title: Phosphotyrosine phosphatase-activity in membranes from endometrial carcinoma.
abstract: The phosphotyrosine phosphatase (PTPase) decreases the level of phosphotyrosine of intracellular protein substrates, thereby reversing the action of tyrosine phosphorylation to promote cell growth and differentiation. We determined the activities of PTPases in normal and cancerous tissues of the endometrium. The PTPase activity was determined with the synthetic substrate p-nitrophenyl in a spectrophotometric assay. Over 90% of the activity was particulate and the values in proliferative- and secretory-phase endometria and endometrial carcinomas fell within a similar range. This work demonstrates the existence of PTPase activity, counterbalancing the growth-promoting effects of tyrosine kinases, in endometrial carcinoma.
authors: GIFU UNIV,SCH MED,DEPT OBSTET & GYNECOL,GIFU 500,JAPAN.
authors: T
authors: T
authors: Furui
authors: A
authors: A
authors: Imai
authors: H
authors: H
authors: Takagi
authors: S
authors: S
authors: Horibe
authors: T
authors: T
authors: Fuseya
authors: T
authors: T
authors: Tamaya