辣椒素调控MKK3/p38MAPK信号通路抑制鼻咽癌增殖和转移的分子机制

At present, the distant metastasis rate of moderate-advanced nasopharyngeal carcinoma is up to 30% and combined radio-chemotherapy is needed. The patients usually have poor compliance due to the large adverse reaction of chemotherapy. So, how to identify natural active compound as a drug or to be used with chemotherapy drugs to reduce the adverse reaction is the key to further improve the therapeutic effect of nasopharyngeal carcinoma on the basis of traditional chemotherapy. Our previous studies have shown that capsaicin could suppress the tumor growth, migration, invasion and induce apoptosis in nasopharyngeal carcinoma. But what is the molecular mechanism? We have found that capsaicin could downregulate the expression of MKK3 and the downstream p38 MAPK protein and corresponding phosphorylated protein by PCR microarray and immune imprinting and it is time-dependent. Further experiments have shown that the expression level of MKK3 is upregulated in nasopharyngeal carcinoma cells, and the aberrant overexpression of MKK3 can promote the migration ability of nasopharyngeal carcinoma cells by establishing the MKK3 overexpression cell lines stably. Therefore, we hypothesize that capsaicin could suppress the tumor growth and metastasis by modulating MKK3/p38 MAPK pathway in nasopharyngeal carcinoma. In this project, experiments such as animal models, kinase inhibitors and siRNA, etc. will be used to elucidate the key role of capsaicin in the proliferation and metastasis of nasopharyngeal carcinomain by regulating the MKK3/p38 MAPK signaling pathway. The implementation of this project will provide a sufficient scientific basis for the treatment of nasopharyngeal carcinoma.

中晚期鼻咽癌远处转移率高达30%，需联合放化疗，而化疗毒副反应大，患者顺应性差。在化疗基础上，如何鉴定出天然活性化合物作为一种药物或与化疗配合使用，减轻化疗毒副反应，是进一步提高鼻咽癌疗效的关键。我们前期研究已证明辣椒素在鼻咽癌中起着抑制增殖、迁移、侵袭和诱导凋亡的作用，但分子机制是什么？我们通过PCR芯片和免疫印迹实验发现辣椒素可下调MKK3及下游p38MAPK蛋白及相应磷酸化蛋白的表达并存在时间依赖性。进一步实验显示MKK3在鼻咽癌细胞表达升高，构建稳定过表达细胞株发现MKK3异常过表达可促进鼻咽癌细胞的迁移。据此我们提出假设：辣椒素通过调控MKK3/p38MAPK信号通路抑制鼻咽癌的增殖和转移。本项目拟采用动物模型、激酶抑制剂和siRNA等方法阐明辣椒素调控MKK3/p38MAPK信号通路在鼻咽癌增殖和转移中的关键作用及其调控机制，为鼻咽癌的治疗提供新思路奠定充分的科学依据。

中晚期鼻咽癌远处转移率高达30%，需要联合放化疗，而以顺铂为基础的联合化疗或同步放化疗毒副反应大，患者顺应性差，是转移鼻咽癌患者治疗失败的主要原因之一。在传统化疗基础上，如何联合应用天然活性化合物作为一种药物或与化疗配合使用，减轻化疗毒副反应，是进一步提高鼻咽癌疗效的关键。辣椒素是各类辣椒中发挥辛辣作用的主要成分，在肿瘤发生发展中起着重要作用。该研究主要探讨了辣椒素联合顺铂在抑制鼻咽癌细胞转移中的协同作用及分子机理。.我们研究发现：辣椒素和顺铂在鼻咽癌细胞中具有抑制增殖、迁移和侵袭的作用，辣椒素可诱导鼻咽癌细胞凋亡并影响相关蛋白的表达；MKK3在鼻咽癌细胞株中表达升高，MKK3异常过表达可促进鼻咽癌细胞的迁移能力；进一步辣椒素干预后MKK3、磷酸化MKK3（p-MKK3）及p38 MAPK、磷酸化p38 MAPK（p-p38）的蛋白表达水平逐渐降低，并存在时间依赖性；辣椒素联合顺铂在抑制鼻咽癌细胞的增殖、迁移和侵袭方面存在协同作用并对上皮间质转化（EMT）过程具有调控作用；PCR array结果显示辣椒素干预还可显著下调鼻咽癌SerpinB2基因的表达，进一步Western Blotting实验证实了辣椒素处理鼻咽癌细胞SUNE1和HONE1可以上调SerpinB2的蛋白表达水平；此外，发现SerpinB2在鼻咽癌细胞株和组织中的mRNA和蛋白水平表达均下调。体内外功能实验表明，SerpinB2异常过表达可显著抑制鼻咽癌细胞的迁移和侵袭能力；进一步体内外实验结果表明辣椒素和顺铂干预可增强SerpinB2过表达对鼻咽癌细胞迁移和侵袭能力的抑制作用；SerpinB2过表达可以调控EMT过程中的关键分子的表达水平，而辣椒素和顺铂可增强这一调控作用。上述结果提示，辣椒素可能通过抑制SerpinB2/EMT通路而提高顺铂在鼻咽癌中的抗转移作用。该研究为鼻咽癌的治疗提供新思路奠定了充分的科学依据。.