[Frequency and clinicopathological associations of K-ras mutations in Venezuelan patients with colo-rectal cancer].
Mutations in the K-ras oncogene are common in colo-rectal cancer, which affect the biological behaviour and may influence the susceptibility to therapy in these tumors. The objective of this work was to identify the types of K-ras mutations observed in referred patients with colo-rectal cancer and to relate them to their degree of histological differentiation and clinical stage. Histopathological and clinical data were obtained from medical records. DNA was obtained from both, fresh tissue and tumor tissue embedded in paraffin. The K-ras gene was amplified through the polymerase chain reaction (PCR) and the amplified fragments were digested with restriction enzymes. We found mutations in codons 12 and 13 of the K-ras oncogene in 23.33% of patients. Of these, 28.57% were located at codon 12, 57.14% were at codon 13 and 14.29% at both codons. They were more frequent in tumors located in the left hemicolon and, according to their histological type, were more frequent in well differentiated adenocarcinomas (58.70%) and in mucinous (28.57%). The identified mutations were more frequent in advanced stages (C2) of Dukes' classification. The molecular analysis of the K-ras oncogene made mutations evident, which could be useful in the diagnosis and prognosis of colorectal tumors. The frequency of mutations found in this work is similar to some of those reported worldwide; however, they differ in the more frequent type of mutation, which, in our study, was located at codon 13 in more than 50% of the cases.
Universidad Centro Occidental Lisandro Alvarado, Barquisimeto, Venezuela.
Pedro
P
Estrada
Alicia
A
Rojas-Atencio
William
W
Zabala
Lisbeth
L
Borjas
Lazaro
L
Soca
Karelis
K
Urdaneta
Francisco
F
Alvarez-Nava
Jenny
J
Cañizales
Janeth
J
Rojas
Marisol
M
Soto
D000230:Adenocarcinoma / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000453:epidemiology / Q000235:genetics / Q000473:pathology; D002454:Cell Differentiation; D003062:Codon / Q000235:genetics; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000473:pathology; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D011905:Genes, ras; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D014687:Venezuela / Q000453:epidemiology
D003062:Codon; D004273:DNA, Neoplasm