Establishment and characterization of novel human oral squamous cell carcinoma cell lines from advanced‑stage tumors of buccal mucosa.

Oral squamous cell carcinoma (OSCC) is a leading cause of mortality in India owing to the high percentage of tobacco chewers, smokers and alcohol consumption. OSCC is highly heterogeneous in nature; therefore poses a challenge in the treatment of the patient. To better understand the heterogeneity of the tumors, an in vitro cell line model is required. However, the efficiency of establishing cell lines from the oral tumors is low. In the present study, three novel cell lines, namely ACOSC3, ACOSC4, and ACOSC16, were isolated and characterized from advanced‑stage treatment‑naive OSCCs originating from the buccal mucosa. The three cell lines exhibited polygonal morphology, which is typical of epithelial cells. Furthermore, immunofluorescence revealed the expression of keratins 8 and 14, thereby confirming the epithelial origin of the cells. DNA content analysis of the three OSCC cell lines revealed aneuploidy. Furthermore, an in vitro orosphere assay revealed the formation of primary orospheres. Notably, the OSCC cell lines were able to give rise to tumors when administered subcutaneously into non‑obese diabetic/severe combined immune deficiency mice. The novelty of the cell lines was also validated by performing short tandem repeat profiling; the STR profiles of the present cell lines did not significantly match with any known established OSCC cell lines present in the DSMZ database, thereby confirming the unique identity of these lines. These cell lines established from tumor samples derived from Indian OSCC patients provide a valuable resource to understand the molecular mechanism involved in tumor resistance and recurrence.