The Effects Of MiR-155 Expression Level And Cell Proliferation Of Liver Cancer Cell Lines By Chronic Inflammatory Stress Components

[Objective]Observing the changes of miR-155 expression level, cell proliferation and cell cycle of liver cancer cell line by chronic inflammatory stress components, to evaluate the effects of miR-155 expression level and cell proliferation of liver cancer cell line caused by chronic inflammatory stress components.[Methods]MiR-155 stem-loop specific primers, TaqMan fluorescent probe, qRT-PCR method were used to detect expression level of miR-155 in normal human liver cell line L02 cells which was exposed to H₂O₂ and not did so after 0h, 1h, 4h, 8h, 12h and 24h.,and to detect the expression level of miR-155 in human liver cancer cell line SMMC-7721 cells and HepG2 cells which were or not added in H₂O₂ or SPER/NO or HU after 0h, 1h, 4h, 8h, 12h and 24h. The cell of normal human liver cell and human liver cancer cell lines SMMC-7721 and HepG2 added or not in H₂O₂ or SPER/NO or HU after 0h, 1h, 4h, 8h, 12h and 24h were counted, the cell growth curve was drawn and the cell cycle was observed at 24h using flow cytometry.[Resluts](1) Under normal circumstance, the expression level of miR-155 of L02 cells was not observed, but a small amount of miR-155 expression of SMMC-7721 cells and HepG2 cells were detected. (2) The expression level of miR-155 in L02 after exposed to H₂O₂ was slightly increased. After handled by H₂O₂ or SPER/NO or HU, the expression level of miR-155 of SMMC-7721 cells and HepG2 cells increased. (3) There was no significantly accelerated the cell proliferation of L02 between treated by H₂O₂ and not. The cell proliferation of SMMC-7721 cells and HepG2 cells handled by H₂O₂ or SPER/NO or HU were significantly accelerated than that of SMMC-7721 cells and HepG2 cells without H₂O₂ or SPER/NO or HU. (p<0.05) (4) L02 cells treated by H₂O₂, the proportion of S phase was slightly increased. SMMC-7721 cells and HepG2 cells handled by H₂O₂ or SPER/NO, the proportion of S phase was increased; SMMC-7721 cells handled by HU the proportion of G1 phase was increased and S phase was decreased; HepG2 cells handled by HU, the proportion of G1 at 12h was decreased and S phase was increased, and the proportion of S phase was decreased gradually with time. (5).The tendency of miR-155 expression level increase and cell proliferation significant acceleration caused by three drugs acting on SMMC-7721 cells and HepG2 cells was no clearly difference between different drugs or cells. (p>0.05)[Conclusion]1. No expression of miR-155 in normal human liver cell line, but a small amount of expression level of miR-155 in human liver cancer cell lines was observed.2. The expression level of miR-155 of normal human liver cell slightly increased by chronic inflammatory stress components.3. Under the action of chronic inflammatory stress components, the expression level of miR-155 in liver cancer cell lines was increased, liver cancer cell proliferation was accelerated and its cell cycle was changed.4. There was no significant difference among the above changes of two liver cancer cell lines caused by three chronic inflammatory stress components.