MGST1 overexpression promotes hepatocellular carcinoma development / 基础医学与临床

Objective To investigate the expression of microsomal glutathione S-transferase 1 ( MGST1) in hepa-tocellular carcinoma ( HCC) and its significance in the development of HCC. Methods Western blot was used to measure MGST1 expression in human hepatocellular carcinoma and adjacent tissues and HCC cell lines. Further-more, shRNA targeting MGST1 was constructed and transected into MHCC97H and HCCLM3 cells to deplete MGST1 expression. MGST1 was over-expressed in SK-Hep-1 cells using pCDH lentivirus system. Cell proliferation and migration were analyzed by colony formation and Transwell migration assay, respectively. The subcutaneous xenograft model of MHCC97H cells in nude mice was established to check tumor development and mouse survival.Results MGST1 was higher in 71% (17/24) of HCC tissues compared with their adjacent liver tissues. Cell proliferation and migration were significantly decreased by MGST1 knockdown, while they were increased by MGST1 overexpression. Furthermore, mice implanted with shMGST1 MHCC97H cells exhibited retarded tumor formation and tumor progression compared with control group. Conclusions MGST1 overexpression promotes hepatocellular carcinoma development and this molecule targeted for HCC treatment.

Autophagy in fibrotic and postoperative remnant liver in rat / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the characteristics of autophagy in fibrotic and postoperative remnant liver.</p><p><b>METHODS</b>Male Wistar rats were randomly divided into three groups: control group; fibrosis group, which received the solution of CCl4 in oil twice a week for 5 weeks; and hepatectomy group, which underwent 70% hepatectomy. Liver tissues and plasma were harvested 18 hours after the surgery. The rats' general conditions and plasma liver function were observed. Histopathological characteristics and regeneration were observed with microscope and transmission electron microscope. Qualitative analysis of autophagosome was made base on the data from transmission electron microscope.</p><p><b>RESULTS</b>Compared with the control group, plasma total protein and albumin level significantly decreased in the fibrosis group (P < 0.01). Proliferating cell nuclear antigen (PCNA) index was 85%-95% in the fibrosis group. Plasma alanine aminotransferase and aspartate aminotransferase levels significantly increased in the hepatectomy group compared with the control group (P < 0.01), while the autophagical index significantly decreased in both the fibrosis group and hepatectomy group compared with the control group (-95%, P < 0.01; -19%, P < 0.05, respectively). PCNA index was 20%-30% in the hepatectomy group.</p><p><b>CONCLUSIONS</b>Autophagy is weakened after fibrosis and hepatectomy, although it differs between these two processes. Proper regulation of autophagy may help facilitate the recovery of the residual liver function after hepatectomy.</p>

Z-ajoene causes cell cycle arrest at G2/M and decrease of telomerase activity in HL-60 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the molecular mechanisms of Z-ajoene mitosis blocking and telomerase inhibitory effects on HL-60 cells.</p><p><b>METHODS</b>Proliferation inhibition of HL-60 cell line was evaluated by MTT assay. Z-ajoene-induced mitotic blocking effect was investigated by flow cytometry. Immunoblotting analysis was used to determine cell cycle regulatory proteins. The telomerase activity of HL-60 cells was detected by TRAP-silver stain assay. Telomerase hTRT and TP1 mRNA level were determined by RT-PCR.</p><p><b>RESULTS</b>Z-ajoene displayed great proliferation inhibiting effect on HL-60 cells. Progressive increase in the percentage of mitotic block at G(2)/M phase was observed from 4 h to 12 h after treatment with 10 micromol/L Z-ajoene, with a peak at 10 h, which was 1.95 times higher than that in control. Z-ajoene also caused an increase in cyclin B1 accumulation and a decrease of p34(cdc2) expression. But Z-ajoene did not change the level of cyclin A. After treating with 10 micromol/L Z-ajoene for 24 h, the telomerase activity of HL-60 cells was also decreased in a dose-independent manner. Furthermore, telomerase hTRT and TP1 mRNA levels decreased after 10 micromol/L Z-ajoene treatment for 24 h.</p><p><b>CONCLUSION</b>The results suggest that Z-ajoene has potent anti-cancer activity, and that its inhibitory effect on telomerase activity and on cell growth might be the result of G(2)/M phase blocking.</p>