Effect of combined treatment with lobaplatin and osthole on inducing apoptosis and inhibiting proliferation in human breast cancer MDA-MB-231 cells

Abstract

The present study investigates the underlying mechanisms of treatment with osthole (OST) combined with lobaplatin in human triple-negative MDA-MB-231 breast cancer cells. Human triple-negative MDA-MB-231 breast cancer cells were treated with different concentrations of OST (0.1, 1, 5, 10, 20, 50, and 100 μM) alone or in combination with 10 μM lobaplatin for 48 h. Cell viability was determined and compared between the treatment groups with the Cell Counting Kit-8 assay. Transcriptome sequencing (Project Number: M-GSGC0250521) was employed to elucidate the gene expression profile of the control group and the OST treatment group, and differentially expressed genes (DEGs) were identified based on the following criteria: log₂FC > 0, P < 0.05. KEGG enrichment analysis was employed to determine the biological functions of these DEGs and the related signaling pathways. Finally, flow cytometry and western blotting were used to assess differences in the apoptosis rate and protein expression in MDA-MB-231 cells subjected to different treatments. The findings showed that OST inhibited the growth of MDA-MB-231 cells in a concentration-dependent manner and cell proliferation was significantly inhibited (as indicated by a decrease of 40%) at the OST concentration of 50 μM (P < 0.05). Transcriptome sequencing identified 4712 DEGs, including 2169 upregulated DEGs and 2543 downregulated DEGs. Enrichment analysis indicated that the DEGs played a role in apoptosis, p53 signaling, DNA replication, and cell cycle. In vitro experiments showed that OST and lobaplatin could significantly induce apoptosis in the MDA-MB-231 cells (P < 0.05), as indicated by elevation in the translation level of p53/Bax/caspase-3 p17 and downregulation of the Bcl-2 protein. Finally, combined treatment with OST and lobaplatin had an enhanced anti-tumor effect (P < 0.05) on proliferation and apoptosis, as well as more obvious effects on the related proteins (p53, Bax, Bcl-2, and caspase-3 p17). Thus, OST enhanced the apoptosis-mediated growth inhibitory effect of lobaplatin on breast cancer cells and has potential for the treatment of breast cancer in the future.

Keywords: Apoptosis; Breast cancer; Lobaplatin; Osthole; Transcriptomics; p53 signaling.