Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Iran Biomed J. 2024 Jan 1;28(1):46-52. doi: 10.61186/ibj.3993. Epub 2023 Nov 21.
The potential anticancer effect of melittin has motivated scientists to find its exact molecular mechanism of action. There are few data on the effect of melittin on the UPR and autophagy as two critical pathways involved in tumorigenesis of colorectal and drug resistance. This study aimed to investigate the effect of melittin on these pathways in the colorectal cancer (CRC) HCT116 cells.
MTT method was carried out to assess the cytotoxicity of melittin on the HCT116 cell line for 24, 48, and 72 h. After selecting the optimal concentrations and treatment times, the gene expression of autophagy flux markers (LC3-βII and P62) and UPR markers (CHOP and XBP-1s) were determined using qRT-PCR. The protein level of autophagy initiation marker (Beclin1) was also determined by Western blotting.
MTT assay showed a cytotoxic effect of melittin on the HCT116 cells. The increase in LC3-βII and decrease in P62 mRNA expression levels, along with the elevation in the Beclin1 protein level, indicated the stimulatory role of melittin on the autophagy. Melittin also significantly enhanced the CHOP and XBP-1s expressions at mRNA level, suggesting the positive role of the melittin on the UPR activation.
This study shows that UPR and autophagy can potentially be considered as two key signaling pathways in tumorigenesis, which can be targeted by the BV melittin in the HCT116 cells. Further in vivo evaluations are recommended to verify the obtained results.
蜂毒素具有潜在的抗癌作用，这促使科学家们寻找其确切的作用机制。关于蜂毒素对未折叠蛋白反应（UPR）和自噬这两条涉及结直肠肿瘤发生和耐药的关键途径的影响，数据较少。本研究旨在探讨蜂毒素对结直肠癌细胞（HCT116 细胞）中这些途径的影响。
采用 MTT 法检测蜂毒素对 HCT116 细胞系 24、48 和 72 h 的细胞毒性。选择最佳浓度和处理时间后，采用 qRT-PCR 检测自噬通量标记物（LC3-βII 和 P62）和 UPR 标记物（CHOP 和 XBP-1s）的基因表达。Western blot 法测定自噬起始标记物（Beclin1）的蛋白水平。
MTT 试验显示蜂毒素对 HCT116 细胞具有细胞毒性作用。LC3-βII 表达增加和 P62mRNA 表达水平降低，以及 Beclin1 蛋白水平升高，表明蜂毒素对自噬具有刺激作用。蜂毒素还显著增强了 CHOP 和 XBP-1s 的 mRNA 表达，提示蜂毒素对 UPR 激活具有积极作用。
本研究表明，UPR 和自噬可能被认为是肿瘤发生的两个关键信号通路，蜂毒素可以靶向 HCT116 细胞中的这两个通路。建议进行进一步的体内评估以验证所获得的结果。
