Aptamer‐siRNA chimeras: Promising tools for targeting HER2 signaling in cancer

RNA interference is a transformative approach and has great potential in the development of novel and more efficient cancer therapeutics. Immense prospects exist in the silencing of HER2 and its downstream genes which are overexpressed in many cancers, through exogenously delivered siRNA. However, there is still a long way to exploit the full potential and versatility of siRNA therapeutics due to the challenges associated with the stability and delivery of siRNA targeted to specific sites. Aptamers offer several advantages as a vehicle for siRNA delivery, over other carriers such as antibodies. In this review, we discuss the progress made in the development and applications of aptamer‐siRNA chimeras in HER2 targeting and gene silencing. A schematic workflow is also provided which will provide ample insight for all those researchers who are new to this field. Also, we think that a mechanistic understanding of the HER2 signaling pathway is crucial in designing extensive investigations aimed at the silencing of a wider array of genes. This review is expected to stimulate more research on aptamer‐siRNA chimeras targeted against HER2 which might arm us with potential effective therapeutic interventions for the management of cancer. Aptamers that can bind to HER2, selected and enhanced by SELEX are conjugated with siRNAs which have the ability to target HER2 signalling pathways. The aptamer‐siRNA chimera enters the cancer cells through HER2 receptor and the delivered siRNA carries out silencing of the target gene resulting in tumor inhibition.