Colorectal cancer is a digestive tract malignancy and the third leading cause of cancer‑related mortality worldwide. Norcantharidin (NCTD), the demethylated form of cantharidin, has been reported to possess anticancer properties. Family‑with‑sequence‑similarity‑46c (Fam46c), a non‑canonical poly(A) polymerase, has been reported to be critical in NCTD‑mediated effects in numerous types of cancer, including hepatoma. In the current study, it was found that Fam46c expression was reduced in colorectal cancer tissues and cells. Treatment with NCTD was observed to significantly enhance apoptosis and inhibit glycolysis in colorectal cancer cells. In addition, Fam46c and cleaved caspase 3 expression levels were found to be increased in response to NCTD treatment, in contrast to tumor‑specific pyruvate kinase M2 and phosphorylated ERK expression, which was reduced. Importantly, overexpression of Fam46c exerted similar effects as NCTD treatment on the apoptosis and glycolysis of colorectal cancer cells, whereas Fam46c knockdown strongly attenuated the effect of NCTD. Moreover, epidermal growth factor, which acts as an agonist of ERK1/2 signaling, weakened the effects of NCTD on colorectal cancer cells. Taken together, the results indicated that NCTD promotes apoptosis and suppresses glycolysis in colorectal cancer cells by possibly targeting Fam46c and inhibiting ERK1/2 signaling, hence suggesting that Fam46c may act as a tumor suppressor in colorectal cancer. Thus, the present study identified a novel therapeutic target of NCTD in the clinical treatment of colorectal cancer.
This study focused on developing a self-nanoemulsifying drug delivery system (SNEDDS) containing bioactive surfactants under an efficient screening approach for overcoming problems associated with the delivery of norcantharidin (NCTD), a high dose chemotherapy agent having pH dependent solubility. Preliminary screening was implemented to select proper components combination. Besides the solubility of NCTD in the oil phase, emulsifying efficiency, droplet size and size distribution were also employed to select components of the SNEDDS. Moreover, the influence of surfactant and co-surfactant on the interfacial tension and droplets of nanoemulsions were investigated to further understand the mechanism of spontaneous emulsification. Co-surfactant addition promoted the emulsification via reducing the water/oil interfacial tension and viscosity. Ternary phase diagrams were constructed to investigate the phase behavior and designate the optimum systems. The alternative formulations were characterized for cloud point, dilution robustness, droplet size, polydispersity index (PDI) and transmission electron microscopy (TEM). In vitro dissolution study showed that the dissolution rate of optimized formulation (NCTD 10 mg/g, EO 50 wt.%, Cremophor EL 35 wt.%, ethylene glycol 15 wt.%) was slower than drug suspension under the same conditions, confirming that the developed SNEDDS formulation would exhibit sustained release potential.
A polymer of Galactosamine-hyaluronic acid-Vitamin E succinate (Gal-HA-VES) was designed to prepare multifunctional self-assembled micelles for delivery of Norcantharidin (NCTD) to Hepatic carcinoma. NCTD/Gal-HA-VES showed higher cytotoxicity toward CD44-overexpressing MCF-7 cells, MCF-7/Adr cells and ASGP-R overexpressing HepG2 cells, consistent with the enhanced cellular uptake in the selected cell models, indicating Gal-HA-VES micelles were taken up in MCF-7 and HepG2 cells by CD44 and ASGPR receptor mediated endocytosis, respectively. Moreover, the accumulation of Rhodamine 123 demonstrated that Gal-HA-VES has the same action of TPGS as a P -glycoprotein inhibitor blocked drug efflux-related MDR mechanism in resistant MCF-7/Adr cells. The Cell apoptosis assays indicated that NCTD/Gal-HA-VES were more effective in triggering apoptosis, compared with free NCTD or NCTD/HA-VES groups. In vivo study demonstrated that NCTD/Gal-HA-VES group exhibited enhanced tumor targeting and antitumor activity with lower systemic toxicity. Hence NCTD/Gal-HA-VES micelles system can achieve significant tumor targeting and effective treatment of hepatic carcinoma.