INHIBITION OF ULTRAVIOLET-C IRRADIATION-INDUCED AP-1 ACTIVITY BY ASPIRIN IS THROUGH INHIBITION OF JNKS BUT NOT ERKS OR P38 MAP KINASE

The exposure of mammalian cells to ultraviolet (UV) irradiation leads to the activation of transcription factors, such as AP-1 and NF kappa B. We demonstrate that aspirin, a promising cancer chemopreventative a gent, inhibited UVC-induced AP-1 activity in JB6 cells. In JB6 cells, UVC stimulated Erks, JNKs and P38 kinase activities; aspirin only inhi bited activation of JNKs, but not the other MAP kinases. Since the tra nscription factor AP-1 is important for the process of tumor promotion , the inhibitory effect of aspirin on AP-1 activation suggests that it can be used as a chemopreventative agent against skin cancer.