Characterization of the canine mda-7 gene, transcripts and expression patterns.
Characterization of the canine mda-7 gene, transcripts and expression patterns.
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犬 mda-7 基因、转录本和表达模式的表征。
DOI：
10.1016/j.gene.2014.05.054
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发表时间：
2014
期刊：
影响因子：
3.5
通讯作者：
Smith,BruceF
中科院分区：
文献类型：
--
作者：
Sandey,Maninder;Bird,RCurtis;Das,SwadeshK;Sarkar,Devanand;Curiel,DavidT;Fisher,PaulB;Smith,BruceF
人黑色素瘤分化相关基因-7/白细胞介素-24（mda-7/IL-24）对多种人类和啮齿动物癌细胞显示出有效的生长抑制和细胞杀伤活性。在这项研究中，我们确定了犬直系同源的humanmda-7/IL-24基因位于7号染色体上的一簇IL-10家族成员。确定了犬股动脉-7的全长mRNA序列，其编码与人MDA-7/IL-24具有66%相似性的186个氨基酸的蛋白质。犬MDA-7在培养的正常犬表皮角质形成细胞（NCEK）中组成型表达，其表达水平在脂多糖刺激后增加。在培养的NCEK中，通过外显子跳跃和交替的5′-剪接供体位点，caninemda-7前mRNA被差异剪接，产生5种剪接变体（caninemda-7sv 1、caninemda-7sv 2、caninemda-7sv 3、caninemda-7sv 4和caninemda-7sv 5），编码犬MDA-7蛋白的4种蛋白亚型。这些蛋白质同种型具有保守的N-末端（信号肽序列），并且在它们的C-末端的氨基酸序列上是不同的。犬MDA-7在原发性犬肿瘤样品中不表达，并且大多数测试的肿瘤衍生的癌细胞系与其人类对应物一样。与人MDA-7/IL-24不同，caninemda-7 mRNA在未刺激或脂多糖（LPS）、伴刀豆球蛋白A（ConA）或植物血凝素（PHA）刺激的犬外周血单核细胞（PBMC）中不表达。此外，计算机模拟分析显示，典型犬MDA-7具有潜在的28个氨基酸的信号肽序列，可以靶向其进行主动分泌。这些数据表明，caninemda-7确实是人MDA-7/IL-24的直系同源物，其蛋白产物与人MDA-7/IL-24蛋白具有高度的氨基酸相似性，并且其可能具有与人MDA-7/IL-24相似的生物学特性，但其表达模式比其人直系同源物更受限制。
Human melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) displays potent growth suppressing and cell killing activity against a wide variety of human and rodent cancer cells. In this study, we identified a canine ortholog of the humanmda-7/IL-24 gene located within a cluster of IL-10 family members on chromosome 7. The full-length mRNA sequence of caninemda-7 was determined, which encodes a 186-amino acid protein that has 66% similarity to human MDA-7/IL-24. Canine MDA-7 is constitutively expressed in cultured normal canine epidermal keratinocytes (NCEKs), and its expression levels are increased after lipopolysaccharide stimulation. In cultured NCEKs, the caninemda-7 pre-mRNA is differentially spliced, via exon skipping and alternate 5′-splice donor sites, to yield five splice variants (caninemda-7sv1, caninemda-7sv2, caninemda-7sv3, caninemda-7sv4 and caninemda-7sv5) that encode four protein isoforms of the canine MDA-7 protein. These protein isoforms have a conserved N-terminus (signal peptide sequence) and are dissimilar in amino acid sequences at their C-terminus. Canine MDA-7 is not expressed in primary canine tumor samples, and most tumor derived cancer cell lines tested, like its human counterpart. Unlike human MDA-7/IL-24, caninemda-7 mRNA is not expressed in unstimulated or lipopolysaccharide (LPS), concanavalin A (ConA) or phytohemagglutinin (PHA) stimulated canine peripheral blood mononuclear cells (PBMCs). Furthermore, in-silico analysis revealed that canonical canine MDA-7 has a potential 28 amino acid signal peptide sequence that can target it for active secretion. This data suggests that caninemda-7 is indeed an ortholog of humanmda-7/IL-24, its protein product has high amino acid similarity to human MDA-7/IL-24 protein and it may possess similar biological properties to human MDA-7/IL-24, but its expression pattern is more restricted than its human ortholog.