口腔前癌病変および扁平上皮癌における増殖細胞核抗原 （PCNA）と p53 蛋白の発現に関する免疫組織化学的研究

抄録

The activity of cellular proliferation was immunohistochemically studied in 26 hyperkeratoses (HK), 25 epithelial dysplasias (ED), 49 squamous cell carcinomas (SCC) and 24 states after treatment of SCC (t-SCC) of the oral cavity.These lesions were compared with normal mucosa adjacent to them.

The tissues of these lesions were fixed in neutral phosphate buffered formalin and embedded in paraffin. Serial sections cut at 3μm were mounted on silane-coated glass slides. The monoclonal mouse antibody against human proliferating cell nuclear antigen (PCNA, PC10) and polyclonal rabbit antibody against human p53 (CM-1) were used as primary antibodies. The deparaffinized sections were immunostained by streptoavidin-biotin complex methods using Pathostain ABC kit.

The numbers of positive cells were counted by using a computer-accessed image analyzer (IBAS-2000), and then calculated appearance index and labeling index. In each lesion, the appearance indexes(%) of PCNA and p53 positive cells were 32.0 and 24.0 in normal mucosa, 72.9 and 26.9 in HK,80.0 and 40.0 in ED, and 83.7 and 53.1 in SCC, respectively. Labeling indexes of PCNA and p53 positive cells were 2.4±0.9 and l.7±0.7 in normal mucosa, 9.7±8.9 and 4.8±1.8 in HK, 20.4±9.2 and 11.6±2.0 in ED and 22.6±10.3, and 24.8±11.0 in SCC, respectively. The ratio of p53-positive cells to 100tumor cells was significantly higher in SCC than any other lesions (ρ<0.01). In t-SCC, the appearance and labeling indexes (%) of p53 positive cells were 50.0 and 20.3±13.8, respectively.

These results suggested that p53 tumor suppressor gene product was a beneficical marker for estimating malignant formation in lesions of the oral cavity.