EPHA5
小结
EPHA5编码蛋白是EPH-受体酪氨酸激酶家族的一员。EPHA5在其家族成员中是独特的，其几乎只在神经系统中表达，特别是在皮层神经元、小脑浦肯野细胞以及皮质和海马体的锥体神经元中表达。EPHA5在脑发育中起重要作用，从神经发生到可塑性。除了其在神经系统中的作用外，EPHA5还介导胰岛细胞之间的通讯，从而调节葡萄糖刺激的胰岛素分泌。在乳腺癌和前列腺癌中已经观察到由于启动子甲基化而导致的EPHA5下调，这表明EPHA5可能作为这些类型肿瘤诊断和预后的生物标志物。在91％的急性淋巴细胞白血病病例中观察到EPHA5启动子的异常甲基化，特别是老年患者。在卵巢癌，胰腺导管腺癌和肺癌等癌种中观察到EPHA5的表达增加和体细胞突变。
EPHA5 is a member of the Eph receptor tyrosine kinase family. Unique from its family members, EPHA5 is almost exclusively expressed in the nervous system—specifically in cortical neurons, cerebellar Purkinje cells and pyramidal neurons of the cortex and hippocampus . EPHA5 plays a major role in brain development, from neurogenesis to plasticity. In addition to its role in the nervous system, EPHA5 mediates communication between pancreatic islet cells, thereby regulating glucose-stimulated insulin secretion. Downregulation of EPHA5 due to promoter methylation has been observed in both breast and prostate cancer, and it has been suggested that EPHA5 might represent a biomarker for diagnosis and prognosis of these tumor types. Aberrant methylation of the EPHA5 promoter was observed in 91% of cases of acute lymphoblastic leukemia, in particular in older patients. Increased expression and somatic mutations of EPHA5 have been observed in ovarian cancer, pancreatic ductal adenocarcinoma and lung cancer, among others.