title: Epigenetic alteration of the purinergic type 7 receptor in salivary epithelial cells.
abstract: Purinergic receptors, particularly type 7 (P2RX7), are involved in apoptotic cell death. However, the expression and function of P2RX7 are suppressed in HSG cells. In the present study, we explored whether P2RX7 function is regulated by epigenetic alteration of the receptors in two different cell lines, HSG cells derived from human submandibular ducts, and A253 cells, originated from human submandibular carcinoma. We discovered that HSG cells expressed all subtypes of purinergic receptors, excluding P2RX7, at the mRNA level. However, treatment of the cells with 5-Aza-CdR, a DNA demethylating agent, increased the mRNA expression levels of P2RX7 in a time-dependent manner. Furthermore, 5-Aza-CdR completely rescued the calcium response induced by P2RX7 agonist BzATP, a response that was absent in untreated HSG cells. In contrast, A253 cells showed a moderate methylation pattern in the P2RX7 CpG island. Most CG pairs from the first to the 21st were methylated in untreated HSG cells, but 5-Aza-CdR-treatment partially demethylated the methylated CG pairs. We obtained similar results when investigated human tissues; the CG pairs in the P2RX7 CpG islands showed hypermethylation and hypomethylation patterns in human normal and cancer tissues, respectively. Our results suggest that the expression level and function of P2RX7 are regulated by DNA methylation in epithelial cells.
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Shin
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Minkyoung
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Nahyun
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Seul-Ki
authors.initials: SK
authors.lastname: Choi
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Eun
authors.initials: E
authors.lastname: Namkoong
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Se-Young
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea.
authors.forename: Jong-Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Departments of Oral and Maxillofacial Diagnostic Sciences, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
authors.forename: Seunghee
authors.initials: S
authors.lastname: Cha
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, South Korea. Electronic address: kppark@snu.ac.kr.
authors.forename: Kyungpyo
authors.initials: K
authors.lastname: Park
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D002460:Cell Line; D018899:CpG Islands; D019175:DNA Methylation; D000077209:Decitabine; D044127:Epigenesis, Genetic; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D058911:Purinergic P2X Receptor Agonists / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D058486:Receptors, Purinergic P2X7 / Q000235:genetics* / Q000378:metabolism*; D012469:Salivary Glands / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
chemical_list: C546468:P2RX7 protein, human; D058911:Purinergic P2X Receptor Agonists; D012333:RNA, Messenger; D058486:Receptors, Purinergic P2X7; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D000077209:Decitabine; D000255:Adenosine Triphosphate; D001374:Azacitidine
keywords: 5-Aza-CdR; DNA methylation; Hypermethylation; Hypomethylation; Purinergic receptor; Salivary glands