Department of Pediatric Oncology/Hematology, Erasmus MC/Sophia Children’s Hospital, Rotterdam, The Netherlands.
Haematologica. 2012 Feb;97(2):258-61. doi: 10.3324/haematol.2011.051722. Epub 2011 Nov 4.
Translocation of the LYL1 oncogene are rare in T-cell acute lymphoblastic leukemia, whereas the homologous TAL1 gene is rearranged in approximately 20% of patients. Previous gene-expression studies have identified an immature T-cell acute lymphoblastic leukemia subgroup with high LYL1 expression in the absence of chromosomal aberrations. Molecular characterization of a t(7;19)(q34;p13) in a pediatric T-cell acute lymphoblastic leukemia patient led to the identification of a translocation between the TRB@ and LYL1 loci. Similar to incidental T-cell acute lymphoblastic leukemia cases with synergistic, double translocations affecting TAL1/2 and LMO1/2 oncogenes, this LYL1-translocated patient also had an LMO2 rearrangement pointing to oncogenic cooperation between LYL1 and LMO2. In hierarchical cluster analyses based on gene-expression data, this sample consistently clustered along with cases having TAL1 or LMO2 rearrangements. Therefore, LYL1-rearranged cases are not necessarily associated with immature T-cell development, despite high LYL1 levels, but elicit a TALLMO expression signature.
LYL1 癌基因易位在 T 细胞急性淋巴细胞白血病中很少见，而同源的 TAL1 基因在大约 20%的患者中发生重排。先前的基因表达研究已经确定了一个不成熟的 T 细胞急性淋巴细胞白血病亚组，其特征是在没有染色体异常的情况下高表达 LYL1。对一名儿科 T 细胞急性淋巴细胞白血病患者的 t(7;19)(q34;p13)进行分子特征分析，导致发现 TRB@ 和 LYL1 基因座之间的易位。与偶然发生的协同性、双重易位影响 TAL1/2 和 LMO1/2 癌基因的 T 细胞急性淋巴细胞白血病病例类似，这个 LYL1 易位的患者也有 LMO2 重排，表明 LYL1 和 LMO2 之间存在致癌合作。在基于基因表达数据的层次聚类分析中，该样本与具有 TAL1 或 LMO2 重排的病例一致聚类。因此，尽管 LYL1 水平较高，但 LYL1 重排的病例不一定与不成熟的 T 细胞发育相关，而是表现出 TALLMO 表达特征。
