THE MONOCLONAL-ANTIBODY BQ16 IDENTIFIES THE ALPHA-6-BETA-4 INTEGRIN ON BLADDER-CANCER
THE MONOCLONAL-ANTIBODY BQ16 IDENTIFIES THE ALPHA-6-BETA-4 INTEGRIN ON BLADDER-CANCER
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DOI：
10.1089/hyb.1993.12.67
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发表时间：
1993-02-01
期刊：
影响因子：
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通讯作者：
GROSSMAN, HB
中科院分区：
文献类型：
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作者：
LIEBERT, M;WEDEMEYER, G;GROSSMAN, HB
抗人膀胱癌UM-UC-9细胞株的单抗BQ16与大多数膀胱癌组织标本和细胞系均有较强的反应性。在正常尿路上皮中，BQ16仅在与固有层交界处的尿路上皮细胞基底面染色。BQ16免疫共沉淀有两条约140 kDa和180 kDa的蛋白质带(在非还原条件下)，而在Western blotts上，BQ16只检测到140 kDa的蛋白质，表明BQ16与二聚体蛋白复合体的一条链结合。BQ16抗原的二聚体结构、分子大小和基本取向与单抗UM-A9鉴定的α6β4整合素进行了比较。在大多数组织中，BQ16和UM-A9产生相同的染色模式。然而，正常淋巴细胞和某些膀胱癌细胞系BQ16呈阳性，但不能与UM-A9反应，表明BQ16和UM-A9表位可以独立表达。脉冲追逐免疫沉淀实验表明，在BQ16早期沉淀中，α6亚基更为突出，而在UM-A9早期沉淀中，β4亚基更为突出。此外，用抗α6抗体(GoH3)预清细胞提取物可去除所有的BQ16反应性，在UM-A9阴性、BQ16阳性的细胞中，BQ16沉淀出α6beta1复合体。我们的结论是，BQ16确定了α6整合素亚基，并且α6β4整合素在大多数膀胱癌中强烈表达。
Monoclonal antibody BQ16, raised against UM-UC-9, a human bladder cancer cell line, exhibited strong reactivity with most bladder carcinoma tissue samples and cell lines. In normal urothelium, BQ16 stained only the basal surface of urothelial cells at the junction with the lamina propria. BQ16 immunoprecipitated two protein bands of approximately 140 and 180 kDa (under non-reducing conditions), while on Western blots, BQ16 identified only the 140 kDa protein indicating that BQ16 binds to one chain of a dimeric protein complex. The dimeric structure, molecular size, and basal orientation of the BQ16 antigen prompted a comparison with the alpha6beta4 integrin identified by monoclonal antibody UM-A9. In most tissues BQ16 and UM-A9 produced identical staining patterns. However, normal lymphocytes and certain bladder cancer cell lines were BQ16 positive but failed to react with UM-A9, indicating that the BQ16 and UM-A9 epitopes can be expressed independently. Pulse-chase immunoprecipitation experiments showed that the alpha6 subunit was more prominent in early BQ16 precipitates and the beta4 subunit was more prominent in early UM-A9 precipitates. Furthermore, preclearing cell extracts with the anti-alpha6 antibody (GoH3 removed all BQ16 reactivity and in UM-A9-negative, BQ16-positive cells, BQ16 precipitated the alpha6beta1 complex. We conclude that BQ16 identifies the alpha6 integrin subunit and that alpha6beta4 integrin is strongly expressed in most bladder cancers.