SP600125, a JNK inhibitor, suppresses growth of JNK-inactive glioblastoma cells through cell-cycle G2/M phase arrest.

SP600125 is a well studied inhibitor of c-Jun N-terminal kinase (JNK). Its direct biochemical effects on JNK-inactive tumor cells are usually ignored. In this study, we investigated the effects of SP600125 on JNK-inactive U251 human glioblastoma cells. Our results demonstrate that, 20 microM or more SP600125 can induce significant cell growth inhibition and cell-cycle G2/M phase arrest in U251 cells. Interestingly, we also found that SP600125 can stop the duplicated chromosomes from separating into two cells and the karyokinesis progression. Our study opened up a new perspective for further studies involved in JNK inhibitors or anti-glioma therapy.