Exposure to Phthalates and Alternative Plasticizers Is Associated with Methylation Changes of ESR1 and PGR in Uterine Leiomyoma: The ELENA Study

Yoon Hee Cho,Younglim Kho,Young Ah Kim,Wanseo Kim,Yang Jee Kim,Kyoung Chul Chun,Sunmi Kim,Yeong Sook Yoon,Eun Jeong Choi,Jae Whoan Koh,Haewon Choi,Min Sun Koo

doi:10.3390/app11094234

Abstract

Uterine leiomyomas are estrogen-dependent benign tumors with unknown etiologies. Phthalates are endocrine-disrupting chemicals and ubiquitous in the environment; thus, it has been suggested that they play a role in the development of uterine leiomyoma. We aimed to investigate whether the pathogenesis of uterine leiomyoma is related to methylation changes in promoter regions of estrogen receptor α (ESR1) and progesterone receptor (PGR) genes in response to phthalates and alternative plasticizers exposure. Urinary concentrations of 20 phthalate metabolites and seven metabolites of di-2-ethylhexyl terephthalate (DEHTP) and di (isononyl) cyclohexane-1,2-dicarboxylate (DINCH) were measured by UHPLC-MS/MS in thirty leiomyoma patients, who provided both paired leiomyoma and myometrium tissues. Methylation levels of ESR1 and PGR were analyzed by pyrosequencing assay. A total of 12 phthalate metabolites and 5 alternative metabolites (3 DEHTP and 2 DINCH) were detected >70% among study participants. The methylation of ESR1 and PGR were significantly lower in leiomyoma tissues compared to those in myometrium (18.10 ± 4.41 vs. 28.72 ± 4.95; 2.32 ± 0.81 vs. 3.27 ± 0.56, respectively). ESR1 methylation in leiomyoma was negatively associated with mono-2-carboxylmethyl-hexyl phthalate (2cx-MMHP) and mono-3-carbocyl-propyl phthalate (MCPP) after adjusting for confounding factors. However, 1-mono-2-ethyl-5-oxohexyl-benzene-1,4-dicarboxylate (5OXO-MEHTP), one of the alternatives, showed positive association with ESR1 methylation in leiomyoma. PGR methylation in leiomyoma was significantly associated with mono butyl phthalate (MnBP), but negatively associated with cyclohexane-1,2-dicarboxylate-mono-7-hydroxy-4-methyl-heptyl ester (cx-MINCH). Our results suggest that phthalates exposure may contribute to leiomyoma pathogenesis via ESR1 and PGR methylation changes.

Highlights

Phthalates are high-volume-produced chemicals that have been used in many settings, including industrial, commercial, personal, and household applications
We aimed to investigate whether the pathogenesis of uterine leiomyoma is related to methylation changes in promoter regions of ESR1 and progesterone receptor (PR) gene (PGR) in response to phthalates and alternative plasticizers exposure
Sixteen leiomyoma patients were accompanied by endometriosis (n = 3), adenomyosis (n = 9), or endometriosis and adenomyosis (n = 4)

Summary

Introduction

Phthalates are high-volume-produced chemicals that have been used in many settings, including industrial, commercial, personal, and household applications. Phthalates are known to be estrogenic and androgenic endocrine disruptors; adverse effects of phthalates on the human reproductive system have been reported [2,3,4,5,6,7]. Considering the negative health effects of phthalates to animals and humans, there is a need to develop and/or use alternative plasticizers with low toxicity and less severe consequences for human health [8,9]. Alternative plasticizers have been recently and rapidly used; there is very limited information regarding their toxicity and health effects [10]. Some animal studies may raise the concern that adverse human health effects will emerge with increasing use and exposure to these materials

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