[Construction of eukaryotic expression vector of major histocompatibility complex class I -related chain A and establishment of its stable transfected Tca8113-Tb cell line].

Objective: To construct the eukaryotic expression vector, encoding major histocompatibility complex class I-related chain A gene (MICA), for the further research of transfecting Tca8113-Tb cell line(a metastatic cell line of brain metastasis from human tongue cancer Tca8113 cells in nude mouse), and to establish a stable MICA overexpression oral squamous cell line.

Methods: cDNA of MICA gene from pCMV-SPORT6-MICA was amplified by PCR, and subcloned into eukaryotic expression vector pEGFP-N1 marked with green fluorescent protein (GFP). The recombinant plasmid was sequenced and transfected into Tca8113-Tb cell line by lipofectamine 2000. After screen culture by G418, stable tranfected Tca8113-Tb cell line was established using definite dilution method. The expressions of GFP protein was viewed directly with fluorescence microscopy and the overexpression of MICA was identified by RT-PCR, real time PCR and immunocytochemistry.

Results: The MICA gene was amplified by PCR and then cloned into the vector, whose sequence was identical to that in the GenBank. The transfected cells showed the expression of GFP. And the overexpression of MICA gene in transfected cells was detected by RT-PCR, real time PCR and immunocytochemistry.

Conclusion: The recombinant eukaryotic expression vector pEGFP-N1-MICA has been constructed successfully and stably expressed in Tca8113-Tb cell line, providing a foundation for further studies on the function of MICA in vitro.