MiR-106b And MiR-93 Regulate Cell Progression By Suppression Of PTEN Via PI3J/Akt Pathway In Breast Cancer

Objective: To investigate the differential expression of miR-106 b and miR-93 in MCF-7 and MDA-MB-231 cells.To clarify the functional mechanism of the two miRNAs in the progression of breast cancer.This research might provide novel directions for the early diagnosis and treatment of breast cancer.Methods:(1)Using qRT-PCR to detect the relative expression of miR-106 b and miR-93 in breast cancer tissues or cells.(2)Using network prediction softwares(TargetScan Human 7.1 and microRNA.org)to forecast the target mRNA of miR-106 b and miR-93,which was further confirmed based on luciferase assays.(3)To examine PTEN level and the functional experiments after upregulation of miR-106 b,miR-93 in MCF-7 or downregulation of the two miRNAs in MDA-MB-231.(4)To check the effect of upregulated PTEN on functional experiments and PI3K/Akt pathway in MCF-7 cells overexpressed miR-106 b or miR-93.To detect the roles of reductive PTEN in functional experiments and PI3K/Akt pathway in MDA-MB-231 cells with reductive miR-106 b or miR-93.(5)To test the functional experiments in MDA-MB-231 cells transfected with si Akt.Results:(1)MiR-106 b and miR-93 were both highly expressed in breast cancer tissues and cells.(2)Based on the network prediction softwares,PTEN was the common target of miR-106 b and miR-93,which was also confirmed by luciferase assays.(3)Overexpressed miR-106 b or miR-93 decreased PTEN level and promoted the capacity of cell migration,invasion and proliferation in MCF-7.Reduced miRNAs in MDA-MB-231 increased the expression of PTEN and attenuated the capability of cell migration,invasion and proliferation.(4)Overexpressed PTEN reversed the effect of overexpressed miR-106 b or miR-93 on the functional experiments and PI3K/Akt pathway in MCF-7.Downregulation of the two miRNAs attenuated the capability of cell migration,invasion and proliferation and PI3K/Akt pathway in MDA-MB-231,which was blocked by the reductive PTEN.(5)The capability of cell migration,invasion and proliferation was attenuated after transfection with siAkt in MDA-MB-231 cells.Conclusion:(1)The expression of the miRNAs was significantly different in breast cancer tissues and the adjacent nontumor tissues or in MCF-7 and MDA-MB-231 cells.The difference might be associated with the progression of breast cancer.(2)MiR-106 b,miR-93 targeted PTEN to promote the progression of breast cancer.(3)MiR-106 b,miR-93 targeted PTEN to promote the PI3K/Akt pathway in breast cancer.(4)MiR-106 b,miR-93 regulated cell progression by suppression of PTEN via PI3K/Akt pathway in breast cancer.