MicroRNAs (miRNAs) are endogenous ∼23 nt RNAs that play important gene-regulatory roles in animals and plants by pairing to the mRNAs of protein-coding genes to direct their posttranscriptional repression. This review outlines the current understanding of miRNA target recognition in animals and discusses the widespread impact of miRNAs on both the expression and evolution of protein-coding genes.

MicroRNAs: Target Recognition and Regulatory Functions

LB-194 Lung cancer is the most prevalent form of cancer worldwide and accounts for the most cancer deaths. MicroRNAs (miRNAs) are small, non-protein coding RNAs that have recently emerged as important regulators of gene expression and direct proper cellular growth, differentiation and cell death - all mechanisms that go awry in cancer. The let-7 miRNA is postulated to function as a tumor suppressor gene in a variety of human tissues, particularly in the lung, by negatively regulating the post-transcriptional expression of multiple oncogenes including RAS, MYC, and HMGA2, as well as other cell cycle progression genes. Here we have used both in vitro and in vivo approaches to show that let-7 directly represses cancer growth in  the lung. We show that let-7 inhibits the growth of multiple human lung cancer cell lines in culture, as well as the growth of lung cancer cell xenografts in immunodeficient mice. Using the established Lox-Stop-Lox K-ras mouse lung cancer model, we find that intranasal let-7 administration can reduce tumor formation in vivo in the lungs of animals expressing a G12D activating mutation for the K-ras oncogene. These findings support the notion that let-7 functions as a tumor suppressor in the lung and indicates that this miRNA could be used as a therapeutic agent to treat lung cancer.

The let-7 microrna reduces tumor growth in mouse models of lung cancer

In vivo delivery of miRNAs for cancer therapy: challenges and strategies.

http://bps.lab.uic.edu/PDF/JControlRel_172_962_2013.pdf

Progress in microRNA delivery

This review is focused essentially on the synthesis and applications of gold nanoparticles in the field of medicine and targeted drug delivery. Nanotechnology has become one of the most interesting and advanced areas of research in this field. Among nanoparticles, gold nanoparticles demonstrate special advantages in this field due to their unique properties, small size and high surface area-to-volume ratio. These particles have been widely used in various biomedical applications and drug delivery systems due to their inert nature, stability, high dispersity, non-cytotoxicity and biocompatibility. Keywords : Biosynthesis, Gold nanoparticles, Biomedical applications, Targeted drug delivery, Nanotechnology.

/pdf/gold-nanoparticles-synthesis-and-applications-in-drug-nakvwvmiuh.pdf

Gold Nanoparticles: Synthesis and Applications in Drug Delivery

A gold nanoparticle platform for the delivery of functional microRNAs into cancer cells.

Provided herein are gold nanoparticles mediated non-viral delivery of miRNAs, siRNAs, genes and drugs. Nanoparticle platforms and combinatorial drug delivery vehicles comprises gold nanoparticles with a plurality of thilolated hyperbranched dendrons conjugated to the nanoparticle surface. The thiolated hyperbranched dendrons comprise chemically-modifiable surface groups, functionalized interior groups and nano-cavities within the hyperbranched structure to which a variety of payload molecules may be conjugated, optionally via a linker. Payload molecules may comprise nucleic acids, anticancer drugs and small molecule inhibitors, optionally with, non-cytotoxic signaling agents, for example, fluoroscein isothiocyanate. Successful manipulation of the degree of PEGylation and the amount of gold nanoparticles in a polyelectrolyte complex to evaluate the best formulation for highest payload delivery of chemically unmodified miRNA duplexes and stemloops is presented. Also provided are methods for delivering one or more therapeutic agents to a cell or tissue or for treating a pathophysiological condition in a subject by delivering the combinatorial drug delivery vehicles to a cell or tissue associated with the pathophysiological condition to facilitate internalization of the vehicle to effect treatment.

Lalithya C. Singh

Papers

A gold nanoparticle platform for the delivery of functional microRNAs into cancer cells.

Compositions and Methods for Delivery of MicroRNA to Cells