Delivery of CRISPR/Cas systems for cancer gene therapy and immunotherapy.

The clustered, regularly interspaced, short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) systems are efficient and versatile gene editing tools, which offer enormous potential to treat cancer by editing genome, transcriptome or epigenome of tumor cells and/or immune cells. A large body of works have been done with CRISPR/Cas systems for genetic modification, and 16 clinical trials were conducted to treat cancer by ex vivo or in vivo gene editing approaches. Now, promising preclinical works have begun using CRISPR/Cas systems in vivo. However, efficient and safe delivery of CRISPR/Cas systems in vivo is still a critical challenge for their clinical applications. This article summarizes delivery of CRISPR/Cas systems by physical methods, viral vectors and non-viral vectors for cancer gene therapy and immunotherapy. The prospects for the development of physical methods, viral vectors and non-viral vectors for delivery of CRISPR/Cas systems are reviewed, and promising advances in cancer treatment using CRISPR/Cas systems are discussed.

Investigating the Fate of MP1000-LPX In Vivo by Adding Serum to Transfection Medium.

BACKGROUND: Cationic liposomes (CLs) based messenger RNA (mRNA) vaccine has been a promising approach for cancer treatment. However, rapid lung accumulation after intraveous injection and significantly decreased transfection efficacy (TE) in serum substantially hamper its application. OBJECTIVE: In this study, we attempt to investigate the fate of Mannose-PEG1000-lipoplex (MP1000-LPX) in vivo, a previous reported mRNA vaccine, and potential mechanism in it. METHODS: MP1000-CLs and different type of MP1000-LPX were produced by previous method and characterized by dynamic light scattering (DLS). Organ distribution and Luc-mRNA expression of DiD loaded luciferase (Luc-mRNA)-MP1000-LPX were evaluated by IVIS Spectrum imaging system. Cellular transfection and uptake under serum-free and serum-containing conditions were analysed by flow cytometry and counted by FlowJo software. RESULTS: MP1000-CLs had an average size of 45.3 ± 0.9 nm, a positive charge of 39.9 ± 0.9 mV. When MP1000-LPX formed, the particle size increased to about 130 nm, and zeta potential decreased to about 30 mV. All formulations were in narrow size distribution with PDI < 0.3. 6 h after intraveous injection, Luc-MP1000-LPX mostly distributed to liver, lung and spleen, while only successfully expressed Luc in lung. DC2.4 cellular transfection assay indicated serum substantially lowered TE of MP1000-LPX. However, the cellular uptake on DC2.4 cells was enhanced in the presence of serum. CONCLUSION: MP1000-LPX distributed to spleen but failed to transfect. Because serum dramatically decreased TE of MP1000-LPX on DC2.4 cells, but not by impeding its interaction to cell membrane. Serum resistance and avoidance of lung accumulation might be prerequisites for CLs based intravenous mRNA vaccines. Lay Summary: mRNA vaccine has been promising immunotherapy to treat cancer by delivering mRNA encoding tumor antigens to APCs and activating immune system against tumor cells. We are investigating the in vivo fate of MP1000-LPX, a CLs based mRNA vaccine. To see if serum causes the fate, we'll be looking at the influence of serum on transfection and uptake efficacy of MP1000-LPX by DC2.4 cells experiments in vitro. Our findings will imply that serum inhibits transfection but not by decreasing uptake. Thus, we can ultilize serum to enhance transfection if we make intracellular process of MP1000-LPX successful.

Clinical translation of gene medicine.

Gene therapy has recently witnessed accelerated progress as a new therapeutic strategy with the potential to treat a range of inherited and acquired diseases. Billions of dollars have been invested in basic and clinical research on gene medicine, with ongoing clinical trials focused on cancer, monogenic diseases, cardiovascular diseases and other refractory diseases. Advances addressing the inherent challenges of gene therapy, particularly those related to retaining the delivery efficacy and minimizing unwanted immune responses, provide the basis for the widespread clinical application of gene medicine. Several types of genes delivered by viral or non-viral delivery vectors have demonstrated encouraging results in both animals and humans. As augmented by clinical indications, gene medicine techniques have rapidly become a promising alternative to conventional therapeutic strategies because of their better clinical benefit and lower toxicities. Their application in the clinic has been extensive as a result of the approval of many gene therapy drugs in recent years. In this review, we provide a comprehensive overview of the clinical translation of gene medicine, focusing on the key events and latest progress made regarding clinical gene therapy products. We also discuss the gene types and non-viral materials with respect to developing gene therapeutics in clinical trials.