Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand.
Molecules. 2021 Oct 22;26(21):6377. doi: 10.3390/molecules26216377.
Betulinic acid (BA) is a pentacyclic triterpene usually isolated from botanical sources. Numerous studies have reported the inhibitory effect of BA against human colorectal cancer cells (CRC). However, its effect on the expression of the molecular chaperone HSPA is unclear. The aim of this research is to investigate the anti-cancer activities of BA purified from and study its effect on the expression of HSPA in colorectal cancer HCT116 and SW480 cells. The viability of both cancer cells was reduced after they were treated with an increasing dosage of BA. Flow cytometry assay revealed that levels of cell apoptosis significantly increased after incubation with BA in both cancer cells. Pro-apoptotic markers including Bax, cleaved-caspase-3 and cleaved-caspase-9 were increased while anti-apoptotic marker Bcl-2 was decreased after BA treatment. Western blot also showed that the expression of HSPA fluctuated upon BA treatment, whereby HSPA was increased at lower BA concentrations while at higher BA concentrations HSPA expression was decreased. Preliminary molecular docking assay showed that BA can bind to the nucleotide binding domain of the HSP70 at its ADP-bound state of the HSP70. Although further research is needed to comprehend the BA-HSPA interaction, our findings indicate that BA can be considered as potential candidate for the development of new treatment for colorectal cancer.
白桦脂酸 (BA) 是一种五环三萜，通常从植物来源中分离得到。许多研究报告了 BA 对人结直肠癌细胞 (CRC) 的抑制作用。然而，其对分子伴侣 HSPA 的表达的影响尚不清楚。本研究旨在从 中纯化 BA，研究其对结直肠癌细胞 HCT116 和 SW480 中 HSPA 表达的影响。用递增剂量的 BA 处理后，两种癌细胞的活力均降低。流式细胞术分析显示，BA 孵育后两种癌细胞的细胞凋亡水平明显增加。促凋亡标志物 Bax、cleaved-caspase-3 和 cleaved-caspase-9 增加，而抗凋亡标志物 Bcl-2 减少。Western blot 也显示，BA 处理后 HSPA 的表达发生波动，BA 浓度较低时 HSPA 增加，BA 浓度较高时 HSPA 表达减少。初步的分子对接实验表明，BA 可以与 HSP70 的核苷酸结合域结合，处于 HSP70 的 ADP 结合状态。虽然需要进一步研究来理解 BA-HSPA 相互作用，但我们的发现表明，BA 可以被认为是开发结直肠癌新治疗方法的潜在候选药物。
