The carcinogen cadmium elevates CpG-demethylation and enrichment of NFYA and E2F1 in the promoter of oncogenic PRMT5 and EZH2 methyltransferases resulting in their elevated expression in vitro Krishna Ghosh a, b , Biji Chatterjee a , Parameswar Behera a , Santosh R. Kanade b, * a Department of Biochemistry and Molecular Biology, School of Biological Sciences, Central University of Kerala, Kasargod, 671316, Kerala, India b Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Central University P.O., Hyderabad, 500046, Telangana, India highlights graphical abstract  Cadmium (Cd) exposure modulates DNMTs expression that induces global DNA hypomethylation in vitro.  Cd-mediated DNMT downregulation leads to failure of methylation of the promoter CpGs of PRMT5 and EZH2.  Nonmethylated promoter allows enrichment of NFYA/E2F1 and in- duces expression of PRMT5/EZH2.  The elevated methyltransferases ca- talyse formation of SDMA, H4R3me2s, and H3K27me3 globally. article info Article history: Received 6 September 2019 Received in revised form 18 October 2019 Accepted 21 October 2019 Available online 23 October 2019 Handling Editor: David Volz Keywords: Cadmium Epigenetics DNA hypomethylation DNMT EZH2 PRMT5 abstract Cadmium (Cd) is considered as a carcinogenic chemical with potential to endanger normal cellular functioning. The present study was aimed to investigate the impact of Cd on the expression of two oncogenic epigenetic regulators, viz., protein arginine methyltransferase 5 (PRMT5) and the polycomb repressive complex 2 (PRC2) member enhancer of Zeste homolog 2 (EZH2). Our results indicate that Cd at 1 mM concentration increases the viability of HepG2 and MCF7 cells and significantly upregulates the expression of PRMT5 and EZH2, leading to an increased global level of symmetric dimethylarginine (SDMA), H4R3me2s, and H3K27me3. The luciferase reporter assay showed that the promoter activity of PRMT5 and EZH2 is significantly enhanced in both cell lines. Furthermore, Cd exposure induces global DNA hypomethylation due to a decrease in DNA methyltransferases (DNMTs) expression. Methylation- specific and bisulfite sequencing PCR reveal that the proximal promoters of PRMT5 and EZH2, which harbour CpG islands, are almost demethylated when exposed to Cd. The Cd exposure also increases the protein level of transcription factors NFYA and E2F1; consistently, the two transcription factors are found to be enriched at the PRMT5 and EZH2 promoter in chromatin immunoprecipitation experiments. The alterations induced by Cd in the two cancer cell lines were also observed in a non-cancerous cell line (HEK-293). In conclusion, we propose that Cd increases the expression of two oncogenic methyl- transferases, possibly with a DNA methylation-dependent mechanism. Further studies focused on the Abbreviations: BSP, bisulfite-sequencing PCR; Cd, Cadmium; DMEM, Dulbecco’s modified Eagle’s medium; DNMTs, DNA methyltransferases; EZH2, enhancer of zeste homolog 2; H3K27me3, trimethylated lysine 27of histone H3; H4R3me2s, symmetric dimethyl arginine 3 of histone H4; MEP50, methylosome protein 50; MSP, methylation- specific PCR; PRMT5, Protein arginine methyltransferase 5; SDMA, symmetric dimethylarginine; SUZ12, suppressor of zeste 12 protein homolog. * Corresponding author. Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Central University P.O., Hyderabad-500046, Telangana, India E-mail address: san@uohyd.ac.in (S.R. Kanade). Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere https://doi.org/10.1016/j.chemosphere.2019.125186 0045-6535/© 2019 Elsevier Ltd. All rights reserved. Chemosphere 242 (2020) 125186