Abstract: Objective To construct human lung cancer cell model with human MutS homologous protein 2 (hMSH2) overexpression, for exploring the effect of hMSH2 molecule in the cytotoxicity of γδ T cell against lung cancer cells. Methods hMSH2 coding sequence was cloned by PCR for construction of recombinant vector which over expressed hMSH2-EGFP fusion protein using homologous recombination. The recombinant vector was transfected to lung cancer cell line NCI-H520 to construct human lung cancer cell model overexpressing hMSH2 molecule. The expression of hMSH2 molecule in NCI-H520 was detected by Western blot. The expression of hMSH2 on the cell membrane was measured by flow cytometry. Cytotoxicity of expanded γδ T cells from peripheral blood mononuclear cells against NCI-H520 cells was detected by LDH release assay in vitro. Results hMSH2 coding sequence (2805 bp) was cloned and the result of restriction endonuclease digestion of Fugw-hMSH2 recombinant vector was accordance with the anticipated objective strip size. Exogenous hMSH2-EGFP fusion protein was expressed in NCI-H520 cells. The level of hMSH2 molecule on the surface of NCI-H520 cells with overexpression of hMSH2 was significantly increased (P<0.001). Cytotoxicity of γδ T cells against NCI-H520 cells with overexpression of hMSH2 was significantly increased compared to the wild type NCI-H520 cells (P<0.05). Conclusions Lung cancer cell model that overexpressed hMSH2 molecule is successfully constructed, hMSH2 molecule on the cell membrane is increased and the cytotoxicity of γδ T cells against lung cancer cells is enhanced.

Key words: Key words: hMSH2, γδ T cell, NCI-H520 cell