The Individual Cell Properties of Oral Squamous Cell Carcinoma and p53 Tumor Suppressor Gene Mutation

There is no consensus on the relationship between variations in TP53 mutations and tumor properties in oral squamous cell carcinoma (OSCC). To further the basic research required to eventually develop individualized (order-made) treatments and prognoses for OSCC, we established six human OSCC lines from patients within our department. Together with another nine cell lines derived from donations by other organizations, we determined the TP53 mutation and single nucleotide polymorphism (SNP) of codon 72 in a total of 15 cell lines, and examined in vitro cell invasion activity and anti-cancer drug sensitivity. The missense mutation at codon 248 was most abundant, and was noted in four cell lines, but other diverse mutation variations were also revealed. The cells which expressed the mutated p53 protein (the p53(+) group) showed slightly higher invasion activity than did the p53 (−) group. In p53(+) group, the 72R of SNP (72P/R) was higher than the 72P in invasion activity, although the difference was not significant. Surprisingly, an anti-cancer drug sensitivity test with four different types of drugs showed that the p53 (−) group was more resistant in other than CDDP, and that 72R was more sensitive than 72P in the p53(+) group. To clarify the characteristics of the R248Q mutation, which is the most abundant missense mutation, the gene was introduced with an expression plasmid vector into a TP53 null Saos-2 cell. The transformant of R248Q mutation gained higher activity of invasion, while its anti-cancer drug sensitivity also increased. Our findings suggest that it may be possible to estimate oral cancer cell characteristics and the malignancy level based on differences in the TP53 mutation.