The effect and mechanism of arsenic trioxide on hepatocellular carcinoma

Abstract

To investigate the effect and mechanism of arsenic trioxide on hepatoma cell line BEL-7402 and observe the effect and best administration method of arsenic trioxide on hepatocellular carcinoma patients who were not suitable for operation. The cell activity and morphologic changes were studied after being treated with arsenic trioxide in different concentrations. The apoptosis was detected by flow cytometry assay and DNA fragmentation assay. The caspase-3 level of mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and fluoro-spectrophotometer. The growth inhibition of implant tumor was observed in nude mice treated with arsenic trioxide in different concentrations. Arsenic trioxide was used in hepatocellular carcinoma patients by intravenous dropping and continuous regional infusion through hepatic artery. The effect of arsenic trioxide on hepatoma cell lines was dependent on the time and concentration obviously. The decrease in cell number was preceded by morphological changes in the treated BEL-7402 cells that were characteristic of apoptosis, including membrane blebbing, shrunken cytoplasm, nuclear condensation and loss of adhesion. Flow cytometry assay showed an arrestment at G(2)/M phase and sub-G(1) cell peak. DNA fragmentation assay showed a marked DNA ladder. The mRNA level of caspase-3 was no change in RT-PCR whereas the protein of caspase-3 was increased after added As(2)O(3) 1 - 36 h. Caspase-3 activity began to increase after 2 h and reached a maximal level after 12 h in a linear fashion. Then, the level of caspase-3 was decreased, but still in a high level. The growth inhibition of implant tumors was obviously in nude mice. The intravenous usage of arsenic trioxide could improve the quality of life with low toxicity in hepatocellular carcinoma patients not suitable for operation. The tumor size decreased in 30 patients and AFP value decreased in 19 patients by continuous regional infusion through hepatic artery. Arsenic trioxide can obviously inhibit the growth of hepatoma cell line BEL-7402 through inducing hepatoma cell apoptosis. The activation and increase of Caspase-3 is the possible mechanism of apoptosis, and the acting point is in pro-enzyme level. The best result of arsenic trioxide on non-operative patients should be gotten in continuous infusion through hepatic artery.