中文摘要：

LRRC4是一个脑组织相对特异性表达基因，是采用表达序列标签（EST）介导的定位．候选克隆策略结合5’-RACE技术从染色体7q31～32区域克隆出来的一个富亮氨酸重复（LRR）超家族的新成员．LRRC4是神经系统发育与轴突生长的功能基因．LRRC4的表达与胶质瘤的级别进展呈负相关，其表达缺失参与脑胶质瘤进展的晚期事件．LRRC4能够下调一系列神经生长因子或受体（如IGF，EGF，PDGF，CNTF，bFGF，GDNF和BDNF等）的表达，通过调控多种信号转导通路（K．Ras／c．Ra饨RKm4APK，PI．3K／AKT／NF．KB，p70S6／PKC，STAT3以及JNK2／c．Jun／mp53等）将U251细胞阻滞在G1晚期，抑制脑胶质瘤细胞的增殖和侵袭，而且这种抑制作用依赖于它的LRR结构域．LRRC4不能诱导胶质瘤细胞的凋亡，而是诱导胶质瘤细胞向胶质样细胞分化．

英文摘要：

LRRC4, a novel member ofLRR （leucine-rich repeat） superfamily, is cloned by expressed sequence tag （EST）-mediated positional cloning strategy combined with 5＇-RACE technology. Normal expression of LRRC4 is highly specific for brain, whereas absent or significantly down-regulated in primary tumors including glioma, meningioma and pituitary adenoma. LRRC4 is a functional gene in neural development and axon growth, and associated with glioma grade progression. LRRC4 expression is gradually reduced, even absent accompany with glioma grade increase. Absent expression of LRRC4 is involved in the late event of malignant glioma progression. The reexpression of LRRC4 can decrease a series of growth factors/neurotrophic factors （IGF, EGF, PDGF, CNTF, bFGF,GDNF and BDNF） or receptors gene expression to regulate RTK-mediated many signaling transduction pathway, such as K-Ras/c-Raf/ERK/MAPK, PI-3K/AKT/NF-kB, p70S6/PKC, STAT3 and JNK2/c-Jun/mp53, which block U251 cells in late phase of G1 to inhibit glioma cells proliferation and invasion. This inhibitory effect of LRRC4 is dependent on its LRR domain. LRRC4 induces glioma cells to differentiate into astrocyte-like cells more than apoptosis.