E-MTAB-4752
DNA methylation variations are required for reversible EMT induced by cancer-associated fibroblasts in PCa cells
Epithelial-to-mesenchymal transition (EMT) and cancer stem cells play relevant roles in metastasis and drug resistance in castration-resistant PCa. Conditioned-media from Cancer-Associated Fibroblasts from two patients with aggressive PCa induce EMT, reversible DNA methylation and transcriptional variations in androgen independent PC3, but not in androgen dependent LN-CaP cells. Focal CpG islands hyper-methylation associated to transcriptional repression of epithelial markers occurs together with widespread hypo-methylation, including promoters of EMT and stemness regulating genes resulting in their transcriptional activation. Remarkably, DNA methylation and transcription patterns are entirely reverted upon exposure to serum-free medium (mesenchymal-to-epithelial transition). DNMT3A is required for de novo methylation and silencing of CDH1 and GRHL2, the ZEB1 direct repressor, while its knock-down prevents EMT entry. These unprecedented results highlight that CAF-released factors induce reversible DNA methylation patterns required for transcriptional variations essential for EMT and stemness in androgen independent PCa cells, suggesting that similar plasticity might occur in tumour microenvironment.
Epithelial-to-mesenchymal transition (EMT) and cancer stem cells play relevant roles in metastasis and drug resistance in castration-resistant PCa. Conditioned-media from Cancer-Associated Fibroblasts from two patients with aggressive PCa induce EMT, reversible DNA methylation and transcriptional variations in androgen independent PC3, but not in androgen dependent LN-CaP cells. Focal CpG islands hyper-methylation associated to transcriptional repression of epithelial markers occurs together with widespread hypo-methylation, including promoters of EMT and stemness regulating genes resulting in their transcriptional activation. Remarkably, DNA methylation and transcription patterns are entirely reverted upon exposure to serum-free medium (mesenchymal-to-epithelial transition). DNMT3A is required for de novo methylation and silencing of CDH1 and GRHL2, the ZEB1 direct repressor, while its knock-down prevents EMT entry. These unprecedented results highlight that CAF-released factors induce reversible DNA methylation patterns required for transcriptional variations essential for EMT and stemness in androgen independent PCa cells, suggesting that similar plasticity might occur in tumour microenvironment.