Expression of micrornas in molecular genetic breast cancer subtypes.
BACKGROUND
It is shown that each type of human malignancies has a unique set of expressed miRNAs, and tumor-specific miRNAs in biological tissues of a patient are stable. The aim of this study was to determine the differences in the expression of miRNAs in tumor tissue of invasive breast carcinoma compared to normal tissue, as well as to analyze the variable expression of miRNAs in molecular genetic subtypes of breast cancer.


METHODS
We determined differences in mRNA expression in 35 biopsies of tumor tissue of various molecular genetic subtypes of breast cancer and 35 biopsies of adjacent conventionally normal breast tissue by RT-PCR in real time. We assessed the expression levels of miRNA-21, 221, 222, 155, 205, 20a , 125b and 200a.


RESULTS
A significant increase in the level of expression of the oncogenic miRNA-20a (p=0.000141) and miRNA-221 (p=0.037777) in the triple negative cancer in comparison with the luminal A and luminal B/HER2/neu-negative breast cancer subtypes was established. Assessment of significance of the results was conducted using ROC analysis. For miRNA-221 AUC value was 0.772, for miRNA-20a AUC value was 0.949. The obtained results suggest the possibility of using the levels of miRNA-21, 155, 205, 125b expression in tumor tissue to assess a malignant potential of a breast carcinoma. The levels of expression of oncogenic miRNA-221 and miRNA-20a are increased in TNBC compared with luminal A and luminal B/HER2/neu-negative breast cancer subtypes, supporting the characteristic of TNBC as the most aggressive subtype of breast cancer. MiRNA-20a is a marker of TNBC compared with luminal subtypes of breast cancer.


MICRO ABSTRACT
To identify markers for breast cancer with triple-negative phenotype, we evaluated expression levels of siRNA-21, 221, 222, 155, 205, 20a, 125b, 200a and 146b in the tumor tissue of 35 patients by RT-PCR. AUC value equal to 0.949 in the ROC-analysis allows us to recommend the miRNA-20a as a marker of triple negative breast cancer to differentiate it from the luminal subtypes.
['Kolesnikov|N N|NN|', 'Veryaskina|Yu A|YA|', 'Titov|S E|SE|', 'Rodionov|V V|VV|', 'Gening|T P|TP|', 'Abakumova|T V|TV|', 'Kometova|V V|VV|', 'Torosyan|M Kh|MK|', 'Zhimulev|I F|IF|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D014408:Biomarkers, Tumor D001706:Biopsy D001943:Breast Neoplasms D005260:Female D020869:Gene Expression Profiling D015972:Gene Expression Regulation, Neoplastic D006801:Humans D035683:MicroRNAs D008875:Middle Aged D060787:Neoplasm Grading D009367:Neoplasm Staging D011379:Prognosis D012372:ROC Curve D059467:Transcriptome D047368:Tumor Burden
Breast cancer miRNA ROC-analysis