电压门控质子通道蛋白Hv1对肿瘤发生和发展作用机制的研究

Solid malignant tumor cells often exist in a hypoxic microenvironment with an acidic extracellular pH than that of surrounding normal cells. The glycolysis and proton secretion in tumor cells are proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. The high-glycolytic activity and acidic metabolites in cancer cells result in the excessive production of intracellular acidity. The intracellular pH is vital for all biological processes in cells, which influences cell proliferation, cell motility, tumorigenesis, metastasis and apoptosis. To survive in this harsh environment, tumor cells must exhibit a dynamic cytosolic pH regulatory system. Voltage-gated proton channel Hv1 is essential for proton transfer. In our previous work, we showed, for the first time, that Hv1 is specifically expressed in highly metastatic human breast tumor tissues and cell lines, but not in poorly metastatic breast cancer tissues and cell lines. Inhibition of Hv1 expression in highly metastatic breast cancer cells significantly decreases the invasion and migration of the cells through inhibiting Hv1 proton secretion in the cells. We expressed, purified and crystallized the protein Hv1, and obtained its crystals with 3.0 ? resolution. Based on these results, in this project, we plan to investigate as follows: (1) the mechanism of effects of Hv1 on the growth, invasion and migration of tumor cells; (2) effects of Hv1 inhibitors on the growth of tumor cells; (3) the interactions of inhibitors with Hv1 and proton transporting mechanism of Hv1. The results of this project have significant roles in exploring the tumor markers for diagnosis and prognosis, target for anticancer drugs in cancer therapy, and elucidating the pathological mechanism of tumors.

实体恶性肿瘤一般生长在缺氧的环境中，缺氧导致细胞内乳糖酵解增强在细胞内产生过量的酸，为了维持细胞内稳定的pH值，过量的酸必须排到细胞外，这样导致了实体瘤的酸性微环境，酸性微环境对肿瘤的发生和发展起重要的作用。电压门控质子通道Hv1具有跨膜传输质子的功能，本研究组初步研究发现Hv1具有调节肿瘤细胞内外pH值的功能，在多种恶性肿瘤组织中高表达，并对乳腺癌细胞的迁移和侵袭能力有一定的影响；表达和纯化了Hv1，得到了3.0埃左右分辨率的蛋白晶体。本项研究拟在现有工作的基础上，深入系统地研究Hv1对肿瘤生长、迁移和侵袭的影响，阐明其机理；研究Hv1调节肿瘤细胞内外pH值的分子机制；在体内和体外研究Hv1抑制剂对肿瘤生长的抑制作用；阐明抑制剂和Hv1相互作用及Hv1传输质子的分子机制。研究成果对阐明肿瘤的病理学机制、寻找诊断的标志物和探索药物作用的靶点具有重要的意义。

实体恶性肿瘤一般生长在缺氧的环境中，缺氧导致细胞内乳糖酵解增强在细胞内产生过量的酸，过量的酸排到细胞外，进而导致了实体瘤的酸性微环境，对肿瘤的发生和发展起重要的作用。电压门控质子通道Hv1 具有跨膜传输质子的功能，本研究组初步研究发现Hv1 具有调节肿瘤细胞内外pH 值的功能，在多种恶性肿瘤组织中高表达，并对乳腺癌细胞的迁移和侵袭能力有一定的影响。本项研究在已有工作的基础上，深入系统地研究了Hv1与肿瘤间的关系，包括Hv1在癌组织中的表达情况，Hv1与肿瘤恶性化程度、预后以及死亡率之间的关系；同时发现了Hv1抑制剂对癌细胞的生长的抑制作用并研究了可能的分子机制；最后通过研究Hv1相关结构特性进一步研究了Hv1调节肿瘤细胞内外pH值的分子机制。