논문검색
Author Michael Lee, Ph.D., Jun-Ho Ahn, M.S., Ki-Hwan Eum, M.S.
Place of duty Department of Biology, College of Natural Sciences, University of Incheon, Incheon, Korea
Title The Difference in Biological Properties between Parental and v-Ha-rasTransformed NIH3T3 Cells
Publicationinfo Cancer Res Treat 2009 Jun; 041(02): 93-99.
Key_word v-Ha-ras, Transformed cells, Raf-1, Negative feedback
Full-Text
Abstract Purpose: We performed experiments to investigate the change in cellular signaling that occurs during the transformation of a normal cell to a cell capable of cancerous growth, and we did so by using the NIH 3T3 cells that were transformed by transfection with the v-Ha-rasoncogene. Materials and Methods: Parental and v-Ha-rastransfected NIH 3T3 cells were chosen as test systems. The siRNA transfections were performed using Lipofectamine 2000. The cell proliferation reagent WST-1 was used for the quantitative determination of cellular proliferation. Immunoblot analysis was performed using the ECL-Plus chemiluminescent system and a KODAK Image Station 4000R. Results: The v-Ha-ras-transformed cells were found to be significantly more resistant to PP2 treatment, which is a potent inhibitor of the Src family tyrosine kinases, than were the parental cells at earlier times after treatment. However, PP2 induced growth arrest and the senescence-like phenotypes in both cell lines after longer treatment. Furthermore, the Raf-1 kinase of the v-Ha-ras-transformed cells was not affected by the expressed level of Sprouty proteins, which are negative regulators of the MAPK pathway, as evidenced by the failure of siRNA-mediated knockdown of Spry4 to activate Raf-1 kinase. Dephostatin (a tyrosine phosphatase inhibitor) effectively inhibited the proliferation of the v-Ha-rastransformed cells, whereas dephostatin had only a small effect on the parental cells' proliferation. This implied an inhibitory role for tyrosine phosphatase that is specific to the signaling pathway in the v-Ha-rastransformed cells. Conclusion: Taken together, our results show that the sustained activation of the oncogenic pathways through their resistance to negative feedback regulation might contribute to the transformation of NIH 3T3 cells.
출판정보 대한암학회지 2009 Jun; 041(02): 93-99.