P19INK4D OVEREXPRESSION ENHANCE DNA REPAIR EFFICIENCY AND INCREASE RESISTANCE TO UV DAMAGE IN MA-10 LEYDIG CELLS

MARAZITA, MARIELA; SCASSA, MARÍA; PIGNATARO, OMAR; CANEPA, EDUARDO TOMAS

Pinamar, Buenos Aires, Argentina

Congreso; XLI Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2005

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

INK4 family, that participate in cell cycle regulation as CDK4/6 inhibitors, also carry out different functions in processes like differentiation, apoptosis and senescence. We have previously reported that p19INK4d is induced by UV in  MA-10 Leydig cells and that the overexpression of p19 remarkably improves repair of a foreign damaged DNA in this cell line. Going further, this work aims to study on one hand if p19 modifies the ability of endogenous DNA repair in MA-10 Leydig stable cell lines that overexpress or silence p19 expression, and on the other hand, to evaluate in this cell lines the ability to recover from UV damage. MA-10 Leydig stable cell lines were established containing p19 sense or antisense gene under a metallothionein promoter inducible by Zn2+. The clones obtained were assayed by Northern blot for p19 expression and tested for DNA repair ability by UDS and comet assay. We found out that overexpression of p19 strongly enhances DNA repair efficiency and besides enlarge the number of cells going through DNA repair process. Adding to that, MTT, clonogenic and chromosomic aberrations assays showed that p19 also greatly raises the faculty of the cells to get over UV damage and continue growing. To conclude, we can say that not only does p19 increase DNA repair efficiency but enables the cells to resist better to DNA damage as well.