The tumorigenesis and the progression of oral squamous cell carcinoma(OSCC) are related to the genetic and chromosomal abnomalities of the tumor cells. The aim of this study was to clarify the conrrelation between chromosome 17 aberrations and other variants such as the grade of histologic differentiation, mitotic index, and p53 overexpression. Paraffin-embedded tissue from seven OSCCs was inverstigated for chromosome 17 copy number by interphase cytogenetics using fluorescence in situ hybridization(FISH) with a centromere-speicific DNA probe. The following results were obtained.
1.The percentage of cells with more than 3 copy number of chromosome 17 was 10.3% in OSCC, whrereas 1.5% in normal epithelium.
2.The expression of p53 was strong in 3 cases, mild in 1 case, weak in 2 cases, and negative in 1 case.
3.While mitotic index of OSCC was 5.7, that of normal epithelium was 0.8.
4.The cells showing more than 3 signals were the highest in two cases(17% and 19.5%)and the others were lower than 2 signals.
5.The increasing copy number of chromosome 17 in poorly differentiated OSCC was related intimately to the mitotic index.
6.In general, the results indicate that there is no complete correlation between copy number of chromosome 17 and p53 expression and mitotic index.
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