Yoshioka N, Inoue H, Nakanishi K, Oka K, Yutsudo M, Yamashita A, Hakura A, Nojima H
Department of Tumor Virology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
J Virol. 2000 Jan;74(2):1008-13. doi: 10.1128/jvi.74.2.1008-1013.2000.
We have reported that suppressive factors for transformation by viral oncogenes are expressed in primary rat embryo fibroblasts (REFs). To identify such transformation suppressor genes, we prepared a subtracted cDNA library by using REFs and a rat normal fibroblast cell line, F2408, and isolated 30 different cDNA clones whose mRNA expression was markedly reduced in F2408 cells relative to that in REFs. We referred to these as TRIF (transcript reduced in F2408) clones. Among these genes, we initially tested the suppressor activity for transformation on three TRIF genes, TRIF1 (neuronatin), TRIF2 (heparin-binding growth-associated molecule), and TRIF3 (lumican) by focus formation assay and found that lumican inhibited focus formation induced by activated H-ras in F2408 cells. Colony formation in soft agar induced by v-K-ras or v-src was also suppressed in F2408 clones stably expressing exogenous lumican without disturbing cell proliferation. Tumorigenicity in nude mice induced by these oncogenes was also suppressed in these lumican-expressing clones. These results indicate that lumican has the ability to suppress transformation by v-src and v-K-ras.
我们曾报道，病毒癌基因转化的抑制因子在原代大鼠胚胎成纤维细胞（REFs）中表达。为了鉴定此类转化抑制基因，我们利用REFs和大鼠正常成纤维细胞系F2408制备了一个消减cDNA文库，并分离出30个不同的cDNA克隆，其mRNA表达在F2408细胞中相对于REFs明显降低。我们将这些称为TRIF（F2408中表达降低的转录本）克隆。在这些基因中，我们最初通过焦点形成试验测试了三个TRIF基因（TRIF1（神经调素）、TRIF2（肝素结合生长相关分子）和TRIF3（光蛋白聚糖））对转化的抑制活性，发现光蛋白聚糖抑制了F2408细胞中由活化H-ras诱导的焦点形成。在稳定表达外源性光蛋白聚糖的F2408克隆中，v-K-ras或v-src诱导的软琼脂中集落形成也受到抑制，且不干扰细胞增殖。这些表达光蛋白聚糖的克隆中，这些癌基因在裸鼠中的致瘤性也受到抑制。这些结果表明，光蛋白聚糖具有抑制v-src和v-K-ras转化的能力。
