title: Mitochondrial DNA D-loop in pancreatic cancer: somatic mutations are epiphenomena while the germline 16519 T variant worsens metabolism and outcome.
abstract: We ascertained the frequency of mitochondrial DNA (mtDNA) D-loop region somatic mutations in pancreatic cancer (PC) and verified whether polymorphisms were linked to diagnosis, prognosis, and PC-associated diabetes mellitus (DM) in 99 PC cases, 42 chronic pancreatitis (CP) cases, 18 pancreatobiliary tract tumors, and 87 healthy control subjects (CSs). Tissue samples were obtained from 19 patients with PC and 5 with CP. The D-loop region was sequenced from all tissue samples and from blood DNA of the same patients and 12 CSs. D-loop somatic mutations were found in 3 PC tissue samples (16%). Four single nucleotide polymorphisms (SNPs; T152C, T16189C, T16519C, A73G), more frequently found in PC than in CS, were analyzed by denaturing high-performance liquid chromatography-restriction fragment length polymorphism using blood DNA as the starting template in all cases. The T allele of 16519 SNP correlated with DM. The survival of patients with PC correlated with tumor stage and grade and with DM at diagnosis. When survival analysis was performed considering only patients with locally advanced disease, the T allele of mtDNA 16519 SNP correlated with shorter life expectancy. mtDNA D-loop somatic mutations, rarely found in PC, cannot be considered causative events for this tumor type and probably are epiphenomena; the mtDNA D-loop 16519 variant, which worsens PC prognosis, seems to be a predisposing genetic factor for DM.
authors.affiliation: Department of Laboratory Medicine, University of Padova, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Navaglia
authors.forename: Daniela
authors.initials: D
authors.lastname: Basso
authors.forename: Paola
authors.initials: P
authors.lastname: Fogar
authors.forename: Cosimo
authors.initials: C
authors.lastname: Sperti
authors.forename: Eliana
authors.initials: E
authors.lastname: Greco
authors.forename: Carlo-Federico
authors.initials: CF
authors.lastname: Zambon
authors.forename: Alessia
authors.initials: A
authors.lastname: Stranges
authors.forename: Alessandra
authors.initials: A
authors.lastname: Falda
authors.forename: Sara
authors.initials: S
authors.lastname: Pizzi
authors.forename: Anna
authors.initials: A
authors.lastname: Parenti
authors.forename: Sergio
authors.initials: S
authors.lastname: Pedrazzoli
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
mesh_terms: D000230:Adenocarcinoma / Q000150:complications / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000150:complications / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D003920:Diabetes Mellitus / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000150:complications / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D050500:Pancreatitis, Chronic / Q000150:complications / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D015996:Survival Rate
chemical_list: D004272:DNA, Mitochondrial