT during tumorigenesis. This review discusses the multilayer interaction between the ECM and the EMT process, focusing on contributions of discrete mediators, a strategy that may identify novel potential target molecules. Developmental Dynamics 247:368-381, 2018. © 2017 Wiley Periodicals, Inc.

Rab5a is overexpressed in oral cancer and promotes invasion through ERK/MMP signaling

Ras-related protein Rab-5A (Rab5a) has been identified to be overexpressed in several types of human cancer. However, its clinical significance and biological roles in oral cancer remain unclear. In the present study, the protein expression of Rab5a was examined in 79 cases of oral squamous cell carcinoma samples using immunohistochemistry. It was demonstrated that Rab5a protein was upregulated in 49.3% (39/79) of cancer samples. Small interfering RNA knockdown was performed on Detroit 562 cells with high endogenous expression. Rab5a transfection was performed in FaDu cells with low endogenous levels. Rab5a depletion was revealed to inhibit cell growth, invasion and colony formation while its overexpression facilitated cell growth, invasion, and colony formation. In addition, Rab5a facilitated cell cycle progression and cell migration. It was also demonstrated that Rab5a depletion downregulated and its overexpression upregulated the expression levels of various cell cycle-associated proteins, and matrix metalloproteinase-2 (MMP-2). Furthermore, Rab5a positively regulated the extracellular signal-regulated kinase (ERK) signaling pathway and promoted epithelial-mesenchymal transition (EMT). ERK inhibitor PD98059 partially inhibited the role of Rab5a on MMP-2, cyclin D1, cell proliferation and invasion. The results of the present study suggest that Rab5a is overexpressed in oral cancer tissue samples and promotes the malignant phenotype through EMT and the ERK/MMP-2 signaling pathway.

Cancer-associated fibroblasts promote bone invasion in oral squamous cell carcinoma

Background:

The molecular mechanisms involved in the invasion of bone by oral squamous cell carcinomas (OSCC) are poorly understood, and little is known about the role of cancer-associated fibroblasts (CAF), the presence of which confers a poor prognosis.

Methods:

Clinicopathological data from 277 OSCC cases involving bone resections were reviewed, and 32 cases thoroughly analysed histologically. Immunohistochemistry was used to examine αSMA, RANKL and OPG. Western blotting and qPCR were used to assess myofibroblast (CAF-like) differentiation, RANKL and OPG expression in vitro, and RANKL secretion was analysed by ELISA. Osteoclastogenesis was examined using TRAP staining, multinucleation and pit forming assays.

Results:

Fibrous stroma intervened between tumour and bone in the majority of cases, with no direct contact between cancer cells and bone. RANKL and OPG, two proteins key to regulating bone resorption, were expressed in tumour cells as well as fibrous stroma adjacent to bone and αSMA-positive myofibroblastic CAF were consistently seen infiltrating into bone ahead of tumour cells. Human primary osteoblasts cultured with conditioned media from human OSCC-derived cells and human primary CAF showed a significant increase in RANKL and a decline in OPG mRNA expression. RANKL secretion was significantly increased in primary oral fibroblasts induced to differentiate into a CAF-like phenotype by transforming growth factor-β1 (TGF-β1) treatment and in primary CAF. Indirect co-culture of murine macrophages with conditioned media from CAF (experimentally derived and isolated from OSCCs) resulted in a marked increase in osteoclastogenesis (in excess of that provoked by cancer cells) determined by tartrate-resistant acid phosphatase activity, multinucleation and resorption pit formation.

Conclusions:

This study is the first to describe a functional role for CAFs in bone invasion and turnover, identifying a novel potential therapeutic target and diagnostic indicator in this difficult to treat bone invasive malignancy.

Breast Carcinoma-associated Fibroblasts Share Similar Biomarker Profiles in Matched Lymph Node Metastasis

This study sought to understand the role of breast carcinoma-associated fibroblasts in the progression of cancer cells into lymph nodes. We compared fibroblasts of primary tumors and matched the involved lymph nodes to select fibroblast activation markers, namely α-smooth muscle actin (α-SMA), S100A4, and vimentin, as well as to determine the frequency of transforming growth factor β1, a pleiotropic cytokine that induces the differentiation of fibroblasts to myofibroblasts, and its downstream effectors: CXCR4 and p-AKT. We disposed samples of 80 primary invasive ductal carcinomas and matched the involved lymph nodes from 43 cases into 3 tissue microarrays, and analyzed stromal and tumor epithelial cells separately by immunohistochemistry. Control uninvolved lymph nodes were analyzed by whole-tissue sections. Cancer-associated fibroblast in lymph nodes with macrometastasis expressed similar profiles of vimentin, α-SMA, and S100A4 as those found in primary tumors. Cancer-associated fibroblast were uniformly estrogen receptor, progesterone receptor, HER-2, Ki-67, and p53 negative, but expressions of transforming growth factor β1 (TGFβ1), CXCR4, and p-AKT staining (62.3%, 52.4%, 65%, respectively) were equivalent between primary and lymph node metastasis (LNM) fibroblasts. A significant coexpression of TGFβ1 with p-AKT and CXCR4 in LNMs suggested the involvement of these proteins with TGFβ1 signaling. These biomarkers, including α-SMA and S100A4, were negative in fibroblasts of cancer-free lymph nodes, with the exception of vimentin. Our finding that expressions of biological markers were similar in fibroblasts of the primary tumors and in matched LNMs, but were absent in cancer-free lymph nodes, supports the assumption that the lymph node stroma mimics the microenvironment observed in primary tumors.

Serglycin in tumor microenvironment promotes non-small cell lung cancer aggressiveness in a CD44-dependent manner

Tumor microenvironment (TME) plays an active role in promoting tumor progression. To further understand the communication between TME and tumor cells, this study aimed at investigating the involvement of CD44, a type I cell surface receptor, in the crosstalk between tumor cells and TME. We have previously shown that chondroitin sulfate proteoglycan serglycin (SRGN), a CD44-interacting factor, was preferentially secreted by cancer-associated fibroblasts (CAFs) for promoting tumor growth in breast cancer patients. In this study, we show that SRGN is overexpressed in primary non-small cell lung cancers (NSCLCs), by both carcinoma and stromal cells. Using gain-of-function and loss-of-function approaches, we show that SRGN promotes NSCLC cell migration and invasion as well as colonization in the lung and liver in a CD44-dependent manner. SRGN induces lung cancer cell stemness, as demonstrated by its ability to enhance NSCLC cell sphere formation via Nanog induction, accompanied with increased chemoresistance and anoikis-resistance. SRGN promotes epithelial-mesenchymal transition by enhancing vimentin expression via CD44/NF-κB/claudin-1 (CLDN1) axis. In support, CLDN1 and SRGN expression are tightly linked together in primary NSCLC. Most importantly, increased expression of SRGN and/or CLDN1 predicts poor prognosis in primary lung adenocarcinomas. In summary, we demonstrate that SRGN secreted by tumor cells and stromal components in the TME promotes malignant phenotypes through interacting with tumor cell receptor CD44, suggesting that a combined therapy targeting both CD44 and its ligands in the TME may be an attractive approach for cancer therapy.

THBS1 is induced by TGFB1 in the cancer stroma and promotes invasion of oral squamous cell carcinoma

BACKGROUND

THBS1 (thrombospondin-1) is the extracellular matrix (ECM) protein that affects diverse cellular activities. It constitutes the tumor stroma, but the role of THBS1 in oral squamous cell carcinoma (OSCC) development is unclear. The aim of this study was to clarify the relevance of THBS1 in the pathogenesis of OSCC.

MATERIALS AND METHODS

The expression of THBS1 was examined in 44 OSCC by immunohistochemical analysis and in 43 OSCC by cDNA microarray analysis. Cell culture experiments were conducted using human OSCC cell lines HSC3 and HO1N1 and mouse fibroblast ST2 cells to examine the effect of TGFB1 on THBS1 expression, and the effect of THBS1 on cellular behaviors.

RESULTS

THBS1 was specifically induced in the tumor microenvironment of OSCC. THBS1 appeared to be produced mainly by the stromal cells, but also by OSCC cells. TGFB1 stimulated THBS1 expression in ST2, primary fibroblasts, and the OSCC cells. THBS1 promoted migration and invasion of HSC3 and HO1N1 in transwell migration assays. THBS1 stimulated the expression of MMP3 (matrix metalloprotease 3), MMP9, MMP11, and MMP13 in ST2 cells and MMP3, MMP11, and MMP13 in HO1N1 cells. The RGD peptide suppressed the THBS1-stimulated migration and upregulation of MMP11 and MMP13.

CONCLUSIONS

THBS1 is a tumor-specific ECM protein that is induced by TGFB1 and promotes migration of cancer cells and stimulates the expression of MMPs partly through the integrin signaling, thereby favoring OSCC invasion.

Immunoexpression of Epithelial Mesenchymal Transition Proteins E-Cadherin, β-Catenin, and N-Cadherin in Oral Squamous Cell Carcinoma

Aims Epithelial mesenchymal transition (EMT) is a crucial process for acquisition of malignant phenotype, aggressiveness, and metastatic capacity in neoplasms. It is characterized by loss of epithelial markers and gain of mesenchymal markers. Studies on EMT and its potential association with the histological grading are sparse in oral squamous cell carcinoma (OSCC). This study aims to evaluate the expression of EMT-associated proteins-E-cadherin, β-catenin, and N-cadherin-in different grades of OSCC. Methodology In all, 60 cases of OSCC further subdivided into 20 cases each of well-, moderately, and poorly differentiated OSCCs were stained immunohistochemically with E-cadherin, β-catenin, and N-cadherin antibodies. The differences in the expression were evaluated using χ² and Fisher exact tests, whereas Spearman's correlation was used to analyze the correlation between the markers. Results A reduced E-cadherin expression noted in 40% of the OSCCs was associated with reduced β-catenin expression in 66.6% of the cases and increase in the expression of mesenchymal N-cadherin seen in 80% of cases. This expression pattern demonstrated a significant association with histological grades. A membrane to cytoplasmic shift of E-cadherin (73.3%) and β-catenin (78.3%) increased with histological grade. A negative correlation was observed with the E-cadherin and N-cadherin localization, though it did not reach statistical significance. Conclusion OSCC tissues had high levels of EMT phenotype as compared with the normal oral mucosa. This phenotype was characterized by reduced E-cadherin and β-catenin expression and overexpression of N-cadherin. Aberrant localization of the studied proteins was a hallmark for depicting EMT.

Fibroblast activation and senescence in oral cancer

There is now compelling evidence that the tumour stroma plays an important role in the pathogenesis of cancers of epithelial origin. The pre-eminent cell type of the stroma is carcinoma-associated fibroblasts. These cells demonstrate remarkable heterogeneity with activation and senescence being common stress responses. In this review, we summarise the part that these cells play in cancer, particularly oral cancer, and present evidence to show that activation and senescence reflect a unified programme of fibroblast differentiation. We report advances concerning the senescent fibroblast metabolome, mechanisms of gene regulation in these cells and ways in which epithelial cell adhesion is dysregulated by the fibroblast secretome. We suggest that the identification of fibroblast stress responses may be a valuable diagnostic tool in the determination of tumour behaviour and patient outcome. Further, the fact that stromal fibroblasts are a genetically stable diploid cell population suggests that they may be ideal therapeutic targets and early work in this context is encouraging.

Significance of oral cancer-associated fibroblasts in angiogenesis, lymphangiogenesis, and tumor invasion in oral squamous cell carcinoma

BACKGROUND

Cancer-associated fibroblasts (CAFs) are recognized as a pivotal promoter in cancer initiation and development. However, the role of CAFs in the progression and metastasis of oral squamous cell carcinoma (OSCC) has not been fully elucidated.

MATERIALS AND METHODS

Lymphatic vessel density (LVD) and microvessel density (MVD) and the expression of α-smooth muscle actin (α-SMA) and matrix metalloproteinase-9 (MMP-9) were evaluated by immunohistochemistry in 86 cases of OSCC. The correlations between α-SMA expression and MMP-9 expression, LVD, MVD, and other clinicopathological parameters were analyzed. In vitro invasion assay was performed to assess the effect of CAFs on the invasion of OSCC cells. We also investigated the effect of CAFs on the angiogenesis and lymphangiogenesis by inoculating CAFs with OSCC cells into nude mice subcutaneously.

RESULTS

Positive expression of α-SMA protein was detected in 69.8% of the tumors. Increased α-SMA expression was correlated strongly with enhanced tumor invasion, higher tumor grade, increased risk of recurrence, lymph node involvement, and higher peritumoral lymphatic vessel density and microvessel density (P < 0.05). CAFs induced more cancer cells to invade relative to normal fibroblasts (NFs) (P < 0.05). Compared with co-injection of OSCC cells and NFs or injection of tumor cells alone, co-injection of OSCC cells and CAFs resulted in earlier tumor formation and bigger tumor volume accompanied with increased angiogenesis and lymphangiogenesis (P < 0.05).

CONCLUSION

CAFs may play critical roles in OSCC progression as an inducer of tumor invasion, angiogenesis, and lymphangiogenesis. Therapeutic strategies targeting CAFs against OSCC is promising and need further exploration.

Immunohistochemical Study EMT-Related Proteins in HPV-, and EBV-Negative Patients with Sinonasal Tumours

Epithelial to mesenchymal transition (EMT) is a biological process in which the epithelial cells, transform to mesenchymal cells via multiple biochemical modifications. Immunohistochemical method was used to examine the expression of EMT-related proteins: Slug, E-cadherin and fibronectin, in 41 cases of sinonasal inverted papilloma (SIP), 33 cases of sinonasal squamous cell carcinoma (SNC), and 22 cases of normal mucosa as a control. In all cases negative viral status was previously confirmed using both in situ hybridization and immunohistochemical method. The immunoexpression of Slug and fibronectin were significantly increased in the SNC group as compared to SIPs and control cases. The immunoexpresssion of Slug was also higher in SIPs as compared to controls. The immunoexpression of E-cadherin was significantly lower in SNCs group as compared with SIPs and controls, but no statistically significant difference in E-cadherin immunoexpression was noted between SIPs and control cases. There were statistically significant negative correlations between immunoexpression of Slug vs E-cadherin, E-cadherin vs fibronectin and positive correlation between Slug vs fibronectin in SNC. Statistically significant correlation between Slug and fibronectin immunoexpression in SIPs was also found. In conclusion, our findings suggest that relationships between Slug, E-cadherin and fibronectin could potentially point to EMT in the sinonasal cancer. Lack of correlation between EMT-related proteins in tested SIPs could reflect a benign nature of those cases.

Reduced serum levels of syndecan-1 in patients with tongue squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

To investigate soluble syndecan-1 (Sdc-1) in the sera of patients with tongue squamous cell carcinoma (SCC) and its correlation with the histopathological criteria of tumors.

STUDY DESIGN

In a case-control study using a convenient method of sampling, 18 female and 25 male patients with confirmed diagnosis of tongue SCC, and 19 healthy females and 27 males were studied.

METHODS

Soluble Sdc-1 was measured in the sera of 43 patients with tongue SCC and was compared with that of healthy age-/sex-matched controls using a commercial enzyme-linked immunosorbent assay. Clinical and pathological data, along with the demographic characteristics of the patients, were recorded at the time of sampling.

RESULTS

The levels of soluble Sdc-1 were decreased in the sera of patients compared to controls (91.17 ± 88.60 vs. 158.17 ± 103.47 ng/mL, P = .002). Although patients who smoke tended to have higher grades (P = .043), there was no significant difference in the level of syndecan-1 between smokers and non-smokers. A significant difference between syndecan-1 in the sera of patients with tumors of different stages was observed (Kruskal-Wallis test P=0.039); however, scarcity of patients in stages I and III decreased the power of the comparison.

CONCLUSIONS

Sdc-1 levels in the sera of patients do not correlate with the tumor progression in the tongue SCC. This is in contrast with the reported inverse correlation between the expression level of membranous Sdc-1 and the histological grade and size of head and neck tumors. Therefore, Sdc-1 shedding may not be a major mechanism in the progressive loss of its expression regarding tongue tumor.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:E191-E195, 2016.