MiRNA and Target Oncogene Regulation in Triple Negative Breast Cancer: An Age, Ethnic and Environmental Related Neoplastic Event

Main Article Content

Jude Ogechukwu Okoye
Francis Obinna Okoye


Triple-negative breast cancer is a type of aggressive breast cancer without the immunohistochemical expression of estrogen receptors, progesterone receptors and human epidermal growth factor receptor-2; with poor prognosis, greater relapse risk and worse survival in general. Its proportion in all breast cancer cases ranges from 15 to 20%. Triple negative breast cancer is more prevalent among younger women, particularly African, African-American, Latino and obese women. This observed prevalence, is an age and ethnic related factor which fingers estrogenic agents as a common feature in TNBC occurrence. Inherited variation in the let-7 binding site on the KRAS oncogene has been revealed to confer increased susceptibility to triple negative breast cancer, especially in premenopausal, African-American and Hispanic women. About 15-40% of triple negative breast tumors have BRCA-related epigenetic down-regulation and increased expression of the inhibitors of BRCA1 function, which have be found to be related to indirect regulation of ID4 oncogene by miR-342. When compared with wholesome breast tissues, miR-21, miR-210 and miR-221 expression are observed to be elevated in the triple-negative breast cancer; whereas expression of miR-10b, miR-145, miR-205, miR-122a, miR-200a/miR-200b, miR-146b and miR-148a are decreased. Interestingly, eight miRNAs are differentially expressed in metastatic breast cancer tissues (miR-200b, miR- 148a, miR-424, miR-125a-5P, miR-627, miR-579, let-7g and miR-101) when compared with the non-metastatic type. The consequence of differential miRNA expression in triple negative breast is a function of target oncogene modulation which may be related to nutritional, environmental and socio-cultural factors. Insights into the risk factors, miRNA and their validated target may provide novel diagnostic tools and treatment options for triple negative breast cancer.


Triple negative breast cancer, age, ethnicity, environmental factor, oncogenes, miRNA, BRCA mutations

Article Details

How to Cite
Ogechukwu Okoye, J., & Obinna Okoye, F. (2015). MiRNA and Target Oncogene Regulation in Triple Negative Breast Cancer: An Age, Ethnic and Environmental Related Neoplastic Event. Journal of Cancer and Tumor International, 2(2), 66-80. https://doi.org/10.9734/JCTI/2015/18131
Review Article