pp GalNAcT-10对TGF-βR的糖基化修饰及其在肺癌发生中的机制研究

pp GalNAcT-10 is the initial glycosyltransferase for synthesizing the O-sugar chains of the glycoprotein. Our previous studies showed that the regulation of pp GalNAcT-10 expression level in lung cancer cell lines could affect cell migration and proliferation, the mechanisms may related with the glycosylation of TGF-βR and then the degradation of the false modified glycoprotein by FBOX-6 mediated ubiquitin-proteasome pathway. In this study, we plan to over-express and knock down pp GalNAcT-10 in different lung cancer cell lines, and investigate its role in the regulation of lung cancer through in vitro and in vivo experiments. Then the O-glycosylation removal experiment and mass spectrometry identification is going to be applied for determining glycosylation state of TGF-βR under the regulation of pp GalNAcT-10. Co-transfection of genes and proteasome inhibition experiments are going to be used to reveal whether the false glycosylated TGF-βR could be recognized by FBXO-6 and then play an important role in the mechanism of pp GalNacT-10 regulated lung cancer development. Furthermore, tissuemicroarray will be applied to validate the relationship between PP GalNAcT-10 , FBXO-6, TGF-βR and histopathological parameters of lung cancer, so as to elucidate the molecular mechanism of PP GalNAcT-10 in lung cancer as well as to provide theoretical basis for screening of the novel biomarkers of lung.

pp GalNacT-10是O-糖链合成的起始糖基转移酶。我们前期研究发现在肺癌细胞中调控pp GalNacT-10的表达会影响细胞的迁移及增殖；其机制可能涉及TGF-βR的糖基化修饰，并与FBXO-6介导的泛素-蛋白酶体通路对错误修饰的糖蛋白降解相关。本研究拟在多种肺癌细胞株中过表达及敲减pp GalNAcT-10，首先通过体内外实验明确其对肺癌的调控作用；其次通过去除O-糖基化、糖蛋白质谱鉴定等方法，确定pp GalNAcT-10对TGF-βR糖链修饰的作用；然后通过基因共转染、蛋白酶体抑制实验揭示pp GalNacT-10对肺癌的影响是否通过FBXO-6识别TGF-βR的错误糖基化修饰发挥作用；最后采用组织芯片验证pp GalNAcT-10、FBXO-6、TGF-βR与肺癌病理指标的关系；以期阐明pp GalNAcT-10在肺癌发生中的分子机制，同时寻找肺癌早期诊断的分子标记物。