N-4-iodophenyl-N′-2-chloroethylurea, a novel potential anticancer agent with colon-specific accumulation: radioiodination and comparative in vivo biodistribution profiles

Diabetes mellitus drug discovery: insights into targeting feline and human amylin with small molecules

BACKGROUND

Type 2 diabetes (T2D) is a health concern for both humans and cats, with cases rising over the past decade. Around 70% of patients from either species exhibit pancreatic aggregates of islet amyloid polypeptide (IAPP), a protein that proves toxic upon misfolding. These misfolded protein aggregates congregate in the islets of Langerhans of the pancreas, diminishing the capability of β-cells to produce insulin and further perpetuating disease.

OBJECTIVE

Our team's drug discovery program is investigating newly synthesized compounds that could diminish aggregates of both human and feline IAPP, potentially disrupting the progression of T2D.

MATERIAL AND METHODS

We prepared 24 compounds derived from diaryl urea, as ureas have previously demonstrated great potential at reducing accumulations of misfolded proteins. Biophysical methods were employed to analyze the anti-aggregation activity of these compounds at inhibiting and/or disrupting IAPP fibril formation in vitro.

RESULTS

The results demonstrate that compounds 12 and 24 were most effective at reducing the fibrillization and aggregation of both human and feline IAPP. When compared with the control for each experiment, samples treated with either compound 12 or 24 exhibited fewer accumulations of amyloid-like fibrils.

CONCLUSION

Urea-based compounds, such as compounds 12 and 24, may prove crucial in future pre-clinical studies in the search for therapeutics for T2D.

Synthesis of Radioiodinated Compounds. Classical Approaches and Achievements of Recent Years

This review demonstrates the progress in the synthesis of radioiodinated compounds over the past decade. The possibilities and limitations of radiopharmaceuticals with different iodine isotopes, as well as the synthesis of low and high molecular weight compounds containing radioiodine, are discussed. An analysis of synthesis strategies, substrate frameworks, isolation methods, and metabolic stability, and the possibility of industrial production of radioiodinated organic derivatives which can find applications in the synthesis of drugs and diagnostics are presented.

Laser-responsive liposome for selective tumor targeting of nitazoxanide nanoparticles

Nitazoxanide [2-(Acetyloxy)-N-(5-nitro-2-thiazolyl)benzamide], usually referred as NTZ, is an antiparasites drug with a potential anti-cancer reactivity. However, the bioavailability of nitazoxanide is limited due to its poor water solubility. In this study, nitazoxanide could be successfully incorporated in a stable biocompatible liposome (NTZ-LP) using a modified thin film hydration technique. Further, a novel lipophilic phthalocyanine star polymer R₄PcZn was prepared as photosensitizer and in situ incorporated with NTZ in the liposome formulation affording a laser-responsive liposome (NTZ-ZnPc-LP). Both (NTZ-LP) and (NTZ-ZnPc-LP) showed high entrapment efficiency (EE) and high in vitro drug release rates. Transmission electron microscope (TEM) images and dynamic light scattering (DLS) measurements of (NTZ-LP) and (NTZ-ZnPc-LP) showed unilamellar vesicles of mean diameter 192.2 and 87.4nm, respectively. In addition, NTZ nanoparticles (NTZ NPs) were prepared via membrane extrusion method using DMF and water as solvents. All formulations were similarly prepared using radiolabeled nitazoxanide ¹²⁵I-NTZ. After induction of solid tumor in mices using Ehrlich Ascites Carcinoma, the prepared formulations were injected in the tail vein of the mices. Tumor sites of the animal injected with (¹²⁵I-NTZ-ZnPc-LP) were illuminated with a HeNe laser (λ=630nm). Afterwards, the biodistriburtion of ¹²⁵I-NTZ was tagged using γ counter. Results showed that the light-responsive formulation (¹²⁵I-NTZ-ZnPc-LP) affords a higher accumulation of ¹²⁵I NTZ in the tumor sites after illumination. This can be attributed to the rupture of liposome lipid bilayer as a result of the photosensitization process and the singlet oxygen species resulted thereof. Despite (NTZ NPs) formulation showed a rapid accumulation of NTZ in tumor, it showed unfavoured rapid blood clearance rate.

Discovery of ethyl urea derivatives as inhibitors of islet amyloid polypeptide fibrillization and cytotoxicity

Islet amyloid polypeptide (IAPP) has been shown to form amyloid deposits in pancreatic islets, thereby furthering type 2 diabetes disease progression. Further discovery of new molecules is needed to create a diverse set of molecules that impede pancreatic amyloidosis. We have recently designed and synthesized N-phenyl-N'-(2-ethyl)ureas (EU) that are non-cytotoxic small molecules, to evaluate the role of the aryl-substituted moiety on the inhibition of hIAPP fibrillization. Several EUs were tested in vitro for their anti-amyloidogenic activity using the fluorometric ThT assay, the photo-induced cross-linking (PIUCP) assay, and cell survival assay in pancreatic MIN-6 cells. EU-362 and EU-418 were able to significantly inhibit the formation of hIAPP fibrils and protected cells from amyloid cytotoxic effects. Our results suggest that increasing the nucleophilic potency of the aryl moiety significantly enhances the anti-amyloidogenic activity of the molecules.

Intramolecular cyclization of N-phenyl N'(2-chloroethyl)ureas leads to active N-phenyl-4,5-dihydrooxazol-2-amines alkylating β-tubulin Glu198 and prohibitin Asp40

The cyclization of anticancer drugs into active intermediates has been reported mainly for DNA alkylating molecules including nitrosoureas. We previously defined the original cytotoxic mechanism of anticancerous N-phenyl-N'-(2-chloroethyl)ureas (CEUs) that involves their reactivity towards cellular proteins and not against DNA; two CEU subsets have been shown to alkylate β-tubulin and prohibitin leading to inhibition of cell proliferation by G₂/M or G₁/S cell cycle arrest. In this study, we demonstrated that cyclic derivatives of CEUs, N-phenyl-4,5-dihydrooxazol-2-amines (Oxas) are two- to threefold more active than CEUs and share the same cytotoxic properties in B16F0 melanoma cells. Moreover, the CEU original covalent binding by an ester linkage on β-tubulin Glu198 and prohibitin Asp40 was maintained with Oxas. Surprisingly, we observed that Oxas were spontaneously formed from CEUs in the cell culture medium and were also detected within the cells. Our results suggest that the intramolecular cyclization of CEUs leads to active Oxas that should then be considered as the key intermediates for protein alkylation. These results will be useful for the design of new prodrugs for cancer chemotherapy.