Analysis of the tumor suppressor activity of the K-rev-1 gene in human tumor cell lines.
Overexpression of the human K-rev-1 gene in v-Ki-ras-transformed NIH 3T3 cells has been reported to result in the reversal of transformation and tumor suppression. To address whether human K-rev-1 is a tumor suppressor gene of human tumor cells, we have systematically transfected epitope-tagged wild-type or activated mutant K-rev-1 complementary DNA expression vectors into a series human tumor cell lines that express an activated ras oncogene, namely HT1080, EJ, and SW480. Using the epitope-tag-specific monoclonal antibody, it is shown that the K-rev-1 protein localizes to the medial/trans-Golgi network. Ectopic expression of the wild-type or activated mutant K-rev-1 protein did not significantly affect the morphology or in vitro growth of any clones. Furthermore, all clones expressing the wild-type or activated mutant K-rev-1 protein were tumorigenic. Western blot analysis of tumor reconstitutes demonstrated that there was no decrease or loss of introduced K-rev-1 protein expression. The results in the present study demonstrate that expression of K-rev-1 does not reverse the transformed phenotype or significantly affect the tumorigenic phenotype of human tumor cell lines that express endogenous ras oncogenes.
Sato
K Y
KY
Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine 92717.
Polakis
P G
PG
Haubruck
H
H
Fasching
C L
CL
McCormick
F
F
Stanbridge
E J
EJ
D000818:Animals; D015152:Blotting, Northern; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D015694:Gene Products, rev / Q000032:analysis* / Q000502:physiology; D015757:Genes, rev / Q000502:physiology*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D015689:Oncogene Protein p21(ras) / Q000032:analysis; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis*; D012334:RNA, Neoplasm / Q000032:analysis*; D014162:Transfection; D014407:Tumor Cells, Cultured
D015694:Gene Products, rev; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D015689:Oncogene Protein p21(ras)