Effect of NAIF1 on IFIT Family Proteins in Gastric Cancer / 肿瘤防治研究

Objective To investigate the effect of NAIF1 in gastric cancer cell lines MKN45. Methods We constructed pLVX-Tight-Flag-NAIF1-puro plasmid with Tet-on system. DOX was added to induce NAIF1 expression in MKN45 cells. The cells were collected at 0, 6, 12 and 24 hours after DOX addition for gene expression microarray detection and biological analysis of differentially expressed genes. qRT-PCR and Western blot were used to verify the changes in mRNA and protein levels of the selected target differential genes. Results The biological analysis of gene microarray hybridization results showed that IFIT1, IFIT2 and IFIT3 expression significantly increased at 24h, qRT-PCR also showed this change, and Western blot further verified the change in protein level. However, IFIT5 showed no significant change in mRNA and gene expression. Conclusion Over-expression of NAIF1 in gastric cancer cells can promote the expression of some immune system-related IFIT family proteins.

Expression and purification of truncated human recombinant nuclear apoptosis-inducing factor 1 in E.coli / 中国免疫学杂志

Objective:Nuclear apoptosis-inducing factor 1(NAIF1) is a novel apoptosis gene cloned in laboratory. To analyze the binding proteins of NAIF1 by pulldown method, the fusion expression vector of truncated human nuclear apoptosis-inducing factor 1〔NAIF1(73-327)〕 was constructed, were expressed and purified the recombinant GST-NAIF1(73-327) fusion protein in E.coli.Methods:The cDNA encoding human NAIF1(73-327) was amplified by PCR and cloned into pGEX-KG vector. The GST-NAIF1(73-327) fusion protein was expressed in E.coli and purified by affinity chromatography. The purified protein was detected by SDS-PAGE, Western blot and ESI-Q-TOF-MS/MS.Results:A prokaryotic expression vector of GST-NAIF1(73-327) was constructed and the GST-NAIF1(73-327) fusion protein was expressed in E.coli at high level. SDS-PAGE analyses indicated that the purified protein was about 53 kD. Western blot and MS/MS analyses verified the recombinant fusion protein.Conclusion:An efficient method for obtaining recombinant GST-NAIF1(73-327) fusion protein had been established and it could be used for further studies on the structure and function of NAIF1.