新型微管靶向化合物WX-127-07体外抗肿瘤活性及作用机制

Anti-tumor activity and mechanism of new microtubule-targeting compound WX-127-07

目的：体外评价新型微管靶向化合物WX-127-07的抗肿瘤活性，并探讨其作用机制。方法以3种微管靶向药物紫杉醇、长春新碱和秋水仙碱为阳性对照，化合物WX-127-07在0.3~300nmol·L-1浓度下作用于5种细胞，72h后用SRB法检测细胞增殖抑制活性，用流式细胞术检测细胞周期阻滞，用高内涵分析（HCA）技术分析该化合物的细胞毒性特征及其与肿瘤和炎症等相关的信号转导途径，用秋水仙碱/荧光-长春碱竞争实验和胰酶消化微管蛋白实验在分子水平测定该化合物的微管蛋白结合位点。结果WX-127-07对肝癌HepG2细胞、宫颈癌HeLa细胞、非小细胞肺癌A549细胞、人胚肺成纤维细胞及脐静脉血管内皮细胞增殖均具有明显的抑制活性，lC50分别为4.47±0.05，5.18±0.08，4.90±0.19，4.10±0.16和（5.04±0.08）nmol·L-1，低于秋水仙碱〔lC50分别为21.17±1.22，14.19±0.53，43.80±1.64，145.89±10.97和（27.67±1.79）nmol·L-1〕和长春新碱〔lC50分别为16.51±0.36，16.76±0.33，27.80±2.75，43.80±1.48和（9.15±0.78）nmol·L-1〕，低于或近似于紫杉醇〔lC50分别为10.68±0.61，12.86±0.25，4.81±0.61，102.07±15.17和（3.04±0.12）nmol·L-1〕。用HCA技术进行细胞多参数分析显示，与长春新碱和秋水仙碱相似，WX-127-07浓度依赖性地诱发A549细胞微管含量降低（P＝0.0075），且作用浓度低于对照药物紫杉醇、长春新碱和秋水仙碱；WX-127-07、紫杉醇、长春新碱和秋水仙碱均能诱发A549细胞出现G2/M期阻滞，并使HepG2细胞核膜通透性增加，出现早期凋亡现象，但不影响肿瘤以及炎症相关的信号通路。微管蛋白位点竞争实验结果表明，WX-127-07浓度依赖性地抑制秋水仙碱与微管蛋白的结合（P＝0.0259）。化合物与微管蛋白作用后用胰酶消化，其产物经SDS电泳，发现WX-127-07作用后的条带与秋水仙碱相似。结论WX-127-07具有较强的体外抗肿瘤细胞增殖活性，其抗肿瘤作用机制符合微管靶向药物的作用特点，选择性地作用于微管秋水仙碱位点，是新型高活性的微管解聚剂。

OBJECTIVE To evaluate the anti-tumor activities of WX-127-07,a new microtubule-tar-geting agent invitroand probe its molecular mechanism. METHODS The well-known microtubule-targe-ting anti-tumor drugs taxol,vincristine and anti-gout drug colchicine were used as positive controls. The anti-proliferation activity was examined in five different cell lines after treatment with WX-127-07（0.3 -300 nmol·L-1 ）for 72 h by SRB assay. The cell cycle arrest profile was assayed by flow cytometry. The multiparameters of cytotoxicity,cell morphology,apoptosis and different signaling pathways related to tumorigenesis and inflammation were analyzed using the high content analysis platform. Tubulin tryptic digestion and competition inhibition assay for colchicine or vinblastine site were used to confirm the bind-ing site in microtubules at a molecular level. RESULTS All the tested compounds obviously inhibited the growth of A549,HepG2,HeLa,HLF and HUVEC cells. The lC50 values of WX-127-07 were 4.47±0.05, 5.18±0.08,4.90±0.19,4.10±0.16 and（5.04±0.08）nmol·L-1 respectively,lower than those of colchicine〔the lC50 values were 21. 17 ± 1. 22,14. 19 ± 0. 53,43. 80 ± 1. 64,145. 89 ± 10. 97 and（ 27. 67 ± 1.79）nmol·L-1 ,respectively〕and those of vincristine〔the lC50 values were 16.51±0.36,16.76±0.33, 27.80±2.75,43.80±1.48 and（9.15±0.78）nmol·L-1 ,respectively〕,but were similar to or lower than those of taxol〔the lC50 values were 10. 68 ± 0. 61,12. 86 ± 0. 25,4. 81 ± 0. 61,102. 07 ± 15. 17 and（ 3. 04 ± 0.12）nmol·L-1 ,respectively〕. High content multi-parameter analysis revealed that WX-127-07 induced a concentration-dependent microtubular depolymerization（P=0.0075）with the same pattern as colchicine and vincristine,but at a lower concentration. Both WX-127-07 and positive drugs could induce cell cycle arrest in A549 cells,increase nuclear membrane permeability and early signs of apoptosis in HepG2 cells,but neither cancer related pathways nor inflammation related pathways were affected. Microtubular competition inhibition assay showed that WX-127-07 inhibited the binding of colchicine with tubulin（P =0.0259）. Tryptic digestion of tubulin-WX-127-07 premixture showed a similar electrophoretic band to that of tubulin-colchicine premixture. CONCLUSION WX-127-07 is a novel microtubule-depolymerizing agent with anti-proliferation activity and acting on the colchicine binding site.