Li Nan, Pang Feng-Xiang, Zhou Yu-Wan, Ding Shou-Chang, Shi Chuan-Jian, Wen Rui-Jia, Mai Yong-Xin, Wu Xian-Lin, Zhang Jin-Fang
Cancer center, Shenzhen Hospital (Futian) of Guangzhou University of Chinese Medicine, Shenzhen, Guangdong, 518000, PR China; Lingnan Medical Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, PR China.
Department of Traditional Chinese Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, PR China.
Bioorg Chem. 2025 Jul 15;162:108583. doi: 10.1016/j.bioorg.2025.108583. Epub 2025 May 12.
Osteosarcoma (OS) is a malignant primary tumor in bone tissues, and Methotrexate (MTX) is widely used as a chemotherapeutic drug for OS in clinical treatment. However, MTX resistance is a major challenge for OS patients. Polydatin (PD) is an extract derived from Reynoutria japonica Houtt and has been identified as a potential agent for reversing chemotherapy resistance in cancer. We therefore wondered whether PD could alleviate MTX resistance in OS.
The effect of PD on MTX resistance was investigated. And H19 expression was examined in the PD-treated OS cells. The association between H19 and MTX resistance in osteosarcoma was investigated.The effects of H19 on MTX resistance in osteosarcoma were evaluated by cell proliferation, colony formation, ChIP and western blotting assays. In order to investigate the molecular mechanism of PD underlying methotrexate resistance in OS, the cell proliferation, colony formation, q-PCR and western blotting were examined.
In the present study, PD was found to act as a novel MTX sensitizer, and significantly enhanced the suppressive effects of MTX on OS in vitro and in vivo. Mechanically, PD was demonstrated to suppress the expression of long non-coding RNA H19 as well as its binding protein histone methyltransferase Enhancer of zeste homolog 2 (EZH2), and thus reduced the trimethylation of histone H3K9 (H3K9me3) and K27 (H3K27me3). Furthermore, H19 knowndown increased the binding ability of H3K9me3 and H3K27me3 with the folate metabolism-related genes RFC-1 and PCFT's promoter, and influenced folate metabolism and MTX resistance.
In conclusion, our results indicated that PD alleviated MTX resistance in OS via the H19/H3K27me3/H3K9me3 mediated folate metabolism regulatory axis.
The findings of this study validate the function of PD in alleviating MTX resistance, and provide the new insight into developing PD as a promising drug candidate for the MTX resistant OS patients.
骨肉瘤（OS）是骨组织中的一种恶性原发性肿瘤，甲氨蝶呤（MTX）在临床治疗中被广泛用作骨肉瘤的化疗药物。然而，MTX耐药是骨肉瘤患者面临的主要挑战。虎杖苷（PD）是从虎杖中提取的一种提取物，已被确定为逆转癌症化疗耐药的潜在药物。因此，我们想知道PD是否能减轻骨肉瘤中的MTX耐药性。
研究了PD对MTX耐药性的影响。检测了PD处理的骨肉瘤细胞中H19的表达。研究了骨肉瘤中H19与MTX耐药性之间的关联。通过细胞增殖、集落形成、染色质免疫沉淀（ChIP）和蛋白质印迹分析评估了H19对骨肉瘤中MTX耐药性的影响。为了研究PD逆转骨肉瘤中MTX耐药性的分子机制，检测了细胞增殖、集落形成、定量聚合酶链反应（q-PCR）和蛋白质印迹。
在本研究中，发现PD可作为一种新型的MTX增敏剂，显著增强MTX在体外和体内对骨肉瘤的抑制作用。机制上，PD被证明可抑制长链非编码RNA H19及其结合蛋白组蛋白甲基转移酶zeste同源物2增强子（EZH2）的表达，从而减少组蛋白H3赖氨酸9（H3K9me3）和赖氨酸27（H3K27me3）的三甲基化。此外，H19基因敲低增加了H3K9me3和H3K27me3与叶酸代谢相关基因还原型叶酸载体1（RFC-1）和质子偶联叶酸转运体（PCFT）启动子的结合能力，并影响叶酸代谢和MTX耐药性。
总之，我们的结果表明，PD通过H19/H3K27me3/H3K9me3介导的叶酸代谢调节轴减轻骨肉瘤中的MTX耐药性。
本研究结果验证了PD在减轻MTX耐药性方面的作用，并为将PD开发成为MTX耐药骨肉瘤患者有前景的候选药物提供了新的见解。
