Main author: Mohammad Abdi
Institution or Company: Kurdistan University of Medical Sciences
Co-Authors, Institution or Company:
Seyedeh Parinaz Mahdavi (presenter), Kurdistan University of Medical Sciences.
Introduction: Breast Cancer (BC) is the most common cancer among women. Triple-Negative Breast Cancer (TNBC) accounts for 10–20% of breast cancer which has some characteristics such as earlier onset age, earlier metastasis, higher invasiveness, and mortality. MicroRNA (mir) is the large group of non-coding single-strand RNAs that can stop post-transcriptional patterns of protein expression. Mir-99b-5p was demonstrated as a tumor suppressor in some cancers and does the function by regulating some molecules in a cancer-related pathway. This study aimed to determine the expression level of mir-99b-5p in TNBC tissues and study the mir-related cellular parameters.
Methods: The expression level of mir-99b-5p was analyzed in TNBC tissues using qRT-PCR. After statistical analysis, related cellular parameters were checked in transfected BC cell lines (MDA-MB-231, MDA-MB-468, and MCF-7) in comparison with control groups.
Results: We found that miR-99b-5p was significantly down-regulated in TNBC tissues (P=.03). In continue, the suppressor effect of miR-99b-5p on MDA-MB-231 cell line proliferation (P<.0001), colony formation (P<.0001), VEGF protein expression (P=.0002), MMP2 and MMP9 gene expression (P=.003, P=.04), and G0/G1 cells number in cell cycle analysis (P=.001) was depicted. Furthermore, Proliferation (P=.04), colony formation (P<.0001), and G0/G1 cells number have declined (P<.0001), in MDA-MB-468 in comparison with the control group. Besides, in transfected MCF-7 cells colony formation (P<.0001), VEGF protein expression (P=.0008), and MMP2 and MMP9 gene expression have been decreased (P=.004, P=.01) compared to the control group.
Conclusions: Consequently, the effect of miR-99b-5p on mentioned cellular parameters in BC cells especially MDA-MB-231 was shown the tumor-suppressor function of miR-99b-5p.
