Rad51C-ATXN7 fusion gene expression in colorectal tumors.
Rad51C-ATXN7 fusion gene expression in colorectal tumors.
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DOI：
10.1186/s12943-016-0527-1
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发表时间：
2016-06-13
期刊：
影响因子：
37.3
通讯作者：
Duan W
中科院分区：
文献类型：
--
作者：
Kalvala A;Gao L;Aguila B;Dotts K;Rahman M;Nana-Sinkam SP;Zhou X;Wang QE;Amann J;Otterson GA;Villalona-Calero MA;Duan W
融合蛋白具有独特的致癌特性，其鉴定可用作诊断或治疗靶点。下一代测序数据此前已显示MCF7乳腺癌细胞系中Rad51C和ATXN7基因形成的融合基因。然而，结直肠患者肿瘤组织中是否存在这种融合基因很大程度上仍不清楚。我们通过 RT-PCR、PCR、Topo TA 克隆、实时 PCR、免疫沉淀和免疫印迹技术评估了结直肠肿瘤和细胞中 Rad51C-ATXN7 融合基因的存在。我们在结直肠肿瘤中鉴定了 Rad51C 和 ATXN7 之间的两种形式的融合 mRNA，包括变体 1（Rad51C 外显子 1-7 和 ATXN7 外显子 6-13 之间的融合转录本）和变体 2（Rad51C 外显子 1-6 和 ATXN7 外显子 6-13 之间）。计算机分析显示变体 1 产生截短的蛋白质，而变体 2 预计产生分子量为 110 KDa 的融合蛋白。免疫沉淀和蛋白质印迹分析进一步显示结直肠肿瘤中存在 110 KDa 的蛋白质。通过实时 PCR 评估，与未处理对照相比，LS-174 T 细胞的 5-氮杂胞苷处理导致融合基因（变体 2）的表达增加了 3.51 倍。总之，我们在结直肠肿瘤中发现了DNA修复基因Rad51C和神经脑共济失调Ataxin-7基因之间的融合基因。变体 2 的框内融合转录物产生分子量为 110 KDa 的融合蛋白。此外，我们发现融合基因的表达与结直肠肿瘤中范可尼贫血（FA）DNA修复途径的功能损伤有关。 Rad51C-ATXN7 在肿瘤中的表达值得进一步研究，因为它表明融合基因在结直肠癌的治疗和预测价值中的潜力。本文的在线版本 (doi:10.1186/s12943-016-0527-1) 包含补充材料，可供授权用户使用。
Fusion proteins have unique oncogenic properties and their identification can be useful either as diagnostic or therapeutic targets. Next generation sequencing data have previously shown a fusion gene formed between Rad51C and ATXN7 genes in the MCF7 breast cancer cell line. However, the existence of this fusion gene in colorectal patient tumor tissues is largely still unknown. We evaluated for the presence of Rad51C-ATXN7 fusion gene in colorectal tumors and cells by RT-PCR, PCR, Topo TA cloning, Real time PCR, immunoprecipitation and immunoblotting techniques. We identified two forms of fusion mRNAs between Rad51C and ATXN7 in the colorectal tumors, including a Variant 1 (fusion transcript between Rad51C exons 1–7 and ATXN7 exons 6–13), and a Variant 2 (between Rad51C exons 1–6 and ATXN7 exons 6–13). In silico analysis showed that the Variant 1 produces a truncated protein, whereas the Variant 2 was predicted to produce a fusion protein with molecular weight of 110 KDa. Immunoprecipitation and Western blot analysis further showed a 110 KDa protein in colorectal tumors. 5-Azacytidine treatment of LS-174 T cells caused a 3.51-fold increase in expression of the fusion gene (Variant 2) as compared to no treatment controls evaluated by real time PCR. In conclusion we found a fusion gene between DNA repair gene Rad51C and neuro-cerebral ataxia Ataxin-7 gene in colorectal tumors. The in-frame fusion transcript of Variant 2 results in a fusion protein with molecular weight of 110 KDa. In addition, we found that expression of fusion gene is associated with functional impairment of Fanconi Anemia (FA) DNA repair pathway in colorectal tumors. The expression of Rad51C-ATXN7 in tumors warrants further investigation, as it suggests the potential of the fusion gene in treatment and predictive value in colorectal cancers. The online version of this article (doi:10.1186/s12943-016-0527-1) contains supplementary material, which is available to authorized users.