Background: The re-expression of pluripotent markers (Oct-4 and Nanog) and the

Oct4, c-Myc and CD44 can be used to predict local recurrence and the outcome of treatment in oral cancer patients. In addition, these molecules may find use as molecular targets for effective therapy.

The present study focuses on the correlation between the expression pattern of β-catenin (component of Wnt signaling), ΔNp63 (proliferation marker), and Notch 1 (transmembrane receptor) in oral squamous cell carcinoma. The study also aims to investigate the interaction between β-catenin and ΔNp63 in oral cancer. Furthermore, we also analyzed the prognostic significance of β-catenin, ΔNp63, and Notch 1 in oral squamous cell carcinoma. Immunohistochemical analysis of β-catenin, ΔNp63, and Notch 1 were done in 62 cases of oral squamous cell carcinoma. Co-immunoprecipitation analysis was done to study the possible interaction between β-catenin and ΔNp63 in oral cancer. Kaplan-Meier method was used to estimate overall and disease-free survival, and the Log-rank test was used to compare the resulting curves. Statistically significant positive correlation was found between the localization of β-catenin and the expression of ΔNp63 (p = 0.001**, r (s) = 0.427), whereas, no significant association was found between the expression pattern of β-catenin and Notch 1. Interestingly, interaction between β-catenin and ΔNp63 was observed in oral carcinoma. Moreover, β-catenin and ΔNp63 may be related to worst survival in oral carcinoma. Statistically significant positive association between localization of β-catenin and expression of ΔNp63 suggests that they might have dependent roles in maintaining the proliferation of oral carcinoma cells. In addition, the downregulated expression of Notch 1 was related to invasion and differentiation status of oral carcinoma cells. Furthermore, β-catenin and ΔNp63 may be used as independent prognostic markers of oral carcinoma. On the other hand, interaction of β-catenin with ΔNp63 may be a key event in maintaining the proliferation of oral carcinoma cells. The present study indicates that β-catenin and ΔNp63 may be used as independent prognostic markers of oral carcinoma and the interaction of β-catenin with ΔNp63 may be a crucial event in regulating proliferation and differentiation of oral carcinoma cells, which may be used as a target for therapeutic implications.

A gradual increase in the expression of CD133 and Musashi-1 from normal to dysplasia to carcinoma suggests the possible involvement of these 2 proteins in oral carcinogenesis. The overexpression of CD133 and Musashi-1 in advanced stages and also in poorly differentiated tumors reveals their relationship with invasion and differentiation status of oral carcinoma cells. Moreover, the significant positive correlation between CD133 and Musashi-1 expression suggests that they might have a functional relationship in oral carcinoma cells, which needs further investigation.

Head and neck squamous cell carcinoma (HNSCC) is generalized term that encompasses a diverse group of cancers that includes tumours of the oral cavity (OSCC), oropharynx (OPSCC) and nasopharynx (NPC). Genetic alterations that are common to all HNSCC types are likely to be important for squamous carcinogenesis. In this study, we have investigated the role of the homeodomain-only homeobox gene, HOPX, in the pathogenesis of HNSCC. We show that HOPX mRNA levels are reduced in OSCC and NPC cell lines and tissues and there is a general reduction of HOPX protein expression in these tumours and OPSCCs. HOPX promoter methylation was observed in a subset of HNSCCs and was associated with a worse overall survival in HPV negative tumours. RNAseq analysis of OSCC cells transfected with HOPX revealed a widespread deregulation of the transcription of genes related to epithelial homeostasis and ectopic over-expression of HOPX in OSCC and NPC cells inhibited cell proliferation, plating efficiency and migration, and enhanced sensitivity to UVA-induced apoptosis. Our results demonstrate that HOPX functions as a tumour suppressor in HNSCC and suggest a central role for HOPX in suppressing epithelial carcinogenesis.

Nestin and Musashi-1 are found to be independent prognostic markers of oral cancer, and they might be used as molecular targets for effective therapy.

Notch pathway molecules crosstalk with Wnt/β-catenin signaling cascade in stem cells and tumors. However, the correlation between the expression pattern of Notch intracellular domain NICD, Hes-1 and c-Myc has not been studied in oral squamous cell carcinoma. The aim of this study is to investigate the correlation and prognostic significance of NICD, Hes-1 and c-Myc in oral cancer. Immunohistochemistry was used to study the expression pattern of NICD, Hes-1 and c-Myc in oral preneoplastic and neoplastic tissues. In addition, double immunofluorescence was used to examine the co-localization of NICD, Hes-1 and c-Myc in H314 cells. The expression pattern of NICD and Hes-1 was gradually increased from normal to dysplasia to carcinoma. Interestingly, statistically significant correlation was not observed between NICD, Hes-1 and c-Myc in oral squamous cell carcinoma. Furthermore, NICD+/c-Myc+ and Hes-1+/c-Myc+ double positive cases showed worst survival when compared with other cases in oral cancer. Notch signaling molecules, NICD and Hes-1, are found to be involved in the progression of oral squamous cell carcinoma. Interestingly, NICD, Hes-1 and c-Myc may have independent roles in oral cancer. On the other hand, we have demonstrated that NICD+/c-Myc+ and Hes-1+/c-Myc+ double positivity might be used as independent prognostic indicator of oral carcinoma.

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