Limits...
Fusogenic-oligoarginine peptide-mediated delivery of siRNAs targeting the CIP2A oncogene into oral cancer cells.

Cantini L, Attaway CC, Butler B, Andino LM, Sokolosky ML, Jakymiw A - PLoS ONE (2013)

Bottom Line: However, an obstacle for RNAi-mediated therapies has been delivery, in particular, the retention of small interfering RNAs (siRNAs) in endosomes and their subsequent degradation in lysosomes, resulting in inefficient gene silencing.In fact, quantitative measurements of siRNA delivery into cells demonstrated that a 50∶1 peptide-to-siRNA molar ratio could deliver 18-fold higher amounts of siRNAs compared to cells treated with siRNA alone with no significant long-term cytotoxic effects.Most importantly, the 599 peptide-mediated siRNA delivery promoted significant CIP2A mRNA and protein silencing which resulted in decreased oral cancer cell invasiveness and anchorage-independent growth.

View Article: PubMed Central - PubMed

Affiliation: Depatment of Craniofacial Biology and Center for Oral Health Research, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States of America.

ABSTRACT
Despite a better understanding of the pathogenesis of oral cancer, its treatment outcome remains poor. Thus, there is a need for new therapeutic strategies to improve the prognosis of this disease. RNA interference (RNAi) appears to be a promising therapeutic tool for the treatment of many diseases, including oral cancer. However, an obstacle for RNAi-mediated therapies has been delivery, in particular, the retention of small interfering RNAs (siRNAs) in endosomes and their subsequent degradation in lysosomes, resulting in inefficient gene silencing. Thus, the current study examined the feasibility of designing and utilizing a peptide, termed 599, consisting of a synthetic influenza virus-derived endosome-disruptive fusogenic peptide sequence and a stretch of cationic cell-penetrating nona(D-arginine) residues, to deliver siRNAs into oral cancer cells and induce silencing of the therapeutic target, CIP2A, an oncoprotein overexpressed in various human malignancies including oral cancer. Increasing the 599 peptide-to-siRNA molar ratio demonstrated a higher binding capacity for siRNA molecules and enhanced siRNA delivery into the cytoplasm of oral cancer cells. In fact, quantitative measurements of siRNA delivery into cells demonstrated that a 50∶1 peptide-to-siRNA molar ratio could deliver 18-fold higher amounts of siRNAs compared to cells treated with siRNA alone with no significant long-term cytotoxic effects. Most importantly, the 599 peptide-mediated siRNA delivery promoted significant CIP2A mRNA and protein silencing which resulted in decreased oral cancer cell invasiveness and anchorage-independent growth. Together, these data demonstrate that a chimeric peptide consisting of a fusogenic sequence, in combination with cell-penetrating residues, can be used to effectively deliver siRNAs into oral cancer cells and induce the silencing of its target gene, potentially offering a new therapeutic strategy in combating oral cancer.

Show MeSH

Related in: MedlinePlus

Particle characterization of the 599/siCIP2A complex.(A) Size distribution and zeta potential of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. (B) Darkfield-based optical microscopy image of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. Scale bar: 10,000 nm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3760901&req=5

pone-0073348-g004: Particle characterization of the 599/siCIP2A complex.(A) Size distribution and zeta potential of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. (B) Darkfield-based optical microscopy image of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. Scale bar: 10,000 nm.

Mentions: To assess the 599 peptide in terms of particle size and surface charge after complexation with siCIP2A both dynamic light scattering and zeta potential measurements were performed (Fig. 4A). Based on the measurements, 96% of the particles formed were centered at 74 nm and 4% at 220 nm by number-weighted size distribution, with the average particle size of the major population being 80±0.5 nm. The zeta potential of the 599/siCIP2A complex was determined to be positive with a value of 32.5±0.5 mV. The 599/siCIP2A complex was also visualized using darkfield-based optical illumination (Fig. 4B). Using this imaging technology the 599/siCIP2A complex was found to exhibit fairly uniform spherical structures.


Fusogenic-oligoarginine peptide-mediated delivery of siRNAs targeting the CIP2A oncogene into oral cancer cells.

Cantini L, Attaway CC, Butler B, Andino LM, Sokolosky ML, Jakymiw A - PLoS ONE (2013)

Particle characterization of the 599/siCIP2A complex.(A) Size distribution and zeta potential of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. (B) Darkfield-based optical microscopy image of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. Scale bar: 10,000 nm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3760901&req=5

pone-0073348-g004: Particle characterization of the 599/siCIP2A complex.(A) Size distribution and zeta potential of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. (B) Darkfield-based optical microscopy image of the 599 peptide complexed with siCIP2A at a 50∶1 peptide-to-siRNA molar ratio 20 minutes after formulation in water. Scale bar: 10,000 nm.
Mentions: To assess the 599 peptide in terms of particle size and surface charge after complexation with siCIP2A both dynamic light scattering and zeta potential measurements were performed (Fig. 4A). Based on the measurements, 96% of the particles formed were centered at 74 nm and 4% at 220 nm by number-weighted size distribution, with the average particle size of the major population being 80±0.5 nm. The zeta potential of the 599/siCIP2A complex was determined to be positive with a value of 32.5±0.5 mV. The 599/siCIP2A complex was also visualized using darkfield-based optical illumination (Fig. 4B). Using this imaging technology the 599/siCIP2A complex was found to exhibit fairly uniform spherical structures.

Bottom Line: However, an obstacle for RNAi-mediated therapies has been delivery, in particular, the retention of small interfering RNAs (siRNAs) in endosomes and their subsequent degradation in lysosomes, resulting in inefficient gene silencing.In fact, quantitative measurements of siRNA delivery into cells demonstrated that a 50∶1 peptide-to-siRNA molar ratio could deliver 18-fold higher amounts of siRNAs compared to cells treated with siRNA alone with no significant long-term cytotoxic effects.Most importantly, the 599 peptide-mediated siRNA delivery promoted significant CIP2A mRNA and protein silencing which resulted in decreased oral cancer cell invasiveness and anchorage-independent growth.

View Article: PubMed Central - PubMed

Affiliation: Depatment of Craniofacial Biology and Center for Oral Health Research, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States of America.

ABSTRACT
Despite a better understanding of the pathogenesis of oral cancer, its treatment outcome remains poor. Thus, there is a need for new therapeutic strategies to improve the prognosis of this disease. RNA interference (RNAi) appears to be a promising therapeutic tool for the treatment of many diseases, including oral cancer. However, an obstacle for RNAi-mediated therapies has been delivery, in particular, the retention of small interfering RNAs (siRNAs) in endosomes and their subsequent degradation in lysosomes, resulting in inefficient gene silencing. Thus, the current study examined the feasibility of designing and utilizing a peptide, termed 599, consisting of a synthetic influenza virus-derived endosome-disruptive fusogenic peptide sequence and a stretch of cationic cell-penetrating nona(D-arginine) residues, to deliver siRNAs into oral cancer cells and induce silencing of the therapeutic target, CIP2A, an oncoprotein overexpressed in various human malignancies including oral cancer. Increasing the 599 peptide-to-siRNA molar ratio demonstrated a higher binding capacity for siRNA molecules and enhanced siRNA delivery into the cytoplasm of oral cancer cells. In fact, quantitative measurements of siRNA delivery into cells demonstrated that a 50∶1 peptide-to-siRNA molar ratio could deliver 18-fold higher amounts of siRNAs compared to cells treated with siRNA alone with no significant long-term cytotoxic effects. Most importantly, the 599 peptide-mediated siRNA delivery promoted significant CIP2A mRNA and protein silencing which resulted in decreased oral cancer cell invasiveness and anchorage-independent growth. Together, these data demonstrate that a chimeric peptide consisting of a fusogenic sequence, in combination with cell-penetrating residues, can be used to effectively deliver siRNAs into oral cancer cells and induce the silencing of its target gene, potentially offering a new therapeutic strategy in combating oral cancer.

Show MeSH
Related in: MedlinePlus