脾酪氨酸激酶与肿瘤

脾酪氨酸激酶(spleen tyosine kinase,Syk)在较长时间里被认为是造血细胞特有的信号分子,在淋巴细胞的成熟和免疫细胞的激活中起重要作用.近年来发现Syk在多种非造血细胞也有表达.最初观察到Syk在乳腺癌的演进中显著降低,后来发现Syk异常表达也见于其它许多肿瘤.研究表明,Syk有抑制肿瘤发生和转移的功能,但Syk抑癌的分子机制仍大部分未明.Syk基因启动子超甲基化是其沉默的机制之一.日益增多的临床研究显示,Syk的低表达与肿瘤转移形成呈正相关,表明Syk可能是一个潜在的肿瘤抑制因子.

Functions of spleen tyrosine kinase (Syk) gene and its correlation to neoplasms

Spleen tyrosine kinase (Syk) was thought to be a hematopoietic cell-specific signaling molecule and plays an essential role in maturation of lymphocytes and activation of immune cells. Recent evidences show that it is also expressed by many non-hematopoietic cell types. Down-regulation of Syk expression was first observed during breast cancer progression, now its abnormal expression has also been detected in many other types of tumors. Syk could suppress tumorigenesis and metastasis, but the molecular mechanism remains unknown. Promoter hypermethylation is one of the mechanisms that lead to silencing of Syk gene. Increasing clinical evidences reveal a positive correlation of reduced Syk expression to increased risk for metastasis, and indicate that Syk may be a potential new tumor suppressor.