Beta 1 integrin expression on human small cell lung cancer cells.
Beta 1 integrin expression on human small cell lung cancer cells.
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DOI：
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发表时间：
1991-02
期刊：
影响因子：
11.2
通讯作者：
L. Feldman;K. Shin;R. Natale;R. Todd
中科院分区：
文献类型：
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作者：
L. Feldman;K. Shin;R. Natale;R. Todd
整合素是促进细胞粘附的细胞表面糖蛋白的超基因家族。该家族的每个成员是由不同的α亚基非共价连接到至少六个共同β亚基之一组成的α/β异二聚体。这些包括代表细胞外基质蛋白受体的六种β 1整联蛋白（α 1-6/β 1）和由白细胞表达并结合C3 bi和/或内皮配体的三种β 2整联蛋白（α L、α M、α X/β 2）。最近，据报道，某些人肿瘤细胞表达β 1整联蛋白，小细胞肺癌（SCLC）细胞系表达β 2整联蛋白Mo 1（α M/β 2）。为了扩展这些初步观察，我们检查了SCLC细胞系的整合素表达在糖蛋白和mRNA水平，并评估这些整合素在促进SCLC粘附的潜在功能。使用α和β亚基特异性单克隆抗体对5种SCLC细胞系（NCI-H187、H345、H146、H209和N417）进行的间接免疫荧光分析证明了β 1的均匀表达（β 1远大于β 2，β 3大于或等于β 4）。在β 1相关α亚基中，所有5种细胞系均以高表面密度均匀表达α 3（在H345细胞中通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析抗β 1和抗α 3免疫沉淀物证实），而未检测到α 5。白细胞（β 2-相关）α M和α L亚基也在5个细胞系中表达。与β 1整联蛋白基因产物的表面表达一致，通过北方印迹分析在SCLC细胞中检测到β 1（而不是β 2）mRNA。H345细胞对层粘连蛋白的粘附表明β 1整联蛋白表达参与SCLC粘附，层粘连蛋白是α 3 β 1整联蛋白的已知配体。此外，特异于β 1亚基的抗体抑制这种粘附，表明β 1亚基促进与层粘连蛋白的粘附。我们得出结论，β 1整合素分子表达的人SCLC细胞（与均匀表达的α 3/β 1），并促进其粘附层粘连蛋白。
The integrins are a supergene family of cell surface glycoproteins that promote cellular adhesion. Each member of the family is an alpha/beta heterodimer composed of a distinct alpha subunit noncovalently linked to one of at least six common beta subunits. These include the six beta 1 integrins (alpha 1-6/beta 1) which represent receptors for extracellular matrix proteins and the three beta 2 integrins (alpha L, alpha M, alpha X/beta 2) that are expressed by leukocytes and which bind to C3bi and/or endothelial ligands. Recently, it was reported that certain human tumor cells express the beta 1 integrins and that small cell lung cancer (SCLC) cell lines express the beta 2 integrin Mo1 (alpha M/beta 2). To extend these initial observations, we examined SCLC cell lines for integrin expression at the glycoprotein and mRNA levels and assessed the potential function of these integrins in promoting SCLC adhesion. An indirect immunofluorescence analysis of five SCLC cell lines (NCI-H187, H345, H146, H209, and N417) using alpha and beta subunit-specific monoclonal antibodies demonstrated the uniform expression of beta 1 (beta 1 much greater than beta 2 greater than or equal to beta 3 congruent to beta 4). Among the beta 1-associated alpha subunits, alpha 3 was uniformly expressed at high surface density by all five cell lines (as confirmed in H345 cells by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of anti-beta 1 and anti-alpha 3 immunoprecipitates), while alpha 5 was not detected. The leukocyte (beta 2-associated) alpha M and alpha L subunits were also variably expressed by the five lines. Consistent with the surface expression of beta 1 integrin gene products, beta 1 (but not beta 2) mRNA was detected in SCLC cells by Northern blot analysis. That beta 1 integrin expression was involved in SCLC adhesion was suggested by the adherence of H345 cells to laminin, a known ligand for the alpha 3 beta 1 integrin. Moreover, an antibody specific for the beta 1 subunit inhibited this adhesion, indicating that the beta 1 subunit promotes adhesion to laminin. We conclude that beta 1 integrin molecules are expressed by human SCLC cells (with uniform expression of alpha 3/beta 1) and promote their adhesion to laminin.