title: Functional significance of SPINK1 promoter variants in chronic pancreatitis.
abstract: Chronic pancreatitis is a progressive inflammatory disorder of the pancreas, which often develops as a result of genetic predisposition. Some of the most frequently identified risk factors affect the serine protease inhibitor Kazal type 1 (SPINK1) gene, which encodes a trypsin inhibitor responsible for protecting the pancreas from premature trypsinogen activation. Recent genetic and functional studies indicated that promoter variants in the SPINK1 gene might contribute to disease risk in carriers. Here, we investigated the functional effects of 17 SPINK1 promoter variants using luciferase reporter gene expression assay in four different cell lines, including three pancreatic acinar cell lines (rat AR42J with or without dexamethasone-induced differentiation and mouse 266-6) and human embryonic kidney 293T cells. We found that most variants caused relatively small changes in promoter activity. Surprisingly, however, we observed significant variations in the effects of the promoter variants in the different cell lines. Only four variants exhibited consistently reduced promoter activity in all acinar cell lines, confirming previous reports that variants c.-108G>T, c.-142T>C, and c.-147A>G are risk factors for chronic pancreatitis and identifying c.-52G>T as a novel risk variant. In contrast, variant c.-215G>A, which is linked with the disease-associated splice-site mutation c.194 + 2T>C, caused increased promoter activity, which may mitigate the overall effect of the pathogenic haplotype. Our study lends further support to the notion that sequence evaluation of the SPINK1 promoter region in patients with chronic pancreatitis is justified as part of the etiological investigation.
authors: Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts; Department of Gastroenterology and Hepatology, Radboud UMC, Nijmegen, The Netherlands.
authors: Monique H M
authors: MH
authors: Derikx
authors: Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts;
authors: Andrea
authors: A
authors: Geisz
authors: Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts;
authors: Éva
authors: É
authors: Kereszturi
authors: Department of Molecular and Cell Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts; miklos@bu.edu.
authors: Miklós
authors: M
authors: Sahin-Tóth
mesh_terms: D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D057809:HEK293 Cells; D006801:Humans; D049409:Luciferases, Firefly / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D046790:Pancreas, Exocrine / Q000187:drug effects / Q000378:metabolism; D050500:Pancreatitis, Chronic / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011401:Promoter Regions, Genetic; D051381:Rats; D014162:Transfection; D014359:Trypsin Inhibitor, Kazal Pancreatic
chemical_list: D002352:Carrier Proteins; C486642:SPINK1 protein, human; D014359:Trypsin Inhibitor, Kazal Pancreatic; D003907:Dexamethasone; D049409:Luciferases, Firefly
keywords: acinar cell; chronic pancreatitis; luciferase reporter; promoter mutation; trypsin inhibitor