Abstract:

Objective To investigate the effect on natural killer（NK） and cytotoxic T lymphocyte（CTL）-mediated cytotoxicity by genetic overexpression of MHC class Ⅰ chain-related protein A（MICA） in oral squamous cell carcinoma （OSCC）. Methods The OSCC cells by genetic overexpression of MICA were detected to identify the biological features including cell growth curve, cell cycle distribution, plate clone forming rate and tumorigenicity in nude mice. The expression of natural killer group 2, member D（NKG2D） receptor and the cytotoxicity to target tumor cells of NK92 and CTL cells, which co-cultured with the transfected OSCC cells or the non-transfected or blank vector-transfected controls, were measured by flow cytometry and lactate dehydrogenase（LDH） release assay. Results There was no difference in biological features before and after MICA gene transfection to OSCC cells. Flow cytometry and LDH release assay showed that MICA-overexpressed OSCC cells enhanced the cytotoxicity to target tumor cells and up-regulated the expression of NKG2D on NK92 and CTL（P<0.05）. Conclusion MICA may be considered as a promising immunotherapy target of OSCC.

Key words: oral, squamous cell carcinoma, MHC class Ⅰ chain-related protein A, cytotoxicity, gene therapy