Differential Proteomics Analysis Of Human Colon Cancer LoVo Cell Line Treated By Oxaliplatin Or Irinotecan

Objective: To analyse differential expression proteins of human colon cancer Lovo cell line treated by oxaliplatin,and to investigate the antitumor mechanism of oxaliplatin.Methods: Cell proliferation was assayed by MTT.50% inhibitory concentration of oxaliplatin (IC50) was calculated. The Lovo cell lines were divided into two groups stochastically and then were cultured,oxaliplatin was added to 100ml medium of experimental group but not to the medium of control group. After rehydration, isoelectric focusing, balance, vertical gel electrophoresis and coomassie brilliant blue staining,the gels were scaned and analyzed.Differential spots were found out and identified by mass spectrometry between the two groups.The last step was bioinformatics analysis.Results: 1013 and 1021 protein spots were received on experiment group and control group;The average match spots of experimental group was 812, which of control group was 829;10 spots with most significant difference between the experimental group and control group were selected.After MALDI-TOF/TOF-MS,nine proteins were successfully identified.In the experiment group,the down-regulated proteins were A1-RLA2, A2,A4-G3P, A3-AK1C2, A5-GNΒ2L1 and A6-NDKB,the up-regulated proteins were B7-β2MG, B8-SFRS3, B9-HNRH3 and B10-UNG..The differential proteins are related to the DNA damage repair,pre-mRNA transcription,myc gene,modification,translation and post-translational regulation,immune escape,energy metabolism,signal transduction pathways reference to apoptosis.Conclusion: The differential proteins from human colon cancer LoVo cell line treated by oxaliplatin were UNG etc;These differential proteins are related to the DNA damage repair metabolism etc;Inhibition of colon cancer by oxaliplatin may be related to the above mechanism. Objective: To analyse differential expression proteins of human colon cancer Lovo cell line treated by irinotecan,and to investigate the antitumor mechanism of irinotecan.Methods: Cell proliferation was assayed by Bradford method.50% inhibitory concentration of irinotecan (IC50) was calculated. The Lovo cell lines were divided into four groups stochastically and then were cultured.Irinotecan was added to 100ml medium and incubated for 24h,48h and 72h of experimental B,C and D group,but not to the medium of control A group.After rehydration, isoelectric focusing, balance,vertical gel electrophoresis and silver nitrate staining, the 2-DE gels were obtained and were scaned,analyzed. The differential spots were found out from the three groups and were identified by mass spectrometry.The last step was bioinformatics analysis.Results:1100,1087,1097 and 929 protein spots were obtained in the control A group and experiment B,C,D group.The average match spots of experiment B,C,D group was 892,920 and 758 , which control A group was 965;17 spots with most difference were picked out.After MALDI-TOF/TOF-MS, nine proteins were successfully identified.They were C2-PRDX2, B6-ECHM, B7-HSPβ1, B8-KPYM, B9,A12-ENOA, A13-SCOT1, B15-TCPD, B16-ATPA and B17-GβLP. The differential proteins are related to the antioxidant,signal transduction pathways reference to apoptosis, molecular chaperone,energy metabolism.Conclusion: The differential proteins from human colon cancer LoVo cell line treated by irinotecan were PRDX2 etc;These proteins are related to the antioxidant metabolism etc;Inhibition of colon cancer by irinotecan may be related to the above mechanism.