Using transfection of NIH 3T3 cells, we have recently demonstrated that multiple endocrine neoplasia (MEN) 2A mutations activate the c-Ret protein by inducing its disulfide-linked homodimerization on the cell surface. To investigate whether the homodimers are present in original tumors, the expression of the c-Ret protein was analyzed in eight sporadic and two MEN 2A-associated pheochromocytomas, the latter two of which contained mutations in cysteine 618 or 634 of Ret. The c-Ret protein was expressed at variable levels in all pheochromocytomas examined. By labeling the c-Ret protein immunoprecipitated from tumor tissues with [γ-32P]ATP in vitro, its homodimers were detected in pheochromocytomas from MEN 2A patients but not in a sporadic tumor. This result represents the first demonstration of Ret homodimers in original tumors.
|ジャーナル||Biochemical and Biophysical Research Communications|
|出版ステータス||Published - 17-01-1996|
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