IMMUNOREACTIVITY FOR P53 AND MDM2 AND THE DETECTION OF P53 MUTATIONS IN HUMAN-MALIGNANT MESOTHELIOMA

Previous immunohistochemical studies on malignant mesothelioma with an tibodies recognizing both the wild and the mutant types of the p53 pro tein have shown immunoreactivity in 25-70% of cases. This study was de signed to determine whether there is immunoreactivity for p53 and mdm2 protein in malignant mesothelioma and to correlate p53 expression wit h the detection of mutations in p53 at DNA level. In 10 of 15 cases th ere was immunoreactivity for p53. In 6 of these cases immunoreactivity for mdm2 was also detected. In one p53-immunonegative case, a mutatio n of the p53 gene resulting in a stop codon was found. These results s uggest that mdm2 might be involved in the inhibition of p53 in maligna nt mesothelioma, Also, these data suggest the existence of other prote ins than mdm2 that may associate with p53.