Search of MicroRNAs Regulating the Receptor Status of Breast Cancer In Silico and Experimental Confirmation of Their Expression in Tumors.

MicroRNA whose expression depends on the receptor status of breast cancer were selected using bioinformatic analysis. The expression of 9 microRNAs (16, 17, 21, 27, 125, 146, 155, 200a, and 221) was analyzed in 76 samples of breast cancer with various receptor phenotypes. The expression of microRNAs 155, 27, and 200a did not differ in various types of breast cancer. The data on positive correlation between the expression of microRNA-21 and microRNA-221 and negative receptor status of the tumor were confirmed. The expression of the tumor suppressing microRNA-125b decreased in samples of breast cancer expressing HER2 and ER and in triple negative breast cancer, which characterizes it as a universal marker of breast cancer. An increase in the expression of microRNA-16 was shown in samples of breast cancer expressing HER2 and ER. The expression of microRNA-17 decreased in triple negative breast cancer and increased in ER+ , PR+ , and HER+ types of breast cancer. MicroRNAs 16, 17, 21, 125b, 146b, and 221 can be promising markers for differential diagnostics of various phenotypes of breast cancer.