Trikha M, Cai Y, Grignon D, Honn K V
Department of Radiation Oncology, Wayne State University, and Barbara Ann Karmanos Cancer Center, Detroit, Michigan 48202, USA.
Cancer Res. 1998 Nov 1;58(21):4771-5.
Integrin alphaIIb beta3 requires its cytoplasmic tails to participate in tumor cell adhesion, spreading, and migration. Using 3' rapid amplification of cDNA ends, we have amplified two alphaIIb cDNAs from human leukemia, prostate adenocarcinoma, and melanoma cells. One of these is the predicted wild-type alphaIIb cDNA, and the other is a novel truncated alphaIIb variant. This variant is unique in that it lacks the transmembrane and cytoplasmic portions of the alphaIIb light chain. The truncated alphaIIb integrin protein is expressed by human leukemia, prostate adenocarcinoma, and melanoma cells but not by platelets or normal prostate epithelial or normal breast epithelial cells. Tumor cells secrete this protein and deposit it on the extracellular matrix. To our knowledge, this is the first report of a naturally occurring variant of an alpha integrin that lacks the transmembrane and cytoplasmic tail.
整合素αIIbβ3需要其胞质尾来参与肿瘤细胞的黏附、铺展和迁移。利用cDNA末端的3'快速扩增技术，我们从人白血病细胞、前列腺腺癌细胞和黑色素瘤细胞中扩增出了两种αIIb cDNA。其中一种是预测的野生型αIIb cDNA，另一种是新型截短的αIIb变体。该变体的独特之处在于它缺少αIIb轻链的跨膜和胞质部分。截短的αIIb整合素蛋白在人白血病细胞、前列腺腺癌细胞和黑色素瘤细胞中表达，但在血小板、正常前列腺上皮细胞或正常乳腺上皮细胞中不表达。肿瘤细胞分泌这种蛋白并将其沉积在细胞外基质上。据我们所知，这是首次报道一种天然存在的缺乏跨膜和胞质尾的α整合素变体。
