Abstract

Cytogenetic rearrangements were studied in bone marrow cells of 24 patients with relapse of acute lymphoblastic leukemia (ALL). The authors have noted a high percentage of mosaic karyotypes (75.0%) with a predominance of abnormal clones combined with normal karyotypes (33.3%). Trisomies of chromosomes led to the formation of hyperdiploid clones, among which trisomies of chromosomes 6, 21, 15, and 5 were the most frequent events. Additional marker chromosomes were recorded in 22.2%. To characterize the mechanisms underlying the abnormal clone formation in relapse of ALL, structural chromosomal anomalies were recorded and divided into balanced (translocations, inversions) and imbalanced (deletions, isochromosomes, additional material of unknown origin, duplications, and imbalanced translocations) abnormalities. Losses of genetic material (deletions) (24.1%) and translocations (33.3%) were most frequently detected. The total number of events with translocation t(9;22)(q34;q11.2) reached 20.4%. The evolution of clonal chromosomal abnormalities occurred due to the emergence of additional numerical and imbalanced structural abnormalities. The comparison between chromosome abnormalities at diagnosis and in relapse of B-cell ALL has not led to any general mechanisms for the formation of chemotherapy-resistant clones. Trisomy of chromosome 5, deletion del(6)(q23), and translocation t(9;22) (q34;q11.2) were involved in the formation of chemotherapy-insensitive clones. The group of unfavorable prognosis included 95.8% of karyotypes.

中文翻译：

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细胞遗传学重排在急性淋巴细胞白血病复发耐药形成中的作用

摘要

研究人员对 24 名急性淋巴细胞白血病 (ALL) 复发患者的骨髓细胞进行了细胞遗传学重排研究。作者注意到嵌合核型的比例很高（75.0%），其中异常克隆与正常核型相结合（33.3%）占主导地位。染色体三体导致超二倍体克隆的形成，其中6、21、15和5号染色体三体是最常见的事件。22.2% 的人记录了额外的标记染色体。为了表征 ALL 复发时异常克隆形成的机制，记录了结构染色体异常，并将其分为平衡（易位、倒位）和不平衡（缺失、等染色体、来源不明的附加材料、重复和不平衡易位）异常。最常检测到遗传物质丢失（缺失）（24.1%）和易位（33.3%）。t(9;22)(q34;q11.2)易位事件总数达到20.4%。克隆染色体异常的演变是由于额外的数量和不平衡结构异常的出现而发生的。B 细胞 ALL 诊断时和复发时的染色体异常之间的比较并未得出化疗耐药克隆形成的任何一般机制。5号染色体三体性、del(6)(q23)缺失和t(9;22)(q34;q11.2)易位参与化疗不敏感克隆的形成。预后不良组包括95.8%的核型。