CRISPR/Cas9-mediated knockout of DYRK1B in triple-negative breast cancer cells: implications for cell proliferation, apoptosis, and therapeutic sensitivity

Abstract

Breast cancer is the most common cancer among women worldwide, with the triple-negative subtype (TNBC) having a poor prognosis and limited treatment options. DYRK1B is a dual-specificity kinase that regulates the cell cycle and quiescence. While its role in several cancers has been characterized, its role in TNBC remains unknown. In this study, we used CRISPR/Cas9 to delete DYRK1B in MDA-MB-231 cells, a model of TNBC and investigated its effects on cell proliferation, apoptosis, invasion, migration, angiogenesis, and response to Paclitaxel. The DYRK1B knockout (KO) was confirmed by PCR, Real-time qPCR, and Sanger sequencing. KO cells showed a significant reduction in cell proliferation, colony formation, invasion, and migration. Additionally, there were alterations in mRNA expression levels of several genes related to the cell cycle, angiogenesis, and cell motility, such as CCND1, MCM2, PCNA, CDKN1B, HIF1A, VEGFA, and WASF3, compared to MDA-MB-231 wild type (WT) cells. Immunocytochemistry results assessing Ki67 expression, a marker of cell proliferation, indicated that DYRK1B knockout cells had significantly lower Ki67 expression than WT cells. Furthermore, KO cells exhibited increased apoptosis and sensitivity to contact inhibition. Additionally, the IC₅₀ for Paclitaxel was significantly decreased in KO cells. These results suggest that DYRK1B plays an important role in the survival and invasion of TNBC cells and might be a potential candidate as a new therapeutic target for this disease.