Basic research and clinical application of SAP-1, a protein tyrosine phosphatase expressed in gastrointestinal cancers.

胃肠道肿瘤表达的蛋白酪氨酸磷酸酶SAP-1的基础研究和临床应用。

• 批准号: 08557041
• 负责人: MATOZAKI Takashi
• 金额: $ 1.79万
• 依托单位: Kobe University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08557041/
• 关键词: Protein tyrosine phosphatse; SAP-1; Gastrointestinal cancer; Antibody; Inhibitor; チロシンガスファターゼ; チロシンホスファターゼ; モノクローナル抗体; CEA; 腫瘍マーカー

Since the level of tyrosine phosphorylation is determined by the balance between the actions of both protein tyrosine kinases and protein tyrosine phosphatases (PTPases), not only the unregulated activation of PTKs but also the inactivation of PTPases may be involved in the malignant transformation of gastrointestinal cells. SAP-1 is a human transmembrane-type PTPase that has recently been molecularly cloned. This enzyme contains a single PTPase domain in the cytoplasmic region and eight fibronectin type III-like domains with multiple potential N-glycosylation sites in the extracellular region. SAP-1 is abundant in human colorectal cancer cell lines and pancreatic cancer cell lines but not in the corresponding normal tissues. In this study, we investigated the physiological roles of SAP-1 and clinical applications of SAP-1. (1) Overexpression of SAP-1 inhibited growth of cultured cells. SAP-1 binds to EGF receptors. (2) Genomic DNA of SAP-1 promoter region was cloned and several transcription factor binding elements were observed. (3) With the use of immunohistochemistry, we have now examined the expression of SAP-1 in surgically or endoscopically excised colorectal cancers, adenoma and normal colon mucosa. Normal colon tissue or adenomas with mild dysplasia showed no detectable expression of SAP-1. In contrast, 19 of 48 (40%) adenocarcinomas expressed SAP-1. Sequencing of the K-RAS gene revealed that 10 of 15 (67%) SAP-1-positive cancers contained a mutation in codon 12. These results suggest that SAP-1 is frequently overexpressed in human colorectal cancers and that such overexpression may occur relatively late in the adenoma-carcinoma sequence. We will further investigate the existance of soluble form of SAP-1 in serm of patients with cob-rectal or pancreatic cancers.

由于酪氨酸磷酸化水平取决于蛋白酪氨酸激酶和蛋白酪氨酸磷酸酶（PTPases）之间的平衡，因此不仅PTKs的不受调节的激活而且PTPases的失活可能参与胃肠细胞的恶性转化。SAP-1是最近被分子克隆的人跨膜型PTB。该酶在胞质区含有一个单一的PTB结构域，在胞外区含有8个具有多个潜在N-糖基化位点的纤连蛋白III型样结构域。SAP-1在人结肠直肠癌细胞系和胰腺癌细胞系中含量丰富，但在相应的正常组织中不存在。在本研究中，我们探讨了SAP-1的生理作用和SAP-1的临床应用。(1)SAP-1的过表达抑制了培养细胞的生长。SAP-1与EGF受体结合。(2)克隆了SAP-1启动子区的基因组DNA，并观察到几个转录因子结合元件。(3)利用免疫组化方法，我们检测了SAP-1在手术或内镜切除的结直肠癌、腺瘤和正常结肠粘膜中的表达。SAP-1在正常结肠组织和轻度异型增生的结肠腺瘤中均未检测到表达。相反，48例腺癌中有19例（40%）表达SAP-1。K-RAS基因测序显示，15例SAP-1阳性癌症中有10例（67%）在密码子12中含有突变。这些结果表明，SAP-1是经常过度表达在人类结直肠癌，这种过度表达可能发生在相对较晚的腺瘤癌序列。我们将进一步研究SAP-1在结直肠癌和胰腺癌患者血清中的可溶性存在。

项目成果

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Tetsuya Noguchi：“在中国海里斯特口腔细胞中与 SH-P1P2（一种具有 Schonology 2 结构域的蛋白质酪氨酸磷酸酶）结合的 115 kDa 蛋白质的表征”J.Biol.Chem.271·44（1996）。

Y.Fujioka et al.: "A novel membrane glycoprotein,SHPS-1,that binds the SH2 domaincontaining protein tyrosine phosphatase SHP-2 in response to mitogens and cell adhesion." Mol.Cell.Biol.16. 6887-6899 (1996)

Y.Fujioka 等人：“一种新型膜糖蛋白 SHPS-1，它结合含有 SH2 结构域的蛋白酪氨酸磷酸酶 SHP-2，响应有丝分裂原和细胞粘附。”

Y.Fujioka, T.Matozaki, T.Noguchi, A.Iwamatsu, et al.: "A novel membrane glycoprotein, SHPS-1, that binds the SH2 domain-containing protein tyrosine phosphatase SHP-2 in response to mitogens and cell adhesion." Mol.Cell.Biol.16. 6887-6899 (1996)

Y.Fujioka、T.Matozaki、T.Noguchi、A.Iwamatsu 等人：“一种新型膜糖蛋白 SHPS-1，可结合含有 SH2 结构域的蛋白酪氨酸磷酸酶 SHP-2，响应有丝分裂原和细胞粘附

T.Matozaki, M.Kasuga.: "Roles of protein tyrosine phosphatases in growth factor signaling." Cell.Signal.8. 3-19 (1996)

T.Matozaki, M.Kasuga.：“蛋白质酪氨酸磷酸酶在生长因子信号传导中的作用。”

T.Takada, T.Matozaki, H.Takeda, K.Fukunaga, et al.: "Roles of the complex formation of SHPS-1 with SHP-2 in insulin-stimulated MAP kinase activation." J.Biol.Chem.273. 9234-9242 (1998)

T.Takada、T.Matozaki、H.Takeda、K.Fukunaga 等人：“SHPS-1 与 SHP-2 复合物形成在胰岛素刺激的 MAP 激酶激活中的作用。”