Establishment and characterization of an HPV16 E6/E7-expressing oral squamous cell carcinoma cell line with enhanced tumorigenicity.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the oral and maxillofacial region. The mechanism of carcinogenesis of OSCC is still unclear. Based on the previous cell line, HIOEC-B(a)P-96 (HB96), which we obtained by HPV16 E6/E7-immortalized human oral epithelial cells (HIOEC) and benzo(a)pyrene inducement, we prepared a new HB-second generation cancer cell line (HB-2) by continuous passage. Its characteristics such as morphology, proliferation activity, karyotype, and tumorigenesis were studied. The HB-2 cells displayed uncontrolled cell division and lost contact inhibition leading to cell overlap. Cells were polygonal and unevenly shaped, with an increased nucleus versus plasma ratio. Increased proliferative activity was confirmed by MTT assays. The tumorigenicity was confirmed by tumor growth experiments in nude mice. Therefore, the HB-2 and HB96 cell lines are useful tools to study the mechanism of carcinogenesis of OSCC in vitro for future genomic and proteomic analyses.