Solid-phase synthesis, characterization and RNAi activity of branch and hyperbranch siRNAs

Bioorg Med Chem Lett. 2013 Oct 1;23(19):5270-4. doi: 10.1016/j.bmcl.2013.08.033. Epub 2013 Aug 12.

Abstract

Linear, branch and hyperbranch siRNAs were effectively prepared for down-regulating GRP78 expression and inducing cell death in HepG2 liver cancer cells. Branch and hyperbranch GRP78 siRNAs were synthesized by automated solid-phase synthesis in good yields (44-78%) and isolated in excellent purities (>99%) following HPLC purification. Moreover, siRNAs adopted stable intramolecular hybrids as discerned by native PAGE and thermal denaturation studies. These sequences also exhibited the pre-requisite A-type helical trajectory for triggering RNAi activity as determined by CD spectroscopy. Biological studies confirmed potent suppression of GRP78 expression (50-60%) while compromising cancer cell viability by ~20%. Thus, branch and hyperbranch siRNAs may serve as potent siRNA candidates in cancer gene therapy applications.

Keywords: Branch siRNA; GRP78 silencing; Hyperbranch siRNA; Oncogene therapy; RNAi.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Cell Survival / drug effects
  • Endoplasmic Reticulum Chaperone BiP
  • Hep G2 Cells
  • Humans
  • Microscopy, Confocal
  • RNA Interference*
  • RNA, Small Interfering / chemical synthesis*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / pharmacology
  • Solid-Phase Synthesis Techniques

Substances

  • Antineoplastic Agents
  • Endoplasmic Reticulum Chaperone BiP
  • HSPA5 protein, human
  • RNA, Small Interfering