| Hepatocellular carcinoma (HCC) is one of the malignant tumors which have a high prevalence and mortality rate in the countries through out the world, among which its mortality in China ranks the first place. The therapies for liver cancers have been under constant study. The current therapy for liver cancers, excision is only applicable to some of the patients in the early stage and has a high reoccurrence rate postoperation. Therefore, our tentative study on the pathologic mechanism of HCC and its therapies are necessary.Survivin gene is a new member of inhibitors of apoptosis protein (IAP) family. It is observed to express mainly in the developing embryonic tissues and the common human malignant tumor tissues, but not in the adult differentiated tissues. It has been found in previous studies that Survivin possesses a double regulatory activity on cell apoptosis and cell division cycle by exerting a direct inhibitory effect on the activities of caspase, especially caspase-3 and caspase-7 or caspase-9,to block the corporate pathway of the down-stream cell apoptosis induced by various stimulants. Besides, Survivin has a specific expression in the cells in G2/M stage of cell division circle, and is involved in the regulation of cell gene's transcription by combing with the microtubule of cell mitosis spindle. And Survivin can directly inhibit the activity of caspase-3 to reduce tumor cells'sensitivity to chemotherapeutic agents. Survivin gene's selective expression in tissues and its special activity on the inhibition of cell apoptosis suggest that it is likely to be identified as a special index in diagnosis and a potential therapeutic target in HCC.It has been demonstrated that occurrence of HCC combines with many oncogenes' activation and anti-oncogenes' inactivation. Therefore, we select the oncogenes and anti-oncogenes which play important roles in the occurrence of HCC, and employ antisense oligonucleotide technology, gene knockdown gene substitute and gene transduction, the oncegenes' expression can be inhibited and knocked down and a gene therapy for HCC can be achieved.The advantage of the target-oriented therapy with tumor apoptosis-inhibiting gene as its target is that it can increase tumor cells' apoptosis and inhibit their proliferation, while it has no bad effect on normal tissues. RNA interference (RNAi) can specifically and efficiently degrade mRNA, resulting in post-transcriptional gene silencing. Besides, its blocking action on gene expression has been successfully observed in rats and human cells cultured in vitro, and the knockdown of cell genes has been achieved. The present study was designed mainly to identify whether Survivin gene expression in the HCC cells can be knockdown so as to induce cell apoptosis and inhibit proliferation.Aims: To study Survivin gene's possible mechanism in HCC cell proliferation and cell apoptosis and to provide a tentative theoretical basis for gene therapy for HCC.Methods:1. SABC immunohistochemical staining, reverse transcription polymerase chain reaction (RT-PCR) and Western blot method were employed to detect Survivin gene, P53, Bcl-2, Survivin mRNA and cell apoptosis in 87 HCC tissues, 50 adjacent noncancerous tissues of deparaffinized sections, 8 HCC tissues and 4 human hepatocellular carcinoma cells line (HepG2, SMMC-7721, HHCC, and HCC-9724) respectively.2. Human hepatocellular carcinoma cells line (HepG2) was transfected with Survivin gene through lipofection to constructSW-HepG2 cell model, which showed a stable expression of Survivin. And then SABC immunohistochemical staining, RT-PCR, Flow cytometry (FCM), and measuring the cell growth curve were utilized to detect Survivin protein expression, its mRNA expression, cell cycle and cell growth in HepG2 before and after transfection.3. Human hepatocelluar carcinoma cells line (SMMC-7721) was transfected with the eukaryotic expression vector of dsRNAi of Survivin gene through a lipofectin transfection method to construct S-RNAi-7721 cell model. And then SABC...
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