基因融合對於很多癌症相關疾病而言，是重要的體細胞突變；主要由易位，倒置和刪除引起的。超過80％的已知的融合基因在不常發生的癌症被發現，如白血病，淋巴瘤，骨與軟組織相關的肉瘤。因為融合基因產生的癌症，其相關所導致死亡的佔了其中80％，但卻只有10％融合基因在上皮癌被發現。然而，基因重組導致融合基因在上皮性腫瘤的主要發病機制仍然是值得探討的。如今，許多治療方法，針對融合基因所產生的蛋白激酶活性，或是腫瘤生成過程的相關因子，進行標靶治療並且成功應用在臨床上。這表示融合基因為治療癌症的關鍵戰略。因此，要有成功的治療，在實體腫瘤以高通量篩選方法來檢測融合基因是必要的。
RACE（快速放大cDNA末端法）是一個檢測融合基因的常用工具，由於融合型比上野生型轉錄的比例較低，因此這種技術的限制是需要大量的DNA測序，為了增加檢驗結果，我們採用次世代基因定序(NGS)；比起RACE完後進行clone再定序， NGS可以提供高通量的定序結果。結合RACE和NGS為新的檢測方法，該方法將被用於檢測癌症的融合基因。我們將進行了ALK的融合基因分析，評估NGS可行性。 ALK是一種酪氨酸激酶接受體，第一個ALK融合基因為NPM-ALK在ALCL被發現； 2007年在非小細胞肺癌（NSCLC）中亦發現有2號染色體異常，帶inv(2)(p21p23)轉位，融合基因的產物是EML4-ALK融合蛋白。ALK的轉位已與超過 20個不同的夥伴基因，仍然有一些具有功能的融合夥伴尚未找到，因此增加了常規分子診斷的難度。簡而言之，我們研究的主要目的為偵測到導致腫瘤的融合基因，並且結合標靶治療。我們針對ALK融合基因建立了一個5'-RACE與NGS結合之特別的系統，並進一步使用NGS篩選大量樣品應用在大腸直腸癌的患者，希望可以提供患者有更多治療的機會。

Gene fusion is an important somatic mutation in cancers and mainly caused by translocation, inversion and deletion. More than 80% of the known fusion genes were found in rarely happened cancers such as leukemia, lymphoma, bone and soft tissue sarcoma. However, only 10% were discovered in epithelial cancers which account for 80% of cancer-related deaths. Whether such translocation fusion oncogene plays a major role in the pathogenesis of epithelial tumors is still open to question. Nowadays, many treatments targeted to fusion genes which encode proteins with kinase activity and are required for tumorgenesis were validated and applied successfully in the clinical setting. It demonstrated that fusion genes are crucial therapeutic strategies for cancers. Therefore, a high-throughput screening method is needed for differentially detecting fusion genes in solid tumors and discovering possible targets for treatments.
RACE (Rapid amplification of cDNA ends, RACE) is a common tool for detecting the fusion gene. Due to the low fusion / wild-type transcript ratio, the limitation of this technique is the necessity for large amount of DNA sequencing. Hence, in order to increase the screening throughput, we applied NGS (Next generation sequencing) after RACE. NGS can give high throughput than RACE alone. This novel detection method which combined RACE and NGS will be used to detect fusion gene in cancer. We performed ALK (anaplastic lymphoma kinase) fusion gene analysis to evaluate the feasibility of NGS. ALK is a receptor tyrosine kinase and first discovered as a product of gene rearrangement in anaplastic large cell lymphoma (ALCL). In 2007, a recurrent chromosome translocation, inv(2)(p21p23), was founded in non–small cell lung cancer (NSCLC). The fusion product is an EML4-ALK fusion-type protein tyrosine kinase. KIF5B-ALK is another fusion-type of ALK in NSCLC discovered in 2009. In the same year, Eva Lin et al. used the exon array profiling detects EML4-ALK fusion in breast, colorectal, and non-small cell lung cancers. ALK translocations have been known to recombine with more than 10 different partner genes and still have a number of promisingly fusion partners which had not been found yet. This consequently increases the difficulty on routine molecular diagnosis. Accordingly, in the present study, for the purpose of detecting druggable fusion genes in solid tumors, we established a specific 5’-RACE system for ALK gene and combined with NGS and further expect to use NGS to screen large amount samples of colorectal cancer patients at same time.

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