Evaluation of 3D Brain Spheroids as a Predicative Model for RNAi

Evaluation of 3D Brain Spheroids as a Predicative Model for RNAi



Tuyen Nguyen, Alex Eaton, Adam Castoreno, Kirk Brown, Samantha Chigas, Haiyan Peng

Alnylam Pharmaceuticals, Cambridge MA 02142

RNA interference (RNAi) is a process where double-strand RNA (dsRNA) inhibits the expression of a target gene by specifically degrading the complementary messenger RNA (mRNA). RNAi therapeutics are a new class of medicines that can address unmet medical needs across therapeutic areas including neurological disorders by silencing disease-causing genes. Drug development is a lengthy and expensive process ranging from target identification to lead discovery and optimization, preclinical validation, and clinical trials. A reliable predicative model in early stage can significantly accelerate the drug discovery process. Currently, the majority of cell-based assays are being carried out in two-dimensions (2D) settings, lacking the complex tissue microenvironment. To achieve biological relevance and improve in vivo translation to larger species, cell-based models need to better mimic the cellular architecture in organs, such as, three-dimensional (3D) cell culture models, which are more closely resemble in vivo cell environments. Here, we report the delivering of siRNA with various chemical modifications resulting in sustained and robust target mRNA knockdown in 3D brain spheroids and secreted target proteins in culture media. In contrast, minimal siRNA activity was observed in 2D culture that consists of the same cells. Importantly, data from co-culture 3D brain spheroids correlates strongly with efficacy data in non-human primate (NHP), suggesting the powerful translatability of the 3D brain spheroids model in CNS research.