Studies On RIZ1 Expression And Its Promoter Methylation Status In Breast Tumor

【Objective】To investigate RIZ1 mRNA expression and its promoter methylation status in human breast tumor tissues, as well as to explore the relationship between each other and their relations to the clinical and pathological indexes of the patients, providing new experimental data for the carcinogenesis mechanism and for prevention and treatment of breast cancer.【Methods】1. Human breast cancerous tissue with para-cancerous tissue specimens and human breast benign tumor tissue specimens, and their related clinical and pathological data were collected.2. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression of RIZ1 mRNA in human breast cancerous tissue with para-cancerous tissue specimens and in huamn breast benign tumor tissue specimens. The results were analyzed combined with the related clinical and pathological data of the patients.3. Methylation-specific PCR (MSP) was performed to detect the methylation status of RIZ1 promoter in human breast cancerous tissue with para-cancerous tissue specimens and in human breast benign tumor tissue specimens. The results were analyzed combined with the related clinical and pathological data of the patients and with the RT-PCR results.【Results】1. Lower expression of RIZ1 mRNA in human breast cancerous tissues were found, compared with that in their para-cancerous tissues (P<0.05) or in the benign tumor tissues (P<0.05), which has no directly proportion to the age of patients, TNM stages, lymph node metastasis and ER status (P>0.05, respectively).2. Among the 34 human breast cancerous tissue specimens, RIZ1 promoter methylation was detected in 15 cases (44.1%), 5 cases with RIZ1 promoter methylated both in the cancerous tissues and the para-cancerous tissues. No RIZ1 promoter methylation in the benign tumor tissue specimens was detected. RIZ1 promoter methylation status has no directly proportion to the age of patients, TNM stages, lymph node metastasis and ER status (P>0.05, respectively).3. The expression of RIZ1 mRNA was found to be lower in the specimens with RIZ1 promoter methylated than that with its unmethylated (P<0.05). Among 22 cases of lower or undetectable expression of RIZ1 mRNA, 13 cases (59.1%) were found with RIZ1 promoter methylated, but only 16.7%(2/12) with...