Pathological Detection Of Fhit And P53 Gene In Bronchial Hyperplastic Epithelial Lesions

Objective:1. Detailed criteria for bronchial preinvasive lesions are welcome and provide an objective framework on which to compare various molecular and gene changes.2. To identify essential discrepancy in preinvasive bronchial lesions and provide potential biomarker for early diagonosis of truly preneoplastic lesions by detection and analysis of FHIT and p53 gene and its expression in bronchial preinvasive lesions from the operative specimen with lung cancer and lung inflammatory lesions .Methods:A total of 360 lung resection specimens from patients with lung cancer and pulmonary inflammatory lesions were collected . By HE staining , preinvasive bronchial lesions in those specimens were observed microscopically. By using PCR-denaturing polyacrylamide gel electrophoresis-silverstaining, the loss of heterozygosity (LOH) and microsatellite instability (MI) in FHIT gene were examined in eighty-two samples of bronchial hyperplastic lesions obtained from patients with squamous cell carcinoma (SCC) and fifty-seven matched epithelial lesions obtained from patients with pulmonary inflammatory lesions . p53 gene mutations in hyperplastic epithelial lesions obtained from 80 patients with squamous cell carcinoma and matched epithelial lesions obtained from 51 patients without lung cancer were screened by polymerase chainreaction-single strand conformation polymorphism and DNA sequencing analysis. Using immunohistochemistry, the discrepancy of expression of the FHIT and p53 gene between bronchial hyperplastic lesions from patients with lung cancer and similar lesions from patients with pulmonary inflammatory lesions were compared.Results:1. Morphological aspects of various hyperplastic lesions occurring in the bronchi were described. In lung cancer group, 24%(55/230) of the specimens had mild-moderate atypia; 35%( 80/230) was severe atypia and CIS . In lung inflammatory lesions group, only 9% (12/130) had mild- moderate dysplasia, and there was none of severe atypia /CIS. The process of squamous metaplasia starts in preexisting basal cell hyperplasia. . It is interesting that 54%( 80/147 ) of dysplasia may appear in a hyperplastic basal zone, which is still surrounded by a differentiated respiratory columnar epithelium (immatuee squamous metaplasia). In these places ,under a ciliated and mucus secreting epithelium, we can frequently find areas of cells with atypia and CIS. SD/CIS had two main growth pattern . Most cases (86%) were classified as the "creeping type" whose dominant growth pattern was a horizontal spread within the mucosa . The remainder seemed to have a predominantly transmural rather than longitudinal growth pattern (penetrating type).2. The results of FHIT LOH/MI and immunohistochemistry staining of FHIT protein(1) The rate of LOH/MI of FHIT (four microsatellite site , D3S1234,D3S1300,D3S1481,D3S1313) in squamous metaplasia and mild-moderate dysplasia obtained from patients with SCC (53.8% and 70% respectively) was statistically(p=0.041; p=0.030 ) greater than matched lesions from patients with lung inflammatory lesions(12.5% and 18.2%) . The frequency of LOH/MI of FHIT in normal bronchial mucosa and basal cell hyperplasia (BCH) obtained from patients with SCC (18.8% and 33.3%respectively) was not statistically(p=0.226, p=0.148 ) greater than that from patients with inflammatory lesions (0.0% and 7.1% ) . There is significantly different frequency of FHIT LOH/MI among groups of lung cancer(p=0.000). No significant difference (p = 0.878) was observed among the rate of four locus, D3S1234 D3S1300 D3S1481 D3S1313 in lung cancer group.(2) The data indicate that frequency of the loss of FHIT protein is singnificantly higher in BCH from lung cancer group (60.0%)than those from lung inflammatory lesions (0.0%; P=0.004). Frequency of the loss of FHIT expression was higher in normal bronchial epithelia,BCH and metaplasia from lung cancer group compared to matched lesions from lung inflammatory lesions group (41.7% versus 5.1%;P<0.001).