Design and Synthesis of a Cell-Permeable, Drug-Like Small Molecule Inhibitor Targeting the Polo-Box Domain of Polo-Like Kinase 1
作者:Ganipisetti Srinivasrao、Jung-Eun Park、Sungmin Kim、Mija Ahn、Chaejoon Cheong、Ky-Youb Nam、Pethaiah Gunasekaran、Eunha Hwang、Nam-Hyung Kim、Song Yub Shin、Kyung S. Lee、Eunkyung Ryu、Jeong Kyu Bang
DOI:10.1371/journal.pone.0107432
日期:——
Background Polo-like kinase-1 (Plk1) plays a crucial role in cell proliferation and the inhibition of Plk1 has been considered as a potential target for specific inhibitory drugs in anti-cancer therapy. Several research groups have identified peptide-based inhibitors that target the polo-box domain (PBD) of Plk1 and bind to the protein with high affinity in in vitro assays. However, inadequate proteolytic resistance and cell permeability of the peptides hinder the development of these peptide-based inhibitors into novel therapeutic compounds. Methodology/Principal Findings In order to overcome the shortcomings of peptide-based inhibitors, we designed and synthesized small molecule inhibitors. Among these molecules, bg-34 exhibited a high binding affinity for Plk1-PBD and it could cross the cell membrane in its unmodified form. Furthermore, bg-34-dependent inhibition of Plk1-PBD was sufficient for inducing apoptosis in HeLa cells. Moreover, modeling studies performed on Plk1-PBD in complex with bg-34 revealed that bg-34 can interact effectively with Plk1-PBD. Conclusion/Significance We demonstrated that the molecule bg-34 is a potential drug candidate that exhibits anti-Plk1-PBD activity and possesses the favorable characteristics of high cell permeability and stability. We also determined that bg-34 induced apoptotic cell death by inhibiting Plk1-PBD in HeLa cells at the same concentration as PEGylated 4j peptide, which can inhibit Plk1-PBD activity 1000 times more effectively than bg-34 can in in vitro assays. This study may help to design and develop drug-like small molecule as Plk1-PBD inhibitor for better therapeutic activity.
背景:类泊洛激酶-1(Plk1)在细胞增殖中扮演着关键角色,抑制Plk1被视为抗癌治疗中特异抑制药物的潜在目标。多个研究小组已识别出针对Plk1的泊洛框区域(PBD)的肽类抑制剂,并在体外实验中以高亲和力结合该蛋白。然而,这些肽类抑制剂在蛋白酶抗性和细胞通透性方面不足,阻碍了其发展为新型治疗化合物。
方法/主要发现:为了克服肽类抑制剂的缺点,我们设计并合成了小分子抑制剂。在这些分子中,bg-34对Plk1-PBD表现出高度的结合亲和力,并且可以以未修饰形式跨越细胞膜。此外,bg-34依赖性抑制Plk1-PBD足以在HeLa细胞中诱导凋亡。此外,对Plk1-PBD与bg-34复合体进行的建模研究显示,bg-34能够有效与Plk1-PBD相互作用。
结论/意义:我们证明了分子bg-34是一个具有潜力的药物候选者,表现出抗Plk1-PBD活性,并具备高细胞通透性和稳定性等有利特征。我们还确定,bg-34通过抑制HeLa细胞中的Plk1-PBD诱导凋亡性细胞死亡,其浓度与PEG化4j肽相同,而后者在体外实验中能够比bg-34更有效地抑制Plk1-PBD活性1000倍。本研究可能有助于设计和开发像Plk1-PBD抑制剂的药物样小分子,以提高治疗活性。