Molecular crosstalk between cancer cells and tumor microenvironment components suggests potential targets for new therapeutic approaches in mobile tongue cancer

Prognostic Role of Tumor-Infiltrating Lymphocytes in Oral Squamous Cell Carcinoma

BACKGROUND

In oral squamous cell carcinoma (OSCC), the tumor-node-metastasis (TNM) staging system is a significant factor that influences prognosis and treatment decisions for OSCC patients. Unfortunately, TNM staging does not consistently predict patient prognosis and patients with identical clinicopathological characteristics may have vastly different survival outcomes. Host immunity plays an important role in tumor progression but is not included in the TNM staging system. Tumor-infiltrating lymphocytes (TILs) are part of the host immune response that recognizes tumor cells; and the presence of TILs has emerged as potential candidates for prognostic markers for many types of cancers. The present study aims to determine the association of T cell-specific markers (CD3, CD4, CD8, and FOXP3) with clinicopathological characteristics and survival outcomes in OSCC patients. The prognostic value of CD3, CD4, and CD8 will also be evaluated based on tumor stage.

METHODS

Tissue microarrays were constructed containing 231 OSCC cases and analyzed by immunohistochemical staining for the expression of CD3, CD4, CD8, and FOXP3. The expression scores for each marker were correlated with clinicopathological parameters and survival outcomes. The prognostic impact of CD3, CD4 and CD8 were further analyzed based on tumor stage (early or advanced).

RESULTS

CD3, CD4, and CD8 were found to be significantly associated with both overall survival and progression-free survival using univariate analysis. However, none of these markers were found to independently predict the survival outcomes of OSCC using multivariate analysis. Only conventional factors such as nodal status, tumor differentiation and perineural invasion (PNI) were independent predictors of survival outcomes, with nodal status being the strongest independent predictor. Additionally, low CD4 (but not CD3 or CD8) expression was found to identify early-stage OSCC patients with exceptionally poor prognosis which was similar to that of advanced staged OSCC patients.

CONCLUSIONS

TIL markers such as CD3, CD4, CD8, and FOXP3 can predict the survival outcomes of OSCC patients, but do not serve as independent prognostic markers as found with conventional factors (i.e. nodal status, tumor differentiation and PNI). CD4 expression may assist with risk stratification in early-stage OSCC patients which may influence treatment planning and decision making for early-stage OSCC patients.

Exosomes: Mediators of cellular communication in potentially malignant oral lesions and head and neck cancers

Exosomes are a unique type of extracellular vesicles that contain a plethora of biological cargo such as miRNA, mRNA, long non-coding RNA, DNA, proteins and lipids. Exosomes serve as very effective means of intercellular communication. Due the presence of a lipid bilayer membrane, exosomes are resistant to degradation and are highly stable. This makes them easily identifiable in blood and other bodily fluids such as saliva. The exosomes that are secreted from a parent cell directly release their contents into the cytoplasm of a recipient cell and influence their cellular activity and function. Exosomes can also transfer their content between cancer cells and normal cells and regulate the tumor microenvironment. Exosomes play a vital role in tumor growth, tumor invasion and metastasis. Exosomes provide a multitude of molecular and genetic information and have become valuable indicators of disease activity at the cellular level. This review explores the molecular characteristics of exosomes and the role that exosomes play in the tumorigenesis pathway of potentially malignant oral lesions and head and neck cancers The application of exosomes in the treatment of oral cancers is also envisioned. Exosomes are very small and can easily pass through various biological barriers, making them very good delivery vectors for therapeutic drugs as well as to selectively induce DNA's mRNA and miRNAs into targeted cancer cells.

Tumour-infiltrating lymphocyte subsets and their individual prognostic impact in oral squamous cell carcinoma

AIMS

Current understanding of oral squamous cell carcinoma (OSCC) is incomplete with regard to prognostic factors that lead to the considerable heterogeneity in treatment response and patient outcomes. We aimed to evaluate the impact of individual tumour-infiltrating lymphocyte (TIL) subsets on prognosis as a possible rationale for this, in a retrospective observational study.

METHODS

Immunohistochemistry was performed to quantitatively assess cell densities of CD3+, CD20+, CD4+, CD8+ and FOXP3+TIL subsets in 50 surgically treated OSCC cases. Results were correlated with disease-free survival (DFS) and overall survival (OS). Receiver operating characteristic curve analysis and Youden index were applied to determine prognostically significant cut-off values.

RESULTS

Mean counts for CD3+, CD4+, CD8+, CD20+ and FOXP3+TILs were 243, 52, 132, 53 and 116 cells per high power field, respectively. High CD8+ and low FOXP3+TIL counts, and high ratio of CD8:FOXP3 were significantly associated with longer DFS and OS, as well as with improved tumour-host interface parameters.

CONCLUSIONS

Host immune response and its interaction with cancer cells have a significant impact on OSCC outcomes, with some TIL subsets being more clinically relevant than others. High cytotoxic T-cell (CD8) and low Treg (FOXP3) counts, and high cytotoxic T-cell to Treg (CD8:FOXP3) ratio are significantly associated with favourable prognosis. These results may serve as a leading point in identifying novel therapeutic agents that can redesign the tumour immune microenvironment by reducing infiltrating FOXP3-lymphocytes, and modifying their signalling pathways.

The Immune Cells in the Development of Oral Squamous Cell Carcinoma

A still unresolved issue surrounding tumor formation concerns the role that the immune system plays in preventing the formation and progression of neoplasia, including oral squamous cell carcinoma (OSCC). Antitumor immunity has historically been seen as a critical barrier for cancer cells to develop, grow and spread, and this can be modulated using immunotherapies to achieve antitumor clinical responses. However, it has recently become clear that tumor-associated immunity, particularly the inflammatory microenvironment, has the paradoxical effect of enhancing tumorigenesis and progression. In this review, we discuss the multifaceted function of infiltrating immune cells in suppressing or promoting premalignancy and cancer. In particular, we report on the evidence supporting a role for T lymphocytes, dendritic cells, macrophages, and neutrophils in the development and progression of oral potentially malignant disorders (OPMD) and OSCC. We also draw attention to the clinical relevance of immune cell phenotypes and associated molecules for use as biomarkers and to the translatability of current research findings to improve classification systems and precision medicine in patients with OSCC.

Tumour Microenvironment as a Potential Immune Therapeutic Target for Tongue Cancer Management

Immunotherapy is a promising approach in the management of human cancers and has been proven to provide a durable response in many cancers. It is helpful as an adjuvant therapy for cancers and at present is considered as a fourth pillar supporting surgery, chemotherapy and radiotherapy. In the treatment of oral cancer, immunotherapy is approved in late-stage diseases where surgical resection cannot be carried out or fails, leading to recurrences and metastasis. Evidences suggest that when given as a first-line treatment, it can elicit an immune response that shrinks tumours, which could provide long-term benefit for patients. But unlike the traditional approach which follows the uniform protocol for all oral cancer patients, effective immunotherapy requires a more site-specific personalized approach. The aim of this paper is to review the various immune evasive mechanisms adopted by tumour cells and their relevance as potential targets for immunotherapy in oral tongue squamous cell carcinoma.

Extracellular Vesicles Are Important Mediators That Regulate Tumor Lymph Node Metastasis via the Immune System

Extracellular vesicles (EVs) are particles with a lipid bilayer structure, and they are secreted by various cells in the body. EVs interact with and modulate the biological functions of recipient cells by transporting their cargoes, such as nucleic acids and proteins. EVs influence various biological phenomena, including disease progression. They also participate in tumor progression by stimulating a variety of signaling pathways and regulating immune system activation. EVs induce immune tolerance by suppressing CD8⁺ T-cell activation or polarizing macrophages toward the M2 phenotype, which results in tumor cell proliferation, migration, invasion, and metastasis. Moreover, immune checkpoint molecules are also expressed on the surface of EVs that are secreted by tumors that express these molecules, allowing tumor cells to not only evade immune cell attack but also acquire resistance to immune checkpoint inhibitors. During tumor metastasis, EVs contribute to microenvironmental changes in distant organs before metastatic lesions appear; thus, EVs establish a premetastatic niche. In particular, lymph nodes are adjacent organs that are connected to tumor lesions via lymph vessels, so that tumor cells metastasize to draining lymph nodes at first, such as sentinel lymph nodes. When EVs influence the microenvironment of lymph nodes, which are secondary lymphoid tissues, the immune response against tumor cells is weakened; subsequently, tumor cells spread throughout the body. In this review, we will discuss the association between EVs and tumor progression via the immune system as well as the clinical application of EVs as biomarkers and therapeutic agents.

Cancer-associated fibroblasts in gynecological malignancies: are they really allies of the enemy?

Molecular and cellular components of the tumor microenvironment are essential for cancer progression. The cellular element comprises cancer cells and heterogeneous populations of non-cancer cells that satisfy tumor needs. Immune, vascular, and mesenchymal cells provide the necessary factors to feed the tumor mass, promote its development, and favor the spread of cancer cells from the primary site to adjacent and distant anatomical sites. Cancer-associated fibroblasts (CAFs) are mesenchymal cells that promote carcinogenesis and progression of various malignant neoplasms. CAFs act through the secretion of metalloproteinases, growth factors, cytokines, mitochondrial DNA, and non-coding RNAs, among other molecules. Over the last few years, the evidence on the leading role of CAFs in gynecological cancers has notably increased, placing them as the cornerstone of neoplastic processes. In this review, the recently reported findings regarding the promoting role that CAFs play in gynecological cancers, their potential use as therapeutic targets, and the new evidence suggesting that they could act as tumor suppressors are analyzed and discussed.

Infiltration of LPAR5+ macrophages in osteosarcoma tumor microenvironment predicts better outcomes

Introduction

Tumor microenvironment (TME) has been shown to be extensively involved in tumor development. However, the dynamic change of TME components and their effects are still unclear. Here, we attempted to identify TME-related genes that could help predict survival and may be potential therapeutic targets.

Methods

Data was collected from UCSC Xena and GEO database. ESTIMATE and CIBERSORT algorithms were applied to estimate the components and the proportions of TIICs in TME. We analyzed the gene expression differences of immune components and stromal components, respectively, and finally got the overlapped DEGs. Through protein-protein interaction (PPI) network and univariate Cox regression analysis based on shared DEGs, we screened out and validated the TME-related genes. Focusing on this gene, we analyzed the expression and prognostic value of this gene, and investigated its relationship with immune cells by correlation analysis, single cell analysis, immunohistochemistry and immunofluorescence analysis.

Results

Through a series analysis, we found that the proportion of immune and stromal components was an important prognostic factor, and screened out a key gene, LPAR5, which was highly correlated with prognosis and metastasis. And the expression of LPAR5 was positively correlated with immune cells, especially macrophages, indicating LPAR5⁺ macrophages played an important role in tumor microenvironment of osteosarcoma. Meanwhile, the genes in LPAR5 high expression group were enriched in immune-related activities and pathways, and differentially expressed genes between LPAR5⁺ macrophages and LPAR5^- macrophages were enriched in the biological processes associated with phagocytosis and antigen presentation. What' more, we found that LPAR5 was mainly expressed in TME, and high LPAR5 expression predicting a better prognosis.

Conclusion

We identified a TME-related gene, LPAR5, which is a promising indicator for TME remodeling in osteosarcoma. Particularly, LPAR5⁺ macrophages might have great potential to be a prognostic factor and therapeutic target for osteosarcoma.

Epithelial PD-L1 expression at tumor front predicts overall survival in a cohort of oral squamous cell carcinomas from Sudan

BACKGROUND

We recently described the tumor immune microenvironment (TIME) in oral squamous cell carcinomas (OSCC) from Sudan by assessing the core of the lesions. However, the invasive tumor front (ITF) is the most active part of OSCC lesions; thus, TIME should also be characterized at the ITF in this patient cohort.

OBJECTIVES

We aimed to evaluate patterns of immune cell infiltration at the ITF in a cohort of OSCC patients from Sudan previously investigated at the tumor center and their association with clinicopathological parameters.

METHODS

This study was performed on a prospective cohort of 22 OSCC patients attending Khartoum Dental Teaching Hospital with a median follow-up of 48 months. Inflammatory infiltrate densities of CD4-, CD8-, FoxP3-, CD20-, CD66b-, M1 (CD80/CD68)-, M2 (CD163/CD68)-, and PD-L1-positive cells were assessed at the ITF by immunohistochemistry, followed by digital quantitative analysis at the stromal and epithelial compartments separately. Histopathological parameters such as the worst pattern of invasion, differentiation, and tumor budding (TB) were also assessed. Correlations between clinicopathological parameters and survival analysis were investigated using SPSS.

RESULTS

All inflammatory cell subsets investigated were found to be higher in the stromal compartment as compared to the epithelial one, except for the PD-L1⁺ subset. Stromal infiltration with the CD8⁺ cell subset was associated with low TB. Kaplan-Meier analyses identified higher epithelial and stromal CD4⁺ cell subsets. The presence of PD-L1 was found to be associated with unfavorable overall survival. Further, Cox's regression analysis using an age- and tumor-stage-adjusted model identified epithelial PD-L1 expression at the ITF as the only independent prognosticator.

CONCLUSIONS

Epithelial PD-L1 expression at the ITF was found to be an independent prognostic biomarker for OSCC in a cohort of Sudanese patients.

The role of soluble CD80 in patients with soft tissue tumors

BACKGROUND

Immune checkpoint protein (ICP), which is a central factor group of the immune system, has been reported to have a correlation between the degree of its expression and the prognosis of patients with malignant tumors, and many inhibitors have appeared as therapeutic targets. On the other hand, a soluble form of ICP in circulating blood induced systemic immunosuppression. In this study, we investigated the relationship between the soluble form of CD80 (sCD80) which is a ligand for the inhibitory system CTLA-4, in blood, and clinicopathological parameters in patients with soft tissue tumors.

METHODS

A total of 119 patients with primary soft tissue tumors were enrolled in this study. The sCD80 levels were measured by enzyme immunoassay.

RESULTS

There were no significant differences in sCD80 levels between benign (34) and soft tissue sarcoma (STS) patients (85). In STS, the high-sCD80 group had significantly lower metastasis-free survival (MS) and lower overall survival (OS) than the low-sCD80 group at 5 years using the log-rank test (OS: high > 404 pg/mL, low ≤ 404 pg/mL, MS: high > 531 pg/ml, low ≤ 531 pg/ml). On multivariate Cox proportional hazard analysis, the high-sCD80 group had significant differences in 5MS and 5OS compared to the low-sCD80 group.

CONCLUSIONS

In conclusion, sCD80 may negatively affect systemic immune circumstances, in STS, and may have potential as a therapeutic target.

The Impact of Corticosteroid Administration at Different Time Points on Mucosal Wound Healing in Rats: An Experimental Pilot In Vivo Study

Simple Summary

The objective of this pilot study was to evaluate the impact of corticosteroid (CS) administration at different time points on palatal wound healing in rats. Thirty-six young male rats were divided into three groups. The test groups were treated by CS in the early (1–4 days) and late (5–9 days) stages after palatal wounding, while the control group was left for spontaneous healing. Our findings do not support the positive impact of CS administration on palatal wound healing. While microscopically, we found no difference between the CS and control groups, CS exposure was associated with a macroscopically larger final wound area, reflecting a possible harmful effect of CS.

Abstract

Background: Conflicting results were found regarding the effect of corticosteroid (CS) administration upon wound healing. The objective of this pilot study was to evaluate the impact of CS administration at different time points on palatal wound healing in rats. Methods: A 4.2 mm diameter punch created a secondary healing excisional palatal defect in thirty-six (36) Wistar-derived, two-month-old male rats weighing 250–270 g. We evaluated the effect of CS by comparing wound healing between three equal groups: 12 rats who were not exposed to CS and two additional groups in which 1 mg/kg dexamethasone (1 mg/kg) was administered daily, early (1–4 days) and late (5–9 days) after injury. The dynamics of the healing process were evaluated weekly in 4 sacrificed rats from each group for three weeks. The wound area was assessed both macroscopically and microscopically; the inflammation score was assessed microscopically. Results: The initial wound area in all the rats was 13.85 mm². At the end of the study, it decreased to 4.11 ± 0.88 mm², 7.32 ± 2.11 mm², and 8.87 ± 3.01 mm² in control, early, and late CS administration groups, respectively (p = 0.075). Inflammation scores showed a tendency to decrease in the third week in all groups, with no statistical differences. Conclusions: Our findings do not support the positive impact of CS administration on palatal wound healing. While microscopically, we found no difference between the CS and control groups, CS exposure was associated with a macroscopically larger final wound area, reflecting a possible harmful effect of CS.

Bioinformatics evaluation of a novel angiogenesis related genes-based signature for predicting prognosis and therapeutic efficacy in patients with gastric cancer

OBJECTIVE

Tumor angiogenesis plays a pivotal role in the development and metastasis of tumors. This study aimed to elucidate the association between angiogenesis-related genes (ARGs) and the prognosis of patients with gastric cancer (GC).

METHODS

Transcriptomics and clinical data of GC samples were obtained from The Cancer Genome Atlas (TCGA) as the training group and those from Gene Expression Omnibus (GEO, including GSE26253, GSE26091 and GSE66229) as the validation groups. Single-sample gene set enrichment analysis (ssGSEA) was performed for gene set enrichment analysis on the gene set of angiogenesis and divided patients into high- or low-ARG group. Subsequently, to improve the availability of the ARG signature, a ARGs subtype predictor was then constructed by integrating of four machine learning methods, including support vector machine (SVM), least absolute shrinkage and selection operator (LASSO) regression, Random Forest and Boruta (RFB) and extreme gradient boosting (XGBoost). Kaplan-Meier and receiver operating characteristic curves were used to evaluate the performance of prognosis prediction. The EPIC and xCELL method were used to calculate the profile of tumor-infiltrated immune cells.

RESULTS

The expression levels of a total of 36 ARGs that correlated with the survival of patients with GC were identified and utilized to establish an ARG-related prognosis signature. The area under the curve for predicting overall survival (OS) in the training group at the 1-, 3- and 5-year was 0.61, 0.64 and 0.76, respectively, and this was further validated using three independent GEO datasets. Moreover, the ARG signatures were significantly correlated with cancer-associated fibroblasts (CAFs), and GC patients that exhibited both high ARG expression level and matrix CAFs level had the most inferior outcomes. The multiple machine learning algorithms were applied to establish a 10-gene ARG subtype predictor, and notably, a high ARG-subtype predictor score was associated with reduced efficacy of immunotherapy, and potential anti-HER2 or FGFR4 therapy, but an increased sensitivity to anti-angiogenesis-related therapy.

CONCLUSION

The novel ARGs-based classification may act as a potential prognostic predictor for GC and be used as a guidance for clinicians in selecting potential responders for immunotherapy and targeted therapy.

Hsa_circ_0056686, derived from cancer-associated fibroblasts, promotes cell proliferation and suppresses apoptosis in uterine leiomyoma through inhibiting endoplasmic reticulum stress

Abnormal expression of circular RNAs (circRNAs) in cancer-associated fibroblasts (CAFs) is involved in the tumor-promoting ability of CAFs. Hsa_ circ_ 0056686 has been reported to affect leiomyoma size. The purpose of this study is to investigate the regulatory role of hsa_circ_0056686 in CAFs on uterine leiomyoma (ULM). The primary CAFs and corresponding normal fibroblasts (NFs) were isolated from the tumor zones of ULM tissues and adjacent, respectively. Hsa_circ_0056686 level was higher in CAFs than NFs, and also higher in ULM tissues than in adjacent tissues. CAFs-CM significantly increased the proliferation and migration and inhibited apoptosis of ULM cells, as confirmed by CCK-8, transwell, and flow cytometry assays. Moreover, conditioned medium (CM) from CAFs transfected with hsa_circ_0056686 shRNA (CAFssh-circ_0056686-CM) abolished CAFs-mediated proliferation, migration and apoptosis of ULM cells. CAFs-CM suppressed the expression of endoplasmic reticulum stress (ERS) marker proteins and induced the expression of extracellular matrix (ECM) marker proteins, thus suppressing ERS and increasing ECM accumulation, which could be declined by CAFssh-circ_0056686-CM. Meanwhile, knockdown of hsa_circ_0056686 reversed the inhibitory effects of CAFs-CM on brefeldin A-induced cell apoptosis. Luciferase gene reporter and RNA pull-down assays indicated that miR-515-5p directly bound with hsa_circ_0056686. MiR-515-5p overexpression restored the hsa_circ_0056686-shRNA-mediated malignant biological behaviors of ULM cells. Hsa_circ_0056686 contributed to tumor-promoting effects of CAFs in ULM, manifested by promoting ULM cell proliferation and migration and reducing ERS-induced apoptosis through sponging miR-515-5p.

Exosomal miRNAs and lncRNAs: The Modulator Keys of Cancer-Associated Fibroblasts in the Genesis and Progression of Malignant Neoplasms

The tumor microenvironment is made up of a universe of molecular and cellular components that promote or inhibit the development of neoplasms. Among the molecular elements are cytokines, metalloproteinases, proteins, mitochondrial DNA, and nucleic acids, within which the ncRNAs: miRNAs and lncRNAs stand out due to their direct modulating effects on the genesis and progression of various cancers. Regarding cellular elements, the solid tumor microenvironment is made up of tumor cells, healthy adjacent epithelial cells, immune system cells, endothelial cells, and stromal cells, such as cancer-associated fibroblasts, which are capable of generating a modulating communication network with the other components of the tumor microenvironment through, among other mechanisms, the secretion of exosomal vesicles loaded with miRNAs and lncRNAs. These ncRNAs are key pieces in developing neoplasms since they have diverse effects on cancer cells and healthy cells, favoring or negatively regulating protumoral cellular events, such as migration, invasion, proliferation, metastasis, epithelial-mesenchymal transition, and resistance to treatment. Due to the growing number of relevant evidence in recent years, this work focused on reviewing, analyzing, highlighting, and showing the current state of research on exosomal ncRNAs derived from cancer-associated fibroblasts and their effects on different neoplasms. A future perspective on using these ncRNAs as real therapeutic tools in the treatment of cancer patients is also proposed.

Effect of Programmed Death-Ligand 1 in Cancer-Associated Fibroblasts on Advanced Laryngeal Squamous Cell Carcinoma

This study aimed to explore the effect of programmed death-ligand 1 (PD-L1) in cancer-associated fibroblasts (CAFs) on advanced laryngeal squamous cell carcinoma (LSCC). The expression of PD-L1 in advanced LSCC tumor tissues was observed in 83 patients with LSCC by immunofluorescence microscopy and compared with that in normal laryngeal mucosa. The CAFs of LSCC and normal fibroblasts (NFs) were isolated, cultured, purified, and examined by fluorescence. The expression of PD-L1 in purified CAFs and NFs was measured by flow cytometry. The expression of PD-L1 in CAFs was downregulated through small interferring RNA (siRNA) transfection. The proliferation and migration capacities of CAFs were observed using proliferation and scratch tests, respectively. The proliferation of HEP-2 cells and T cells was measured after cocultured with CAFs. The secretion of interleukins IL-2 and IL-10 was detected using enzyme-linked immuno sorbent assay (ELISA). PD-L1 was expressed in 62 of 83 cases of the advanced LSCC tumor tissues. Also, CAFs expressed more PD-L1 compared with NFs. The proliferation and migration capacities of CAFs were significantly lower after transfection with PD-L1-siRNA. The proliferation rate of HEP-2 cells cocultured with CAFs decreased in PD-L1-siRNA-transfected cells. However, the proliferation rate of T cells increased in transfected cells. The ELISA results showed that the secretion of IL-2 increased and that of IL-10 decreased in PD-L1-siRNA-transfected cells. The expression of PD-L1 in CAFs of advanced LSCC was higher than that in NFs. The downregulation of PD-L1 reduced the proliferation and migration of CAFs and HEP-2 cells but enhanced the proliferation and pro-inflammatory function of T cells in the coculture experiment.

MKP-1 is required to limit myeloid-cell mediated oral squamous cell carcinoma progression and regional extension

Mitogen-activated protein kinases (MAPKs) require MAPK phosphatases (MKPs) for deactivation of MAPK intracellular signaling. MKP-1 (encoded by Dusp1) is a key negative regulator of MAPKs and prior reports have indicated that MKP-1 regulates oral cancer-associated inflammation and leukocyte infiltration.

OBJECTIVE

To determine the significance of myeloid-based expression of MKP-1 in oral cancer.

METHODS

The Cancer Genome Atlas (TCGA) was used to address DUSP1 expression in oral squamous cell carcinoma (OSCC). Syngeneic and carcinogen-induced mouse models using global and myeloid-specific Dusp-1 deficient mice with immunophenotypic, histologic, and transcriptomic analyses and in vitro migration assays.

RESULTS

Data from TCGA indicates the DUSP1 expression is inversely related to oral cancer burden and nodal involvement. Using murine models of OSCC, the role of MKP-1 signaling in tumor associated macrophages (TAMs) was assessed. Dusp1-deficient mice had increased tumor burden and TAM infiltrate with increased M2 macrophage polarization. Transcriptomic signatures of TAMs from Dusp1-deficent mice indicated a pro-metastatic phenotype as well as concomitant differences in myeloid-associated genes, cytokine/chemokine signaling, and Notch signaling consistent with tumor progression. In vitro and in vivo assays revealed mouse OSCC cells had a higher migration rate using TAM cell-free supernatant from Dusp1 deficiency mice compared to controls with enhanced regional cervical lymph node metastasis, respectively. To validate TAM studies using implantable mouse models, an OSCC progression model with conditional myeloid-specific Dusp-1 deficient mice demonstrated enhanced OSCC disease progression, characterized by advanced onset, histological stage, and tumor burden.

CONCLUSION

Myeloid-based Dusp1-deficiency increases OSCC burden and metastasis through alteration in TAM recruitment, gene profile, and polarity suggesting that MKP-1 could be a viable target to reprogram TAM to limit local/regional OSCC extension.

Tumor Microenvironment in Oral Cancer Following Neoadjuvant Pembrolizumab: Preliminary Analysis of the Histopathologic Findings

Background: The tumor microenvironment (TME) of oral squamous cell carcinoma (OSCC) is associated with immune suppression, one of the pathways being the programmed death receptor 1 (PD-1) and its ligands (PD-L1/PD-L2). Checkpoint inhibitors of PD-1/PD-L1, like pembrolizumab, have been recently approved for treatment of OSCC. We described the histologic findings in OSCC following neoadjuvant pembrolizumab, including identification of immune-related cell populations and cancer-associated fibroblasts (CAFs).

Materials and Methods: Patients with OSCC clinical stages 3 and 4 and a combined PD-L1 score >1 were randomized either to the standard oncologic protocol or to the pembrolizumab arm of MK-3475-689 study for Head and Neck, Lip, and Oral Cavity. The latter were given two standard doses of 200 mg of pembrolizumab, 3 weeks apart, and then underwent surgical oncologic procedure according to the initial stage. Sections from the resection specimens were analyzed for pathological response to pembrolizumab. Various populations of immune-related cells within the tumor microenvironment were characterized by immunohistochemistry, as were the CAFs.

Results: Three patients who were randomized to the pembrolizumab study were described. One patient presented with a tongue SCC, the other two had SCC of the mandibular ridge with bony involvement. Only the patient with tongue SCC showed clinical complete response. Microscopically, the tumor was replaced by a granulomatous type of inflammation. Immunohistochemical stains revealed massive T cell rich (CD3⁺) infiltrate, with approximately equal amounts of CD4⁺ and CD8⁺ cells, numerous macrophages of CD68⁺ and CD163⁺ phenotypes; no CAFs were identified. The other two patients were regarded as non-responders as at least 50% of the tumor was viable. The tumor microenvironment of these tumors was generally associated with a lesser extent of inflammatory response compared to the tongue tumor, a variable CD4⁺/CD8⁺ ratio and presence of CAFs. Neither T regulatory cells (FOXP3⁺) nor natural killer cells (CD56⁺, CD57⁺) were identified in any of the cases.

Conclusion: We showed that characterizing the specific populations of immune-related cells and CAFs after treatment with pembrolizumab, may add to our understanding of the tumor-TME interactions in this setting. These findings should be investigated in future studies on a larger number of patients.

Age-Related Palatal Wound Healing: An Experimental In Vivo Study

We assessed age-related excisional palatal mucoperiosteal wound closure in rats. A 4.2 mm diameter punch was used to create a secondary healing defect in the palate of Wistar rats. Study group-21, 18-month-old vs. control 21, 2-month-old males. The 2-dimensional area, maximum length and width of the soft tissue defect served as clinical outcome parameters. The dynamics of the initial three healing weeks were assessed. Semi-quantitative histomorphometric analysis of inflammation and myofibroblasts served for the evaluation of the inflammatory and proliferative wound healing phases. Complete wound closure was faster in the old rats. A dimensional related wound closure was observed in the young rats versus a symmetrical wound closure in the old rats. Inflammatory response was significantly delayed and of lower intensity in the old rats. Myofibroblastic response, representing the proliferative stage, was delayed and of lower intensity in the old rats, albeit not statistically significant. Reduced initial tissue damage due to decreased and delayed inflammatory response in the old rats ultimately led to faster clinical wound healing compared to the young rats, despite a statistically non-significant lower proliferative response in the old rats.

Development of a novel 7 immune-related genes prognostic model for oral cancer: A study based on TCGA database

Oral squamous cell carcinoma (OSCC) is an aggressive tumor whose prognosis has little improvement in the last three decades. Various immune-related genes have been suggested as significant roles in the development and progression of malignant cancers. In this study, we acquired and integrated differentially expressed genes of OSCC patients, including immune-related genes and transcription factors (TFs), from The Cancer Genome Atlas (TCGA) database. TF-mediated network was established to exploring the regulatory mechanisms of prognostic immune-related genes. A 7 immune-related genes prognostic model for OSCC was obtained, including CGB8, CTLA4, TNFRSF19, CCL26, NRG1, TPM2 and PLAU, which was further proved to be an independent prognostic indicator after adjusting for other clinical factors. The immune-related genes prognostic index was significantly negatively correlated to the infiltration abundances of B cells (P < 0.05) and CD8+ T cells (P < 0.05). The novel proposed immune-based prognostic model not only provided a promising biomarker and a way to monitor the long-term treatment of OSCC, but also gave a new insight into a potential immunotherapy strategy.

Legumain Induces Oral Cancer Pain by Biased Agonism of Protease-Activated Receptor-2

Oral squamous cell carcinoma (OSCC) is one of the most painful cancers, which interferes with orofacial function including talking and eating. We report that legumain (Lgmn) cleaves protease-activated receptor-2 (PAR₂) in the acidic OSCC microenvironment to cause pain. Lgmn is a cysteine protease of late endosomes and lysosomes that can be secreted; it exhibits maximal activity in acidic environments. The role of Lgmn in PAR₂-dependent cancer pain is unknown. We studied Lgmn activation in human oral cancers and oral cancer mouse models. Lgmn was activated in OSCC patient tumors, compared with matched normal oral tissue. After intraplantar, facial or lingual injection, Lgmn evoked nociception in wild-type (WT) female mice but not in female mice lacking PAR₂ in Na_V1.8-positive neurons (Par₂Na_v1.8), nor in female mice treated with a Lgmn inhibitor, LI-1. Inoculation of an OSCC cell line caused mechanical and thermal hyperalgesia that was reversed by LI-1. Par₂Na_v1.8 and Lgmn deletion attenuated mechanical allodynia in female mice with carcinogen-induced OSCC. Lgmn caused PAR₂-dependent hyperexcitability of trigeminal neurons from WT female mice. Par₂ deletion, LI-1, and inhibitors of adenylyl cyclase or protein kinase A (PKA) prevented the effects of Lgmn. Under acidified conditions, Lgmn cleaved within the extracellular N terminus of PAR₂ at Asn³⁰↓Arg³¹, proximal to the canonical trypsin activation site. Lgmn activated PAR₂ by biased mechanisms in HEK293 cells to induce Ca²⁺ mobilization, cAMP formation, and PKA/protein kinase D (PKD) activation, but not β-arrestin recruitment or PAR₂ endocytosis. Thus, in the acidified OSCC microenvironment, Lgmn activates PAR₂ by biased mechanisms that evoke cancer pain.SIGNIFICANCE STATEMENT Oral squamous cell carcinoma (OSCC) is one of the most painful cancers. We report that legumain (Lgmn), which exhibits maximal activity in acidic environments, cleaves protease-activated receptor-2 (PAR₂) on neurons to produce OSCC pain. Active Lgmn was elevated in OSCC patient tumors, compared with matched normal oral tissue. Lgmn evokes pain-like behavior through PAR₂ Exposure of pain-sensing neurons to Lgmn decreased the current required to generate an action potential through PAR₂ Inhibitors of adenylyl cyclase and protein kinase A (PKA) prevented the effects of Lgmn. Lgmn activated PAR₂ to induce calcium mobilization, cAMP formation, and activation of protein kinase D (PKD) and PKA, but not β-arrestin recruitment or PAR₂ endocytosis. Thus, Lgmn is a biased agonist of PAR₂ that evokes cancer pain.

Human myoma tissue-based extracellular matrix models for testing the effects of irradiation on the HPV positive cells

Background

This study was designed to investigate the invasion of human papillomavirus (HPV) positive human cervical carcinoma cell lines in human leiomyoma-based extracellular matrices in vitro, and to test the suitability of the model for studying the irradiation effects on the cancer cell invasion.

Methods

HPV positive cervical carcinoma cell lines SiHa and CaSki, and HPV negative squamous cell carcinoma cell line HSC-3 were used. CaSki cells contain around 600 copies of HPV 16 virus in the genome, whereas SiHa have only 1–2 copies per cell. Cells were analyzed using two different human tumor derived extracellular matrix methods (3D myoma disc model, and Myogel Transwell invasion assay). Cultures were irradiated with 4 Gy. Myoma invasion area and the depth of invasion were measured with ImageJ 1.51j8 software. Statistical analyses were performed with SPSS Statistics (IBM SPSS® Statistics 25).

Results

All cells invaded through Myogel coated Transwell membranes and within myoma discs. In myoma discs, a difference in the invasion depth (p = 0.0001) but not in invasion area (p = 0.310) between the HPV positive cell lines was seen, since SiHa (less HPV) invaded slightly better than CaSki (more HPV). HSC-3 cells (HPV negative) invaded deepest (p = 0.048) than either of the HPV positive cell line cells. No difference was detected in the invasion area (p = 0.892) between HPV positive and HPV negative cells. The ionized radiation significantly reduced the invasion depth of HSC-3 (p = 0.008), SiHa (p = 0.0001) and CaSki (p = 0.005). No significant effect on the invasion area was detected in any of the cell lines. However, a significant difference was observed between SiHa and CaSki in the reduction of the invasion depth after radiation (p = 0.013) as the reduction was greater with SiHa than CaSki.

Conclusions

Both solid and gelatinous human leiomyoma-based extracellular matrix models were suitable platforms to study the invasion of HPV positive cervical carcinoma cells in vitro. SiHa cells with less HPV copy number cells invaded slightly better and were slightly more sensitive to irradiation than CaSki cells with high HPV copy number. However, there was no drastic differences between the invasion properties of these carcinoma cells.

The Immune Microenvironment in Head and Neck Squamous Cell Carcinoma: on Subsets and Subsites

PURPOSE

To understand why some patients respond to immunotherapy but many do not, a clear picture of the tumor microenvironment (TME) of head and neck squamous cell carcinoma (HNSCC) is key. Here we review the current understanding on the immune composition per HNSCC subsite, the importance of the tumor's etiology and the prognostic power of specific immune cells.

RECENT FINDINGS

Large cohort data are mostly based on deconvolution of transcriptional databases. Studies focusing on infiltrate localization often entail small cohorts, a mixture of HNSCC subsites, or focus on a single immune marker rather than the interaction between cells within the TME. Conclusions on the prognostic impact of specific immune cells in HNSCC are hampered by the use of heterogeneous or small cohorts. To move forward, the field should focus on deciphering the immune composition per HNSCC subsite, in powered cohorts and considering the molecular diversity in this disease.

The dynamics of closure following excisional mid-palatal mucoperiosteal wound in a rat model

OBJECTIVES

The aim of the present study was to assess macroscopically the time-related dimensional pattern of excisional palatal mucoperiosteal wound closure in rats, concomitantly with microscopic analysis of the density of inflammatory infiltrate and myofibroblasts.

MATERIALS AND METHODS

Excisional palatal wounds, 4.2 mm in diameter, were made in twenty-one 2-month-old male Wistar rats. The total area and anteroposterior/laterolateral dimensions of the wounds were measured macroscopically at 1, 2, and 3 weeks post-operatively. In addition, histomorphometry was used for assessment of the intensity of inflammation and density of myofibroblasts in the wound area.

RESULTS

A significant decrease was found in the total area and anteroposterior but not the laterolateral dimension of the wounds during the 2nd week. These changes were less prominent in the 3rd week. Three weeks post-operatively, the density of inflammatory infiltrate remained high in the central part of the wound concomitant with a significant increase in the number of myofibroblasts.

CONCLUSIONS

We concluded that the second week was the most significant in wound closure, with wound contraction first occurring in an anteroposterior plane followed by the laterolateral plane. The increased inflammatory reaction and changes in the density of myofibroblasts may explain the macroscopic decrease in wound dimensions in a time-related manner.

CLINICAL RELEVANCE

These findings emphasize the importance of the amount of soft tissue left at surgery, and suggest that the most appropriate time for the use of healing promoters would be the second post-operative week.

Central giant cell granuloma: A clinicopathological and immunohistochemical study of macrophages, blood vessels, lymphatic vessels and regulatory proteins

OBJECTIVE

This study seeks to investigate immunohistochemical parameters that could distinguish non-aggressive Central giant cell granuloma (CGCG) from aggressive CGCG, two groups of lesions which differ in their clinical and radiographic features and prognosis.

MATERIAL AND METHODS

12 cases of non-aggressive CGCG and 11 cases of aggressive CGCG were investigated and associated the immunohistochemical expression of macrophages (CD68 and CD163), blood vessels (CD34 and CD105), lymphatic vessels (D2-40) and regulator proteins (p63 and Ki-67). Clinical and radiographic features were also studied.

RESULTS

Associations between all proteins in non-aggressive and aggressive CGCG were not significant (p > 0.05). With respect to non-aggressive CGCG, there were no significant correlations, while in aggressive CGCG there was a significant positive correlation between CD68 and CD163 (p = 0.031), between CD34 and D2-40 proteins (p = 0.04), whereas a significant negative correlation was observed between CD105 and CD68 (p = 0.040). However, regardless of aggressiveness of CGCG, there was a significant positive correlation between CD68 and CD163 (p = 0,04). Among the clinical and immunohistochemical aspects, only the symptomatology was a significant risk factor for the occurrence of aggressive CGCG (OR = 12.00/p = 0.016).

CONCLUSION

Macrophages and angiogenesis contribute to their maintenance and development of CGCG. In addition, immunohistochemistry used here was not able to differentiate their aggressiveness. However, symptomatology was proved to be a risk factor for the occurrence of aggressive CGCG. It is possible that clinical features, particularly symptomatology, represent the most appropriate parameter to attempt to distinguish GCCG.

Increased Tumor Immune Microenvironment CD3+ and CD20+ Lymphocytes Predict a Better Prognosis in Oral Tongue Squamous Cell Carcinoma

Background: Oral tongue squamous cell carcinoma (OTSCC) causes over 350,000 cases annually and particularly impacts populations in developing countries. Smoking and alcohol consumption are major risk factors. Determining the role of the tumor immune microenvironment (TIME) in OTSCC outcomes can elucidate immune mechanisms behind disease progression, and can potentially identify prognostic biomarkers. Methods: We performed a retrospective study of 48 OTSCC surgical specimens from patients with tobacco and alcohol exposures. A panel of immunoregulatory cell subpopulations including T (CD3, CD4, CD8) and B (CD20) lymphocytes, dendritic cells (CD1a, CD83), macrophages (CD68), and immune checkpoint molecules programmed cell death protein 1 (PD-1) and ligand 1 (PD-L1) were analyzed using immunohistochemistry. The levels of immune effector cell subpopulations and markers were analyzed in relation to overall survival. Results: Pathological characteristics of the tumor microenvironment included inflammatory infiltrates (83.3%), desmoplasia (41.6%), and perineural invasion (50.0%). The TIME contained high levels of T cells (CD3+, CD4+, and CD8+) and B cells (CD20+), as well as immature (CD1a) and mature (CD83) dendritic cells, PD-1, and PD-L1. Higher numbers of TIME infiltrating CD3+ T cells and CD20+ B cells were predictive of better survival, while higher levels of CD83+ mature dendritic cells predicted better survival. CD3+ T cells were identified as an independent prognostic marker for OTSCC. Lastly, CD3+ T cells were strongly correlated with the number of CD8+ cells and PD-L1 expression. Conclusion: Our findings provide evidence that the TIME profile of OTSSC impacted prognosis. The high expression of CD3+ T cells and B cells are predictive of better overall survival and indicative of an immunologically active, inflammatory TIME in patients with better survival. The number of CD3+ T cells was an independent prognostic marker.

Cancer-associated fibroblasts in the tumor microenvironment of tongue carcinoma is a heterogeneous cell population

OBJECTIVES

To examine different immunophenotypes of cancer-associated fibroblasts (CAFs) in tongue squamous cell carcinoma (TSCC) and to investigate how they related to clinical outcomes.

METHODS

Serial sections from 54 cases of TSCC were immunohistochemically stained with α-smooth muscle actin (αSMA, CAF marker) to determine CAF density, and double-immunostained with αSMA combined with CD80 and CD86 (myeloid/monocytic-derived cell markers), Nanog (mesenchymal stem cell marker) and CD133 (hematopoietic/endothelial stem cell marker). Density of cells co-expressing these marker combinations was semi-quantitatively assessed in 5 randomly selected high power fields within the tumor area and scored as 1 - one-to-five stained cells in each field, 2 - more than 5 stained cells in each field; any finding less than score 1, was allocated a score of 0.

RESULTS

There were 26 CAF-poor, 16 CAF-rich and 12 CAF-intermediated cases. CD86⁺αSMA⁺ cells were the most frequent (80.4%) followed by CD80⁺αSMA⁺ (72%) and Nanog⁺αSMA⁺ cells (56%). The CD133⁺αSMA⁺ phenotype was found only in association with blood vessels. High density of αSMA⁺ CAFs was associated with disease recurrence and poor survival (p < 0.05). Increased density of CD86⁺αSMA⁺ cells was significantly associated with CAF-rich tumors and with poor survival (p < 0.05).

CONCLUSION

In TSCC, CAFs demonstrate heterogeneous and overlapping phenotypes with the myeloid/monocytic type being the most frequent and having an impact on the clinical outcomes. Further studies are needed in order to further characterize CAF phenotypes in carcinomas of various oral sites, as this may open new frontiers for personalized medicine.

Exosomes in Head and Neck Squamous Cell Carcinoma

Exosomes are small membranous vesicles that contain proteins, lipids, genetic material, and metabolites with abundant information from parental cells. Exosomes carry and deliver bioactive contents that can reprogram the functions of recipient cells and modulate the tumor microenvironment to induce pathological events through cell-to-cell communication and signal transduction. Tumor-derived exosomes (TDEs) in head and neck squamous cell carcinoma (HNSCC) are involved in most aspects of cancer initiation, invasion, progression, immunoregulation, therapeutic applications, and treatment resistance. In addition, HNSCC-derived exosomes can be used to obtain information on diagnostic and therapeutic biomarkers in circulating blood and saliva. Currently, the biology, mechanisms, and applications of TDEs in HNSCC are still unclear, and further research is required. In this review, we discuss various aspects of exosome biology, including exosomal components, exosomal biomarkers, and molecular mechanisms involved in immunoregulation, cancer metastasis, and therapy resistance. We also describe recent applications to update our understanding of exosomes in HNSCC.

The prognostic role of tumour-infiltrating lymphocytes in oral squamous cell carcinoma: A meta-analysis

It has been suggested that tumour-infiltrating lymphocytes (TILs) are associated with the progression of oral squamous cell carcinoma (OSCC). However, the prognostic value of TILs is inconclusive due to the heterogeneity of immune cells within the tumour microenvironment. In this meta-analysis, we aimed to assess the prognostic value of TILs in OSCC. The PubMed, Cochrane, Embase, Scopus and Web of Science databases were searched up to April 20, 2019, and 33 studies were ultimately included in this meta-analysis. Our pooled meta-analysis showed that high infiltration of CD8⁺ TILs, CD45RO⁺ TILs and CD57⁺ TILs favoured better overall survival (OS). However, high infiltration of CD68⁺ macrophages and CD163⁺ macrophages was associated with poor prognosis in OSCC. These findings suggest that CD8⁺ TILs, CD45RO⁺ TILs, CD57⁺ TILs, CD68⁺ macrophages and CD163⁺ macrophages might serve as novel prognostic factors and therapeutic targets in OSCC.

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.

The role of extracellular vesicles from different origin in the microenvironment of head and neck cancers

The proliferation and metastasis ability of tumors are mediate by the "mutual dialogue" between cells in the tumor microenvironment (TME). Extracellular vesicles (EVs), mainly exosomes and microvesicles, play an important role in achieving intercellular substance transport and information transfer in the TME. Initially considered "garbage dumpsters" and later referred to as "signal boxes", EVs carry "cargo" (proteins, lipids, or nucleic acids) that can redirect the function of a recipient cell. Currently, the molecular mechanisms and clinical applications of EVs in head and neck cancers (HNCs) are still at an early stage and need to be further investigate. In this review, we provide insight into the TME of HNCs, classifying and summarizing EVs derived from different cell types and illuminating their complex signaling networks involved in mediating tumor proliferation, invasion and metastasis, vascular angiogenesis and cancer drug resistance. In addition, we highlight the application of EVs in HNCs, underlining the special pathological and physiological environment of HNCs. The application of tumor heterogeneous EVs in saliva and circulating blood diagnostics will provide a new perspective for the early screening, real-time monitoring and prognostic risk assessment of HNCs. Given the concept of precise and individual therapy, nanostructured EVs are equipped with superior characteristics of biocompatibility, low immunogenicity, loadability and modification ability, making these molecules one of the new strategies for HNCs treatment.

Tissue-infiltrating immune cells as prognostic markers in oral squamous cell carcinoma: a systematic review and meta-analysis

Background

Various immune cells have been suggested as prognostic markers for cancer patients. In this article, we present a systematic review and meta-analysis of studies assessing the prognostic value of tissue-infiltrating immune cells in oral cancer and discuss the reporting quality of these studies.

Methods

We performed a systematic literature search and included studies using immunohistochemistry and survival analysis to assess the prognostic value of tumour-infiltrating T cells, B cells, macrophages, dendritic cells, mast cells and natural killer cells in oral cancer. We performed meta-analysis of studies providing necessary statistical data and investigated the studies’ adherence to the REporting recommendations for tumour MARKer prognostic studies (REMARK) guidelines.

Results

Of the 1960 articles identified, 33 were eligible for this systematic review and 8 were included in the meta-analysis. CD163+ M2 macrophages and CD57+ natural killer cells were the most promising predictors of survival in oral cancer patients. Many studies lacked important information on their design and conduct.

Conclusion

Deficiencies in the reporting of study design and conduct make it difficult to draw reliable conclusions about the suggested markers. The prognostic value of CD163+ M2 macrophages and CD57+ natural killer cells should be validated in large, standardised studies.

Myofibroblasts in oral potentially malignant disorders: Is it related to malignant transformation?

In oral cancer, acquisition of α-smooth muscle actin (α-SMA)-positive fibroblasts, known as myofibroblasts or carcinoma-associated fibroblasts (CAF), is an important event for progression and metastasis. However, the contribution of myofibroblasts in oral potentially malignant disorders (OPMD) remains controversial. This systematic review provides evidence that immunodetection of myofibroblasts may identify oral submucous fibrosis (OSMF) with high risk of malignant transformation, but does not represent an auxiliary tool to predict the malignant potential of leukoplakia and erythroplakia, the most common OPMD.

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’.

Extracellular interleukin-17F has a protective effect in oral tongue squamous cell carcinoma

BACKGROUND

Oral tongue squamous cell carcinoma (SCC) is characterized by early metastasis and poor prognosis. Interleukin-17F (IL-17F) plays a protective role in many tumors. However, IL-17F expression in oral tongue SCC tissue has not been investigated.

METHODS

Immunostaining of 83 oral tongue SCC specimens and blinded-scoring were used to map IL-17F expression, location, and distribution. Survival curves were constructed according to Kaplan-Meier method. The Cox proportional hazard model was applied for univariate and multivariate survival analyses.

RESULTS

Mast cells are the major source of IL-17F in oral tongue SCC. In multivariate analysis, only the extracellular mast cell-derived IL-17F at the tumor invasion front was associated with better disease-specific survival in patients with all-stages and early-stages of oral tongue SCC.

CONCLUSION

Extracellular mast cell-derived IL-17F is antitumorigenic in oral tongue SCC. It separates patients with early-stage disease who are at high risk from patients who are at low risk. Furthermore, when analyzing tentative prognostic molecules, we conclude that in addition to the staining intensity, attention must be paid to the cellular source, distribution, and location of the molecule.

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.

Diagnostic potential of serum exosomal colorectal neoplasia differentially expressed long non-coding RNA (CRNDE-p) and microRNA-217 expression in colorectal carcinoma

In this study, we investigated the diagnostic potential of serum exosomal colorectal neoplasia differentially expressed (CRNDE-p) long coding RNA and microRNA-217 in colorectal carcinoma (CRC). We detected high CRNDE-p and low miR-217 levels in exosomes released by multiple CRC cell lines into culture media as well as in sera from CRC xenograft mice and CRC patients. Conversely, we observed lower CRNDE-p and higher miR-217 levels in serum exosomes from post-chemotherapy than from pre-chemotherapy patient samples. The area under curve (AUC) value for the serum exosomal CRNDE-p and miR-217 combination was higher than CRNDE-p or miR-217 alone. Moreover, high CRNDE-p and low miR-217 serum exosomal levels correlated with advanced clinical stages (III/IV), tumor classification (T3/T4), and lymph node or distant metastasis. Thus combined evaluation of serum exosomal CRNDE-p and miR-217 levels show diagnostic and prognostic potential for CRC patients.

Crosstalk between tongue carcinoma cells, extracellular vesicles, and immune cells in in vitro and in vivo models

The crosstalk between immune cells, cancer cells, and extracellular vesicles (EVs) secreted by cancer cells remains poorly understood. We created three-dimensional (3D) cell culture models using human leiomyoma discs and Myogel to study the effects of immune cells on highly (HSC-3) and less (SCC-25) invasive oral tongue squamous cell carcinoma (OTSCC) cell lines. Additionally, we studied the effects of EVs isolated from these cell lines on the cytotoxicity of CD8⁺ T and NK cells isolated from three healthy donors. Our analysis included the effects of these EVs on innate immunity in zebrafish larvae. Activated immune cells significantly decreased the proliferation of both OTSCC cell lines and associated with a diminished invasion area of HSC-3 cells. In general, EVs from SCC-25 increased the cytotoxic activity of CD8⁺ T and NK cells more than those from HSC-3 cells. However, this effect varied depending on the source and the immune and cancer cell subgroups. In zebrafish, the amount of IL-13 mRNA was decreased by SCC-25 EVs. This study describes promising in vitro and in vivo models to investigate interactions between immune cells, cancer cells, and EVs.

Impact of microRNA dynamics on cancer hallmarks: An oral cancer scenario

MicroRNAs are endogenous small noncoding RNAs that negatively regulate gene expression at posttranscriptional level. The discovery of microRNAs has identified a new layer of gene regulation mechanisms, which play a pivotal role in development as well as in various cellular processes, such as proliferation, differentiation, cell growth, and cell death. Deregulated microRNA expression favors acquisition of cancer hallmark traits as well as transforms the tumor microenvironment, leading to tumor development and progression. Many recent studies have revealed altered expression of microRNAs in oral carcinoma with several microRNAs shown to have key biological role in tumorigenesis functioning either as tumor suppressors or as tumor promoters. MicroRNA expression levels correlate with clinicopathological variables and have a diagnostic and prognostic value in oral carcinoma. For these reasons, microRNA has been a hot topic in oral cancer research for the last few years. In this review, we attempt to summarize the present understanding of microRNA deregulation in oral carcinoma, their role in acquiring cancer hallmarks, and their potential diagnostic and prognostic value for oral cancer management.

Humanized anti-hepatocyte growth factor (HGF) antibody suppresses innate irinotecan (CPT-11) resistance induced by fibroblast-derived HGF

The growth factors derived from the microenvironment create an environment conducive to tumor growth and survival. HGF deprivation using neutralizing antibody enhanced chemosensitivity in colorectal cancer cells (CRC). We determined secreted HGF in fibroblast conditioned medium (CM). Combination treatment of anti-HGF antibody and irinotecan (CPT-11) directly enhanced CPT-11 sensitivity in CRC. We generated xenograft in NOD/SCID mice inoculating HCT-116 human colorectal cancer cells subcutaneously with or without fibroblast. We found that the combination of CPT-11 and anti-HGF antibody induced marked suppression of tumor development. These results suggest that HGF produced by fibroblast induce CPT-11 resistance, and that anti-HGF antibody abrogate such resistance in vivo. fibroblast-derived HGF is important determinant of chemoresistance. Anti-HGF monoclonal antibody treatment confirmed the importance of this growth factor for chemoresistance in CRC. These results present new options toward the early diagnosis of chemoresistance and suggest novel combinations of chemotherapy and anti-HGF agents to prevent or significantly delay the onset of therapy resistance.

Neoplastic extracellular matrix environment promotes cancer invasion in vitro

The invasion of carcinoma cells is a crucial feature in carcinogenesis. The penetration efficiency not only depends on the cancer cells, but also on the composition of the tumor microenvironment. Our group has developed a 3D invasion assay based on human uterine leiomyoma tissue. Here we tested whether human, porcine, mouse or rat hearts as well as porcine tongue tissues could be similarly used to study carcinoma cell invasion in vitro. Three invasive human oral tongue squamous cell carcinoma (HSC-3, SCC-25 and SCC-15), melanoma (G-361) and ductal breast adenocarcinoma (MDA-MB-231) cell lines, and co-cultures of HSC-3 and carcinoma-associated or normal oral fibroblasts were assayed. Myoma tissue, both native and lyophilized, promoted invasion and growth of the cancer cells. However, the healthy heart or tongue matrices were unable to induce the invasion of any type of cancer cells tested. Moreover, when studied in more detail, small molecular weight fragments derived from heart tissue rinsing media inhibited HSC-3 horizontal migration. Proteome analysis of myoma rinsing media, on the other hand, revealed migration enhancing factors. These results highlight the important role of matrix composition for cancer invasion studies in vitro and further demonstrate the unique properties of human myoma organotypic model.

The emerging roles of exosomes in tumor-stroma interaction

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A novel human leiomyoma tissue derived matrix for cell culture studies

Background

The composition of the matrix molecules is important in in vitro cell culture experiments of e.g. human cancer invasion and vessel formation. Currently, the mouse Engelbreth-Holm-Swarm (EHS) sarcoma -derived products, such as Matrigel®, are the most commonly used tumor microenvironment (TME) mimicking matrices for experimental studies. However, since Matrigel® is non-human in origin, its molecular composition does not accurately simulate human TME. We have previously described a solid 3D organotypic myoma disc invasion assay, which is derived from human uterus benign leiomyoma tumor. Here, we describe the preparation and analyses of a processed, gelatinous leiomyoma matrix, named Myogel.

Methods

A total protein extract, Myogel, was formulated from myoma. The protein contents of Myogel were characterized and its composition and properties compared with a commercial mouse Matrigel®. Myogel was tested and compared to Matrigel® in human cell adhesion, migration, invasion, colony formation, spheroid culture and vessel formation experiments, as well as in a 3D hanging drop video image analysis.

Results

We demonstrated that only 34 % of Myogel’s molecular content was similar to Matrigel®. All test results showed that Myogel was comparable with Matrigel®, and when mixed with low-melting agarose (Myogel-LMA) it was superior to Matrigel® in in vitro Transwell® invasion and capillary formation assays.

Conclusions

In conclusion, we have developed a novel Myogel TME matrix, which is recommended for in vitro human cell culture experiments since it closely mimics the human tumor microenvironment of solid cancers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1944-z) contains supplementary material, which is available to authorized users.

Isolation and characterization of circulating micro(nano)vesicles in the plasma of colorectal cancer patients and their interactions with tumor cells

Micro(nano)vesicles (MV) are regarded as important messengers in cell-to-cell communication. There is also evidence for their pivotal role in cancer progression. Circulating MV are of different body cells origin, including tumor cell‑derived MV (TMV) in cancer patients. Determination of circulating TMV is of importance because of their potential diagnostic and therapeutic applications. In the present study, an analysis of circulating MV in colorectal cancer (CRC) patients was undertaken. Plasma from healthy donors was used as the control. In order to define MV characteristics, two plasma fractions: obtained by sequential centrifugation at 15,000 x g (MV15) and 50,000 x g (MV50) were used for analysis. The two fractions possessed a large range of sizes: 70(80)-1,300(1,400) nm and the most common particles with sizes 70-90 nm, both in patients and controls. Atomic force microscopy images of MV50 revealed a heterogeneous population of particles with different shapes and sizes. MV15 contained an increased level of CD41+ and CD61+ particles, suggesting their platelet origin. No difference between patients and controls was observed. A more precise analysis of MV50 showed the increased level of particles expressing EGFR (HER-1/Erb B1), HER-2/neu and Mucin1 (MUC1), suggesting their tumor origin. The total level of MV50‑expressing EGFR, HER-2/neu and MUC1 was enhanced in CRC patients. MV50 both of patients and controls attached to a colon cancer cell line (SW480) and to isolated blood monocytes at 2 h and were engulfed at 24 h. This uptake showed the lack of specificity. Thus, apart from the direct delivery of MV to the tumor site by plasma, monocytes carrying MV may also be involved in their transportation. Taken together, the presented data indicate that MV15 contain mainly platelet‑derived particles, while MV50 from CRC patients are enriched in TMV. Interaction of MV with cancer cells may pin-point their role in communication between tumor cells, resulting in molecular cargo exchange between them.

The prognostic value of histopathological grading systems in oral squamous cell carcinomas

OBJECTIVE

This study evaluated the association of four histopathological grading systems (WHO grading system, malignancy grading of the deep invasive margins (MG), histological risk (HR) model, and tumor budding and depth of invasion (BD) model) with clinicopathological parameters and outcome of 113 oral squamous cell carcinomas to identify their roles in prognosis.

METHODS

Demographic and clinical features were obtained from patients' records. Sections from all paraffin-embedded blocks were evaluated according to the four grading systems. Demographic and clinical associations were analyzed using chi-square test, and correlations between the grading systems were established with the Spearman's rank correlation test. Survival curves were performed with Kaplan-Meier method, and multivariate analysis based on Cox proportional hazard model was calculated.

RESULTS

Significant associations with survival were observed for WHO grading system and BD model in the univariate analysis, but only the BD model was significantly associated with disease outcome as an independent prognostic marker. Age, tumor size, and presence of regional metastasis were also independent markers of reduced survival.

CONCLUSION

A significant association between the BD model and outcome of OSCC patients was observed, indicating this new histopathological grading system as a possible prognostic tool.

Macrophages modulate migration and invasion of human tongue squamous cell carcinoma

Oral tongue squamous cell carcinoma (OTSCC) has a high mortality rate and the incidence is rising worldwide. Despite advances in treatment, the disease lacks specific prognostic markers and treatment modality. The spreading of OTSCC is dependent on the tumor microenvironment and involves tumor-associated macrophages (TAMs). Although the presence of TAMs is associated with poor prognosis in OTSCC, the specific mechanisms underlying this are still unknown. The aim here was to investigate the effect of macrophages (Mfs) on HSC-3 tongue carcinoma cells and NF-kappaB activity. We polarized THP-1 cells to M1 (inflammatory), M2 (TAM-like) and R848 (imidazoquinoline-treated) type Mfs. We then investigated the effect of Mfs on HSC-3 cell migration and NF-kappaB activity, cytokine production and invasion using several different in vitro migration models, a human 3D tissue invasion model, antibody arrays, confocal microscopy, immunohistochemistry and a mouse invasion model. We found that in co-culture studies all types of Mfs fused with HSC-3 cells, a process which was partially due to efferocytosis. HSC-3 cells induced expression of epidermal growth factor and transforming growth factor-beta in co-cultures with M2 Mfs. Direct cell-cell contact between M2 Mfs and HSC-3 cells induced migration and invasion of HSC-3 cells while M1 Mfs reduced HSC-3 cell invasion. M2 Mfs had an excess of NF-kappaB p50 subunit and a lack of p65 subunits both in the presence and absence of HSC-3 cells, indicating dysregulation and pro-tumorigenic NF-kappaB activation. TAM-like cells were abundantly present in close vicinity to carcinoma cells in OTSCC patient samples. We conclude that M2 Mfs/TAMs have an important role in OTSCC regulating adhesion, migration, invasion and cytokine production of carcinoma cells favouring tumor growth. These results demonstrate that OTSCC patients could benefit from therapies targeting TAMs, polarizing TAM-like M2 Mfs to inflammatory macrophages and modulating NF-kappaB activity.