The Study On The MCPH1Protein Expression In Lung Cancer And It’s Function In Apoptosis Of Human Lung Cancer Cells

Objective To evaluated the protein expression of MCPH1in normaland cancerous lung tissues; To construct eukaryotic expression vector forMCPH1; pcDNA3.1-MCPH1eukaryotic expression recombinant plasmidwas transfected to lung cells and to investigate the effect of over-expression of MCPH1gene on apoptosis of human lung cancer cells.Methods First stage：we collected188cancer patients’ tissues and20normal lung tissues form the First Affiliated Hospital of ChongqingMedical University, those tissues were made into paraffin tissue sections,to evaluated the protein expression of MCPH1in lung cancerous andnormal lung tissues by immunohistochemistry. Second stage：To identifyrecombinant plasmid pcDNA3.1-MCPH1with restriction analysis method;pcDNA3.1-MCPH1was transfected to lung cells A549and H1299withLipofectamine2000. The mRNA expression of MCPH1was detected byreal-time fluorescence quantitative PCR(RTFQ PCR), the detection ofMCPH1protein was maded by Western blot, and the apoptosis of A549and H1299cells were determined by FC. Results MCPH1expression showed much lower in lung canceroustissues compared with normal tissues（P=0.002）, MCPH1expression inadenocarcinoma (AC) was higher than its expression in squamous cellcarcinoma (SCC)（P=0.002）, and MCPH1showed cytoplasmic expressionin cancer tissues, whereas the MCPH1protein was mainly located innucleus of normal tissues; Restriction analysis proved that recombinantplasmid pcDNA3.1-MCPH1was constructed correctly; Both the mRNAand protein expressions of MCPH1were up-regulated effectively in A549and H1299cells after transfection, the apoptosis rate of H1299cellstransfected with plasmid pcDNA3.1-MCPH1(18.10±1.87)%was signi-ficantly higher than those transfected with empty plasmid(5.76±1.85)%and those untransfected(5.85±0.57)%(P＜0.05), the apoptosis rate ofA549cells transfected with plasmid pcDNA3.1-MCPH1[(16.82±1.29)%)was significantly higher than those transfected with empty plasmid[(6.27±0.88)%] and those untransfected[(5.36±0.43)%](P＜0.05).Conclusion: MCPH1protein expressed in cytoplasm and showedlower expression in lung cancer tissuses, MCPH1expression in AC washigher than its expression in SCC, and MCPH1showed mainly cytoplasmicexpression in cancer tissues, whereas MCPH1protein was expressedmainly in nucleus in normal cells; over-expression of MCPH1genesignificantly induced the apoptosis rate of human lung cancer cells in vitro,which laid a foundation of further research on the role of MCPH1gene in apoptosis of lung cancer cells and the relevant mechanism.