Therapeutic silencing of KRAS using systemically delivered siRNAs.

Abstract

Despite being among the most common oncogenes in human cancer, to date, there are no effective clinical options for inhibiting KRAS activity. We investigated whether systemically delivered KRAS siRNAs have therapeutic potential in KRAS-mutated cancer models. We identified KRAS siRNA sequences with notable potency in knocking down KRAS expression. Using lung and colon adenocarcinoma cell lines, we assessed antiproliferative effects of KRAS silencing in vitro. For in vivo experiments, we used a nanoliposomal delivery platform, DOPC, for systemic delivery of siRNAs. Various lung and colon cancer models were used to determine efficacy of systemic KRAS siRNA based on tumor growth, development of metastasis, and downstream signaling. KRAS siRNA sequences induced >90% knockdown of KRAS expression, significantly reducing viability in mutant cell lines. In the lung cancer model, KRAS siRNA treatment demonstrated significant reductions in primary tumor growth and distant metastatic disease, while the addition of CDDP was not additive. Significant reductions in Ki-67 indices were seen in all treatment groups, whereas significant increases in caspase-3 activity were only seen in the CDDP treatment groups. In the colon cancer model, KRAS siRNA reduced tumor KRAS and pERK expression. KRAS siRNAs significantly reduced HCP1 subcutaneous tumor growth, as well as outgrowth of liver metastases. Our studies demonstrate a proof-of-concept approach to therapeutic KRAS targeting using nanoparticle delivery of siRNA. This study highlights the potential translational impact of therapeutic RNA interference, which may have broad applications in oncology, especially for traditional "undruggable" targets.

• Authors: Chad V Pecot, Sherry Y Wu, Seth Bellister, Justyna Filant, Rajesha Rupaimoole, Takeshi Hisamatsu, Rajat Bhattacharya, Anshumaan Maharaj, Salma Azam, Cristian Rodriguez-Aguayo, Archana S Nagaraja, Maria Pia Morelli, Kshipra M Gharpure, Trent A Waugh, Vianey Gonzalez-Villasana, Behrouz Zand, Heather J Dalton, Scott Kopetz, Gabriel Lopez-Berestein, Lee M Ellis, Anil K Sood
• Journal: Molecular cancer therapeutics (Mol Cancer Ther) Vol. 13 Issue 12 Pg. 2876-85 (Dec 2014) ISSN: 1538-8514 [Electronic] United States
• PMID: 25281617 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: ©2014 American Association for Cancer Research.

Chemical References

• Liposomes
• RNA, Small Interfering
• ras Proteins

Topics

• Animals
• Cell Line, Tumor
• Disease Models, Animal
• Female
• Gene Expression
• Gene Silencing
• Gene Transfer Techniques
• Humans
• Liposomes
• Mice
• Nanoparticles
• Neoplasms (genetics, pathology, therapy)
• RNA Interference
• RNA, Small Interfering (chemistry, genetics)
• Xenograft Model Antitumor Assays
• ras Proteins (chemistry, genetics)