Role of JNK/c-Jun signaling pathway mediated by endoplasmic reticulum stress in triptolide-induced apoptosis of melanoma A375 cells in mice
- VernacularTitle:内质网应激介导的JNK/c-Jun信号通路在雷公藤内酯醇诱导小鼠体内黑色素瘤A375细胞凋亡中的作用研究
- Author:
Yamei ZHANG
1
;
Guohao LIU
;
Yue TAO
;
Jun BAO
Author Information
- Keywords: Melanoma; Triptolide; Endoplasmic reticulum stress; Apoptosis; A375 cells; JNK/c-Jun signaling pathway
- From: Chinese Journal of Dermatology 2024;57(8):709-714
- CountryChina
- Language:Chinese
- Abstract: Objective:To explore the role of c-Jun N-terminal kinase (JNK) /c-Jun signaling pathway mediated by endoplasmic reticulum stress in triptolide-induced apoptosis of melanoma A375 cells.Methods:Nude mice were subcutaneously inoculated with melanoma A375 cells on the back to establish the animal model of melanoma. Tumor formation could be observed at approximately 3 weeks after inoculation, and then the mice were divided into 4 groups (4 mice in each group) : control group (injected with sodium chloride physiological solution via the tail vein), 0.1-, 0.2-, and 0.4-mg/kg triptolide groups (injected with 0.1, 0.2, and 0.4 mg/kg triptolide via the tail vein, respectively). Injections were performed twice a week. After 3 weeks of injections, tumors were resected, and their size and weight were measured. The apoptosis levels of tumor xenografts were detected by the terminal deoxyribonucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay. qPCR was conducted to determine the mRNA expression of inositol-requiring enzyme 1 (IRE1), JNK, and c-Jun, and Western blot analysis to determine the protein expression of IRE1, JNK, c-Jun, phosphorylated-JNK (p-JNK), and phosphorylated-c-Jun (p-c-Jun). Comparisons among multiple groups were performed using one-way analysis of variance, and multiple comparisons were performed using Dunnett's test.Results:Significant differences were observed in the tumor mass, volume and tumor suppression rate among the control group, 0.1-, 0.2-, and 0.4-mg/kg triptolide groups (all P < 0.05) ; all the triptolide groups showed significantly decreased tumor masses and volumes (all P < 0.05), but significantly increased tumor suppression rates compared with the control group (all P < 0.05). The tumor apoptosis index significantly differed among the control group, 0.1-, 0.2-, and 0.4-mg/kg triptolide groups (7.67% ± 1.15%, 9.67% ± 3.21%, 62.00% ± 6.08%, and 85.67% ± 5.51%, respectively; F = 305.91, P < 0.001), and the 0.2- and 0.4-mg/kg triptolide groups showed significantly increased tumor apoptosis indices compared with the control group ( t = 17.56, 27.72, respectively, both P < 0.05). qPCR and Western blot analysis revealed significant differences in the mRNA expression of IRE1, JNK, and c-Jun among the control group, 0.1-, 0.2-, and 0.4-mg/kg triptolide groups ( F = 112.23, 27.51, 112.37, respectively, all P < 0.05), as well as in the relative protein expression levels of IRE1, JNK, c-Jun, p-JNK, and p-c-Jun among the above 4 groups (all P < 0.05). Additionally, the 0.4-mg/kg triptolide group showed significantly increased mRNA and protein expression of IRE1, JNK and c-Jun (including p-JNK, p-c-Jun) compared with the control group (all P < 0.05). The mRNA and protein expression levels of IRE1, JNK, and c-Jun in the tumor tissues tended to increase with the rise in drug concentrations, and the protein expression levels of p-JNK and p-c-Jun showed the same trend. Conclusion:Triptolide could activate the JNK/c-Jun signaling pathway mediated by the endoplasmic reticulum stress, and then induce apoptosis of melanoma A375 cells in mice.
