Mir-153-3p Modulates the Breast Cancer Cells’ Chemosensitivity to Doxorubicin by Targeting KIF20A

SIMPLE SUMMARY: Breast cancer is a disease that begins in the cells of the breast. Although it is most common in women, it can also occur in men, though this is rare. Early detection and treatment are crucial to improving outcomes and survival rates. Risk factors include age, family history, certain gene mutations, prior history of breast cancer, exposure to estrogen, and lifestyle habits like alcohol consumption and inactivity. Symptoms include changes in the skin on the breast, such as dimpling, lumps or thickening, changes in size or shape, and discharge from the nipple. Diagnosis is often made through a clinical breast exam, mammogram, biopsy, and possibly additional imaging tests. Treatment options include surgery, chemotherapy, radiation therapy, hormone therapy, and targeted therapy. The choice of treatment method depends on the stage and characteristics of cancer. ABSTRACT: Breast cancer is considered the solid tumor most sensitive to chemotherapy. However, it can become resistant to various chemotherapeutic drugs, including doxorubicin, which triggers cell death by intercalation between DNA bases, free radical formation, and topoisomerase II inhibition. When drug resistance develops, several miRNAs are dysregulated, suggesting that miRNAs may play a significant role in resistance formation. In the current study, we investigated how doxorubicin sensitivity of breast cancer cells is affected by miR-153-3p and its target gene. The MTT method was used to determine the chemo-sensitizing effect of miR-153-3p on doxorubicin in MCF-7 and MDA-MB-231 cell lines. Results of Western blot and dual luciferase confirmed that miR-153-3p targets KIF20A and decreases its expression. Transwell and flow cytometry experiments showed that miR-153-3p and doxorubicin together had higher effects on MCF-7 and MDA-MB-231 cell proliferation, migration, and invasion, as well as increasing apoptosis and arresting cells in the G1 phase. Proteins related to apoptosis and the cell cycle exhibited the same tendency. Intracellular vesicle formation was inhibited and RAB26 was also downregulated by treatment with miR-153-3p alone or in combination with doxorubicin. Doxorubicin’s ability to suppress tumors may be enhanced by miR-153-3p, according to in vivo studies. According to our findings, miR-153-3p has a direct effect on KIF20A and may regulate the formation of intracellular vesicles, which in turn makes breast cancer cells more susceptible to doxorubicin.