CLCA2 epigenetic regulation by CTBP1, HDACs, ZEB1, EP300 and miR‐196b‐5p impacts prostate cancer cell adhesion and EMT in metabolic syndrome disease

Abstract

Prostate cancer (PCa) is the most common cancer among men. Metabolic syndrome (MeS) is associated with increased PCa aggressiveness and recurrence. Previously, we proposed C-terminal binding protein 1 (CTBP1), a transcriptional co-repressor, as a molecular link between these two conditions. Notably, CTBP1 depletion decreased PCa growth in MeS mice. The aim of this study was to investigate the molecular mechanisms that explain the link between MeS and PCa mediated by CTBP1. We found that CTBP1 repressed chloride channel accessory 2 (CLCA2) expression in prostate xenografts developed in MeS animals. CTBP1 bound to CLCA2 promoter and repressed its transcription and promoter activity in PCa cell lines. Furthermore, we found that CTBP1 formed a repressor complex with ZEB1, EP300 and HDACs that modulates the CLCA2 promoter activity. CLCA2 promoted PCa cell adhesion inhibiting epithelial-mesenchymal transition (EMT) and activating CTNNB1 together with epithelial marker (CDH1) induction, and mesenchymal markers (SNAI2 and TWIST1) repression. Moreover, CLCA2 depletion in PCa cells injected subcutaneously in MeS mice increased the circulating tumor cells foci compared to control. A microRNA (miRNA) expression microarray from PCa xenografts developed in MeS mice, showed 21 miRNAs modulated by CTBP1 involved in angiogenesis, extracellular matrix organization, focal adhesion and adherents junctions, among others. We found that miR-196b-5p directly targets CLCA2 by cloning CLCA2 3'UTR and performing reporter assays. Altogether, we identified a new molecular mechanism to explain PCa and MeS link based on CLCA2 repression by CTBP1 and miR-196b-5p molecules that might act as key factors in the progression onset of this disease.

Identification of aberrantly methylated‑differentially expressed genes and gene ontology in prostate cancer

“…reduced UBQLN1 expression can cause enhanced cell migration and invasion, actin cytoskeleton rearrangements, and stimulation of the epithelial-mesenchymal transition (eMT) (42,43). Scholars have revealed that cTBP1 is carcinogenic in Pca and other adenomas, and overexpression of cTBP1 is thought to be involved in cell survival, proliferation, migration, invasion, and eMT (44)(45)(46). TriM27 was initially considered to be part of a fusion gene reT (rearranged during transfection), which is a proto-oncogene that is upregulated in multitudinal cancers, including PCa (47,48).…”

Emerging roles for multifunctional ion channel auxiliary subunits in cancer

“…Expression of CLCA2 decreases nasopharyngeal and breast tumourigenesis in vivo [ 307 , 312 , 315 ]. Similarly, CLCA2 depletion increases the number of circulating prostate tumour cells in mice [ 316 ]. At a cellular level, CLCA2 inhibits Wnt signalling [ 317 ], decreases invasion [ 315 ], inhibits proliferation [ 312 ], induces transcellular adhesion [ 316 ], inhibits epithelial-to-mesenchymal transition [ 312 , 316 ], induces differentiation [ 316 , 318 ], inhibits focal adhesion kinase [ 312 , 319 ] and induces p53-mediated cellular senescence [ 320 ].…”

“…Similarly, CLCA2 depletion increases the number of circulating prostate tumour cells in mice [ 316 ]. At a cellular level, CLCA2 inhibits Wnt signalling [ 317 ], decreases invasion [ 315 ], inhibits proliferation [ 312 ], induces transcellular adhesion [ 316 ], inhibits epithelial-to-mesenchymal transition [ 312 , 316 ], induces differentiation [ 316 , 318 ], inhibits focal adhesion kinase [ 312 , 319 ] and induces p53-mediated cellular senescence [ 320 ]. The ability of CLCA2 to inhibit cancer cell migration appears to be I Cl independent, as inhibiting I Cl has a further anti-migratory effect in cells expressing CLCA2 as well as having an anti-migratory effect in cells not expressing CLCA2 [ 312 ].…”

Adipose tissue from metabolic syndrome mice induces an aberrant miRNA signature highly relevant in prostate cancer development

“…Thus, we identified novel pathways regulated by CTBP1 on a MeS environment [4,5]. CTBP1 depletion in androgeninsensitive PCa xenografts from HFD-fed mice affects the expression of genes and microRNAs (miRNAs) involved in hormone biosynthesis, olfactory signaling, and cell adhesion pathways, impacting in PCa development and progression [6][7][8]. Additionally, an androgen-sensitive PCa and MeS-like mice model allowed us to determine that MeS significantly increased tumor growth.…”