Expression pattern of alpha-protein kinase C in human astrocytomas indicates a role in malignant progression.
Expression pattern of alpha-protein kinase C in human astrocytomas indicates a role in malignant progression.
复制标题
人星形细胞瘤中 α-蛋白激酶 C 的表达模式表明其在恶性进展中发挥作用。
作者：
Deborah L. Benzil;Sydney D. Finkelstein;Mel H. Epstein;Paul W. Finch
Protein kinase C (PKC) is a family of isoenzymes which play an important role in regulating cell proliferation and differentiation. Constitutive activation of PKC, either by phorbol esters or overexpression of specific isoenzymes, leads to growth abnormalities in vitro and tumor promotion in vivo. Since stimulation of PKC in cultured astrocytes results in biochemical and morphological alterations associated with the transformed phenotype, we wanted to determine whether abnormal expression of specific isoenzymes of PKC was important in development of human astrocytomas in vivo. We have detected a specific pattern of alpha-PKC expression in human astrocytomas which is noteworthy because the highest transcript levels were detected in well-differentiated (Grade 1) tumors, with intermediate expression in anaplastic (Grade 2) astrocytomas and low or nondetectable levels in glioblastomas (Grade 3 astrocytomas) and normal controls. In comparison, the beta-PKC transcript was not detected in any of the tumors, while the gamma-PKC transcript was present in only one Grade 2 tumor. Immunohistochemistry, using a monoclonal antibody to alpha-PKC, revealed diffuse, positive cytoplasmic signals in most cells of the Grade 1 tumors. Grade 2 tumors exhibited heterogeneity of alpha-PKC expression, although a significant percentage of cells showed positivity. In contrast, only a small number of differentiated cells within Grade 3 tumors were positive for alpha-PKC expression, with the more malignant, dedifferentiated cells uniformly negative. Throughout all tumor grades, the staining pattern of alpha-PKC closely paralleled that of glial fibrillary acidic protein. Taken in conjunction with the established role of PKC in tumor promotion, these results suggest that the alpha-PKC isoenzyme plays a specific role in facilitating clonal expansion of transformed astrocytes in low-grade astrocytomas. Analysis of alpha-PKC may therefore serve as a direct biological marker of malignancy which may serve to enhance the current histopathological grading system.
影响因子：
11.2
作者：
R. Weinberg
通讯作者：
R. Weinberg
免疫化学证据表明，在二甲亚砜和视黄酸诱导的 HL-60 分化过程中，三种蛋白激酶 C 同工酶丰度增加。
DOI：
--
发表时间：
1988
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Makowske,M;Ballester,R;Cayre,Y;Rosen,OM
通讯作者：
Rosen,OM
正常和阿尔茨海默病大脑中中枢神经系统的三种主要人类蛋白激酶 C 同工酶（PKC α、PKC β 和 PKC γ）的特征和差异分布。
DOI：
--
发表时间：
1991
期刊：
Laboratory investigation; a journal of technical methods and pathology
影响因子：
--
作者：
Clark,EA;Leach,KL;Trojanowski,JQ;Lee,VM
通讯作者：
Lee,VM