Experimental Study Of The Molecular Mechanism Of MiRNA-21in Androgen-independent Prostate Cancer Cells

ObjectiveTO elucidate the relationship between miR-21gene abnormalities and theoccurrence of human prostate cancerthis article detected the regulatoryrelationships between p57^kip2miR-21and the protein expression explored theregulatory role of miR-21on the expression of p57^kip2 in prostate cancer, andprovided new ideas for the pathogenesis and research of diagnosis andtreatment in prostate cancer.MethodsCollected20cases of the surgical specimens of prostate cancers and5cases of normal prostate tissue samples to detect the expression of miR-21by using SYBRGreenI real-time fluorescent quantitative PCR detected transcription level of p57^kip2 mRNA with the same method. and to further validate the expression of p57^kip2 and cellular localization in situ hybridization, detected proteinexpression of p57^kip2 by using Immunohistochemical techniques.Expected results1.qPCR: compared with normal prostate tissue, miR-21in the tissue of prostate cancer expression increases3times above, rise significantly higher than the normal group, the difference was statistically significant. And poorly differentiated carcinoma expression is significantly higher than in the high differentia ted carcinoma. P57kip2mRNA expression rate in prostate cancer and normal tissue were68%and60%respectively, compared with the normal prostate tissue, in a sample of prostate cancer with expression of transcription cut rate increased significantly, respectively, the poorly differentiated group of p57^kip2mRNA transcription level lowered obviously. Of miR-21and p57^kip2 mRNA, spearman correlation analysis suggests the transcription level mostly no statistical correlation.2. Immunohistochemical results: p57^kip2 mRNA was not seen expressed in normal prostate tissue, the expression positive rate of prostate cancer was45%, Prostate cancer group and normal group was statistically significant. The expression of p57^kip2 protein was statistically significant in various degrees of differentiation of prostate cancer, significantly lower in the poorly differentiated group.3. The immunohistochemical results: p57^kip2 mRNA not seen expressedin normal prostate tissue, the expression positive rate of prostate cancer was45%, the prostate cancer group and normal group was statistically significant.P57kip2protein expression in different degree of differentiation of prostatecancer （X2=6.195, p=0.045<0.05）, decreased expression in lowdifferentiation group （p=0.047<0.05）.4. Correlation analysis: the miR-21p57^kip2 protein expression with spearman correlation analysis showed that: the prostate cancer group of the correlation coefficient r=0.584, P=0.007＜0.01, clew prostate cancer in the miR-21p57kip2protein expression level was significantly negative related.Conclusions1. p57^kip2mRNA and protein had abnormal expression in prostate cancer,the changed way of p57^kip2 was similar to action mode of the tumor suppressor gene. 2. miR-21was upregulated in prostate cancer, which showed the negativeregulation of p57^kip2 protein.3. miR-21had no upward or downward action of p57^kip2mRNA.it may only inhibited the further translation of p57^kip2,but not fundamental degradation, and protein levels decreased in prostate cancer, tumor cells may got the abilityof invasion and metastasis by transcriptional gene silence of miR-21-mediatedp57^kip2.4. The status of miR-21differential expression could provided clinical value for early screening, pathologic stage, guiding treatment, recurrence detectionin prostate cancer.