Rearrangement in the coding and 5 ' region of p53 gene in human oral tumors

Different postreplicative, transcriptional, and translational mechanisms re sponsible for p53 gene inactivation are slowly unfolding. Rearrangement of the p53 gene is a very rare event in human solid tumors and has been report ed only in osteosarcomas, From our laboratory we have recently reported rea rrangement only in the coding region of the p53 gene in breast tumors, In t his report we hare undertaken a systemic investigation of p53 in oral tumor s, Results have shown rearrangement in the coding region of p53 in 20% of c ases and in the 5' region of p53 gene in similar to 8% Of cases. No allelic loss and amplification of p53 gene was observed in these tumor samples, In our earlier studies on breast tumors, we found no abnormality in the 5' re gion of p53. However, in the present study we report for the first time rea rrangement in the 5' region of p53 in oral tumors. Correlation of p53 gene rearrangement with p53 expression of RNA and protein indicates that rearran gement in the 5' region of p53 might not have a role in p53 expression, How ever rearrangement in the coding region of p53 might play a critical role i n controlling p53 gene activity in the process of tumorigenesis.