不同转移潜能肝癌细胞株的差异蛋白质组的二维液相色谱分析

Proteomic profiling of human hepatocellular carcinoma SMMC-7721 cells under endoplasmic reticulum stress induced with dithiothreitol

AIM: To explore new therapy targets for human hepatocellular carcinoma by proteomic profiling of human hepatocellular carcinoma SMMC-7721 cells under endoplasmic reticulum stress.

METHODS: Cultured SMMC-7721 cells were divided into two groups: experimental group and control group. The experimental group was treated with dithiothreitol (DTT, 2.5 mmol/L), while the control group was treated with equal volume of culture medium. After treatment, total cell proteins were prepared and resolved by two-dimensional electrophoresis (2-DE). The two-dimensional electrophoresis maps for the two groups of cells were analyzed using ImageMaster 2D Platinum software. Proteins that showed obvious expression alteration in the experimental group were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

RESULTS: There were 844 ± 46 protein spots in the 2-DE map for the experimental group and 1 015 ± 63 protein spots for the control group. There were 593 ± 23 pairs of matched protein spots between the two groups, and the matching rate was about 71%. Most of the proteins have an isoelectric point at pH5.2-6.5 and a molecular weight of 15 000-80 000 Da. Three protein spots showed 2-fold or greater differential expression between the two groups and were identified by MALDI-TOF-MS. They were protein fem-1 homolog B, cyclin A1, and proliferation-inducing protein 44.

CONCLUSION: Three differentially expressed proteins in SMMC-7721 cells under endoplasmic reticulum stress were identified and may be useful molecular targets for the diagnosis and treatment of hepatocellular carcinoma.

Prevention and treatment of hepatoma metastasis and recurrence with Chinese medicine

Based on the clinical data and fundamental investigation, this article overviews the current situation in preventing and treating the recurrence and metastasis of hepatoma with traditional Chinese medicine, holding the opinion that researchers ought to perform multi-center, large-sample and random clinical trials to find out an effective therapeutic method or prescription of traditional Chinese medicine; thus promote the research on the mechanism of prevention and treatment with Chinese medicine via multiple approaches.

Dual functions of a monoclonal antibody against cell surface F1F0 ATP synthase on both HUVEC and tumor cells

AIM

To generate a monoclonal antibody (McAb) against cell surface F1F0 ATP synthase (ATPase) and observe its antitumoral activity on both human umbilical vein endothelial cells (HUVEC) and tumor cells.

METHODS

Hybridoma cells secreting McAb against ATPase were produced by polyethylene glycol-mediated fusions and screened by ELISA. The specificity of McAb was demonstrated by immunofluorescence and confocal imaging, as well as flow cytometry analysis. After the blockade of surface ATPase with McAb on HUVEC and human breast adenocarcinoma MDA-MB-231 cells, an ATP determination kit and CellTiter96 AQueous Assay (MTS) assay were used to detect the effect of the antibody on extracellular ATP modification and cell proliferation. A cellular cytotoxicity assay in combination with doxorubicin, and a cell migration assay on MDA-MB-231 cells were used to determine the antitumoral activity. Finally, a HUVEC tube formation assay was used to detect the antiangiogenic effect of McAb178-5G10.

RESULTS

A monoclonal antibody (McAb178-5G10) against the beta-subunit of ATPase was generated, and its reactivity toward HUVEC and tumor cells was studied. We demonstrate that McAb178-5G10 binds to ATPase at the cell surface, where it is able to inhibit ATP synthesis. This antibody also prevents the proliferation of HUVEC and MDA-MB-231 cells. Furthermore, McAb178-5G10 enhances the tumoricidal effects of doxorubicin (P<0.05), inhibits the migration of MDA-MB- 231 in transwell assays (P<0.01), and disrupts HUVEC tube formation on Matrigel (P<0.01).

CONCLUSION

McAb178-5G10 binds preferentially to cell surface ATPase, blocks ATP synthesis, and exhibits both antiangiogenic and antitumorigenic effects.