Pancreatic cancer is associated with mutations in the tumor suppressor gene cyclin-dependent kinase inhibitor 2A (p16(INK4A) ), a regulator of the cell cycle and apoptosis.
CDKN2A mutation carriers were more likely to have a family history of pancreatic cancer (P=0.003) or melanoma (P=0.03), and a personal history of melanoma (P=0.01).
A group I intron ribozyme was designed to trans-splice the 2 base-deleted p16 transcripts with the wild-type sequence in a pancreatic cancer cell line, which originally produced no p16.
Activation of the proto-oncogene K-Ras and inactivation of the tumour suppressor gene loci INK4a, p53 and SMAD4 are characteristic for pancreatic cancer.
Additionally, we analysed the aberrant methylation frequency of cell cycle inhibitor p16(INK4a) and K-ras gene mutations in the pancreatic samples. p16 inactivation was detected in 43% of adenocarcinomas, in 17% of neuroendocrine tumors, in 18% of pancreatitis and in 63% of pancreas cancer cell lines.
Advances in the understanding of pancreas cancer biology have been made over the past decade, including the discovery of critical mutations in oncogenes (i.e., K-Ras) as well as the loss of tumor suppressor genes, such as TP53 and p16(INK4).
All four features in each group, except pancreatic cancer in Australia (p = 0.38), individually showed significant associations with CDKN2A mutations, but the effects varied widely across continents.
Alterations in the ARF tumor suppressor protein (also known as p14ARF in humans and p19ARF in the mouse) occur frequently in cancer and are associated with susceptibility to melanoma, pancreatic cancer and nervous system tumors.
Although early age at melanoma diagnosis and occurrence of multiple primary melanoma in 1 or more patient were significantly associated with the risk of a CDKN2A mutation in F2 families, early age at melanoma diagnosis and occurrence of pancreatic cancer in a family were significantly associated with CDKN2A mutations in F3+ families.
Although it is well known that CDKN2A mutations confer an increased risk for melanoma and pancreatic carcinoma, the association with an increased risk for nerve sheath tumours and other tumour types is under-recognized.
Among US participants familiar with their hereditary melanoma risk through prior epidemiological research participation, CDKN2A/p16 genetic testing provides multiple perceived benefits to both carriers and noncarriers without inducing distress in general or worry about melanoma or pancreatic cancer.
As PC and NSTs have been postulated to be preferentially associated with CDKN2A mutations located in exon 2 and/or affecting p14ARF alone, the position of E27X in exon 1alpha provides interesting insights towards clarifying the mechanisms by which the CDKN2A/ARF locus is involved in cancer predisposition.