Massudi Hassina, Luo Jie-Si, Holien Jessica K, Gadde Satyanarayana, Krishan Sukriti, Herath Mika, Koach Jessica, Stevenson Brendan W, Gorman Michael A, Venkat Pooja, Mayoh Chelsea, Luo Xue-Qun, Parker Michael W, Cheung Belamy B, Marshall Glenn M
Children's Cancer Institute Australia for Medical Research, Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW 2750, Australia.
Department of Paediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510060, China.
Cancers (Basel). 2023 Mar 17;15(6):1822. doi: 10.3390/cancers15061822.
MYCN is a major oncogenic driver for neuroblastoma tumorigenesis, yet there are no direct MYCN inhibitors. We have previously identified PA2G4 as a direct protein-binding partner of MYCN and drive neuroblastoma tumorigenesis. A small molecule known to bind PA2G4, WS6, significantly decreased tumorigenicity in neuroblastoma mice, along with the inhibition of PA2G4 and MYCN interactions. Here, we identified a number of novel WS6 analogues, with 80% structural similarity, and used surface plasmon resonance assays to determine their binding affinity. Analogues #5333 and #5338 showed direct binding towards human recombinant PA2G4. Importantly, #5333 and #5338 demonstrated a 70-fold lower toxicity for normal human myofibroblasts compared to WS6. Structure-activity relationship analysis showed that a 2,3 dimethylphenol was the most suitable substituent at the R position. Replacing the trifluoromethyl group on the phenyl ring at the R position, with a bromine or hydrogen atom, increased the difference between efficacy against neuroblastoma cells and normal myofibroblast toxicity. The WS6 analogues inhibited neuroblastoma cell phenotype in vitro, in part through effects on apoptosis, while their anti-cancer effects required both PA2G4 and MYCN expression. Collectively, chemical inhibition of PA2G4-MYCN binding by WS6 analogues represents a first-in-class drug discovery which may have implications for other MYCN-driven cancers.
MYCN是神经母细胞瘤发生的主要致癌驱动因素，但目前尚无直接的MYCN抑制剂。我们之前已确定PA2G4是MYCN的直接蛋白质结合伴侣，并驱动神经母细胞瘤的发生。一种已知能与PA2G4结合的小分子WS6，可显著降低神经母细胞瘤小鼠的致瘤性，并抑制PA2G4与MYCN的相互作用。在此，我们鉴定了许多结构相似性达80%的新型WS6类似物，并利用表面等离子体共振分析来确定它们的结合亲和力。类似物#5333和#5338显示出与人重组PA2G4的直接结合。重要的是，与WS6相比，#5333和#5338对正常人肌成纤维细胞的毒性降低了70倍。构效关系分析表明，2,3-二甲基苯酚是R位最合适的取代基。将R位苯环上的三氟甲基替换为溴原子或氢原子，可增加对神经母细胞瘤细胞的疗效与对正常肌成纤维细胞毒性之间的差异。WS6类似物在体外可抑制神经母细胞瘤细胞表型，部分是通过影响细胞凋亡实现的，而它们的抗癌作用需要PA_G4和MYCN的表达。总体而言，WS6类似物对PA2G4-MYCN结合的化学抑制代表了一类首创的药物发现，可能对其他由MYCN驱动的癌症具有重要意义。
