BIN1 IS A NOVEL MYC-INTERACTING PROTEIN WITH FEATURES OF A TUMOR-SUPPRESSOR

BIN1 is a novel protein that interacts with the functionally critical Myc box regions at the N terminus of the MYC oncoprotein. BIN1 is stru cturally related to amphiphysin, a breast cancer-associated autoimmune antigen, and RVS167, a negative regulator of the yeast cell cycle, su ggesting roles in malignancy and cell cycle control. Consistent with t his likelihood, BIN1 inhibited malignant cell transformation by MYC. A lthough BIN1 is expressed in many normal cells, its levels were greatl y reduced or undetectable in 14/27 carcinoma cell lines and 3/6 primar y breast tumours. Deficits were functionally significant because ectop ic expression of BIN1 inhibited the growth of tumour cells tacking end ogenous message. We conclude that BIN1 is an MYC-interacting protein w ith features of a tumour suppressor.