Original ArticleLiposome-mediated delivery of the p21 activated kinase-1 (PAK-1) inhibitor IPA-3 limits prostate tumor growth in vivo
Graphical abstract
The small molecule ‘inhibitor targeting P21-activated kinase-1 (PAK1) activation-3’ (IPA-3) has potential anti-cancer effects, but is metabolically unstable. We encapsulated IPA-3 in sterically stabilized liposomes (SSL) that averaged 139 nm in diameter, polydispersity index (PDI) of 0.05, and a zeta potential of − 28.1, which was stable for over 14 days with 70 % of IPA-3 remaining even after 7 days. A 2 day/week administration of 5 mg/kg dose of SSL-IPA-3 significantly inhibited the growth of prostate xenografts in vivo as compared to similar dose of free IPA-3, demonstrating the potential benefits of SSL-IPA-3 for the management of prostate cancer.
Section snippets
Cell lines and cell culture
The human prostate cancer cell lines PC-3, LNCaP and DU-145 and the breast cancer cell lines MCF-7 and MDA-231 were purchased from ATCC (Manassas, VA). PC-3, LNCaP, and DU-145 cells were cultured in F12K, RPMI, and EMEM, respectively. MCF-7 and MDA-231 cells were cultured in RPMI. All culture media were supplemented with 10% FBS and 1% penicillin/streptomycin antibiotics (ATCC). All cells were maintained at 37 °C in incubators with 5% CO2 and humidified atmosphere.
Chemicals and reagents
IPA-3 was purchased from Tocris
Characterization of SSL-IPA-3
SSL-IPA-3 (Table 1) had a hydrodynamic particle diameter of approximately 139 nm, and this value did not change significantly over a period of two weeks (Table 2). The polydispersity index (PDI), a measure of the distribution of diameters was maintained at values less than 0.14 for up to 14 days. These PDI values are within the recommended size for medical applications, which is a PDI of less than 0.3.26 The zeta potential (the overall surface charge of the particles) also did not significantly
Discussion
Serine–threonine kinases PAKs, PAK-1 in particular, have been associated with a variety of pathological conditions, including cancer.1 PAK-1 is regulated by auto-inhibition, and is suggested as a good therapeutic target for cancer therapy by using small molecules that may cause conformational changes in the protein disturbing its autoregulation.1, 27 Previous studies from our laboratory showed that Rac1, an upstream regulator of PAK-1 promotes prostate cancer cell survival, proliferation and
Acknowledgments
The authors would like to thank Mr. Nhat D. Quach for his technical support during liposome preparation.
References (32)
- et al.
Mechanism of p21-activated kinase 6-mediated inhibition of androgen receptor signaling
J Biol Chem
(2004) - et al.
P21 activated kinase-1 (Pak1) promotes prostate tumor growth and microinvasion via inhibition of transforming growth factor beta expression and enhanced matrix metalloproteinase 9 secretion
J Biol Chem
(2013) - et al.
An isoform-selective, small-molecule inhibitor targets the autoregulatory mechanism of p21-activated kinase
Chem Biol
(2008) - et al.
Participation of group I p21-activated kinases in neuroplasticity
J Physiol Paris
(2014) - et al.
P21-activated kinase in inflammatory and cardiovascular disease
Cell Signal
(2014) - et al.
Novel insights into mechanisms for Pak1-mediated regulation of cardiac Ca(2 +) homeostasis
Front Physiol
(2015) - et al.
Secretory phospholipase A responsive liposomes
J Pharm Sci
(2011) - et al.
New self-assembly nanoparticles and stealth liposomes for the delivery of zoledronic acid: a comparative study
Biotechnol Adv
(2012) - et al.
Sterically stabilized liposomes: a hypothesis on the molecular origin of the extended circulation times
Biochim Biophys Acta
(1991) - et al.
Tumor vascular permeability and the EPR effect in macromolecular therapeutics: a review
J Control Release
(2000)
Secretory phospholipase A(2) responsive liposomes
J Pharm Sci
Novel protein kinases and molecular mechanisms of autoinhibition
Curr Opin Struct Biol
An overview of liposome lyophilization and its future potential
J Control Release
PAK1 as a therapeutic target
Expert Opin Ther Targets
PAK signalling during the development and progression of cancer
Nat Rev Cancer
Rac1 activation driven by 14-3-3 zeta dimerization promotes prostate cancer cell–matrix interactions, motility and transendothelial migration
PLoS One
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Conflicts of interest: The authors have declared that no conflicts of interest exist.
Financial support: Funds were provided by the National Institutes of Health (Grant R01HL103952), the UGA-College of Pharmacy, UGA Research Foundation and the American Legion to PRS, National Institutes of Health (Grant R01EB0116100) to B.S.C., and an Achievement Reward for College Scientists Foundation Award to W.N.M. Research was supported with resources and the use of facilities at the Charlie Norwood VAMC, Augusta, GA. The funders had no role in the study design, data collection, analysis and decision to publish. Preparation of the manuscript and the contents do not represent the views of the Department of Veterans Affairs or the United States Government.
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These authors contributed equally to this work.