MiR-490-5p Functions as an OncomiR in Breast Cancer by Targeting NFATc4

Breast cancer is a serious health problem worldwide in women. MicroRNAs are small non-coding RNAs of 18–25 nucleotides in length that posttranscriptionally modulate gene expression. MiR-490 has been reported as a tumor suppressor and oncomiR microRNA in breast cancer with two separate targets, NFAT and Rho. NFAT is one of the targets for miR-490 but the relationship between hsa-miR-490 and NFATc3, NFATc4 are not clear yet. Except for NFAT5, the other members of NFAT are activated by Ca2+ influx in the cell, either via the PLC-γ pathway or via store-operated Ca2+ entry, typically in T lymphoid cells. In a cross-sectional comparative study, peripheral blood samples were collected from 30 subjects with breast cancer and 30 healthy individuals as a control group. Gene expression analysis of peripheral blood mononuclear cells (PBMCs) was performed using reverse transcriptionquantitative polymerase chain reaction (RT-qPCR) to study the NFATc3, NFATc4, and hsa-miR-490-5p gene expression alterations. As per the obtained results, a significant decrease was observed in the expression level of NFATc4 (P 0.05), while hsa-miR-490-5p expression found to be elevated in PBMCs of breast cancer patient (P 0.05). Expression changes were not significant for NFATc3 gene (P 0.05). Taken together findings of this study indicated that serum hsa-miR-490-5p acts as an oncomiR by direct targeting the NFATc4.