title: SFRP1 repression in prostate cancer is triggered by two different epigenetic mechanisms.
abstract: Worldwide, prostate cancer (PCa) is the second cause of death from malignant tumors among men. Establishment of aberrant epigenetic modifications, such as histone post-translational modifications (PTMs) and DNA methylation (DNAme) produce alterations of gene expression that are common in PCa. Genes of the SFRP family are tumor suppressor genes that are frequently silenced by DNA hypermethylation in many cancer types. The SFRP family is composed of 5 members (SFRP1-5) that modulate the WNT pathway, which is aberrantly activated in PCa. The expression of SFRP genes in PCa and their regulation by DNAme has been controversial. Our objective was to determine the gene expression pattern of the SFRP family in prostatic cell lines and fresh frozen tissues from normal prostates (NP), benign prostatic hyperplasia (BPH) and prostate cancer (PCa), by qRT-PCR, and their DNAme status by MSP and bisulfite sequencing. In prostatic cancer cell lines, the 5 SFRPs showed significantly decreased expression levels compared to a control normal prostatic cell line (p<0.0001). In agreement, SFRP1 and SFRP5 genes showed decreased expression levels in CaP fresh frozen tissues compared to NP (p<0.01), while a similar trend was observed for SFRP2. Conversely, increased levels of SFRP4 expression were found in PCa compared to BPH (p<0.01). Moreover, SFRP2, SFRP3, and SFRP5 showed DNA hypermethylation in PCa cell lines. Interestingly, we observed DNA hypermethylation at the promoter of SFRP1 in the PC3 cell line, but not in LNCaP. However, in the LNCaP cell line we found an aberrant gain of the repressive histone posttranslational modification Histone H3 lysine 27 trimethylation (H3K27me3). In conclusion, decreased expression by DNA hypermethylation of SFRP5 is a common feature of PCa, while decreased expression of SFRP1 can be due to DNA hypermethylation, but sometimes an aberrant gain of the histone mark H3K27me3 is observed instead.
authors: Oncogenomics Laboratory, The National Institute of Genomic Medicine, Mexico City 14610, Mexico.
authors: Pilar
authors: P
authors: García-Tobilla
authors: Oncogenomics Laboratory, The National Institute of Genomic Medicine, Mexico City 14610, Mexico.
authors: Susana R
authors: SR
authors: Solórzano
authors: Oncogenomics Laboratory, The National Institute of Genomic Medicine, Mexico City 14610, Mexico.
authors: Iván
authors: I
authors: Salido-Guadarrama
authors: Pharmacogenomics Laboratory, The National Institute of Genomic Medicine, Mexico City 14610, Mexico.
authors: Vanessa
authors: V
authors: González-Covarrubias
authors: Urology Department, Hospital General Dr. Manuel Gea González, Mexico City 14080, Mexico.
authors: Gustavo
authors: G
authors: Morales-Montor
authors: Instituto de Ciencias Forenses, Mexico City 06720, Mexico.
authors: Carlos E
authors: CE
authors: Díaz-Otañez
authors: Oncogenomics Laboratory, The National Institute of Genomic Medicine, Mexico City 14610, Mexico. Electronic address: mrodriguez@inmegen.gob.mx.
authors: Mauricio
authors: M
authors: Rodríguez-Dorantes
mesh_terms: D016022:Case-Control Studies; D045744:Cell Line, Tumor; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D005810:Multigene Family; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics*; D000094742:Secreted Frizzled-Related Proteins
chemical_list: D006657:Histones; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C117636:SFRP1 protein, human; D000094742:Secreted Frizzled-Related Proteins
keywords: DNA methylation; EZH2; H3K27me3; PRC2; Prostate cancer; SFRPs