MTDH介导肿瘤相关巨噬细胞与头颈鳞癌细胞交互作用促进其侵袭转移的分子机制研究

Our previous data demonstrated that MTDH promoted the cytokine secretion in squamous cell carcinoma of the head and neck (SCCHN), recruited macrophages and induced the polarization to M2 tumor-associated macrophages (TAMs) . Meantime, M2 TAMs mediated the epithelial-mesenchymal transition in SCCHN cells and enhanced the invasion and metastasis of SCCHN cells in vitro, which was accompanied by the upregulation of MTDH. These results indicated SCCHN cells and TAMs regulated each other via their cross-talking. Therefore, we hypothesize that MTDH promotes the metastasis of SCCHN via mediating cross-talking between TAMs and SCCHN. To confirm the above hypothesis, we will block or recover the function of these cytokines secreted by SCCHN cells and TAMs via ways of gene regulation, neutralizing antibodies or human recombinant cytokine proteins, and then observe whether the phenotype changes caused by MTDH inTAMs and SCCHN cells will be reversed both in vitro and in vivo. Based on these experiments, we will clarify the mechanisms of the cross-talking and how MTDH regulates the cross-talking between SCCHN and TAMs, and then promotes the metastasis of SCCHN. Finally, the significance of these proteins and cytokines will be examined in SCCHN specimens with intact clinical information. The success of this project will help us to understand that how MTDH promotes the metastasis of SCCHN from the cross-talking between SCCHN and TAMs, which will rich our knowledge about immunological and inflammatory microenvironment in SCCHN and finally discover valuable molecular biomarkers and therapeutic targets associated with the metastasis of SCCHN.

我们前期研究表明：①.MTDH能促进头颈鳞癌细胞（SCCHN）分泌细胞因子，招募并诱导肿瘤相关巨噬细胞（TAMs）发生M2型极化；②.M2型TAMs促进SCCHN细胞上皮-间质转化（EMT）和侵袭转移，并伴有MTDH蛋白表达上调，提示SCCHN细胞和TAMs存在交互作用。据此，我们推测MTDH可介导TAMs和SCCHN细胞交互作用促进其侵袭转移。为此，我们在细胞和动物实验中，采用基因调控、抗体中和或重组人细胞因子刺激等方法，阻断或恢复细胞因子的功能，观察MTDH介导的SCCHN细胞和TAMs表型改变能否逆转，阐明该交互作用的分子机制及MTDH如何调控该交互作用促进SCCHN的侵袭转移。最后临床组织标本证实其临床价值。该项目从SCCHN细胞和TAMs交互作用的角度重新诠释MTDH调控侵袭转移的分子机制，加深对SCCHN免疫炎性微环境的认识，并找寻转移相关的分子标志物和治疗干预靶点。

肿瘤免疫治疗已显示出广阔的临床应用前景。TAMs作为肿瘤免疫炎性微环境中重要的细胞成分，对TAMs与头颈鳞癌细胞交互作用的研究将一步加深对肿瘤免疫的认识。我们前期研究中发现MTDH不仅可通过多种信号途径，直接影响头颈鳞癌细胞“干性”、EMT和肿瘤血管新生等过程，发挥对肿瘤细胞侵袭转移的促进作用，还可以通过分泌相应的细胞因子，招募并促进TAMs向M2型发生极化。而M2型TAMs细胞亦能通过分泌特定的细胞因子，促进头颈鳞癌细胞的侵袭转移和MTDH的表达。基于此本项目拟在前期研究基础上探索MTDH介导头颈鳞癌细胞和TAMs的交互作用，促进头颈鳞癌细胞的侵袭转移机制。.本项目的研究计划是通过拟构建MTDH的慢病毒过表达及沉默载体，细胞因子功能增强等方法，在细胞水平阐明改变头颈肿瘤中MTDH对TAMs极化的影响；M2型TAMs细胞诱导头颈鳞癌EMT及转移相关恶性表型及机制；再通细胞因子功能阻断，观察该轴所介导的上述变化能否逆转；并最终在体内实验中予以证实。.本研究通过在课题组的共同努力下，我们已证实：1.MTDH促单核细胞向M2型 TAMs 细胞转化；2.M2型TAMs促进头颈鳞癌细胞体外侵袭转移；3.M2型TAMs促进头颈鳞癌细胞上皮-间质转化（EMT）及干性增强；4.CCL18参与M2样TAMs介导的SCCHN体外转移；5.CCL18在体外参与SCCHN中M2样TAM诱导的EMT和干性；6.MTDH通过调控细胞因子的表达招募促进TAMs向M2型极化；7.头颈鳞癌患者血清中CCL18显著升高，且与患者的T分期、临床分期、淋巴结转移及组织病理学分型密切相关；8.血清CCL18可作为SCCHN诊断和预后的潜在生物标志物；9.CCL18经MTDH促进头颈鳞癌细胞体外侵袭转移；10.NF-κB激活参与CCL18/MTDH介导的SCCHN细胞转移和EMT；11.miR-30e-5p/MTDH轴介导血管生成抑制头颈鳞癌侵袭转移。.在该项目的资助下，共培养在博士毕业研究生5名，硕士毕业研究生4名。已发表论文28篇，其中SCI论文24篇（Q1区9篇，Q2区15篇，3篇SCI论文IF值>7），总IF达117.936，中文期刊4篇。