Effect Of Liposomal Transfection Of E2F3a SiRNA On Apoptosis Of A549Cell And Clinical Analysis Of Lung Cancer Cases

Objective: E2F3is an activator of transcription that is involved in DNA replicationand cell cycle progression.The E2F3locus encodes two proteins, E2F3a andE2F3b.E2F3is amplified or overexpressed in many tumors including those of bladder,prostate, lung and breast.Some gene therapy researches designed to target E2F3had gotpreliminary results.But its biological function in lung tumorigenesis is still unclear andneed some further research.The purpose of this study is to detect the expressioncondition of E2F3a in lung cancer A549cells,and use gene interference methods toknockdown the E2F3a expression status in A549,thereby to further discuss the role ofE2F3a in lung tumorigenesis and in the clinical outcome for the treatment of lungcancer.We analyze lung cancer cases to prove whether radiographic examination for theearly and timely detection of lung cancer has clinical value.Methods: E2F3a siRNA was synthetized and transfected into A549cell byliposome.RT-PCR was used to detect the level of E2F3a mRNA expression.Westernblot was used to detect the level of E2F3a protein expression of transfected A549cells,and meanwhile BCL-2,Caspase-3protein expression was detected by Western blottoo.Cell morphological changes were observed with microscope.CCK8and Flowcytometry techniques was used to detect cell proliferation and apoptosis.We comparedthe results of imaging report and pathological report to discuss the veracity ofradiographic examination in early and timely detecting lung cancer.Results:Cell morphological change was observed with microscope.Beforetransfection,the growth of cell was adherent,being in good condition,most of the cells were spindle-shaped and medium size,with the nucleolus being clear.48hours aftertransfection,the cell became irregular shape,shrinking,poor wall adherent.RT-PCRanalysis showed that the mRNA levels of E2F3a were notably lower than control groupand negative-control group.Western blot analysis showed that the protein levels ofE2F3a were notably lower than control group and negative control group.Western blotanalysis showed that the protein levels of Bcl-2were notably lower than control groupand negative control group,but the protein levels of Caspase-3were notably higher thanthe other groups.Apoptosis was detected by flow cytometry:the apoptotic rate in thesi-RNAE2F3a group was（15.02±1.7）％,while in the control group was（4.24±1.03）％,and in the negative control group was（5.43±0.81）％.CCK8experimental was usedto detect cell proliferation and the results showed that in48h,72h,96h three points aftertransfected,si-RNAgroup absorbance were0.86±0.52、1.21±0.33、2.01±0.40，controlgroup absorbance were1.34±0.23、2.67±0.14、3.97±0.32，negative control groupabsorbance were1.27±0.18、2.52±0.26、1.21±0.24。Using RNA interferencetechnology to silence E2F3a gene can significantly reduce the proliferation and promoteapoptosis of A549cell.Three lung cancer cases showed the consistency of imagingreport and pathological report. Radiographic examination could be an important meansused for early and timely discovery of lung cancer.Conclusion:Using RNA interference technology to silence E2F3a gene cansignificantly reduce the proliferation and promote apoptosis of A549cell.This providesfoundation for further research using RNA interference technology for the biologicaltreatment of lung cancer.Radiographic examination for early detection of lung cancermight have important significance.