ABSTRACT
@#[Abstract] Objective: To investigate the expression of long non-coding RNA LINC01001 in breast cancer tissues and its effect on the proliferation of breast cancer MCF-7 cells. Methods: The expression levels of lncRNA LINC01001 were analyzed in 12 cases of cancer and para-cancer tissues from breast cancer patients, who underwent surgical resection in Affiliated People’s Hospital of Hubei University of Medicine from March 2016 to June 2017. The plasmid over-expressing LINC01001 was transfected into human breast cancer MCF-7 cells. The cell cycle distribution and proliferation ability of MCF-7 cells were detected by flow cytometry and MTT assay, respectively. The mRNA expressions of miR-485-5p and CDKN1A mRNA were detected by qRT-PCR, and the protein expressions of CDKN1A, CDK4, CDK6 and Cyclin D1 were detected by Western blotting. Results: The expression level of lncRNA LINC01001 in breast cancer tissues was lower than that in para-cancer tissues (P<0.01). LINC01001 recombinant plasmid transfection significantly inhibited cell cycle progression (P<0.05) and cell proliferation (P<0.05) of MCF-7 cells. qRT-PCR showed that the expression level of miR-485-5p was decreased (P<0.01) and the expression level of CDKN1A mRNA was increased (P<0.01) after over-expressing LINC01001. Western blot results confirmed that over-expression of LINC01001 could promote the expression of CDKN1A protein, but decrease the expressions of CDK4, CDK6 and Cyclin D1 proteins. Conclusion: The expression of LINC01001 in breast cancer tissues was decreased. LINC01001 may down-regulate the expression of miR-485-5p to up-regulate the expression of CDKN1A, and further to inhibit the proliferation of breast cancer MCF-7 cells, providing experimental basis for the clinical application of lncRNA.