Clinical Significance Of RUNX3 Gene Expression And CpG Island Methylation In Prostate Cancer

Part I Clinical Significance of RUNX3 Gene Expression in Prostate CancerObjective:To explore the expression of RUNX3 gene in prostate cancer and its relationship with various PSA value, Gleason score and prostate cancer stage.Methods:The expression of RUNX3 protein in 46 cases of prostate carcinoma tissue and 10 cases of normal prostate tissue was detected by using immunohistochemistry (IHC). The expression discrepancy under the conditions of different PSA value, different levels in Gleason score system and clinical stages were compared.Results:The RUNX3 expression ratio in prostate carcinoma tissue was 45.7%, while that in normal prostate tissue amounted to 100 percent. The expression ratio in prostate carcinoma tissue was obviously lower than that in normal prostate tissue. RUNX3 protein expression statue in prostate cancer had nothing to do with serum PSA, but it decreased when the Gleason score and clinical stage increased, which have statistic significance. As a result, the 5-year survival rate decreased with the decrease of RUNX3 expression.Conclusion:The expression of RUNX3 gene is clearly decreased in prostate cancer. Which have a negative correlation with the Gleason score and clinical stage of prostate cancer. RUNX3 gene is expected to become a prognostic factor of prostate cancer.Part II Study of Methylation Status of CpG Island in RUNX3 Gene in Prostate CancerObjective:To detect the methylation status of CpG island in RUNX3 gene in prostate carcinoma and analyze its correlation with the expression of RUNX3 protein. To analyze the difference between the methylation status of CpG island in RUNX3 gene in prostate carcinoma and normal prostate, and to further identify the relationship between the methylation status and clinical data.Methods:The methylation status of RUNX3 gene in 46 cases of prostate carcinoma was detected by methylation sensitive high resolution melting (MS-HRM) method. The correlation between the methylation and the expression of RUNX3 gene, as well as the relation between the methylation of RUNX3 gene and the clinical data, was analyzed.Results:The methylation rate of RUNX3 in normal prostate was zero, but that in prostate carcinoma amounted to 60.9 percent (28/46). The RUNX3 methylation in prostate carcinoma was obvious. Besides, a correlation was found between the methylation of CpG island in RUNX3 gene with the pathology classification, the clinical stages, and the expression of RUNX3 gene. The methylation status of RUNX3 gene have a negative correlation with the expression of RUNX3 protein. As a result, the 5-year survival rate decreased with the increase of RUNX3 methylation.Conclusion:The hypermethylation status of CpG island in RUNX3 gene is abnormal in prostate cancer. The methylation status of CpG island in RUNX3 gene determine the expression of RUNX3 gene in prostate cancer; and the hypermethylation of CpG island in RUNX3 gene is more likely to occur in those patients who have a higher pathology classification or later clinical stage.