Logo image
Somatic alterations of CDKN1B are associated with small bowel neuroendocrine tumors
Journal article   Peer reviewed

Somatic alterations of CDKN1B are associated with small bowel neuroendocrine tumors

Jessica E Maxwell, Scott K Sherman, Guiying Li, Allen B Choi, Andrew M Bellizzi, Thomas M O'Dorisio and James R Howe
Cancer genetics, Vol.208(11), pp.564-570
11/2015
DOI: 10.1016/j.cancergen.2015.08.003
PMCID: PMC4936963
PMID: 26603463

View Online

Abstract

CDKN1B, a cyclin-dependent kinase inhibitor associated with G1 arrest, was recently proposed as an important tumor suppressor gene in small bowel neuroendocrine tumors (SBNETs). The rate of frameshift mutations in SBNET primaries are reportedly 7.4%, and hemizygous deletions are 6.7%. We set out to confirm the role of CDKN1B mutations and copy number variants (CNVs) in primary SBNETs, and whether these are also found in pancreatic neuroendocrine tumors (PNETs). Genomic DNA was isolated from 90 primary SBNETs and 67 PNETs. Coding exons of CDKN1B were amplified by PCR and sequenced. CNV analysis was performed by quantitative PCR, p27 expression was evaluated using immunohistochemistry. In SBNETS, three frameshifts, one missense mutation, and three CNVs were observed. The total rate of CDKN1B alterations was 7.0% (6 of 86; 95% confidence interval (CI) 3.2-4.4%). The frameshift rate was 3.5% (95% CI 1.1-9.8%). One SBNET patient had a hemizygous deletion of CDKN1B, and two patients had duplications (3.4%; 95% CI −0.41-7.2%). One PNET patient had a duplication, and two patients had hemizygous deletions (4.8%; 95% CI −0.44-10%). Alterations of cell-cycle control due to alterations in CDKN1B may be one mechanism by which SBNETs develop, which could have implications for new treatment modalities.
CDKN1B p27 Neuroendocrine tumor small bowel neuroendocrine tumor frameshift mutation pancreatic neuroendocrine tumor

Details

Logo image