LA-CB1, a novel Abemaciclib derivative induces apoptosis in breast cancer cells by inhibiting the CDK4/6-Cyclin D-Rb-E2F pathway path

Triple-negative breast cancer (TNBC) is a subtype of breast cancer (BC) characterized by deletion of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (Her-2). It accounts for 10.0% to 20.8% of all pathological types of BC, has specific biological behavior and clinicopathological features, and has a worse prognosis than other types. TNBC usually has a high mortality and recurrence rate, and a poor prognosis after surgery, radiation, chemotherapy, and endocrine therapy. There are no conventional and effective treatments to control its progression. Therefore, we designed and developed a derivative based on Abemaciclib, named LA-CB1. To investigate the influence of LA-CB1 on biological function of TNBC. We use the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT) to detect the viability of breast cancer cells. Evaluation of drug effects on cell migration and invasion by Transwell assays. Cell clone formation assay detects cell proliferation ability after drug addition. Subsequently, we determined the clinical significance and functional role of LA-CB1 through chick embryo experiments. Then, transcriptome sequencing technology (RNA-Seq) and bioinformatics methods were used to study the main pathway of LA-CB1 action on MDA-MB-231 cells. Western Blot assay verified the effect of LA-CB1 on the expression of CDK4/6-CyclinD1-Rb-E2F pathway protein. The compound LA-CB1 can inhibit the proliferation, colony formation, migration and invasion of TNBC cells. Effect of compound LA-CB1 on apoptosis and cell cycle detected by flow cytometry. The expression levels of CDK4, CDK6, CyclinD1, E2F1 and p-Rb proteins were positively correlated with LA-CB1 concentration. In summary, LA-CB1 showed a good anti-tumor cell proliferation effect, showing potential anti-TNBC drug candidate properties. This study provides new ideas and possibilities for TNBC treatment. Overall design: To investigate the role of LA-CB1 in breast cancer and its mechanism, we treated and did not treat MDA-MB-231 cells with LA-CB1. Then, we performed gene expression profiling using RNA-seq data from MDA-MB-231_LA-CB1 and MDA-MB-231_DMSO cells.