Synthesis and anti-tumor activity of imidazopyrazines as TAK1 inhibitors

Identification of TAK-756, A Potent TAK1 Inhibitor for the Treatment of Osteoarthritis through Intra-Articular Administration

Osteoarthritis (OA) is a chronic and degenerative joint disease affecting more than 500 million patients worldwide with no disease-modifying treatment approved to date. Several publications report on the transforming growth factor β-activated kinase 1 (TAK1) as a potential molecular target for OA, with complementary anti-catabolic and anti-inflammatory effects. We report herein on the development of TAK1 inhibitors with physicochemical properties suitable for intra-articular injection, with the aim to achieve high drug concentration at the affected joint, while avoiding severe toxicity associated with systemic inhibition. More specifically, reducing solubility by increasing crystallinity, while maintaining moderate lipophilicity proved to be a good compromise to ensure high and sustained free drug exposures in the joint. Furthermore, structure-based design allowed for an improvement of selectivity versus interleukin-1 receptor-associated kinases 1 and 4 (IRAK1/4). Finally, TAK-756 was discovered as a potent TAK1 inhibitor with good selectivity versus IRAK1/4 as well as excellent intra-articular pharmacokinetic properties.

Current development of pyrazole-azole hybrids with anticancer potential

Chemotherapy is a critical treatment modality for cancer patients, but multidrug resistance remains one of the major challenges in cancer therapy, creating an urgent need for the development of novel potent chemical entities. Azoles, particularly pyrazole, could interact with different biological targets and exhibit diverse biological properties including anticancer activity. Many clinically used anticancer agents own an azole moiety, demonstrating that azoles are privileged and pivotal templates in the discovery of novel anticancer chemotherapeutics. The present article is an attempt to highlight the recent advances in pyrazole-azole hybrids with anticancer potential and discuss the structure-activity relationships, covering articles published from 2018 to present, to facilitate the rational design of more effective anticancer candidates.

Current scenario of pyrazole hybrids with in vivo therapeutic potential against cancers

Chemotherapeutics occupy a pivotal role in the medication of different types of cancers, but the prevalence and mortality rates of cancer remain high. The drug resistance and low specificity of current available chemotherapeutics are the main barriers for the effective cancer chemotherapy, evoking an immediate need for the development of novel anticancer agents. Pyrazole is a highly versatile five-membered heterocycle with two adjacent nitrogen atoms and possesses remarkable therapeutic effects and robust pharmacological potency. The pyrazole derivatives especially pyrazole hybrids have demonstrated potent in vitro and in vivo efficacies against cancers through multiple mechanisms, inclusive of apoptosis induction, autophagy regulation, and cell cycle disruption. Moreover, several pyrazole hybrids such as crizotanib (pyrazole-pyridine hybrid), erdafitinib (pyrazole-quinoxaline hybrid) and ruxolitinib (pyrazole-pyrrolo [2,3-d]pyrimidine hybrid) have already been approved for the cancer therapy, revealing that pyrazole hybrids are useful scaffolds to develop novel anticancer agents. The purpose of this review is to summarize the current scenario of pyrazole hybrids with potential in vivo anticancer efficacy along with mechanisms of action, toxicity, and pharmacokinetics, covering papers published in recent 5 years (2018-present), to facilitate further rational exploitation of more effective candidates.

Synthesis and Antitumor Evaluation of Menthone-Derived Pyrimidine-Urea Compounds as Potential PI3K/Akt/mTOR Signaling Pathway Inhibitor

A series of novel menthone derivatives bearing pyrimidine and urea moieties was designed and synthesized to explore more potent natural product-derived antitumor agents. The structures of the target compounds were confirmed by FTIR, NMR, and HRMS. The in vitro antitumor activity was tested by standard methyl thiazolytetrazolium assay and showed that 4i, 4g, 4s, and 4m are the best compounds with IC50 values of 6.04 ± 0.62µM, 3.21 ± 0.67µM, 19.09 ± 0.49µM, and 18.68 ± 1.53µM, against Hela, MGC-803, MCF-7, and A549, respectively. The results of the preliminary action mechanism studies showed that compound 4i, the representative compound, could induce cell apoptosis in Hela cells in a dose-dependent manner and might arrest the cell cycle in the G2/M phase. Furthermore, the results of network pharmacology prediction and Western blot experiments indicated that compound 4i might inhibit Hela cells through inhibit PI3K/Akt/mTOR signaling pathway. The binding modes and the binding sites interactions between compound 4i and the target proteins were predicted preliminarily by the molecular docking method.

Therapeutic Implications of TGFβ in Cancer Treatment: A Systematic Review

Transforming growth factor β (TGFβ) is a pleiotropic cytokine that participates in a wide range of biological functions. The alterations in the expression levels of this factor, or the deregulation of its signaling cascade, can lead to different pathologies, including cancer. A great variety of therapeutic strategies targeting TGFβ, or the members included in its signaling pathway, are currently being researched in cancer treatment. However, the dual role of TGFβ, as a tumor suppressor or a tumor-promoter, together with its crosstalk with other signaling pathways, has hampered the development of safe and effective treatments aimed at halting the cancer progression. This systematic literature review aims to provide insight into the different approaches available to regulate TGFβ and/or the molecules involved in its synthesis, activation, or signaling, as a cancer treatment. The therapeutic strategies most commonly investigated include antisense oligonucleotides, which prevent TGFβ synthesis, to molecules that block the interaction between TGFβ and its signaling receptors, together with inhibitors of the TGFβ signaling cascade-effectors. The effectiveness and possible complications of the different potential therapies available are also discussed.

Synthesis, cytotoxicity, pharmacokinetic profile, binding with DNA and BSA of new imidazo[1,2-a]pyrazine-benzo[d]imidazol-5-yl hybrids

Novel derivatives possessing imidazo[1,2-a]pyrazine and 1H-benzo[d]imidazole scaffolds were synthesized using Suzuki-Miyaura cross-coupling reactions. In vitro anticancer activities against NCI-60 cancer cell panels were tested at 10 µM concentration. The best results were obtained from substitution of two 1-cyclohexyl-1H-benzo[d]imidazole groups present at C-6 and C-8 positions of imidazo[1,2-a]pyrazine (31). Compound 31 was found to be cytotoxic against 51 cell lines and cytostatic against 8 cell lines with broad range of growth inhibitions (−98.48 to 98.86%). GI₅₀ value of compound 31 was found in the range of 0.80–2.87 µM for 59 human cancer cell lines at five-dose concentration levels. DNA binding study of potent compound 31 was suggested that this compound was intercalated into DNA base pairs with binding constant of 1.25 × 10⁴ M⁻¹. Compound 31 showed effective binding with bovine serum albumin (BSA) and presented binding constant value of 3.79 ×10⁴ M^-1. Pharmacokinetic studies revealed that all compounds are following Lipinski’s rule of five and expected to be orally active.