Restitution of Tumor Suppressor MicroRNA-145 Using Magnetic Nanoformulation for Pancreatic Cancer Therapy.

INTRODUCTION: The functional significance of lost microRNAs has been reported in several human malignancies, including pancreatic cancer (PC). Our prior work has identified microRNA-145 (miR-145) as a tumor suppressor microRNA (miRNA) in pancreatic cancer. The restoration of miR-145 downregulates a number of oncogenes including mucin MUC13, a transmembrane glycoprotein that is aberrantly expressed in pancreatic cancer, thus efficiently inhibiting tumor growth in mice. However, lack of an effective tumor-specific delivery system remains an unmet clinical challenge for successful translation of microRNAs.
METHODS: We developed a miRNA-145-based magnetic nanoparticle formulation (miR-145-MNPF) and assessed its anti-cancer efficacy. Physico-chemical characterization (dynamic light scattering (DLS), transmission electron microscopy (TEM) and miR-binding efficiency), cellular internalization (Prussian blue and confocal microscopy), miR-145 restitution potential (quantitative reverse-transcription PCR (qRT-PCR), and anti-cancer efficacy (proliferation, colony formation, cell migration, cell invasion assays) of this formulation were performed using clinically relevant pancreatic cancer cell lines (HPAF-II, AsPC-1).
RESULTS: miR-145-MNPF exhibited optimal particle size and zeta potential which effectively internalized and restituted miR-145 in pancreatic cancer cells. miR-145 re-expression resulted in downregulation of MUC13, HER2, pAKT, and inhibition of cell proliferation, clonogenicity, migration, and invasion of pancreatic cancer cells.
CONCLUSIONS: miR-145-MNPF is an efficient system for miR-145 delivery and restitution in pancreas cancer that may offer a potential therapeutic treatment for PC either alone or in conjunction with conventional treatment.