Analysis of structure of MRP-1/CD9 mutation and regulation of metastasis of cancer by means of MRP-1/CD9 control

在我们以前的研究中，我们发现运动相关蛋白-1（MRP-1）是一种被单克隆抗体（MAb）M31-15识别的糖蛋白，其序列与白色细胞分化抗原CD 9的序列相同。MRP-1/CD 9 cDNA转染培养的非造血细胞抑制细胞运动。MRP-1/CD 9的表达水平与肿瘤的生长抑制程度直接相关。此外，MRP-1/CD 9转染的黑素瘤细胞BL 6的转移潜能低于对照BL 6细胞。为了确定这些实验结果是否与实际人类肿瘤相关，我们研究了143例乳腺浸润性导管癌中MRP-1/CD 9的表达。97例MRP-1/CD 9阳性肿瘤中，仅有36例（37.1%）有淋巴结转移。与此相反，MRP-1/CD 9免疫反应性降低的21/39例（53.8%）患者和抗MRP-1/CD 9单克隆抗体未染色的5/7例原发癌患者有淋巴细胞浸润。 关于我们 淋巴结转移比较62例原发肿瘤及其相应转移淋巴结的蛋白表达，发现几乎50%的病例中后者的MRP-1/CD 9水平低于前者。此外，基于逆转录酶聚合酶链反应（RT-PCR）的分析显示，17/32例患者的转移性淋巴结中MRP-1/CD 9基因表达明显低于原发性浸润性导管癌。在所研究的任何样品中均未观察到基因过表达。我们的数据表明，低MRP-1/CD 9表达可能与某些人类肿瘤的转移潜能有关。鉴于此，我们应用RT-PCR技术检测肺癌组织中MRP-1/CD 9基因的表达。我们分析了109例患者的肿瘤组织; 49例肿瘤为I期，15例为II期，45例为III期。我们发现67例患者有MRP-1/CD 9阳性肿瘤，其余42例患者的肿瘤中基因表达降低。阳性肿瘤患者的总体生存率明显高于基因表达降低的患者（62.3% vs.34.9% ; p<0.001）。这也与肺腺癌患者有关（55.4% vs.26.0% ; p<0.001）。考克斯回归模型的多因素分析表明，MRP-1/CD 9阳性与总生存率的相关性优于其他变量，淋巴结状态除外。我们的数据表明，低MRP-1/CD 9表达的肺肿瘤可能与预后不良。可以想象，MRP-1/CD 9检测可以识别淋巴结阴性肺癌患者和早期疾病复发风险高的腺癌患者。另一方面，肺癌的序列分析显示MRP-1/CD 9在密码子143和163处有热点，这两个密码子都从A变为G，前一个氨基酸从LYS变为ARG，后一个氨基酸从A变为ASP。少

In our previous studies we showed that motility related protein-1 (MRP-1) is a glycoprotein recognized by monoclonal antibody (MAb) M31-15, and that the sequence of MRP-1 is identical to that of CD9, a white cell differentiation antigen. Transfection of MRP-1/CD9 cDNA into cultured non-hematopoietic cells suppresses cell motility. The extent of suppression is directly related to the level of MRP-1/CD9 expression. In addition, the metastatic potential of MRP-1/CD9-transfected melanoma cells BL6 is lower than that of control BL6 cells. To determine whether these experimental results are of relevance with respect to actual human tumors, we investigated MRP-1/CD9 expression in 143 invasive ductal carcinomas of the breast. Of 97 patients with MRP-1/CD9-positive tumors, only 36 (37.1%) had lymph node involvement. By contrast, 21/39 (53.8%) patients whose tumors had reduced MRP-1/CD9 immunoreactivity, and 5/7 patients whose primary carcinomas were not stained by the anti-MRP-1/CD9 MAb had lym … More ph node metastases. The comparison of protein expression by 62 primary tumors and their respective metastatic lymph nodes revealed that in almost 50% of the cases the latter had lower MRP-1/CD9 levels than the former. Moreover, reverse transcriptase polymerase chain reaction (RT-PCR)-based analysis disclosed that MRP-1/CD9 gene expression in the metastatic lymph nodes of 17/32 patients was strikingly lower than in the primary invasive ductal carcinomas. Gene overexpression was not observed in any of the samples studied. Our data suggest that low MRP-1/CD9 expression may be associated with the metastatic potential of certain human tumors. In consideration of these findings, we have now applied RT-PCR to determine MRP-1/CD9 gene expression in lung cancer. We analyzed tumor tissues of 109 patients ; 49 tumors were stage I,15, stage II and 45, stage III.We found that 67 patients had MRP-1/CD9 -positive tumors, and that gene expression was reduced in the tumors of the remaining 42 individuals. The overall rate of survival was strikingly higher among patients with positive tumors than in those whose tumors had reduced gene expression (62.3% vs.34.9% ; p<0.001). This also pertained to patients with adenocarcinomas of the lung (55.4% vs.26.0% ; p<0.001). Multivariate analysis with the Cox regression model indicated that MRP-1/CD9 positivity correlated better with overall survival rate than other variables, except lymph node status. Our data suggest that low MRP-1/CD9 expression by tumors of the lung may be associated with poor prognosis. It is conceivable that testing for MRP-1/CD9 may identify node-negative lung cancer patients and patients with adenocarcinomas who are at high risk for early disease recurrence. On the other hand, sequence analysis with lung cancer revealed that MRP-1/CD9 have the hot spots at codon 143 and 163, both of which change from A to G.The former aminoacid changes are from LYS to ARG,and the latter from ASN to ASP. Less