Behrend E I, Craig A M, Wilson S M, Denhardt D T, Chambers A F
London Regional Cancer Centre, University of Western Ontario, Canada.
Cancer Res. 1994 Feb 1;54(3):832-7.
Osteopontin (OPN) is a secreted, calcium-binding phosphoprotein that frequently has been associated with the transformed phenotype. To clarify the function of OPN in tumor cells, we designed experiments to: (a) express antisense OPN RNA in murine PAP2 cells (metastatic, ras-transformed NIH 3T3 cells) and (b) examine the effects of antisense OPN expression on the tumorigenic and metastatic properties of the cells. PAP2 cells were transfected with pNMH-asOPN, an inducible, mammalian expression vector that can generate antisense OPN RNA complementary to the OPN mRNA. Two clones have been identified that expressed antisense OPN RNA in vitro. While reduced OPN protein secretion was not detected when the cells were grown in vitro, the in vivo expression of antisense OPN RNA was associated with reduced tumorigenicity. Tumors that did arise, with greatly extended lag time, had lost expression of antisense OPN RNA in vivo, suggesting that antisense OPN RNA expression was associated with reduced tumorigenicity of these cells.
骨桥蛋白（OPN）是一种分泌型的钙结合磷蛋白，常与转化表型相关。为阐明OPN在肿瘤细胞中的功能，我们设计了实验来：（a）在小鼠PAP2细胞（转移性、经ras转化的NIH 3T3细胞）中表达反义OPN RNA，以及（b）检测反义OPN表达对细胞致瘤性和转移性的影响。用pNMH-asOPN转染PAP2细胞，pNMH-asOPN是一种可诱导的哺乳动物表达载体，能产生与OPN mRNA互补的反义OPN RNA。已鉴定出两个在体外表达反义OPN RNA的克隆。当细胞在体外生长时，未检测到OPN蛋白分泌减少，但反义OPN RNA的体内表达与致瘤性降低相关。确实出现的肿瘤，其延迟时间大大延长，在体内已失去反义OPN RNA的表达，这表明反义OPN RNA表达与这些细胞的致瘤性降低有关。
