title: Hypermethylation contributes to down-regulation of lysosomal β-hexosaminidase α subunit in prostate cancer cells.
abstract: β-Hexosaminidase, involved in degradation of glycoproteins and glycosphingolipids, is altered in several tumours leading to enhanced migration capacity. To date, the expression of the β-hexosaminidase isoenzymes in prostate cancer cells has not been elucidated. By using PC3, LNCaP, DUCaP, MDAPCa 2b, and hyperplasic prostate (BPH-1) cell lines, we analysed the β-hexosaminidase activity in each cell line and determined β-hexosaminidase α subunit gene expression in PC3, LNCaP, and BPH-1. We then investigated the methylation status of the gene promoter and determined the cellular responses of PC3 and LNCaP after transfection with β-hexosaminidase α subunit. We found that each prostate cancer cell line had a decrease in total hexosaminidase activity and that the lack of hexosaminidase A activity, observed in PC3 and LNCaP cells, was associated with mRNA disappearance. The HEXA promoter region in LNCaP and PC3 cell lines had methylated CpG islands, as confirmed by 5'-Aza-2'-deoxycitidine treatment, in PC3 cells, used as cell cancer model. We also tested, the involvement of hexosaminidase A in the migration capacity by migration assay using Hex α subunit-transfected PC3. Finally, we found that, after Hex α subunit transfection, both PC3 and LNCaP were less susceptible to exogenous ceramide treatment. Results indicate a likely contribution of the lysosomal enzyme to the acquisition of cancerous features.
authors.affiliation: Dipartimento Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06124 Perugia, Italy. Electronic address: egidia.costanzi@unipg.it.
authors.forename: Egidia
authors.initials: E
authors.lastname: Costanzi
authors.affiliation: Dipartimento Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06124 Perugia, Italy.
authors.forename: Lorena
authors.initials: L
authors.lastname: Urbanelli
authors.affiliation: Dipartimento Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06124 Perugia, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Bellezza
authors.affiliation: Dipartimento Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06124 Perugia, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Magini
authors.affiliation: Dipartimento Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06124 Perugia, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Emiliani
authors.affiliation: Dipartimento Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, 06124 Perugia, Italy.
authors.forename: Alba
authors.initials: A
authors.lastname: Minelli
mesh_terms: D045744:Cell Line, Tumor; D019175:DNA Methylation; D015536:Down-Regulation; D004794:Enzyme Repression; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D054820:beta-Hexosaminidase alpha Chain / Q000235:genetics* / Q000378:metabolism
chemical_list: C064769:N-acetylsphingosine; C518253:HEXA protein, human; D054820:beta-Hexosaminidase alpha Chain; D013110:Sphingosine
keywords: Ceramide; Hexosaminidase A; Lysosomal glycohydrolases; Promoter methylation