Effect of cell confluence on ultraviolet light apoptotic responses in DNA repair deficient cells.
Helotonio Carvalho, Renata Maria Augusto da Costa, Vanessa Chiganças, Ricardo Weinlich, Gabriela Brumatti, Gustavo P Amarante-Mendes, Alain Sarasin, Carlos Frederico Martins Menck
Mutat Res | Published : 2003
One of the major critical factors for cancer proneness is the cell response to DNA damage. In this work, we used human DNA repair deficient cell lines to investigate the responses to ultraviolet irradiation that lead to apoptosis, and the influence of maintaining the cells resting in confluent state. UV-induced apoptosis is prevented in photolyase-proficient HeLa cells when cyclobutane pyrimidine dimers (CPDs) are removed by photorepair. At the same time, we show recovery of RNA synthesis, thus indicating that blockage of RNA transcription may trigger apoptosis in human cells. On the other hand, confluent primary XPC and trichothiodystrophy (TTD)/XPD cell lines, related to xeroderma pigmento..View full abstract