Drug Sensitive Test of New Type Arsenic Compounds
|Keywords||hepatocellular carcinoma apoptosis reactive oxygen species arsenic compounds|
The success of trioxide (As2O3) in treatment of acute promyelocytic leukemia (APL) has intrigued many researchers to study As2O3 and the relative compounds , which have uncovered the prelude of correlatively international investigations. Besides As2O3, new arsenic compounds, such as melarsoprol, phenylarsine oxide, monomethylarsonous acid and dimethylarsinic, were studied. They all induced apoptosis of some kinds of cancer cell. But the apoptosis of other leukemia cell lines and non-leukemia cell lines need so high concentration that it is unacceptable because of its toxicity. It is very important for us to find a new kind of arsenic compound with the simple structure, which can induce apoptosis of cancer cell in lower concentration and has no or less toxicity to normal cells. Our experimental studies, employing a series of new arsenic compounds in vitro and in vivo, have showed good results.Method: 1 Effect of arsenic compound on the SMMC-7721 cells were measured with MTT method. 2 Ration of apoptotic cell and change of cell cycle were determined by the flow cytometry assay in propidium iodide staining. 3 The effect of free radical on apoptosis by superoxide dismutase(SOD) and the change of SOD in culture solution were investigated. 4 Mitochondrial membrane potential was measured by using rhodamin123. 5 The transmission electron microscope and gel electrophoresis were used to make sure whether the cell death is apoptosis or necrosis. 6 Calculating the value of lethal dosage 50 by the means of the acute toxicity test.Result:1 Arsenic compounds could significantly inhabit the proliferation of SMMC-7721 and this inhibitory effect depends on the dose added and the reaction time. Fatty organoarsenic acid has more effect than aromatic organoarsenic acid on cells. And 2-arsono-acetic acid with a concentration of 10-6mol.l-1 is good effect and low toxicity on cells. 2 Observation of morphological change of cells by transmission electron microscope showed that many necrotic cells appeared while there were only apoptotic cells with a 2-arsono-acetic acid concentration of 10-6mol.l-1.3 Activated oxygen species were involved in the apoptosis of SMMC-7721 and SOD in culture solution decreases when apoptosis occur。4. Mitochondrial membrane potential falls at the early apoptosis, which relates<WP=7>with activated oxygen species.5. The apoptosis of SMMC-7721 induced by arsenic compounds focus on cells in G0/G1 phase of cell cycle.It also increase the proportion of cells in S phase. 6. The lethal dose 50 of 2-arsono-acetic acid showed that the toxicity of 2-arsono-acetic acid is lower than arsenic trixide.