Cloning of genes involved in chromosomal translocations by high-resolution single nucleotide polymorphism genomic microarray
Cloning of genes involved in chromosomal translocations by high-resolution single nucleotide polymorphism genomic microarray
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DOI：
10.1073/pnas.0711039105
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发表时间：
2008-08-19
影响因子：
11.1
通讯作者：
Koeffler, H. Phillip
中科院分区：
文献类型：
--
作者：
Kawamata, Norihiko;Ogawa, Seishi;Koeffler, H. Phillip
高分辨率单核苷酸多态性基因组微阵列（SNP 芯片）是定义整个基因组基因剂量水平的有用工具，可以精确检测癌细胞中染色体的缺失和重复/扩增。我们发现这项新技术还可以识别参与不平衡易位的染色体断点，从而识别融合基因。利用这项技术，我们发现在小儿急性淋巴细胞白血病 (ALL) 中，PAX5 基因被重排为多种伙伴基因，包括 ETV6、FOXP1、AUTS2 和 C20orf112。 PAX5 基因的 3' 末端被伴侣基因取代。 PAX5融合产物与PAX5识别序列的结合与野生型PAX5一样强，并以显性失活方式抑制其转录活性。在人 B 细胞白血病细胞中，野生型 PAX5 与 BLK 调节区（PAX5 的直接下游靶基因之一）的结合因 PAX5 融合蛋白的表达而减弱，从而导致 BLK 的抑制。 PAX5融合基因在小鼠骨髓细胞中的表达阻碍了成熟B细胞的发育。 PAX5 融合蛋白可能通过阻止造血细胞分化为成熟 B 细胞而促进白血病发生。 SNP 芯片是识别人类癌症融合基因的强大工具。
High-resolution single nucleotide polymorphism genomic microarray (SNP-chip) is a useful tool to define gene dosage levels over the whole genome, allowing precise detection of deletions and duplications/amplifications of chromosomes in cancer cells. We found that this new technology can also identify breakpoints of chromosomes involved in unbalanced translocations, leading to identification of fusion genes. Using this technique, we found that the PAX5 gene was rearranged to a variety of partner genes including ETV6, FOXP1, AUTS2, and C20orf112 in pediatric acute lymphoblastic leukemia (ALL). The 3' end of the PAX5 gene was replaced by the partner gene. The PAX5 fusion products bound to PAX5 recognition sequences as strongly as wild-type PAX5 and suppressed its transcriptional activity in a dominant-negative fashion. In human B cell leukemia cells, binding of wild-type PAX5 to a regulatory region of BLK, one of the direct downstream target genes of PAX5, was diminished by expression of the PAX5-fusion protein, leading to repression of BLK. Expression of PAX5-fusion genes in murine bone marrow cells blocked development of mature B cells. PAX5-fusion proteins may contribute to leukemogenesis by blocking differentiation of hematopoietic cells into mature B cells. SNP-chip is a powerful tool to identify fusion genes in human cancers.