Liang Jinrong, Qiao Guanglei, Zhang Yawen, Yuan Ying, Liu Zimei, Jiang Yue, Zhang Yan, Deng Zhoufeng, Yu Liping, Lin Hongjian, Ma Lijun, Luo Yanli, Zhou Yan, Hu Haiyan, Liu Xin, Zhang Jianjun
Department of Oncology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Department of Oncology, Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
Department of Oncology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China.
Phytomedicine. 2025 Jan;136:156258. doi: 10.1016/j.phymed.2024.156258. Epub 2024 Nov 15.
Lung metastasis is the leading cause of death in patients with osteosarcoma (OS), and new drugs are urgently needed. Epigenetic reprogramming is a recently proposed hallmark of malignancy; therefore, targeting epigenetic enzymes might provide a novel therapeutic strategy for OS lung metastasis. We recently reported that ailanthone (AIL), a natural product isolated from the Chinese medicinal plant Ailanthus altissima, inhibits OS cell growth and induces substantial metabolic changes; however, its direct targets remain unclear.
To identify the direct targets of AIL in OS and to explore the effects of AIL on OS lung metastasis in vivo.
Direct target proteins of AIL and downstream signaling pathways were identified in Saos-2 and U-2OS OS cells. The in vivo effects of AIL on OS lung metastasis were investigated using a mouse model.
A novel surface plasmon resonance-high-performance liquid chromatography-mass spectrometry (SPR-HPLC-MS) assay was used to determine direct targets of AIL in OS. A cellular thermal shift assay, molecular docking analysis, enzyme activity assay, qRT-PCR, western blotting, chromatin immunoprecipitation assay, and reverse tests were performed to confirm the target and downstream pathway of AIL. A tumor xenograft model was used to verify the efficacy and mechanisms in vivo.
Histone-lysine N-methyltransferase 2A (KMT2A) together with its scaffold protein menin (MEN1) were identified as direct target proteins of AIL in OS. AIL induced the autophagic degradation of the KMT2A-MEN1 complex. Moreover, AIL inhibited intracellular H3K4 methyltransferase activity and epigenetically inhibited the transcription of genes in the serine biosynthetic pathway (SSP). Furthermore, AIL suppressed OS lung metastasis and downregulated KMT2A, MEN1, and SSP in mouse models.
This work showed that AIL targets the KMT2A-MEN1 complex and inhibits SSP to suppress OS lung metastasis. Notably, AIL exhibits new mechanisms of action, distinct from those of existing anti-OS drugs. On the basis of these findings, we proposed a novel strategy to treat OS by targeting epigenetic enzymes and cancer metabolism.
肺转移是骨肉瘤（OS）患者的主要死亡原因，因此迫切需要新药。表观遗传重编程是最近提出的恶性肿瘤标志；因此，靶向表观遗传酶可能为OS肺转移提供一种新的治疗策略。我们最近报道，从中药臭椿中分离出的天然产物白藓碱（AIL）可抑制OS细胞生长并诱导大量代谢变化；然而，其直接靶点仍不清楚。
确定AIL在OS中的直接靶点，并探讨AIL对OS肺转移的体内影响。
在Saos-2和U-2OS OS细胞中鉴定AIL的直接靶蛋白和下游信号通路。使用小鼠模型研究AIL对OS肺转移的体内影响。
采用一种新型表面等离子体共振-高效液相色谱-质谱（SPR-HPLC-MS）检测方法来确定AIL在OS中的直接靶点。进行细胞热位移分析、分子对接分析、酶活性分析、qRT-PCR、蛋白质印迹、染色质免疫沉淀分析和反向试验以确认AIL的靶点和下游通路。使用肿瘤异种移植模型在体内验证疗效和机制。
组蛋白赖氨酸N-甲基转移酶2A（KMT2A）及其支架蛋白Menin（MEN1）被鉴定为AIL在OS中的直接靶蛋白。AIL诱导KMT2A-MEN1复合物的自噬降解。此外，AIL抑制细胞内H3K4甲基转移酶活性，并在表观遗传上抑制丝氨酸生物合成途径（SSP）中基因的转录。此外，AIL在小鼠模型中抑制OS肺转移并下调KMT2A、MEN1和SSP。
这项工作表明，AIL靶向KMT2A-MEN'复合物并抑制SSP以抑制OS肺转移。值得注意的是，AIL表现出与现有抗OS药物不同的新作用机制。基于这些发现，我们提出了一种通过靶向表观遗传酶和癌症代谢来治疗OS的新策略。
