A 584 bp deletion in CTRB2 inhibits chymotrypsin B2 activity and secretion and confers risk of pancreatic cancer Journal Article
| Authors: | Jermusyk, A.; Zhong, J.; Connelly, K. E.; Gordon, N.; Perera, S.; Abdolalizadeh, E.; Zhang, T.; O'Brien, A.; Hoskins, J. W.; Collins, I.; Eiser, D.; Yuan, C.; PanScan Consortium; PanC4 Consortium; Risch, H. A.; Jacobs, E. J.; Li, D.; Du, M.; Stolzenberg-Solomon, R. Z.; Klein, A. P.; Smith, J. P.; Wolpin, B. M.; Chanock, S. J.; Shi, J.; Petersen, G. M.; Westlake, C. J.; Amundadottir, L. T. |
| Article Title: | A 584 bp deletion in CTRB2 inhibits chymotrypsin B2 activity and secretion and confers risk of pancreatic cancer |
| Abstract: | Genome-wide association studies (GWASs) have discovered 20 risk loci in the human genome where germline variants associate with risk of pancreatic ductal adenocarcinoma (PDAC) in populations of European ancestry. Here, we fine-mapped one such locus on chr16q23.1 (rs72802365, p = 2.51 × 10−17, OR = 1.36, 95% CI = 1.31–1.40) and identified colocalization (PP = 0.87) with aberrant exon 5–7 CTRB2 splicing in pancreatic tissues (pGTEx = 1.40 × 10−69, βGTEx = 1.99; pLTG = 1.02 × 10−30, βLTG = 1.99). Imputation of a 584 bp structural variant overlapping exon 6 of CTRB2 into the GWAS datasets resulted in a highly significant association with pancreatic cancer risk (p = 2.83 × 10−16, OR = 1.36, 95% CI = 1.31–1.42), indicating that it may underlie this signal. Exon skipping attributable to the deletion (risk) allele introduces a premature stop codon in exon 7 of CTRB2, yielding a truncated chymotrypsinogen B2 protein that lacks chymotrypsin activity, is poorly secreted, and accumulates intracellularly in the endoplasmic reticulum (ER). We propose that intracellular accumulation of a nonfunctional chymotrypsinogen B2 protein leads to ER stress and pancreatic inflammation, which may explain the increased pancreatic cancer risk in carriers of CTRB2 exon 6 deletion alleles. © 2021 |
| Keywords: | controlled study; human tissue; unclassified drug; human cell; major clinical study; exon; gene deletion; genetics; stop codon; cancer risk; pancreas cancer; protein function; allele; enzyme inhibition; cohort analysis; gene locus; genome-wide association study; enzyme activity; carcinogenesis; gene mapping; oncogene; endoplasmic reticulum; pancreatitis; pancreatic cancer; enzyme release; cell metabolism; chymotrypsin; chromosome 16q; gene location; dna splicing; human; article; exon skipping; overlapping gene; pancreatic enzymes; polymorphic variation; splicing qtl; protein chymotrypsin b2; ctrb2 gene |
| Journal Title: | American Journal of Human Genetics |
| Volume: | 108 |
| Issue: | 10 |
| ISSN: | 0002-9297 |
| Publisher: | Cell Press |
| Date Published: | 2021-10-01 |
| Start Page: | 1852 |
| End Page: | 1865 |
| Language: | English |
| DOI: | 10.1016/j.ajhg.2021.09.002 |
| PUBMED: | 34559995 |
| PROVIDER: | scopus |
| PMCID: | PMC8546220 |
| DOI/URL: | |
| Notes: | Article -- Source: Scopus |
