Research On Proteome Differential Expression In HepG2 Between G1 Phase And G2/M Phase

Objective To control cell cycle of human hepatocellular carcinoma cell of line HepG2 by thymidine (TdR) and research of total proteome differential expression in HepG2 between G1 phase and G2/M phase using technology of two-dimensional electrophoresis-mass spectrum. in order to explore some cell cycle related proteins. Methods 1. cultured cells were blocked in the end of G1 phase by TdR . Then the synchronous cancer cells were achieved and assayed by flow cytometry (FCM) after culturing for different time without TdR . 2. the synchronous cancer cells in G1 phase and G2/M phase were lysated and then the total proteins were extracted . 3. The differential expressed proteins in G1 phase and G2/M phase were screened using different proteomics technique (two-dimensional electrophoresis and mass spectrum). Results FCM showed that after beeing induced by TdR, (63.62+2.82)% and (75.24+0.17)% synchronous cancer cells in G1 phase and G2/M phase were achieved respectively. 21 differential expressed proteins were achieved via technique of two-dimensional electrophoresis---image analysis--mass spectrum. Among them 10 were expressed both in G2/M phase and the end of G1 phase . There were over triplication difference among 11 differential spots .Two of them were upregulated expressed in G2 phase and nine were upregulated expressed in G2/M phase. Conclusion TdR Can achieve synchronous cancer cells very well .The differential expressed proteins identified by mass spectrum involved in many aspects, for example ,regulation of cell cycle, DNA binding,transcriptional control,mRNA splaing,onset of polypeptide chain synthesis ,folded as well as cell metabolism and so on .