INVESTIGADORES
CANEPA Eduardo Tomas
congresos y reuniones científicas
Título:
Cell Cycle inhibitor, p19INK4d, is up-regulated in cellular senescence triggered by camptothecin
Autor/es:
SILVINA SONZOGNI; GUILLERMO VIDELA RICHARDSON; MARIA F. OGARA; EDUARDO T. CANEPA; MARIA E. SCASSA
Lugar:
Mar del Plata, Buenos Aires
Reunión:
Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
CB-P66.
CELLCYCLE INHIBITOR, p19INK4d, IS UP-REGULATED
IN CELLULAR SENESCENCE TRIGGERED BY
CAMPTOTHECIN
Sonzogni S,Videla RichardsonG, OgaraMF, Cánepa E, Scassa M.
Laboratorio de Biología Molecular, Depto Química Biológica,
FCEN-UBA, Buenos A i re s , Arge n t i n a . E - m a i l :
ssonzogni@qb.fcen.uba.ar
Cellular senescence is a state of stable cell cycle arrest triggered by
stress strimuli. Disruption of DNA damage response prevents
senescence and promotes transformation. Given the function of
cyclin dependent kinase inhibitor, p19INK4d, in cell cycle arrest
and DNArepair, the aim of this work is to elucidate if this protein is
involved in this process. Senescence was induced with
camptothecin. Treated cells exhibit characteristic of senescence
such as flat and enlarged morphology, increase -galactosidase
activity, cell cycle arrest and upregulation of p16INK4a and
p21Cip1. Northern blot analyses show that p19 is upregulated after
camptothecin treatment in BHK cells. Levels of p19 peak at 12 h
after camptothecin addition. This induction is dose dependent and
starts at 20 nM. Reporter gene experiments with a construct
harboring 2250 bp of p19 promoter indicate that camptothecin is
acting at the transcriptional level. Abrogation of ATM kinase
activity severely impairs genotoxic action. Transient expression
assays with a mutagenized promoter construct reveal that upregulation
of transcription requires E2F sites.Asignificant increase
in the percentage of cells undergoing senescence is observed in
BHK stably overexpressing p19 when compared to wild type or p19
deficient counterparts. Our results suggest that p19 may influence
the induction of senescence triggered by camptothecin.