The Effects And Mechanisms Of SD118-2on Human HepG2Cells Proliferation、 Cell Cycle And Cell Apoptosis

Research Background:Heppatocellular carcinoma (HCC), is one of the primary tumor deaths in the world,and also one of the main cause of death in patients with liver cirrhosis. The incidence ofHCC increased continuously in recent years, there are500000to1million new patientsincreased every year[1]. The early diagnosis and effective treatment play important role inextending patients’ life. Liver transplantation and liver surgical resection are the most usedtreatments, but because of lacking liver source and high recurrence rate, these treatmentscan not obtain remarkable curative effect in clinic, also increase the patient’s suffering andeconomic burden. At present, the chemotherapy is used to those patients who do not adaptthe surgery, however the clinical effect of chemotherapy is not very significant. Forexample, the aclarubicin, is the standard treatment drug, it has high toxicity and do nothave remarkable curative effect in clinic[2]. In half of century, people have been committedto the compounds which are extracted from the natural plants for the clinical cancertreatment, have proved its clinical effect is remarkable.The SD118-2was extracted from the deep-sea sediments in the South China Sea,fifteen compounds were purified and characterized, the xanthocillin X(1) was namedSD118-2. The SD118-2exhibited cytotoxicity against MCF-7, HepG2, NCI-H460, HeLaand so on, and it has the most cytotoxicity against HepG2[3].Research Objective:To study the effects of SD118-2on human HepG2cells proliferation、cells apoptosisand cell cycle. To study the mechanisms of SD118-2on cell apoptosis in human HepG2cells.Research Method:The HepG2cells were divided into the treated group and the control group. The HepG2 cells of treated group were exposed to the SD118-2at the concentration of7μg/mL, thecontrol group were exposed to the same concentration of DMSO.1. The effects of SD118-2on the proliferation of human HepG2cells and normal liver cellswere detected by MTT assay: the human HepG2cells and normal liver cells wereexposed to the SD118-2at the concentration of7μg/mlLfor48h. The absorbance wererecorded on a microplate reader at570nm.Cell viability (%)=(average A570nm of treated group/average A570nm of controlgroup)×100%.2. The modality of cells were detected by the fluorescence microscope after DAPI staining：the human HepG2cells were exposed to the SD118-2at the concentration of7μg/mL for12h,24h,48h. After DAPI staining, the modality of cells were detected by thefluorescence microscope.3. Annexin-V-FITC/PI assay of apoptosis cells: the human HepG2cells were exposed tothe SD118-2at the concentration of7μg/mL for12h,24h,48h. The HepG2cells weredetected by the flow cytometry.4. Assay the cell cycle arrest: the human HepG2cells were exposed to the SD118-2at theconcentration of7μg/mL for12h,24h,48h. The HepG2cell cycle was detected by theflow cytometry.5. Mitochondrial membrane potential assay: the human HepG2cells were exposed to theSD118-2at the concentration of7μg/mL for12h、24h、48h. The mitochondrial membranepotential of HepG2cell was determined quantitatively by the flow cytometry using theprobe JC-I.6. Western blot analysis of the change about the expressions of Bcl-2, Bax, PARP andC-PARP: the human HepG2cells were exposed to the SD118-2at the concentration of7μg/ml for12h,24h,48h. Bcl-2, Bax, PARP, C-PARP were detected by Western Blot.Research Results:SD118-2inhibited the proliferation of human HepG2cells、changed the modality、decreased the mitochondrial membrane potential、blocked the cells of G2stage and thedown-regulated expression of Bcl-2and the up-regulated expression of Bax, C-PARP at a time-dependent manner. At the same time, the effects of SD118-2on human normal liverwere very little.Research Conclusion:SD118-2can inhibit the proliferation, induce cell apoptosis, block the cell of G2Stage of HepG2, which might be related to the down-regulated expression of Bcl-2andthe up-regulated expression of Bax, C-PARP. The effects of SD118-2on human normalliver were very little.