Peptides obtained from Dengue virus were used to deliver therapeutic siRNA to leukemia model cells

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Peptides obtained from Dengue virus were used to deliver therapeutic siRNA to leukemia model cells

Monday, 02.01.2017

The authors developed a siRNA-based therapeutic approach in which the siRNA is delivered by pepM or pepR, two cell-penetrating peptides (CPPs) derived from the dengue virus capsid protein. These peptides have a dual role: siRNA delivery into cells and direct action as bioportides, i.e. intracellularly bioactive peptides, targetting cancer-related signaling processes. By such combination, the pepM-siRNA conjugates lowered Bcr-Abl gene expression levels more extensively than conventional siRNA delivery technologies and perturbed leukemogenic cell homeostasis, hence revealing their potential as novel alternative scaffolds for chronic myeloid leukemia therapy.

 

Authors and Affiliations:

Freire JM1, Rego de Figueiredo I2, Valle J3, Veiga AS2, Andreu D3, Enguita FJ2, Castanho MA2
1Institut Pasteur, Department of Virology, Structural Virology Unit (VIST), 28 rue du Dr Roux, 75015 Paris, France
2Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal.
3Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, E-08003 Barcelona, Spain.
 

Abstract:

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by a single gene mutation, a reciprocal translocation that originates the Bcr-Abl gene with constitutive tyrosine kinase activity. As a monogenic disease, it is an optimum target for RNA silencing therapy. We developed a siRNA-based therapeutic approach in which the siRNA is delivered by pepM or pepR, two cell-penetrating peptides (CPPs) derived from the dengue virus capsid protein. These peptides have a dual role: siRNA delivery into cells and direct action as bioportides, i.e. intracellularly bioactive CPPs, targetting cancer-related signaling processes. Both pepM and pepR penetrate the positive Bcr-Abl+ Cell Line (BV173). Five in silico designed anti-Bcr-Abl siRNA were selected for in vitro analysis after thorough screening. The Bcr-Abl downregulation kinetics (48h to 168h) was followed by quantitative PCR. The bioportide action of the peptide vectors was evaluated by genome-wide microarray analysis and further validated by testing BV173 cell cycle and cell proliferation monitoring different genes involved in housekeeping/cell stress (RPL13A, HPRT1), cell proliferation (ki67), cell apoptosis (Caspase 3 and Caspase 9) and cell cycle steps (CDK2, CCDN2, CDKN1A). Assays with a commercial transfection agent were carried out for comparison purposes. Maximal Bcr-Abl gene knockdown was observed for one of the siRNA when delivered by pepM at 120h. Both pepM and pepR showed downregulation effects on proliferative CML-related signaling pathways having direct impact on BV173 cell cycle and proliferation, thus reinforcing the siRNA effect by acting as anticancer molecules. With this work we show the therapeutic potential of a CPP shuttle that combines intrinsic anticancer properties with the ability to deliver functional siRNA into CML cell models. By such combination, the pepM-siRNA conjugates lowered Bcr-Abl gene expression levels more extensively than conventional siRNA delivery technologies and perturbed leukemogenic cell homeostasis, hence revealing their potential as novel alternative scaffolds for CML therapy.

 

Journal: Journal of Controlled Release

 

Link: http://www.sciencedirect.com/science/article/pii/S0168365916312226