Cheng J, Li M, Tzeng CM, Gou X, Chen S. Suppression of Tumorigenicity 5 Ameliorates Tumor Characteristics of Invasive Breast Cancer Cells
via ERK/JNK Pathway.
Front Oncol 2021;
11:621500. [PMID:
34395234 PMCID:
PMC8356645 DOI:
10.3389/fonc.2021.621500]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 06/04/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND
Suppression of tumorigenicity 5 (ST5) has been considered as a tumor suppressor gene in HeLa tumor cells. However, its role in the progression of breast cancer remains vague.
METHODS
Online database analysis was determined by Oncomine and Breast Cancer Gene-Expression Miner v4.4 (bc-GenExMiner v4.4). Tumor biology behaviors were measured by MTT assay, wound healing model, Transwell and Flow cytometry assays. Methylation-specific PCR (MSP) was employed to detect promoter methylation.
RESULTS
Low level of ST5 was observed in breast cancer specimens, particularly in recurrent, invasive breast cancer cases compared to para-carcinoma tissue or non-invasive breast cancer. The downregulation of ST5 was also proved in MDA-MB-231 and SKBR3 cell lines with a high invasive capability as compared to MCF-7 cell with a low invasive capability. ST5 was negatively associated with pathological stages of breast cancer. ST5-downregulation promoted, while ST5-upregulation inhibited the progression of cell proliferation, cell cycle and migration of MDA-MB-231 cells. Additionally, ST5 knockdown inhibited, whereas ST5 overexpression promoted apoptosis of MDA-MB-231 cells. However, ST5 modification, either upregulation or downregulation, had no significant impact on tumor behaviors of MCF-7 cells. Mechanistically, ST5 protein ablation activated, while ST5-upregulation repressed the activities of phosphorylated ERK1/2 and JNK, and subsequently the expression of c-Myc. PD98059-mediated ERK1/2 inhibition abolished the stimulatory effects of ST5-depletion on ERK1/2/JNK/c-Myc signaling axis, and ST5 depletion-mediated cell over-proliferation and migration. Of note, ST5 reduction in invasive breast cancer cells should implicate in the hypermethylation of ST5 promoter region.
CONCLUSION
Our findings suggest that ST5 potentially acts as a tumor suppressor gene in invasive breast cancer through regulating ERK/JNK signaling pathway and provide a novel insight for breast cancer treatment.
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