Tumour-specific Delivery of siRNA-coupled Superparamagnetic Iron Oxide Nanoparticles, Targeted Against PLK1, Stops Progression of Pancreatic Cancer

Gut. 2016 Nov;65(11):1838-1849. doi: 10.1136/gutjnl-2016-311393. Epub 2016 May 12.


Objective: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies and is projected to be the second leading cause of cancer-related death by 2030. Despite extensive knowledge and insights into biological properties and genetic aberrations of PDAC, therapeutic options remain temporary and ineffective. One plausible explanation for the futile response to therapy is an insufficient and non-specific delivery of anticancer drugs to the tumour site.

Design: Superparamagnetic iron oxide nanoparticles (SPIONs) coupled with siRNA directed against the cell cycle-specific serine-threonine-kinase, Polo-like kinase-1 (siPLK1-StAv-SPIONs), could serve a dual purpose for delivery of siPLK1 to the tumour and for non-invasive assessment of efficiency of delivery in vivo by imaging the tumour response. siPLK1-StAv-SPIONs were designed and synthesised as theranostics to function via a membrane translocation peptide with added advantage of driving endosomal escape for mediating transportation to the cytoplasm (myristoylated polyarginine peptides) as well as a tumour-selective peptide (EPPT1) to increase intracellular delivery and tumour specificity, respectively.

Results: A syngeneic orthotopic as well as an endogenous cancer model was treated biweekly with siPLK1-StAv-SPIONs and tumour growth was monitored by small animal MRI. In vitro and in vivo experiments using a syngeneic orthotopic PDAC model as well as the endogenous LSL-KrasG12D, LSL-Trp53R172H, Pdx-1-Cre model revealed significant accumulation of siPLK1-StAv-SPIONs in PDAC, resulting in efficient PLK1 silencing. Tumour-specific silencing of PLK1 halted tumour growth, marked by a decrease in tumour cell proliferation and an increase in apoptosis.

Conclusions: Our data suggest siPLK1-StAv-SPIONs with dual specificity residues for tumour targeting and membrane translocation to represent an exciting opportunity for targeted therapy in patients with PDAC.


Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Carcinoma, Pancreatic Ductal* / drug therapy
  • Carcinoma, Pancreatic Ductal* / pathology
  • Cell Cycle Proteins* / genetics
  • Cell Cycle Proteins* / metabolism
  • Cell Proliferation / drug effects
  • Disease Models, Animal
  • Drug Delivery Systems / methods
  • Drug Monitoring / methods
  • Gene Silencing
  • Magnetite Nanoparticles / therapeutic use*
  • Mice
  • Pancreatic Neoplasms* / drug therapy
  • Pancreatic Neoplasms* / pathology
  • Protein-Serine-Threonine Kinases* / genetics
  • Protein-Serine-Threonine Kinases* / metabolism
  • Proto-Oncogene Proteins* / genetics
  • Proto-Oncogene Proteins* / metabolism
  • RNA, Small Interfering* / metabolism
  • RNA, Small Interfering* / pharmacology


  • Antineoplastic Agents
  • Cell Cycle Proteins
  • Magnetite Nanoparticles
  • Proto-Oncogene Proteins
  • RNA, Small Interfering
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1