Cell autophagy attenuates PM2.5-induced apoptosis of human lung adenocarcinoma cell line H441 / 基础医学与临床

Objective To investigate the function of autophagy in the process of PM2.5-induced apoptosis. Methods PM2.5 was obtained from Zhanjiang in 2016. Human lung adenocarcinoma cells H441 were treated with PM2.5 at different concentrations for different times. Cell proliferation was analyzed by MTT assay; Cell apoptosis was assessed by PI and Annexin V double staining and TUNEL assay. The expression of autophagy marker LC3Ⅱ, AKT and P-AKT protein was examined by Western blot ( WB). H441 cells were treated with PM2.5 following treatment with rapamycin or 3-MA. Cell viability was evaluated by trypan blue staining. Results Compared with the control group, cell proliferation was significantly inhibited by PM2.5 at concentration of 100 μg/mL or more for 24 and 48 h. With the increase of PM2.5 concentration, the cells apoptotic rate significantly increased, the protein ex-pression of LC3Ⅱwas increased as well as the P-AKT was decreased; and the protein expression of LC3Ⅱwas in-creased significantly after AKT inhibitor treatment. Moreover, rapamycin decreased PM2.5-induced cell apoptosis, and 3-MA can promote PM2.5-induced cell apoptosis. Conclusions In H441 cells, PM2.5 activates autophagy by inhibiting activation of AKT pathway, and cell autophagy can mitigate PM2.5-induced apoptosis.

Construction of PLAGL2 siRNA Expression DNA Plasmid and the Interfering Effect on Gene Expression in H441 Cells / 华中科技大学学报(医学版)

Objective To construct human PLAGL2 siRNA expression DNA plasmid and study the interfering effect on gene expression in H441 cells. Methods H441 cells were transfected with PLAGL2 siRNA expression DNA plasmid with Fu-gene6. Real time PCR and Western blot were employed to detect the interfering effect on the expression of PLAGL2.SP-CSP-B mRNA and protein in wildtype and PLAGL2 siRNA expression DNA plasmid transfected H441 cells respectively. Results Real time PCR revealed that,as compared with wildtype H441 cells, the expression level of PLAGL2 mRNA in PLAGL2 siRNA plasmid transfected H441 cells was significantly reduced(P<0. 05) ,but that of SP-C mRNA in PLAGL2 siRNA plasmid transfected H441 cells was significantly increased(P<0. 05). Western blot showed that,as compared with wildtype H441 cells, the expression level of PLAGL2 protein in PLAGL2 siRNA DNA plasmid transfected H441 cells was significantly reduced(P< 0. 05). Conclusion Human PLAGL2 siRNA expression DNA plasmid was constructed successfully,and its transfection into the H441 cells could effectively inhibit the PLAGL2 expression,and simultaneously promote the expression of SP-C.