RESUMO
Cultured fibroblasts from patients with cutaneous malignant melanoma (CMM) were tested for chromosomal instability by determination of micronuclei (MN) and sister chromatide exchange (SCE). The constitutive as well as the UV-induced level of MN was increased in CMM patients, being most pronounced in the familial cases. There was an increased UV sensitivity in CMM by using SCE, but no spontaneously enhanced SCE value. The enhanced UV sensitivity in CMM patients was in a comparable range as those of XP heterozygotes. We thus conclude that chromosomal instability is a concurrent feature of a genetic predisposition for CMM.
Assuntos
Melanoma/genética , Neoplasias Cutâneas/genética , Células Cultivadas , Fibroblastos/ultraestrutura , Humanos , Micronúcleos com Defeito Cromossômico , Troca de Cromátide Irmã , Xeroderma Pigmentoso/genéticaRESUMO
The certainty of a strong genetic predisposition to malignant melanoma was first established over 35 years ago. Since it has been shown that constitutive chromosomal instability is significantly correlated with the familial occurrence of cancer, we have studied spontaneous micronucleus rates in fibroblast cultures from 44 melanoma patients, 44 healthy probands and 78 patients with bronchial carcinoma. Here we report a significantly (p = less than 0.0005) increased spontaneous chromosomal instability in patients with cutaneous malignant melanoma compared to healthy controls and other tumor patients (bronchial carcinoma).
Assuntos
Aberrações Cromossômicas/genética , Melanoma/genética , Testes para Micronúcleos , Neoplasias Cutâneas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Broncogênico/genética , Feminino , Humanos , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
In vitro detection of micronuclei was used to determine spontaneous chromosomal instability in cultured fibroblasts of 28 healthy normal controls, 28 individuals with nonfamilial cutaneous malignant melanoma (CMM) and 14 people with familial occurrence of CMM. Lymphocytes from 40 healthy controls, 40 CMM patients and 6 individuals with familial CMM were also compared for spontaneous expression of micronuclei in vitro. In the familial cases micronucleus frequency was found to be higher, both in cultured fibroblasts (P less than 0.005) and in lymphocytes (P less than 0.001) as compared to normal controls. There was no significant difference between nonfamilial cases and normal controls. We conclude that chromosomal instability may contribute to a genetic risk for development of cutaneous malignant melanoma.
