The Mechanism Of PTS2 Inducing HeLa Cell Apoptosis

Dipyrithione (2, 2'-dithiobispyridine-l, 1'-dioxide, PTS2), one of a pyrithione derivates, has been noted for its highly bacteriocidal and fungicidal action. PTS2 was used as bactericides, pesticides and fungicide.In this study we showed the apoptotic effect and its molecular mechanism of PTS2 on HeLa cells. To characterize the cell apoptosis induced by PTS2, Morphology and chromatin condensation of the cells were detected by fluorescence microscopy using Hoechst 33258 and DAPI staining. cell viability was determined by using MTT assay. Furthermore, flow cytometric analysis was performed. All the results indicated that PTS2 induced HeLa cell death in a dose and time dependent manner.Cytochrome c plays an important role in mitochondrial apoptosis pathway. Cytochrome c releasing from mitochondria activates caspase-3, an important downstream effector in apoptosis pathway. We examined whether PTS2 treatment would lead release of cytochrome c and activiation of caspase-3. The results from Western blot showed that PTS2 induced release of cytochrome c after PTS2 treatment in a time and dose dependent manner. Caspase-3 and PARP were cleavaged after PTS2 treatment in a time and dose dependent manner.It was reported MAPKs were involved in action of chemotherapeutic drugs. We analysed activation of JNK1/2, p38 and ERK1/2 in PTS2 treated cells. ERK1/2 and p38 were markedly activated by PTS2, but JNK1/2 activition was hardly detected. Suppression of p38 activition by SB203580 reduced apoptosis of HeLa cells and also prevented release of cytochrome c, cleavage of caspase-3 and PARP induced by PTS2. But suppression of ERK1/2 by PD98059 showed an opposite effect, which indicated the anti-apoptotic effect of ERK1/2 activation in PTS2 induced HeLa cells apoptosis.Our study first demonstrates that PTS2 possesses anti-tumor activity, cytochrome c caspases-3 and poly (ADP-ribose) polymerase (PARP) are involved in PTS2 induced HeLa cell apoptosis and ERK1/2 and p38 play opposite effect on PTS2 induced HeLa cell apoptosis.