Discovery of anti-cancer effects of Pimavanserin tartrate in Pancreatic cancer


Year:

Session type:

Theme:

Sharavan Ramachandran1,Sanjay Srivastava1
1Texas Tech University Health Sciences Center

Abstract

Background

Pancreatic cancer is one of the most lethal malignancy with a five-year survival rate of 7%.  Recent studies have shown that anti-psychotic drugs exert better anti-proliferative effects in pancreatic cancer cells when compared to conventional chemotherapeutic agents gemcitabine and oxaliplatin.

Method

In-vitro methods:

  • Sulforhodamine-B (SRB) assay
  • Clonogenic assay
  • Annexin-V/FITC assay
  • Western blotting

In-vivo methods

  • Subcutaneous xenograft 
  • Orthotopic pancreatic tumor xenograft 
  • Immunohistochemistry
  • Western blotting
  • TUNEL assay
  • Behavioral analysis

Results

PVT significantly suppressed the proliferation of AsPC1, BxPC3, MIAPaCa2, PANC1 and PO2 pancreatic cancer cells and the IC50 of PVT was observed to be around 3µM - 9µM at 24, 48 and 72 hours. Moreover, treatment with PVT induced apoptosis in pancreatic cancer cells and a 2- 8 fold increase in cell death was observed in response to PVT treatment. Furthermore, mechanistic analysis showed that PVT inhibited the expression of pAkt(S473), Akt, Gli-1, Oct4, SOX-2, NANOG , CD44 and c-Myc. The anti-cancer effects of PVT were mediated through Akt/Gli-1 signaling as inhibition of Akt using PI3K inhibitor LY294002 and Gli1 silencing using Gli-1 siRNA enhances the effects of PVT in pancreatic cancer cells. We further evaluated the efficacy of PVT in two different in-vivo tumour models. Oral administration of PVT suppressed 50% of sub-cutaneously implanted BxPC3 tumours in athymic nude mice. In another setting of orthotopic pancreatic tumour model,  PVT treatment inhibited the growth of orthotopically implanted PANC1-luc pancreatic tumours by 75%. PVT suppressed pancreatic tumour growth in-vivo by inhibiting Akt/Gli-1 signaling as evaluated by western blotting and Immunohistochemistry. Apoptotic effects of PVT in-vivo was confirmed by TUNEL assay. Moreover, chronic administration of PVT did not show any general signs of toxicity and no apparent changes were observed in the behavioural activity of mice.

Conclusion

 Taken together, our study thus indicate that PVT suppresses pancreatic tumour growth in-vitro and in-vivo by inhibiting Akt/Gli-1 signaling