From the Laboratory of Biophysics and Molecular Biology, Institute 0f Biochemistry and Biophysics, University of Tehran, Tehran, I.R. Iran. , goliaei@ibb.ut.ac.ir
Abstract: (5250 Views)
Transforming growth factor betas are multifunctional polypeptides in the
cytokine superfamily. They have a growth inhibitory role on hemopoietic progenitor
cells in semisolid colony assay as well as in long-term bone-marrow culture.
TGF - β2 represses stromal cells, stem cell factor gene transcription, and decreases
the stability of c-kit transcripts in hemopoietic cells. TGF-β also modulates
GM-CSF production from human lymphocytes. The present study reveals
the TGF- β2 role in production of GM-CSF in HTB 5637, human bladder carcinoma
cell line. HTB 5637 cells were treated with 5 ng/mL of human TGF - β2'
viable cells were counted and GM-CSF concentration was determined, No antiproliferate
activity of TGF- β2on HTB 5637 cell line was observed. Biological
assay showed increased levels of GM-CSF in the supernatant of cultured cells.
However this increase was lower than that expected from ELISA. Since TGF- β
may be an active suppressor factor regulating hemopoiesis, it seems that some
inhibitory factor(s) may be produced (increased) in response to TGF- β2 treatment.
It has been shown that GM-CSF mRNA content from HTB 5637 cell line
is very stable and this stabilization is translational dependent. Using Slot blot and
Northern blot analysis, we determined that TGF- β2 upregulated GM-CSF gene
expression in HTB 5637 cell line. The results suggest that TGF- β2 upregulates
the production of GM-CSF gene at the transcriptional level.