Two Novel Cell Culture Models Of Buccal Mucosal Oral Cancer From Patients With No Risk-Habits Of Tobacco Smoking Or Chewing

Objective: Tobacco consumption is one of the major etiological factors for oral cancer, but it also develops in nontobacco users, with unknown etiologies. Cellular models for tobacco associated oral cancer are available, however; reports of cellular models for studying non-tobacco associated oral cancer are limiting. We report here the establishment and characterization of two novel buccal mucosal cancer cell lines 'GBCO2' and 'GBC035' derived from non-tobacco users.Materials and methods: Short tandem repeats (STR) profiling, Next-generation sequencing for whole-genome, exome and copy number alterations, immunofluorescence, flow-cytometry, proliferation, live-cell chemotaxis, 3D-spheroid formation, chemotherapy response, gene-expression micmarray, gene-set enrichment analysis and xenograft development were performed.Results: Sources of the established cultures were matched to their donors through STR profiling. Genome sequence analysis revealed somatic mutations in TP53, CASP8, CDKN2A for GBCO2 with deletions and amplifications encompassing CDKN2A, FATI and CCNDI, PIK3CA, SOX2, EGFR, MYC genes, respectively. GBC035 harbored mutations in FATI, NOTCHI, HRAS, CDKN2A, HLA-B, HLA-A genes. While GBC035 cells showed higher E-Cadherin positive cell-cell junctions and collective cell migration in chemotaxis; GBCO2 cells were vimentinpositive and demonstrated individual cell migration. Further, exhibiting their relevance to preclinical research, GBCO2 3D-spheroids demonstrated enrichment of development-related gene-signatures in micmarray transcriptome analysis and were resistant to Cisplatin, but showed sensitivity to cancer stem cells-targeting drug, Salinomycin. Additionally, tumorigenic ability of GBCO2 was demonstrated.Conclusions: Altogether, we present here comprehensively characterized unique cell lines established from nontobacco associated tumors, which may serve as models for preclinical investigations of oral cancers caused independent of tobacco usage.