DNA methylation patterns of steroid receptor genes ESR1, ESR2 and PGR in deep endometriosis compromising the rectum.
Endometriosis is characterized by the presence of endometrial-like tissue located outside the uterine cavity. Recent evidence suggests that endometriosis may be an epigenetic disease, as well as an estrogen-dependent disease. Based on the unique steroid hormone receptor expression profile observed in endometriotic lesions as compared to eutopic endometrium, the present study aimed to gain further insight into the DNA methylation patterns of alternative promoters of the steroid receptor genes ESR1, ESR2 and PGR in intestinal deep endometriosis, one of the most aggressive forms of endometriosis. The DNA methylation patterns were evaluated by methylation-specific polymerase chain reaction (MS-PCR) after bisulfite modification in 44 endometriotic tissues as well as in 7 matched eutopic endometrium. No differences in the DNA methylation were observed for the ESR1 and ESR2 genes. Methylation of the PGR gene was observed in 39% (17 out of 44) and 19% (7 out of 37) of the cases in the promoter regions B (PGRB) and A (PGRA), respectively. Both PGR promoter regions were methylated in 3 cases. PGRB methylated alleles were detected exclusively in the endometriotic lesions when compared to the eutopic endometrium obtained from the same patient. The effect of DNA methylation in inhibiting the PGR gene expression was corroborated by immuno-staining for PgR protein in a subset of tissue samples. The present study demonstrated that epigenetic changes occur in both promoter regions of the PGR gene in intestinal endometriosis. Since eutopic and ectopic tissues do not respond sufficiently to progesterone in women with endometriosis, further study is necessary to evaluate the effect of epigenetic alterations in progesterone-resistance in this enigmatic disease.
Department of Genetics, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil.
Joana Ladeira
JL
Meyer
Department of Genetics, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil.
Daniela
D
Zimbardi
Department of Obstetrics and Gynecology, São Paulo University (USP), São Paulo, Brazil.
Sérgio
S
Podgaec
Department of Clinical Veterinary Medicine, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil.
Renee Laufer
RL
Amorim
Department of Obstetrics and Gynecology, São Paulo University (USP), São Paulo, Brazil.
Maurício Simões
MS
Abrão
Department of Genetics, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil.
Cláudia Aparecida
CA
Rainho
D000328:Adult; D019175:DNA Methylation / Q000235:genetics*; D004715:Endometriosis / Q000235:genetics* / Q000473:pathology*; D047628:Estrogen Receptor alpha / Q000235:genetics* / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000235:genetics* / Q000378:metabolism; D005260:Female; D006801:Humans; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011980:Receptors, Progesterone / Q000235:genetics* / Q000378:metabolism; D012007:Rectum / Q000473:pathology*
C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011980:Receptors, Progesterone