In vitro cytotoxicity of novel pro-apoptotic agent DM-PIT-1 in PEG-PE-based micelles alone and in combination with TRAIL

Abstract

PURPOSE Develop and characterize a micellar formulations of N-{[(2-hydroxy-5-nitrophenyl)amino]carbonothioyl}-3,5-dimethylbenzamide (DM-PIT-1) – a new small molecule non-lipid antagonist of phopshotidylinositol-3.4.5-triphopshate and inhibitor of the PI3-kinase pathway. METHODS Micelle-forming PEG2000-PE was used to solubilize DM-PIT-1. To improve the specificity of the micellar DM-PIT-1, cancer-targeting anti-nucleosomal mAb2C5 antibodies as well as Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL) were attached to the surface of polymeric micelles. RESULTS DM-PIT-1 was effectively incorporated (>70%) into 14–16 nm micelles, which had a negative surface zeta potential of 4–5 mV. Micellar DM-PIT-1 demonstrated high in vitro cytotoxicity against various cancer cells. An improved potency of the dual-activity DM-PIT-1/TRAIL combination nanoparticles in inducing death of TRAIL-resistant cancer cells was shown. Efficacy of the TRAIL therapy was enhanced by combining it with the 2C5 antibody cancer-targeted micellar form of DM-PIT-1. CONCLUSIONS DM-PIT-1 micellar preparations can be used for targeted combination therapy against TRAIL-resistant cancers.

Micellar formulations of pro-apoptotic DM-PIT-1 analogs and TRAILin vitroandin vivo

“…A2780 is resistant to TRAIL-induced toxicity and as such, TRAIL micelles have no cytotoxic activity alone. Consistent with our previous data showing synergy of DM-PIT-1 with TRAIL in TRAIL-resistant cell lines (Skidan et al, 2009;Miao et al, 2010), the addition of TRAIL to the NCL-176 and NCL-240 formulations resulted in a markedly increased cytotoxicity of formulations ( Figure 4B). …”

“…TRAIL micelles were prepared by the thin-film hydration method as described previously (Skidan et al, 2009). Briefly, PEG 2000 -DSPE dissolved in chloroform was added to roundbottomed flasks.…”

“…However, hepatocyte toxicity and tumor cell resistance to TRAIL signaling has limited the use of TRAIL alone as an anticancer agent (Zhang & Fang, 2004). Previous results have demonstrated that the combination of TRAIL with a PI3K inhibitor is an effective method to induce apoptosis (Skidan et al, 2009;Bagci-Onder et al, 2011;Hellwig & Rehm, 2012).…”

“…Previous studies have indicated the utility of combining DM-PIT-1 and TRAIL into one PEG-PE micellar delivery vehicle (Skidan et al, 2009). This study aims to expand upon that success utilizing the second generation of DM-PIT-1 analogs.…”

Specific delivery of kinase inhibitors in nonmalignant and malignant diseases

“…This targeted delivery system resulted in a higher accumulation of the drug in tumors and stronger antitumor and anti-angiogenic effects in U87MG and PC3 tumors in nude mice compared with control treatment with a sham-targeted drug [71]. The PI3-kinase pathway has also been targeted using tumorcell-specific micelles [72]. This study showed that inclusion of the poorly soluble PI3-kinase pathway inhibitor DM-PIT-1 into micelles improved its solubility.…”