Changes of
Phenotypes Associated with Activated Src by Overexpressed PTPα in NIH3T3 Cells
YANG Jin-Song, ZHENG Xin-Min1,
CHEN Shi-Shu*
（ Department of Biochemistry, Lab of Molecular Biology and Research
Center for Human Gene Therapy, Shanghai Second Medical University, Shanghai 200025,
China; 1Cornell University, New York 14850, USA ）
Abstract NIH3T3
cells transfected with inducible expression vectors harboring the protein
tyrosine phosphatase α (PTPα) gene
were used as a model to study the mechanism of tumor formation, by which
the changes of phenotypes in inducible cells were studied. When NIH3T3 cells
transfected with PTPα were induced for 24 hours, the expression levels
of PTPα in inducible cells was higher than those in uninducible cells as judged
by RT-PCR and Western blotting; the expression level of Src in inducible cells
was the same as those in uninducible cells, but activity of Src kinase in
inducible cells was higher than those in uninducible cells.The level of
phosphated tyrosine in Src was reduced in inducible cells. The malignant
changes of phenotypes in the inducible cells were verified by flow cytometry and
electron microscope.The results show that 24 h induction of PTPα could
initiate the transformation of NIH3T3 cells transfected with PTPα
inducible expression vectors, and the transformation may be associated with activated Src where pTyr527
in the C tail was dephosphorylated by increased expression level of PTPα in the
cells.
Key words PTPα; Src; transformation
*Corresponding author: Tel,
86-21-63846590-776452; e-mail, [email protected]