The relationship between DNA methyltransferase 3B (DNMT3B) and miR 124-3pa expressions in bladder cancer tissues

Background: Cancer bladder is the most common malignant tumor affecting the urinary tract. Genetic alterations are tightly associated with the development of cancer bladder. MicroRNAs (miRNA) are small, noncoding single-stranded RNA molecules that have been linked to bladder cancer. miR-124-3pa exhibits altered expression in various types of human malignancies. DNA methyltransferase 3B (DNMT3B) is responsible for de novo DNA methylation which is a fundamental epigenetic process in carcinogenesis. This work was performed to study the expression of DNMT3B and miR 124-3pa in bladder cancer tissues, and investigate their significance in the diagnosis and prognosis of the disease.

Subjects & methods: This case-control study included one hundred and six tissue samples of patients with primary urothelial bladder cancer. The tissues were separated into two parts. The first part was immediately frozen and kept at - 80 °C for total RNA extraction with subsequent detection of miR 124-3pa and DNMT3B expressions. The other part was preserved in formalin solution for histopathological examination.

Results: There was a highly statistically significant difference between the cancerous and the normal tissues as regarding miRNA-124-3pa and DNMT3B expression (P < 0.001) for each. Also, there was a highly statistically significant strong negative correlation between miRNA-124-3pa and DNMT3B expression (r=-0.750, P < 0.001). The combined performance of miR-124-3pa and DNMT3B revealed that the cutoff point of ≥ 3.3 can be used as a predictor of the presence of cancer bladder with sensitivity of 98.1% and specificity of 80%.

Conclusion: miR-124-3pa and DNMT3B can be used as predictors of the presence of cancer bladder.