# Therapeutic targeting of polo-like kinase 1 using RNA-interfering nanoparticles (iNOPs) for the treatment of non-small cell lung cancer

## TL;DR

Researchers developed RNA-interfering nanoparticles to target and silence a cancer-related protein in lung cancer cells, showing promise for new cancer treatments.

## Contribution

A novel RNAi nanoparticle (iNOP-7) is shown to effectively deliver siRNA to silence PLK1 in NSCLC both in vitro and in vivo.

## Key findings

- iNOP-7 nanoparticles efficiently delivered siRNA to NSCLC cells without toxicity.
- iNOP-7-PLK1 siRNA reduced PLK1 expression and inhibited NSCLC growth in vitro and in mouse models.
- The treatment reduced lung tumor burden in orthotopic mouse models.

## Abstract

Non-small cell lung cancer (NSCLC) remains the most common cause of cancer death worldwide due its resistance to chemotherapy and aggressive tumor growth. Polo-like kinase 1 (PLK1) is a serine-threonine protein kinase which is overexpressed in cancer cells, and plays a major role in regulating tumor growth. A number of PLK1 inhibitors are in clinical trial; however, poor tumor bioavailability and off-target effects limit their efficacy. Short-interfering-RNA (siRNA) holds promise as a class of therapeutics, which can selectively silence disease-causing genes. However, siRNA cannot enter cells without a delivery vehicle. Herein, we investigated whether RNAi-interfering nanoparticles could deliver siRNA to NSCLC cells and silence PLK1 expression in vitro and in vivo. iNOP-7 was non-toxic, and delivered siRNA with high efficiency to NSCLC cells. iNOP-7-PLK1 siRNA silenced PLK1 expression and reduced NSCLC growth in vitro. Notably, iNOP-7 delivered siRNA to orthotopic lung tumors in mice, and administration of iNOP-7-PLK1 siRNA reduced lung tumor burden. These novel data show that iNOP-7 can deliver siRNA against PLK1 to NSCLC cells, and decrease cell proliferation both in vitro and in vivo. iNOP-7-PLK1 siRNA may provide a novel therapeutic strategy for the treatment of NSCLC as well as other cancers which aberrantly express this gene.