Protein markers in Oral Squamous Cell Carcinoma (OSCC)

Oral squamous cell carcinoma (OSCC) is a main reason of oral cancer mortality and morbidity. Cancer of oral cavity in central south Asia, ranks among third most common kinds of cancer. The discovery of candidate markers to differentiate normal from malignant cells in clinical diagnosis of OSCC would be of critical importance because this malignancy has poor prognosis. To improve the clinical outcome in OSCC patients, the present study was aimed at identifying robust candidate biomarkers for early OSCC diagnosis and to enhance understanding of the mechanisms of disease progression and pathogenesis. Of particular interest are proteins that can be found in tissue lysates of OSCC tumor vs normal adjacent mucosa samples and secreted in cell line Secretomes of HNSCC for non-invasive detection. We analysed 17 paired human malignant OSCC tissues and normal adjacent tissue in addition to secretomes of 9 HNSCC cell lines. The proteome dataset of OSCC and normal tissues consisted of 5,123 protein groups, including 299 proteins with strong differential expression (p-value <0.01, fold change barrier to ˃+2 and <-2, 205 upregulated and 94 down regulated) and 134 common proteins were also found out of total dataset of 4473 identified proteins of HNSCC cell line secretomes. Functional data analysis revealed that these differential proteins were significantly associated with multiple biological processes. Myogenesis, Fatty Acid Metabolism and KRAS Signaling DN were associated with the proteins downregulated in cancer tissues, while Protein Secretion, Unfolded Protein Response, Spliceosomal complex assembly, Protein localization to endosome and Interferon Gamma Response were enriched in the set of upregulated proteins and these regulated proteins may be classically or non-classically secreted. Furthermore, we found differential enrichment of Creb3L1, ESRRA, YY, ELF2, STAT1 and XBP transcription factors potentially regulating these major pathways.