Lee Min Seung, Lim So Hyun, Yu Ah-Ran, Hwang Chi Yeon, Kang Insug, Yeo Eui-Ju
Department of Biochemistry, College of Medicine, Gachon University, Incheon 21999, Korea.
Department of Biomedical Sciences, Graduate School, Kyung Hee University, Seoul 02447, Korea.
Biology (Basel). 2021 Feb 15;10(2):153. doi: 10.3390/biology10020153.
Proteasome inhibitors, such as bortezomib (BZ) and carfilzomib (CFZ), have been suggested as treatments for various cancers. To utilize BZ and/or CFZ as effective therapeutics for treating melanoma, we studied their molecular mechanisms using B16-F1 melanoma cells. Flow cytometry of Annexin V-fluorescein isothiocyanate-labeled cells indicated apoptosis induction by treatment with BZ and CFZ. Apoptosis was evidenced by the activation of various caspases, including caspase 3, 8, 9, and 12. Treatment with BZ and CFZ induced endoplasmic reticulum (ER) stress, as indicated by an increase in eIF2α phosphorylation and the expression of ER stress-associated proteins, including GRP78, ATF6α, ATF4, XBP1, and CCAAT/enhancer-binding protein homologous protein. The effects of CFZ on ER stress and apoptosis were lower than that of BZ. Nevertheless, CFZ and BZ synergistically induced ER stress and apoptosis in B16-F1 cells. Furthermore, the combinational pharmacological interactions of BZ and CFZ against the growth of B16-F1 melanoma cells were assessed by calculating the combination index and dose-reduction index with the CompuSyn software. We found that the combination of CFZ and BZ at submaximal concentrations could obtain dose reduction by exerting synergistic inhibitory effects on cell growth. Moreover, this drug combination reduced tumor growth in C57BL/6 syngeneic mice. Taken together, these results suggest that CFZ in combination with BZ may be a beneficial and potential strategy for melanoma treatment.
蛋白酶体抑制剂，如硼替佐米（BZ）和卡非佐米（CFZ），已被提议用于治疗各种癌症。为了将BZ和/或CFZ用作治疗黑色素瘤的有效疗法，我们使用B16-F1黑色素瘤细胞研究了它们的分子机制。用异硫氰酸荧光素标记的膜联蛋白V对细胞进行流式细胞术分析表明，BZ和CFZ处理可诱导细胞凋亡。各种半胱天冬酶（包括半胱天冬酶3、8、9和12）的激活证明了细胞凋亡。BZ和CFZ处理诱导了内质网（ER）应激，这表现为eIF2α磷酸化增加以及ER应激相关蛋白（包括GRP78、ATF6α、ATF4、XBP1和CCAAT/增强子结合蛋白同源蛋白）的表达增加。CFZ对ER应激和细胞凋亡的作用低于BZ。然而，CFZ和BZ协同诱导B16-F1细胞中的ER应激和细胞凋亡。此外，通过使用CompuSyn软件计算联合指数和剂量减少指数，评估了BZ和CFZ对B16-F1黑色素瘤细胞生长的联合药理相互作用。我们发现，亚最大浓度的CFZ和BZ联合使用可通过对细胞生长发挥协同抑制作用来实现剂量减少。此外，这种药物组合减少了C57BL/6同基因小鼠中的肿瘤生长。综上所述，这些结果表明CFZ与BZ联合使用可能是一种有益且有潜力的黑色素瘤治疗策略。
