College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea.
Division of Allergy, Immune and Respiratory System, Department of Internal Medicine, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea.
Int J Mol Sci. 2022 Oct 7;23(19):11900. doi: 10.3390/ijms231911900.
Timosaponin A3 (TA3), extracted from the rhizome of Bunge, has been reported to affect various diseases, such as cancer, Alzheimer's disease, and allergies. However, the underlying molecular mechanisms and impacts are largely unknown. In the present study, we hypothesized that TA3 induces apoptosis through the inhibition of c-Myc expression via CNOT2 or MID1IP1 in HCT116. An MTT assay and colony formation assay were used to measure cell viability and proliferation. The protein expression of apoptotic markers and oncogenes was measured using immunoblotting and immunofluorescence assays. The interaction between MID1IP1 and c-Myc was confirmed by performing an immunoprecipitation assay. TA3 markedly inhibited colon cancer cell proliferation. Consistently, TA3 regulated the apoptotic proteins pro-PARP and caspase 3. TA3 inhibited the half-life of c-Myc and suppressed its expression in response to serum stimulation. In addition, TA3 enhanced the apoptotic effects of doxorubicin and 5-FU in colon cancer cells. Altogether, our results reveal a mechanism by which TA3 induces apoptosis through inhibiting c-Myc expression via CNOT2 or MID1IP1 in HCT116, which may help in the development of new therapies for colon cancer based on TA3 in the future.
知母皂苷 A3（TA3）从知母根茎中提取，据报道可影响多种疾病，如癌症、老年痴呆症和过敏。然而，其潜在的分子机制和影响在很大程度上是未知的。在本研究中，我们假设 TA3 通过 CNOT2 或 MID1IP1 抑制 c-Myc 表达诱导 HCT116 细胞凋亡。通过 MTT 检测和集落形成实验来测量细胞活力和增殖。通过免疫印迹和免疫荧光实验测量凋亡标记物和癌基因的蛋白表达。通过免疫沉淀实验来验证 MID1IP1 和 c-Myc 之间的相互作用。TA3 显著抑制结肠癌细胞增殖。一致地，TA3 调节凋亡蛋白 pro-PARP 和 caspase 3。TA3 抑制 c-Myc 的半衰期并抑制其表达以响应血清刺激。此外，TA3 增强了阿霉素和 5-FU 在结肠癌细胞中的凋亡作用。总之，我们的结果揭示了 TA3 通过 CNOT2 或 MID1IP1 抑制 c-Myc 表达诱导 HCT116 细胞凋亡的机制，这可能有助于未来基于 TA3 开发治疗结肠癌的新疗法。
