Polysaccharopeptide enhanced the anti-cancer effect of gamma-tocotrienol through activation of AMPK
- Equal contributors
1 Australian Prostate Cancer Research Centre-Queensland & Institute of Health and Biomedical Innovation, Queensland University of Technology, Qld, Australia
2 Department of Pathology, Faculty of Medicine, the University of Hong Kong, Hong Kong, SAR, China
3 School of Biomedical Sciences, the University of Queensland, Qld, Australia
4 Translational Research Institute, 37 Kent Street, Brisbane QLD 4102, Australia
5 Room 704, 7/F, Faculty of Medicine Building, 21 Sassoon Road, Hong Kong, SAR, China
BMC Complementary and Alternative Medicine 2014, 14:303 doi:10.1186/1472-6882-14-303Published: 16 August 2014
Prostate cancer (PCa) frequently relapses after hormone ablation therapy. Unfortunately, once progressed to the castration resistant stage, the disease is regarded as incurable as prostate cancer cells are highly resistant to conventional chemotherapy.
We recently reported that the two natural compounds polysaccharopeptide (PSP) and Gamma-tocotrienols (γ-T3) possessed potent anti-cancer activities through targeting of CSCs. In the present study, using both prostate cancer cell line and xenograft models, we seek to investigate the therapeutic potential of combining γ-T3 and PSP in the treatment of prostate cancer.
We showed that in the presence of PSP, γ-T3 treatment induce a drastic activation of AMP-activated protein kinase (AMPK). This was accompanied with inactivation of acetyl-CoA carboxylase (ACC), as evidenced by the increased phosphorylation levels at Ser 79. In addition, PSP treatment also sensitized cancer cells toward γ-T3-induced cytotoxicity. Furthermore, we demonstrated for the first time that combination of PSP and γ-T3 treaments significantly reduced the growth of prostate tumor in vivo.
Our results indicate that PSP and γ-T3 treaments may have synergistic anti-cancer effect in vitro and in vivo, which warrants further investigation as a potential combination therapy for the treatment of cancer.