Effect of GAP-43 on cell cycle progression in NIH3T3 cells stably transfected

K. DE MOLINER; M. WOLFSON; A.ADAMO

Pinamar, Buenos Aires, Argentina.

Congreso; 10th Congress of Panamerican Association for Biochemistry and Molecular Biology, 41th Annual Meeting de la Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular (SAIB) and 20 th Annual Meeting de la Sociedad Argentina de Neuroquímica (SA; 2005

Panamerican Association for Biochemistry and Molecular Biology

EFFECT OF GAP-43 ON CELL CYCLE PROGRESSION IN NIH3T3 CELLS STABLY TRANSFECTEDDe Moliner, K. 1, Wolfson, M. 1, Perrone-Bizzozero, N. 2, Adamo, A. 11 Depto. Quim. Biol.,UBA.IQUIFIB-CONICET, BsAs, Argentina2 Dept.Neurosci,University of New Mexico HSC, Albuquerque, USA   GAP-43 is present in growth cones of developing neurons and presynaptic terminals of some mature neurons where is thought to contribute to the morphological changes associated with neural development and plasticity.It has also been shown that GAP-43 mRNA and protein expression are lost in select human and mouse glioma cell lines and that re-expression of GAP-43 in deficient C6 glioma cells results in growth suppression.In this study,we examined the influence of stable GAP-43 expression in 3T3 on cell adhesion and proliferation.3T3 cells were transfected with pcDNA3 constructs,either empty or containing the GAP-43 coding sequence in the sense orientation.To study differences in cell adhesion,selected clones(control and GAP-43 expressing cells)were fixed at 0.25,0.5,0.75,2,3 and 4h after plating.Adherent cells were stained with crystal violet and counted.Cells expressing GAP-43 showed changes in cell morphology,including the appearance of processes,but no changes in cell adhesion.To investigate the effects of GAP-43 on cell cycle progression,transfected 3T3 cells were synchronized by serum deprivation and propidium iodide-stained nuclei were analyzed by flow cytometry at different times in culture in complete medium.We found that 47% of GAP-43 expressing cells were arrested in the G0/G1 phase after 18h in culture,compared to 23% of control cells.In agreement with the delay in G1 progression,a reduction in cell proliferation was observed after 72h of culture.Although GAP-43 is primarily expressed in post-mitotic neurons,our results suggest that this protein may have a role in cell cycle regulation at early stages of neuronal differentiation.