Inhibition Effect Of Down Regulation Of Survivin By Small RNA On Growth Of Choriocarcinoma Cell

Objective: As a kind of high malignant tumor, choriocarcinoma can lead to hematogenous metastasis early and scatter all over the body. Although there were several therapeutical drugs, the drug tolerance means a bad prognosis,which is also a nodus in clinical therapy of choriocarcinoma. Small RNA is a set of short ribonucleic acid (RNA) molecules, which can bind to target messenger RNA transcripts (mRNAs), usually resulting in gene silencing. We presumed that, by using small RNA or inhibitors, regulating the expression of target mRNA can depress the malignant proliferation and promote the apoptosis of tumor cells. The discovery of small RNA provides a better gene therapy choice of drug tolerance choriocarcinoma. Survivin belongs to the inhibitor of apoptosis protein (IAP) family, and its expression can be detected in most types of human tumor but not in differentiated tissue. Due to its high apoptosis inhibiting and cell promoting activities, survivin means a lot to the tumor onset and can also be used as the therapy target. In contrast to the antisense nucleotide and RNAi, the report of inhibiting survivin can barely be seen. The purpose of this study is to provide the experiment evidences of small RNA in drug tolerance choriocarcinoma therapying.Methods: In this study, non-fusigenic (JEG-3) human choriocarcinoma cell lines were used to investigate the expression of Survivin by RT-PCR and Western blot. Then the expression was silenced by short haipin RNA. The apoptosis and cell growth were examined by flow cytometry and MTT assay. Data were recorded as mean±SD. Two group comparitions were examined using t tests, and means of multiple groups were analyzed using analysis of variance. The above tests were performed in SPSS? (version 13.0; SPSS Inc., Chicago, IL, USA). P < 0.05 was considered statistically significant.Results: Up-regulation of survivin mRNA and protein were detected in JEG-3 cells. The short haipin RNA-mediated knockdown of survivin significantly induced inhibited cell growth at 24hr, 48hr and 72 hr after transfection. The inhibition rate was 48% and 56% at 24hr and 72 hr respectively. The induction of G0 /G1 arrest of cell cycle progression after miRNA-mediated knockdown of surviving was 45% compared to control group. The proportion of S phase cells dropped from 43% to 23%.Conculsion: High survivin expression was found in JEG-3 cells. The short haipin RNA-mediated knockdown of survivin significantly inhibited the expression of survivin which leading to inhibited cell proliferation and increased cell apoptosis. The reason of these results may be partly G0/G1 arrest of JEG-3 cells.