The tumor suppressor Zinc finger protein 471 suppresses breast cancer growth and metastasis through inhibiting AKT and Wnt/β-catenin signaling

Abstract

Background Zinc-finger protein 471 (ZNF471) is a member of the Krüppel-associated box domain zinc finger protein (KRAB-ZFP) family. ZNF471 is methylated in squamous cell carcinomas of tongue, stomach and esophageal. However, its role in breast carcinogenesis remains elusive. Here, we studied its expression, functions, and molecular mechanisms in breast cancer. Methods We examined ZNF471 expression by RT-PCR and qPCR. Methylation-specific PCR determined its promoter methylation. Its biological functions and related molecular mechanisms were assessed by CCK-8, clonogenicity, wound healing, Transwell, nude mice tumorigenicity, flow cytometry, BrdU-ELISA, immunohistochemistry and Western blot assays. Results ZNF471 was significantly downregulated in breast cell lines and tissues due to its promoter CpG methylation, compared with normal mammary epithelial cells and paired surgical-margin tissues. Ectopic expression of ZNF471 substantially inhibited breast tumor cell growth in vitro and in vivo, arrested cell cycle at S phase, and promoted cell apoptosis, as well as suppressed metastasis. Further knockdown of ZNF471 verified its tumor-suppressive effects. We also found that ZNF471 exerted its tumor-suppressive functions through suppressing epithelial-mesenchymal transition, tumor cell stemness and AKT and Wnt/β-catenin signaling. Conclusions ZNF471 functions as a tumor suppressor that was epigenetically inactivated in breast cancer. Its inhibition of AKT and Wnt/β-catenin signaling pathways is one of the mechanisms underlying its anti-cancer effects.

ZNF471 modulates EMT and functions as methylation regulated tumor suppressor with diagnostic and prognostic significance in cervical cancer

“…We have reported the hypermethylation of multiple gene promoters in CC (Bhat et al 2017b). Hypermethylation of ZNF471 is reported in squamous cell carcinoma of the tongue, colorectal cancer, oropharyngeal squamous cell carcinoma, esophageal cancer, breast cancer, and aging (Bhat et al 2017a;Lleras et al 2011;Marttila et al 2015;Mitchell et al 2014;Sun et al 2020;Tao et al 2020). However, the cause and consequences of ZNF471 hypermethylation in CC are yet to be established.…”

Comprehensive Characterization of m6A Regulators-Mediated Methylation Modification Patterns and Tumor Microenvironment Signature in Breast Cancer

“…The dysregulation of epigenetic modi cations is a common feature of most human cancers, including breast cancer [33,34,35]. Apart from DNA methylation and protein phosphorylation or histone modi cations, RNA m6A modi cation has been identi ed as another important layer of epigenetic modi cation in transcription and translation [36], which are involved in regulating RNA stability, RNA export, protein translation, and stem cell renewal [4,37].…”

KRAB-ZFP Transcriptional Regulators Acting as Oncogenes and Tumor Suppressors: An Overview

“…The ZNF471 promoter region occurs frequently methylated in various cancer tissues, including colorectal [ 56 ], tongue squamous cell [ 57 ], breast [ 58 ], gastric [ 59 ], and esophageal cancer ( Figure 4 ) [ 60 ]. ZNF471 transcript may also be downregulated by the oncogenic miR-942-5p, as shown in non-small cell lung cancer (NSCLC) [ 61 ].…”

“…Cao and colleagues demonstrated that the underlying mechanism of ZNF471 TSG potential involves the promoter binding and H3K9me3-mediated transcriptional repression of plastin 3 ( PLS3 ) and transcription factor AP-2 alpha ( TFAP2A ) oncogenes [ 59 ]. In breast cancer (BRCA) cell lines and tissues [ 58 ], the experimental overexpression of ZNF471 also reduced cell growth, both in vitro and in vivo, induced cell cycle arrest at the S phase ( Figure 5 ) enhanced apoptosis, and attenuated metastasis. Such an effect was associated with the inhibitory influence of ZNF471 on EMT, cell stemness, as well as Wnt/β-catenin and AKT signaling pathways [ 58 ].…”

“…In breast cancer (BRCA) cell lines and tissues [ 58 ], the experimental overexpression of ZNF471 also reduced cell growth, both in vitro and in vivo, induced cell cycle arrest at the S phase ( Figure 5 ) enhanced apoptosis, and attenuated metastasis. Such an effect was associated with the inhibitory influence of ZNF471 on EMT, cell stemness, as well as Wnt/β-catenin and AKT signaling pathways [ 58 ]. The Wnt/β-catenin pathway is responsible for cell proliferation, lineage commitment during embryonic development [ 62 ], regulation of migration, apoptosis, stem cell renewal, and genetic stability [ 63 ].…”