狼毒大戟活性成分通过TOX3介导的VEGF/VEGFR2信号通路抑制乳腺肿瘤血管新生

The pathogenesis of breast cancer is unclear. Explore the functions of genes associated with breast cancer may provide the potential targets for early prevention and treatment. TOX3 gene involves the proliferation and invasion of breast cancer cells. However, there is no any report involved in its roles in angiogenesis in breast carcinoma. We found that TOX3 gene can regulate the expression of VEGF, CD34 and E-Gadherin in breast cancer cells. This suggests that it may be involved in the angiogenesis of breast tumor. In addition, the active ingredient of euphorbia fischeriana DP may inhibit the angiogenesis in tumors via VEGF/VEGFR2 pathway and it also may down-regulate the expression of TOX3 and VEGF in breast cancer cells. So we speculate that DP may inhibit angiogenesis in breast carcinoma via TOX3 gene-mediated VEGF/VEGFR2 pathway. This study firstly explores the correlation of TOX3 with mammary tumor angiogenesis and the expression of VEGF, taking TOX3 gene-mediated VEGF pathway as a breakthrough point and illuminates possible mechanism that DP resist the mammary tumor angiogenesis by both in vivo and in vitro experiment. This work is expected to provide experimental basis for further discovering the material basis of the anti-tumor effect from euphorbia fischeriana. It also may lay the foundation for discovering drugs with the new mechanism of action and has important theoretical value and practical significance.

乳腺癌的发病机制尚不清楚，阐明参与乳腺癌发展相关基因的功能，可为乳腺癌早期预防及治疗提供潜在的靶点。TOX3基因参与乳腺癌细胞增殖和侵袭，但其在血管新生中的作用尚无报道。课题组发现TOX3可调控乳腺癌细胞VEGF、CD34和E-Gadherin的表达，表明其可能参与了乳腺肿瘤血管新生过程。此外，狼毒大戟活性成分DP可通过VEGF/VEGFR2通路抑制肿瘤血管新生，又可下调乳腺癌细胞TOX3和VEGF的表达。因此，我们推测DP可能通过TOX3基因介导的VEGF/VEGFR2通路抑制乳腺肿瘤血管新生。本课题首先探讨TOX3与乳腺肿瘤血管生成及VEGF表达的相关性，以TOX3介导的VEGF通路为切入点，通过体内外实验探索DP抗乳腺肿瘤血管新生的机制，为进一步发现狼毒大戟抗肿瘤作用的物质基础及机制提供实验依据，有望为发现新型作用机制的抗肿瘤药物奠定基础，具有重要的理论价值和实际意义。

乳腺癌的发病机制尚不清楚，阐明参与乳腺癌发展相关基因的功能，可为乳腺癌早期预防及治疗提供潜在的靶点。TOX3基因参与乳腺癌细胞增殖和侵袭，但其在血管新生中的作用尚无报道。本项目在前期研究基础上，探讨TOX3与乳腺肿瘤血管生成的相关性，以TOX3介导的VEGF/VEGFR2通路为切入点，通过体内外实验探索狼毒大戟活性成分12-去氧佛波醇-13-棕榈酸酯（DP）抗乳腺肿瘤血管新生的机制。研究发现TOX3与乳腺肿瘤血管生成存在一定的相关性，成功构建稳定沉默和过表达TOX3的乳腺癌细胞系和人脐静脉内皮HUVEC细胞系。功能研究发现TOX3可促进乳腺癌细胞和HUVEC细胞的增殖、侵袭、迁移和管腔形成。在机制研究上，发现干扰TOX3后可抑制乳腺癌细胞和HUVEC细胞VEGF/VEGFR2及其下游信号通路的活化；而过表达TOX3后则可上调VEGF/VEGFR2及其下游信号通路相关基因和蛋白的表达。体内研究进一步揭示TOX3在乳腺肿瘤血管形成中的作用及对VEGF/VEGFR2通路的调控机制；在此基础上，以TOX3基因调控的VEGF/VEGFR2通路为切入点，通过体内外实验发现DP可抑制乳腺癌细胞和HUVEC细胞的增殖、侵袭、迁移和成管能力，抑制乳腺肿瘤生长，使微血管密度下降，同时能够抑制TOX3、VEGF/VEGFR2及其下游通路，表明DP可通过TOX3基因介导的VEGF/VEGFR2通路抑制乳腺肿瘤血管新生。本项目为进一步发现狼毒大戟抗肿瘤作用的物质基础及机制提供实验依据，有望为发现新型作用机制的抗肿瘤药物奠定基础，具有重要的理论价值和实际意义。