engleski

Protein interactions of wild-type p53 in human melanoma

The tumor suppressor protein p53 has been described as “the guardian of the genome” because of its role in conserving genome stability. p53 is mutated in more than 50% of human cancers increasing the oncogenic potential. In metastatic melanoma, p53 is rarely mutated, but, nevertheless fails to execute its tumor suppressor activity. We hypothesize that in malignant melanoma p53 function might be impaired by interactions with yet unknown proteins. Therefore, we are testing possible interactions of p53 with its family members, namely p53 and p73 isoforms and with members of the nm23/NDPK protein family, nm23- H1 and nm23-H2. Experiments were performed with and without the induction of DNA damage, assuming that certain interactions occur only in specific cellular events such as genotoxic stress. Co- immunoprecipitation experiments in cell lines expressing wild-type p53 show interactions of endogenous p53 with several p73 isoforms. DNA damage treatment has enhanced p53-ΔNp73 binding affinity. The subcellular dynamics and co- localization of interacting partners were determined using live cell imaging. The results show that p53 mainly localizes in the nucleus, but occasionally enters the cytosol, p73 isoforms remain in the nucleus while Nm23 proteins, mainly localize in the cytosol but translocate to the nucleus upon DNA damage. Our future plans will involve advanced confocal microscopy techniques, FRET/FLIM, in order to quantify and localize the detected protein interactions. We hope that determination of the nature and localization of p53 protein interactions will lead to a better understanding of its behavior in melanoma.

protein p53 ; metastatski melanom

nije evidentirano