| Summary: | 碩士 === 國立臺灣大學 === 生化學研究所 === 82 === Lung cancers in Taiwan have some epidemio- logical
characteristics, for example, the low male to female ratio, the
high percentage of adenocarcinoma, and the relatively high
percentage of non-smoking victims.Alteration of p53 are the
most common molewlar changes found in all type of lung cancers,
suggesting a crucial role for p53 in bronchiocarcinogenses.To
investigate correlation between p53 gene mutation and the
pathological parameters, we examined 30 primary, resected Non-
small cell lung cancers (NSCLC) specimens and 3 NSCLC cell
lines. We found that 10 cases had p53 gene mutation. Missense
mutation were present in 30% (10/33) of NSCLC, including 30%
(7/21) of adenocarcinomas , and 30% (3/9) of squamous cell
carcinomas. In contrast to previous reports that G to T
transversions are common , we report here that G to A (30%) and
C to T (30%) are observed.The exon 8 mutation occurred most
frequently (50%) , while correlated to the clinicopathological
parameters shows that tumors with exon8 mutation are
significantly linked with the /mediastinal lymph nodes
metastasis. This may serve as a tumor aggressiveness. Recent
experiments show that inactivation of retinoblastoma gene (Rb)
occurred in NSCLC as well.These findigs suggest that loss of Rb
function is a factor in the development of NSCLC. According to
previous studies,two known reasons for disruption of Rb
function have been described; One is the mutation of Rb gene.
nother is the loss of E2F-Rb intcraction, E2F is the most
critically Rb-associated protein. In this study, we examined
both Rb T-binding domain (the functional domain of Tumor
suppression and frequently mutated region of Rb) and E2F Rb-
binding domain (the region of E2F reacted to Rb) .No genetic
alteration was above two genes. Althogh the Rb and E2F genes
seem not involved pathogenesis of NSCLC, more evidence are
required for advaced confirmation.
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