Expression of mucin-1 in oral squamous cell carcinoma and normal oral mucosa: An immunohistochemical study

MUC4 Expression in Oral Dysplastic Epithelium and Oral Squamous Cell Carcinoma: An Immunohistochemical Study

Objective

MUCIN4 (MUC4) glycosylation is linked to the oncogenesis and progression of a neoplastic process. It can suggest information pertaining to tumor progression, management and its natural properties. Thus, MUC4 can play a pivotal role in prognostic diagnosis. This study aimed to analyze the MUC4 expression in oral cell squamous carcinoma and oral dysplastic epithelium.

Materials and Methods

The research included 45 samples of oral epithelial dysplasia (OED) and 45 cases of oral squamous cell carcinoma (OSCC). In order to carry out the investigation, tissue blocks of previously diagnosed cases of OED and OSCC were retrieved from the relevant archives. Forty-five OED cases were categorized into three group's mild, moderate and severe dysplasia, with 15 cases in each respective category. Forty-five OSCC cases were categorized into three groups: well differentiated, moderately differentiated, and poorly differentiated OSCC with 15 cases in each respective category. Ten tissue biopsies of normal oral mucosa were obtained from subjects in the control group. The chi-square test and one-way ANOVA were used for statistical analysis.

Result

There was an absence of MUC4 expression in normal mucosa, whereas the OED and OSCC groups had a significant amount of observable variance. Within the OED category of cases, a consistent progression from mild to severe dysplasia was seen in terms of the staining pattern. Cases with severe dysplasia displayed a staining pattern that covered the complete thickness of the tissue in the epithelium. Expression of MUC4 was shown to be lower in moderate differentiated squamous cell carcinoma (MDSCC), and poorly differentiated squamous cell carcinoma (PDSCC) as compared to well differentiated squamous cell carcinoma (WDSCC). It showed decreasing pattern across all grades of OSCC. In WDSCC, an intense highest staining response was noticed, particularly among the cells that are highly differentiated and take the form of a honeycomb pattern.

Conclusion

Analysis of the expression profile of MUC4 and the aberrant expression of this gene in OSCC suggests that it may serve as a useful diagnostic marker. Therefore, it is possible to draw the conclusion that MUC4 plays a very significant part in the pathogenesis of OSCC and also acts as a marker that may be taken into consideration for the accurate diagnosis of OED and OSCC.

Expression of Mucin1 in saliva in oral squamous cell carcinoma and oral potentially malignant disorders (case control study)

OBJECTIVES

Overexpression of mucin1 is found in head and neck squamous cell carcinoma tissues compared with adjacent non-neoplastic tissues and higher levels are associated with metastasis and invasion. The expression level of mucin1 in saliva of normal individuals, oral potentially malignant disorders and oral squamous cell carcinoma patients and its correlation to clinical and histological variables was evaluated.

SUBJECTS AND METHODS

Forty oral potentially malignant disorders, 40 oral squamous cell carcinoma subjects, and 20 age matched-controls were included. Stimulated salivary samples were collected from all participants, and mucin1 expression was measured by real-time PCR.

RESULTS

Mucin1 expression in saliva was significantly elevated in oral potentially malignant disorders when compared with controls. Similarly, mucin1 expression was significantly elevated in oral squamous cell carcinoma group when compared with oral potentially malignant disorders and controls. Mucin1 expression in OSCC patient showed significant positive correlations with T classification and distant Metastasis. Mucin1 expression in oral potentially malignant disorders patients showed significant positive correlations with degree of dysplasia.

CONCLUSIONS

The expression level of mucin1 in saliva might be a potential biomarker for diagnosing oral potentially malignant disorders and oral squamous cell carcinoma.

Mucin 1 regulates the hypoxia response in head and neck cancer cells

Mucin 1 (MUC1) is a transmembrane glycoprotein that contributes to the cellular response in hypoxic conditions in different carcinomas. We investigated the gene expression pattern of MUCs (1, 2, 4, 5AC, 5B, 6, 15, 16, and 19) in isogenic primary (HN4 and HN30) and metastatic (HN12 and HN31) head and neck squamous cell carcinoma (HNSCC) cell lines. MUC1 was significantly up-regulated at the mRNA and protein levels in HN12 and HN31 cells, whereas, other MUCs exhibited diverse expression patterns between HNSCC cell lines. Immunohistochemistry demonstrated that MUC1 was exclusively expressed in cancer cells; however, there was no significant correlation between MUC1 expression and malignancy grading. Inducing hypoxia with CoCl₂ significantly increased cell viability, MUC1, hypoxia-inducible factor alpha (HIF-1α), and vascular endothelial growth factor A (VEGF-A) expression in HN12 cells, but not HN31 cells. Interestingly, in hypoxia, cell viability, HIF-1α and VEGF-A expression were significantly reduced in MUC1-knockdown HN12 cells. The current report is the first to demonstrate that MUC1 is required in the regulation of hypoxia-related genes in HNSCC cells. Thus, our results suggest that MUC1 modulates the hypoxic effects in HNSCC cells through HIF-1α regulation.

Immunohistochemical Coexpression of MUC1 and MUC4 in Oral Leukoplakia and Oral Squamous Cell Carcinoma

MUC1 and MUC4 are two transmembranous proteins, which have been seen to express aberrantly in various human neoplasms and advocated as independent prognostic markers. Till now no extensive studies have been carried out on combined expression of MUC1 and MUC4 in oral leukoplakia and Oral squamous cell carcinoma. This study is an endeavour to evaluate Immunohistochemical coexpression of MUC1 and MUC4 in Oral Leukoplakia and Oral squamous cell carcinoma and furthr establish them as prognostic markers. Immunohistochemical analysis of MUC1 and MUC4 was done on 24 cases of Oral squamous cell carcinoma, 24 cases of leukoplakia and 12 normal oral mucosal tissues. Chi square test and one way ANOVA test were employed for statistical analysis. Normal oral mucosa and leukoplakia group showed higher frequency of negative immunoexpression compared to oral squamous cell carcinoma group. Furthur in Oral squamous cell carcinoma group, higher frequency of double positive coexpression in well and moderately differentiated oral squamous cell carcinoma and single positive coexpression in poorly differentiated oral squamous cell carcinoma was obtained. A definite rise of immunoexpression of MUC1 and MUC4 was observed from normal oral mucosa to leukoplakia to oral squamous cell carcinoma indicative of their contribution as diagnostic and prognostic markers.

Changes in Protein Glycosylation in Head and Neck Squamous Cell Carcinoma

Glycosylation is an important posttranslational modification of proteins, and it has a profound influence on diverse life processes. An abnormal polysaccharide structure and mutation of the glycosylation pathway are closely correlated with human cancer progression. Glycoproteins such as EGFR, E-cadherin, CD44, PD-1/PD-L1, B7-H3 and Muc1 play important roles in the progression of head and neck squamous cell carcinoma (HNSCC), and their levels of glycosylation and changes in glycosyl structure are closely linked to HNSCC progression and malignant transformation. The regulation of protein glycosylation in HNSCC provides potential strategies to control cancer stem cell (CSC) subgroup expansion, epithelial-mesenchymal transition (EMT), tumor-related immunity escape and autophagy. Glycoproteins with altered glycosylation can be used as biomarkers for the early diagnosis, monitoring and prognostication of HNSCC. However, the glycobiology of cancer is still a new field that needs to be deeply studied, especially in HNSCC.

Optimization of an oral mucosa in vitro model based on cell line TR146

During the last years, the popularity of saliva has been increasing for its applicability as a diagnostic fluid. Blood biomarker molecules have to cross the blood-saliva barrier (BSB) in order to appear in saliva. The BSB consists of all oral and salivary gland epithelial barriers. Within this context, the optimization of in vitro models for mechanistic studies about the transport of molecules across the oral mucosa is an important task. Here, we describe the optimization and comprehensive characterization of a Transwell model of the oral mucosa based on the epithelial cell line TR146. Through systematic media optimization investigating 12 different set-ups, a significant increase of barrier integrity upon airlift cultivation is described here for TR146 cell layers. The distinct improvement of the paracellular barrier was described by measurements of transepithelial electrical resistance (TEER) and carboxyfluorescein permeability assays. Histological characterization supported TEER data and showed a stratified, non-keratinized multilayer of the optimized TR146 model. High-Throughput qPCR using 96 selected markers for keratinization, cornification, epithelial-mesenchymal transition, aquaporins, mucins, tight junctions, receptors, and transporter proteins was applied to comprehensively characterize the systematic optimization of the cellular model and validate against human biopsy samples. Data revealed the expression of several genes in the oral mucosa epithelium for the first time and elucidated novel regulations dependent on culture conditions. Moreover, functional activity of ABC-transporters ABCB1 and ABCC4 was shown indicating the applicability of the model for drug transport studies. In conclusion, a Transwell model of the oral mucosa epithelium was optimized suitably for transport studies.

Screening and identification of biomarkers associated with clinicopathological parameters and prognosis in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a major type of malignant tumor of the oral cavity. Despite marked advances in the management and diagnosis of OSCC, the associated overall survival ratio has only exhibited a modest increase in recent years. The present study aimed to identify potential crucial genes associated with clinical features and prognosis for OSCC, and to provide a basis for further investigation. RNA-sequencing data and corresponding clinical information were downloaded from The Cancer Genome Atlas database and differentially expressed mRNAs (DEmRNAs) were identified using the edgeR package. Bioinformatics analysis was performed to identify differentially expressed clinical features-associated mRNAs (CFmRNAs) and enhance the current knowledge of the function of them. Functional enrichment analysis and protein-protein interplay (PPI) network analysis were then performed to better understand CFmRNAs. Survival-associated genes were analyzed with Kaplan-Meier survival curves and the log-rank test. A total of 2,013 DEmRNAs between OSCC samples and normal tissues were identified, 180 of which were associated with clinical features. A total of 17 GO terms and 4 KEGG pathways were significantly enriched in functional enrichment analysis. A total of 4 hub genes (albumin, statherin, neurotensin and mucin 7) were identified in the PPI network analysis. A total of 6 genes (DDB1 and CUL4 associated factor 4 like 2, opiorphin prepropeptide, R3H domain containing like, transmembrane phosphatase with tensin homology, actin like 8 and protocadherin α 11) were observed to have an influence on survival. The DEmRNAs identified may have a crucial role in the genesis and development of OSCC and may be further developed for diagnostic, therapeutic and prognostic applications for OSCC in the future.