Identification of PECAM-1 in solid tumor cells and its potential involvement in tumor cell adhesion to endothelium.
Identification of PECAM-1 in solid tumor cells and its potential involvement in tumor cell adhesion to endothelium.
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DOI：
10.1016/s0021-9258(18)41609-2
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发表时间：
1993-10
期刊：
影响因子：
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通讯作者：
Dean G Tang;Yong Q Chen;Peter J. Newman;Li Shi;Xiang Gao;Clement A. Diglio;K. Honn
中科院分区：
文献类型：
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作者：
Dean G Tang;Yong Q Chen;Peter J. Newman;Li Shi;Xiang Gao;Clement A. Diglio;K. Honn
PECAM-1(CD31/Endocam)是免疫球蛋白超基因家族中的一种黏附分子，表达于内皮细胞、血小板和某些造血细胞。在本文中，我们利用几种抗PECAM-1的多克隆和单克隆抗体，鉴定了人、大鼠和小鼠实体瘤细胞系上的PECAM-1分子。用多克隆、单克隆或Fab部分抗体进行免疫细胞化学标记和流式细胞仪分析，发现肿瘤细胞表面有明显的分布。免疫印迹显示来自不同物种的肿瘤细胞中的蛋白质大小从120 kDa到130 kDa不等。免疫沉淀和亚细胞分级研究表明，PECAM-1在人类肿瘤细胞(即结肠腺癌)表面有结构性表达。预吸收实验证实了本研究中使用的主要抗PECAM-1多克隆抗体(即SEW-3)的特异性。肿瘤细胞上的PECAM-1分子似乎带有不同于血小板上的末端碳水化合物部分(即唾液酸残基)，因为与血小板不同，神经氨酸酶治疗肿瘤细胞不会导致流动性改变。对不同物种肿瘤细胞系的基因组DNA进行聚合酶链式反应(PCR)分析，发现基因组中存在PECAM-1基因。逆转录-聚合酶链式反应和Southern杂交检测肿瘤细胞中PECAM-1的mRNAs。对20多个人、大鼠和小鼠实体瘤细胞系的筛选表明，PECAM-1广泛表达，尽管在不同的细胞系中表达水平有很大差异。Northern印迹分析证实PECAM-1在肿瘤细胞中有表达。对该片段进行DNA测序表明，人肿瘤细胞PECAM-1与人内皮细胞的同源性为100%。最后，肿瘤细胞PECAM-1参与了介导肿瘤细胞与内皮细胞的黏附，抗PECAM-1抗体能够减少未经刺激的肿瘤细胞与微血管内皮细胞的黏附。
PECAM-1 (CD31/EndoCAM) is an adhesion molecule in the immunoglobulin supergene family that is expressed on endothelial cells, platelets, and some hematopoietic lineage cells. In this paper, using several polyclonal and monoclonal antibodies against PECAM-1, we identified PECAM-1 molecules on human, rat, and murine solid tumor cell lines. Immunocytochemical labeling and flow cytometric analysis using either polyclonal, monoclonal, or Fab portion of the antibodies against PECAM-1 detected a distinct distribution on tumor cell surface. Immunoblotting revealed proteins ranging from 120 to 130 kDa in tumor cells derived from different species. Immunoprecipitation and subcellular fractionation studies indicated that PECAM-1 is constitutively expressed on the surface of human tumor cells (i.e. colon adenocarcinoma). The specificity of a major polyclonal anti-PECAM-1 used in the current study (i.e. SEW-3) was confirmed by the preabsorption studies. PECAM-1 molecules on tumor cells appear to bear terminal carbohydrate moieties (i.e. sialic acid residues) different from those on platelets, since neuraminidase treatment of tumor cells, unlike platelets, did not result in a mobility shift. Polymerase chain reaction (PCR) analysis of genomic DNA derived from tumor cell lines of different species revealed the presence of PECAM-1 gene in the genome. The mRNAs of PECAM-1 in tumor cells were detected by reverse transcription-PCR followed by Southern hybridization. Screening of more than 20 human, rat, and murine solid tumor cell lines indicated that PECAM-1 is widely expressed, although the level of expression varies considerably among different cell lines. The expression of PECAM-1 message in tumor cells was confirmed by Northern blotting. DNA sequencing of the PCR fragment revealed that human tumor cell PECAM-1 matches 100% to the human endothelial cell counterpart. Finally, it was demonstrated that tumor cell PECAM-1 is involved in mediating tumor cell adhesion to endothelium, as evidenced by the ability of anti-PECAM-1 antibodies to decrease the adhesion of unstimulated tumor cells to microvascular endothelial cells.