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Tumor Protein p53 and K-ras Gene Mutations in Peruvian Patients with Gallbladder Cancer

2019; West Asia Organization for Cancer Prevention; Volume: 20; Issue: 1 Linguagem: Inglês

10.31557/apjcp.2019.20.1.289

2476-762X

Tatiana Vidaurre, Sandro Casavilca‐Zambrano, Paola Montenegro, Henry Gómez, Mónica Calderón, Jeannie Navarro, Jessica Aramburu, Ebert Poquioma, Yasuo Tsuchiya, Takao Asai, Yoichi Ajioka, Ayako Sato, Toshikazu Ikoma, Kazutoshi Nakamura,

Genetic factors in colorectal cancer

Background: Recent studies have shown that genetic alterations are associated with the effect of patient geographiclocation on gallbladder cancer development. Peru has a high incidence of gallbladder cancer, but causative factorshave not yet been identified. We examined the frequency of mutations in TP53 and K-ras genes in Peruvian patientswith gallbladder cancer, and compared this with data from Bolivia, Hungary, Chile, and Japan, which have a highgallbladder cancer incidence. Methods: DNA was extracted from formalin-fixed paraffin-embedded gallbladder tissuesections of 30 gallbladder cancer patients (9 men and 21 women) obtained using microdissection. Mutations in exons5 to 8 of TP53 and codons 12, 13, and 61 of K-ras were examined using direct sequencing. Results: TP53 mutationswere observed in 10 (33.3%) of patients, but K-ras mutations were absent. Nine (90%) TP53 mutations were pointmutations (7 missense and 2 silent mutations), and the most frequent substitution was a G:C to A:T transition. G:C toA:T transitions at the CpG site or G:C to T:A transversions were found in one patient each. No significant differenceswere found in the frequency of TP53 and K-ras mutations among patients in the 5 countries. Conclusions: Our findingssuggest that endogenous mechanisms and exogenous carcinogens may affect the carcinogenic process in Peruviangallbladder cancer patients, similar to that in Bolivian patients. Further studies with a larger sample size are neededto clarify these findings.