Huber L A, Pasquali C, Gagescu R, Zuk A, Gruenberg J, Matlin K S
I.M.P., Research Institute of Molecular Pathology, Vienna, Austria.
Electrophoresis. 1996 Nov;17(11):1734-40. doi: 10.1002/elps.1150171111.
We have investigated the effects of viral Kirsten ras oncogene expression in Madin-Darby canine kidney (MDCK) II epithelial cell on the differential protein expression of organelle proteins. MDCK cells, stably transformed via infection with a helper-independent retroviral vector construct, were grown on permeable filter supports. Whereas normal cells form highly polarized monolayers, ras-transformed cells display an unpolarized phenotype, detaching from the substratum and developing multilayers (Schoenenberger, C.-A. et al., J. Cell Biol. 1991, 112, 873-889). We postulate that this breakdown of epithelial polarity reflects disturbed intracellular protein transport and sorting, namely, proteins will no longer be sorted correctly in intracellular organelles and will therefore not reach their appropriate target membrane. Here we emphasize the role of endosomes as sorting platform in epithelial cells. We found significant differences in the molecular composition of endosomes from normal vs. oncogenic transformed epithelial cells, strengthening previous evidence indicating that oncogenic transformation results in abnormal expression of normal genes (Celis, J. E., Olsen, E., Electrophoresis 1994, 15, 309-344) as well as the expression of new ones (Huber, L. A. et al., Electrophoresis 1994, 15, 468-473).
我们研究了病毒Kirsten ras癌基因在Madin-Darby犬肾（MDCK）II上皮细胞中的表达对细胞器蛋白差异表达的影响。通过感染辅助独立逆转录病毒载体构建体而稳定转化的MDCK细胞，在可渗透滤膜支持物上生长。正常细胞形成高度极化的单层，而ras转化细胞表现出非极化表型，从基质上脱离并形成多层（Schoenenberger，C.-A.等人，《细胞生物学杂志》，1991年，112卷，873 - 889页）。我们推测上皮极性的这种破坏反映了细胞内蛋白质运输和分选的紊乱，即蛋白质将不再在细胞内细胞器中正确分选，因此无法到达其适当的靶膜。在这里，我们强调内体作为上皮细胞中分选平台的作用。我们发现正常上皮细胞与致癌转化上皮细胞的内体分子组成存在显著差异，这进一步证明了先前的证据，即致癌转化导致正常基因的异常表达（Celis，J.E.，Olsen，E.，《电泳》，1994年, 15卷, 309 - 344页）以及新基因的表达（Huber，L.A.等人，《电泳》，1994年, 15卷, 468 - 473页）。
