MiR-15b facilitates breast cancer progression via repressing tumor suppressor PAQR3

Recently, breast cancer (BC) has become a common tumor that threatens the physical and mental health of women. Microribonucleic acids (miRNAs) have been chosen as a study object because of their roles in various cancers, including BC. Here, we mainly study the role of miR-15b in BC progression and its underlying mechanism.

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine the level of MiR-15b expression in 60 pairs of BC tissues and para-cancerous specimens, and the relationship between MiR-15b level and clinical features of BC patient prognosis was analyzed. MiR-15b and PAQR3 level in BC tissues and cells was tested by Western blot.

The results showed that miR-15b expression was higher and PAQR3 level was lower in BC. The identification of PAQR3 as a target of miR-15b in BC was carried out by Luciferase reporter assay and the results stated that the Luciferase activity was reduced by miR-15b mimic, indicating PAQR3 being a target of miR-15b in BC. Transwell assay was used for examining BC cell migration and invasion and found that miR-15b could promote BC cell migration and invasion, while the effect of PAQR3 was inhibition. Furthermore, PAQR3 could reverse the promotion effect of miR-15b on BC cell migratory and invasive ability. In addition, miR-15b expression was negatively correlated with PAQR3 performed by regression analysis.

Our data stated that miR-15b could facilitate BC progression via repressing tumor suppressor PAQR3, indicating that miR-15b/PAQR3 axis provided a therapeutic target for treating BC.