RESUMEN
AIMS AND BACKGROUND: The mortality of colorectal cancer continues to stagnate despite the development of new therapeutic approaches. Therefore, identifying high-risk population groups could contribute to the prevention of a considerable part of deaths caused by colorectal tumors. METHODS: Fifty patients with colon cancer and 50 patients with other, nonmalignant diseases were selected for the study. Expression of the c-myc, Ha-ras and p53 genes was determined in the peripheral leukocytes of the participants. RESULTS: Marked elevations of the expression of all three investigated genes were seen in the colon cancer patients when compared to the controls. CONCLUSIONS: Our investigations showed that increases in the expression of c-myc, Ha-ras and p53 genes can be demonstrated in the peripheral leukocytes of colon cancer patients. By applying our method to clinical investigations, individuals with a high risk of having developed colon cancer may be identified and early diagnosis may be established.
Asunto(s)
Adenocarcinoma/sangre , Biomarcadores de Tumor/genética , Neoplasias del Colon/sangre , Regulación Neoplásica de la Expresión Génica/fisiología , Genes ras/genética , Proteínas Proto-Oncogénicas c-myc/genética , Proteína p53 Supresora de Tumor/genética , Estudios de Casos y Controles , Femenino , Humanos , Leucocitos/metabolismo , Leucocitos/patología , Masculino , Persona de Mediana Edad , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
BACKGROUND: Genetic polymorphisms of metabolizing enzymes may affect the risk of cancer formation in humans. Since the diet can contain polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs), the relationship between polymorphisms of enzymes involved in PAH and HA metabolism and the occurrence of sporadic colorectal cancer was studied. PATIENTS AND METHODS: Five hundred colorectal cancer patients and 500 controls were genotyped for cytochrome P450 enzymes (CYP) 1A1 Ile/Val, CYP 1A2*1F, CYP 2E1 c1/c2, microsomal epoxy hydrolase (mEH) exon 3 Tyr113His and exon 4 His139Arg polymorphisms by allele-specific polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism (RFLP). RESULTS: The presence of CYP 1A1 Val, CYP 2E1 c2 and mEH exon 3 His alleles was statistically significantly associated with the occurrence of colorectal cancer (OR: 1.44 95% CI: 1.04-2.00; OR: 1.74 95% CI: 1.15-2.65; OR: 1.79 95% CI: 1.10-2.92, respectively). CONCLUSION: These findings suggest that allelic polymorphism of metabolizing enzymes play an important role in human colorectal carcinogenesis by affecting the metabolism of dietary carcinogens.