RACK1募集肿瘤相关巨噬细胞促进口腔鳞癌生长转移的机制研究

The results of my preliminary studies suggested RACK1 involved in the Oral squamous cell carcinoma(OSCC) metastasis（JCRCO. 2012,138(4):563-71）, but the precise mechanism is unknown. Tumor-associated macrophages (TAM) could promote tumor growth and metastasis by suppressing the immune system and enhancing angiogenesis. TAM has been drawn greater attention as one of the key cells related tumor metastasis and inflammatory response recently. Several technological means, such as cell co-culture models, animal models, gene chips and bioinformatics technology, would be used to study the mechanism of RACK1 in the recruitment of TAM to promote OSCC growth and metastasis in five areas: ① the relationship of RACK1 and TAM in tumor microenvironment; ②the role of RACK1 in the macrophage cell M1/M2 phenotypic transformation; ③ the role of RACK1 recruited TAM on the biology behavior of OSCC cell; ④the regulation mechanism of RACK1 in the recruitment of TAM; ⑤ evaluate the therapeutic efficacy of key regulatory factor in the recruitment of TAM. The implementation of this innovative project will not only help to reveal the molecular mechanisms of RACK1 in the recruitment of TAM and to let us understanding the basic biological processes of OSCC tumorigenicity and metastasis, but also provide some new ideas for the development of new tumor treatment strategies.

申请人前期研究发现RACK1是与口腔鳞癌(OSCC)侵袭转移相关的新分子(JCRCO. 2012 .138(4):563-71)，但机制需进一步阐述。肿瘤相关巨噬细胞(TAM)通过抑制免疫系统和促进血管新生从而促进肿瘤生长转移，是关系肿瘤转移和肿瘤炎症反应的关键细胞之一，近年受关注。本研究拟用细胞共培养模型、动物模型、基因芯片及生物信息学技术，就RACK1募集TAM促进OSCC生长转移的机制及其潜在临床意义进行如下研究：①确定肿瘤微环境中RACK1与TAM的关系；②RACK1对巨噬细胞M1/M2表型转化的影响；③RACK1募集的TAM对OSCC细胞生物学行为的影响；④RACK1募集TAM的相应调控信息网络和关键调控因子； ⑤RACK1蛋白及其募集TAM的关键因子为靶标的干预效果。此课题对阐明OSCC的转移机制及研发有效干预措施具有重要意义。

RACK1是促进口腔鳞癌发生发展及转移的新分子，但具体机制仍不清楚。在本项目中，首先通过临床队列发现RACK1的表达与肿瘤微环境中M2型巨噬细胞具有区域共定位趋势；然后成功构建RACK1高、低表达细胞系，并意外发现RACK1可通过影响细胞周期检查点蛋白表达进而调控OSCC细胞的细胞周期。随后，结合mRNA表达谱、基因芯片和蛋白因子芯片结果以及生物信息学分析发现OSCC细胞RACK1的表达水平可以影响后NF-κB磷酸化水平，从而调节IL-6、IL-1β等因子的表达，进而影响M2型巨噬细胞的极化。并发现过表达RACK1可以显著增强OSCC细胞在动物体内的成瘤率，而消减RACK1可以显著抑制OSCC细胞在动物体内的成瘤率以及淋巴结转移能力。进一步机制研究，RACK1可以通过影响AKT/mTOR通路上关键蛋白的磷酸化水平发挥作用。上述结果表明， RACK1有潜力成为OSCC的干预靶标。