Saadat M, Mizuno Y, Takizawa N, Kakinoki Y, Rikuchi R
Section of Biochemistry, Hokkaido University, Sapporo, Japan.
Cancer Lett. 1995 Aug 1;94(2):165-70. doi: 10.1016/0304-3835(95)03846-o.
Neoplastic alterations of type 1 alpha protein phosphatase (PP1 alpha) have been studied in rat ascites hepatoma cells, using regenerating liver after partial hepatectomy and normal rat liver as controls. In the particulate fraction of hepatomas, potential PP1 activity and the amount of PP1 alpha were remarkably increased compared with either regenerating or normal livers. In the nuclear fraction, PP1 activity and the amount of PP1 alpha were increased in hepatoma compared with the controls. The nuclear PP1 activity in hepatomas was activated by treatment with CO2+/trypsin, whereas that of normal or regenerating liver was not activated. These characteristic alterations of PP1 alpha in its amount and subcellular distribution may be implicated in malignant phenotype(s) such as uncontrolled cell growth.
以部分肝切除后的再生肝和正常大鼠肝脏作为对照，对大鼠腹水肝癌细胞中1α型蛋白磷酸酶（PP1α）的肿瘤性改变进行了研究。与再生肝或正常肝相比，肝癌微粒体部分的潜在PP1活性和PP1α含量显著增加。在细胞核部分，与对照相比，肝癌中的PP1活性和PP1α含量增加。肝癌细胞核中的PP1活性经Co2+/胰蛋白酶处理后被激活，而正常肝或再生肝的则未被激活。PP1α在含量和亚细胞分布上的这些特征性改变可能与诸如细胞生长失控等恶性表型有关。
