Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Ahmedabad, India.
Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research-Ahmedabad, India.
Bioorg Med Chem Lett. 2021 Jun 15;42:128062. doi: 10.1016/j.bmcl.2021.128062. Epub 2021 Apr 24.
Several studies have established that cancer cells explicitly over-express the less active isoform of pyruvate kinase M2 (PKM2) is critical for tumorigenesis. The activation of PKM2 towards tetramer formation may increase affinity towards phosphoenolpyruvate (PEP) and avoidance of the Warburg effect. Herein, we describe the design, synthesis, and development of boronic acid-based molecules as activators of PKM2. The designed molecules were inspired by existing anticancer scaffolds and several fragments were assembled in the derivatives. 6a-6d were synthesized using a multi-step synthetic strategy in 55-70% yields, starting from cheap and readily available materials. The compounds were selectively cytotoxic to kill the cancerous cells at 80 nM, while they were non-toxic to the normal cells. The kinetic studies established the compounds as novel activators of PKM2 and (E/Z)-(4-(3-(2-((4-chlorophenyl)amino)-4-(dimethylamino)thiazol-5-yl)-2-(ethoxycarbonyl)-3-oxoprop-1-en-1-yl) phenyl)boronic acid (6c) emerged as the most potent derivative. 6c was further evaluated using various in silico tools to understand the molecular mechanism of tetramer formation. Docking studies revealed that 6c binds to the PKM2 dimer at the dimeric interface. Further to ascertain the binding site and mechanism of action, rigorous MD (molecular dynamics) simulations were undertaken, which led to the conclusion that 6c stabilizes the center of the dimeric interface that possibly promotes tetramer formation. We further planned to make a tablet of the developed molecule for oral delivery, but it was seriously impeded owing to poor aqueous solubility of 6c. To improve aqueous solubility and retain 6c at the lower gastrointestinal tract, thiolated chitosan-based nanoparticles (TCNPs) were prepared and further developed as tablet dosage form to retain anticancer potency in the excised goat colon. Our findings may provide a valuable pharmacological mechanism for understanding metabolic underpinnings that may aid in the clinical development of new anticancer agents targeting PKM2.
已有多项研究证实，癌细胞明确过表达丙酮酸激酶 M2（PKM2）的活性较低同工型，这对于肿瘤发生至关重要。PKM2 向四聚体形成的激活可能会增加对磷酸烯醇丙酮酸（PEP）的亲和力，并避免瓦博格效应。在此，我们描述了基于硼酸的分子作为 PKM2 激活剂的设计、合成和开发。所设计的分子受现有抗癌支架的启发，并在衍生物中组装了几个片段。6a-6d 是使用多步合成策略，以 55-70%的产率从廉价且易得的材料合成的。这些化合物选择性地杀死癌细胞，其在 80 nM 时具有细胞毒性，而对正常细胞无毒。动力学研究确立了这些化合物是 PKM2 的新型激活剂，并且（E/Z）-（4-（3-（2-（（4-氯苯基）氨基）-4-（二甲基氨基）噻唑-5-基）-2-（乙氧羰基）-3-氧代丙-1-烯-1-基）苯基）硼酸（6c）是最有效的衍生物。6c 进一步使用各种计算工具进行评估，以了解四聚体形成的分子机制。对接研究表明，6c 与 PKM2 二聚体在二聚体界面处结合。为了确定结合位点和作用机制，进行了严格的 MD（分子动力学）模拟，得出的结论是，6c 稳定二聚体界面的中心，这可能促进四聚体形成。我们进一步计划开发一种口服给药的分子片剂，但由于 6c 的水溶性差，这一计划受到严重阻碍。为了提高水溶性并保留在较低的胃肠道中，制备了巯基化壳聚糖基纳米粒子（TCNPs）并进一步开发为片剂剂型，以在切除的山羊结肠中保留抗癌效力。我们的研究结果可能为理解代谢基础提供有价值的药理学机制，这可能有助于开发针对 PKM2 的新型抗癌药物。
