A Slug‐dependent mechanism is responsible for tumor suppression of p53‐stabilizing compound CP‐31398 in p53‐mutated endometrial carcinoma

• Published in: Journal of cellular physiology Vol. 235; no. 11; pp. 8768 - 8778
• Main Authors: Liu, Ling, Yu, Zhi‐Ying, Yu, Tan‐Tan, Cui, Shi‐Hong, Yang, Li, Chang, Hui, Qu, Yan‐Hong, Lv, Xiao‐Feng, Zhang, Xiao‐An, Ren, Chen‐Chen
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.11.2020
• Subjects: Animals; Apoptosis; Apoptosis - drug effects; Carcinoma; Cell Line, Tumor; Cell proliferation; Cell Proliferation - drug effects; CP‐31398; Endometrial cancer; Endometrial Neoplasms - drug therapy; Endometrial Neoplasms - metabolism; Endometrium; Female; Genes; Homology; Humans; Lithium chloride; MDM2 protein; Mice, Nude; Mutation; p53 Protein; p53/Wnt/Puma pathway; p53‐mutated endometrial carcinoma; Proto-Oncogene Proteins c-mdm2 - drug effects; Proto-Oncogene Proteins c-mdm2 - metabolism; Pyrimidines - pharmacology; Ribonucleic acid; RNA; Slug; Tumor cells; Tumor suppressor genes; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; Tumorigenicity; Tumors; Ubiquitination; Uterine cancer; Wnt protein; apoptosis; Slug; CP-31398; p53-mutated endometrial carcinoma; p53/Wnt/Puma pathway
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/jcp.29720

Mutation in the tumor suppressor gene p53 is the most frequent molecular defect in endometrial carcinoma (EC). Recently, CP‐31398, a p53‐stabilizing compound, has been indicated to possess the ability to alter the expression of non‐p53 target genes in addition to p53 downstream genes in tumor cells. Herein, we explore the alternative mechanisms underlying the restoration of EC tumor suppressor function in mutant p53 by CP‐31398. A p53‐mutated EC cell was constructed in AN3CA cells with restored or partial loss of Slug using lentiviral vectors, followed by treatment with 25 μM CP‐31398. A p53‐independent mechanism of CP‐31398 was confirmed by the interaction between mouse double minute 2 homolog (MDM2) and Slug AN3CA cells treated with IWR‐1 (inhibitor of Wnt response 1). Furthermore, the AN3CA cells were treated with short hairpin RNA against Slug, Wnt‐specific activators (LiCl) or inhibitors (XAV‐939) followed by CP‐31398 treatment. Moreover, AN3CA cell proliferation and apoptosis were examined. A tumorigenicity assay was conducted in nude mice. CP‐31398 could promote the apoptosis of p53‐mutated EC cells, while Slug reversed this effect. Slug ubiquitination was found to occur via binding of Slug to MDM2 in AN3CA cells. We found that CP‐31398 increased the GSK‐3ß, p‐Slug, Puma, Wtp53, and Bax expressions whereas Wnt, Mtp‐53, Slug, Bcl‐2, and Ki‐67 expressions were decreased. However, these findings were reversed following the activation of the Wnt pathway and overexpression of Slug. Finally, the in vivo experimental evidence confirmed that CP‐31398 with depleted Slug suppressed tumor growth by downregulating the Slug. Collectively, CP‐31398‐regulated Slug downregulation represses the p53‐mutated EC via the p53/Wnt/Puma pathway. Potential mechanistic action of CP‐31398 treatment in p53‐mutated endometrial carcinoma (EC) cell via Slug degradation. In the p53‐mutated EC cells interfered by CP‐31398, Slug ubiquitination emerges after Slug binding to mouse double minute 2 homolog (MDM2) in EC cells to stabilize Wtp53 expression. Meanwhile, CP‐31398 affects EC cells via the p53/Wnt/Puma pathway by targeting Slug.