关键词: 乳腺癌, 干细胞, miR-193a-3p, 三结构域蛋白14, 迁移, 侵袭

Abstract:

Background and purpose: Breast cancer stem cells play an important role in the occurrence and development of cancer. The high mortality of breast cancer patients is closely related to the recurrence and metastasis of cancer. However, the self-renewal and differentiation ability of breast cancer stem cells can lead to chemotherapy resistance, thus affecting the recurrence and metastasis of cancer. This study aimed to explore the impact of miR-193a-3p on the migration and invasion of breast cancer stem cells by targeting the tripartite motif-containing protein 14 (TRIM14). Methods: Human breast cancer cell T47D was randomly assigned into control group, NC mimics group (transfected with NC mimics), miR-193a-3p mimics group (transfected with miR-193a-3p mimics), miR-193a-3p mimics+pcDNA-NC group (transfected with miR-193a-3p mimics+pcDNA-NC) and miR-193a-3p mimics+pcDNA-TRIM14 group (transfected with miR-193a-3p mimics+pcDNA-TRIM14). Separation of stem cells using flow cytometry and detection of cell spheroidization ability were carried out. Cell counting kit-8 (CCK-8) experiment was used to detect cell proliferation. Transwell experiment was used to measure cell migration and invasion. Flow cytometry was used to detect cell apoptotic rate. Western blot was used to detect the expressions of cyclin D1, matrix metalloproteinase-2 (MMP-2), Bcl-2-associated X protein (Bax), and TRIM14 protein in cells. Dual luciferase assay was used to detect the interaction between miR-193a-3p and TRIM14. Results: T47D stem cells had the ability to form spheroids, and with increasing time, the spheroid volume of T47D stem cells gradually increased. Compared with the Control group and NC mimics group, the miR-193a-3p mimics group showed increased miR-193a-3p expression, apoptotic rate, and Bax protein expression (P<0.05), and decreased TRIM14 mRNA and protein expression, survival rate, clone number, migration number, invasion number, cyclin D1 and MMP-2 (P<0.05). Compared with the miR-193a-3p mimics group and the miR-193a-3p mimics+pcDNA NC group, the miR-193a-3p mimics+pcDNA-TRIM14 group showed decreased cell apoptosis rate and Bax protein (P<0.05), and increased TRIM14 mRNA and protein expression, survival rate, clone number, migration number, invasion number, cyclin D1 and MMP-2 (P<0.05). There were multiple binding sites between miR-193a-3p and TRIM14. Compared with the miR-NC+TRIM14-WT group, the miR-193a-3p mimics+TRIM14-WT group showed a prominent decrease in dual luciferase activity (P<0.05). Conclusion: MiR-193a-3p may inhibit the migration and invasion of breast cancer stem cells through inhibiting TRIM14.

Key words: Breast cancer, Stem cells, miR-193a-3p, Tripartite motif-containing protein 14, Migration, Invasion