Cytogenetic Studies of B-cell Chronic Lymphocytic Leukemia (B-CLL)

B 细胞慢性淋巴细胞白血病 (B-CLL) 的细胞遗传学研究

• 批准号: 7969821
• 负责人: diane c arthur
• 金额: $ 19.65万
• 依托单位: DIVISION OF CLINICAL SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7969821
• 关键词: 11q; 13q; 14q32; Abnormal Cell; Address; B-Lymphocytes; Blood Cells; Chromosomal Loss; Chromosome abnormality; Chronic Lymphocytic Leukemia; Clinical; Clinical Research; Conflict (Psychology); Cytogenetics; DNA; DNA Sequence Rearrangement; Data; Detection; Diagnosis; Diagnostic Procedure; Disease; Disease Outcome; Evaluation; Fluorescent in Situ Hybridization; Frequencies; G-Banding; Gene Expression; Genetic; In Vitro; Interphase; Karyotype; Laboratories; Leukemic Cell; Lipopolysaccharides; Metaphase; Microarray Analysis; Mitogens; Mitotic; Molecular Cytogenetics; Outcome; Patients; Prospective Studies; Reporting; Series; Specificity; Techniques; Technology; Testing; Time; Trisomy 12; Variant; cDNA Arrays; comparative genomic hybridization; disease characteristic; prognostic; 11q; 13q; 14q32; Abnormal Cell; Address; B-Lymphocytes; Blood Cells; Chromosomal Loss; Chromosome abnormality; Chronic Lymphocytic Leukemia; Clinical; Clinical Research; Conflict (Psychology); Cytogenetics; DNA; DNA Sequence Rearrangement; Data; Detection; Diagnosis; Diagnostic Procedure; Disease; Disease Outcome; Evaluation; Fluorescent in Situ Hybridization; Frequencies; G-Banding; Gene Expression; Genetic; In Vitro; Interphase; Karyotype; Laboratories; Leukemic Cell; Lipopolysaccharides; Metaphase; Microarray Analysis; Mitogens; Mitotic; Molecular Cytogenetics; Outcome; Patients; Prospective Studies; Reporting; Series; Specificity; Techniques; Technology; Testing; Time; Trisomy 12; Variant; cDNA Arrays; comparative genomic hybridization; disease characteristic; prognostic

Previous G-banded karyotype analyses have detected clonal chromosome abnormalities in 40-100 percent of B-CLL patients studied after appropriate in-vitro stimulation with polyclonal B-cell mitogens. It is currently unknown whether the wide variations in frequencies of abnormalities reported in different series are due to true differences in disease characteristics or merely to in-vitro culture conditions. Common recurring chromosomal abnormalities include trisomy 12, rearrangements of 14q32, translocations or deletions of 13q, deletions of 6q, and deletions of 11q. Recent studies have shown increased detection of trisomy 12, 13q deletions and 11q deletions with interphase fluorescence in-situ hybridization (FISH) techniques, suggesting these changes do indeed occur early in the course of the disease. Data regarding the clinical and prognostic significance of karyotype in B-CLL are limited, and in some instances are conflicting. Nevertheless, preliminary clinical studies suggest certain karyotypic abnormalities are associated with specific clinicopathologic subsets of B-CLL, and with the course of the disease. To address the questions of timing of karyotypic changes in B-CLL, and the possible specificity and significance of these changes, we are conducting prospective studies of patients with sporadic or familial B-CLL referred to the NCI for evaluation and possible treatment. The cytogenetics specific aims of this project are: to determine the optimal culture conditions for obtaining karyotypically abnormal mitotic cells from peripheral blood of patients with B-CLL; to determine whether or not interphase FISH detects clonally abnormal cells missed by G-banded metaphase analysis; to determine whether or not comparative genomic hybridization (CGH) will detect gains or losses of chromosomal material not found by metaphase or FISH analyses; and to correlate cytogenetics results with clinical, morphologic and immunophenotypic features of the disease, with cDNA microarray analysis of gene expression, and with outcome with new therapies. Data from >120 patients entered on-study reveal clonal chromosome abnormalities in only 30 percent of cases using G-banded metaphase analysis, and demonstrate inferiority of e. coli lipopolysaccharide as a mitogen for the leukemic cells. Interphase FISH with a panel of five probes has confirmed or expanded the G-band findings in patients with abnormal clones, and has detected abnormalities in all but 10 patients tested to date who were "normal" or uninformative by G-banding. From 2002 through 2005 we performed CGH retrospectively on DNA isolated from patients previously entered on-study, and prospectively on DNA from new patients. CGH was less sensitive than interphase FISH in detecting submicroscopic deletions, but detected gains and losses of regions not probed by FISH. Combining G-banding, FISH, and CGH, we are able to find molecular cytogenetic abnormalities in more than 90% of B-CLL patients. Furthermore, dual hybridization with two probes and also sequential analyses in multiple patients have shown certain abnormalities present at diagnosis, and additional abnormalities at the time of transformation. The cytogenetics results are now being correlated with clinical and other laboratory features at diagnosis and transformation, and with cDNA microarray analysis of gene expression and outcome with treatment. This project, which has the potential to yield new information regarding clinical cytogenetics diagnostic techniques, to demonstrate new clinicopathologic subsets of B-CLL patients, and to define genetic rearrangements critical to initiation or progression of B-CLL, is ongoing.

先前的G带核型分析已检测到40-100％使用多克隆B细胞差异刺激后研究的B-CLL患者中的克隆染色体异常。目前尚不清楚不同系列报道的异常频率的广泛差异是由于疾病特征上的真正差异还是仅由于体外培养条件的差异。常见的经常性染色体异常包括第12三体，14q32的重排，13Q的易位或缺失，6q的缺失和11q的缺失。最近的研究表明，三体第12、13q缺失和11Q缺失的检测增加，具有相间荧光原位杂交（FISH）技术，这表明这些变化确实发生在疾病的早期。关于核型在B-CLL中的临床和预后意义的数据有限，在某些情况下是矛盾的。然而，初步临床研究表明，某些核型异常与B-CLL的特定临床病理亚群以及疾病的过程有关。为了解决B-CLL中核型变化时机的问题，以及这些变化的可能特异性和意义，我们正在对零星或家族性B-CLL的患者进行前瞻性研究，该患者提到NCI进行评估和可能的治疗。该项目的细胞遗传学特定目的是：确定从B-CLL患者的外周血中获得核型异常有丝分裂细胞的最佳培养条件；为了确定是否通过G带形的中期分析遗漏的克隆异常细胞是否检测到同相；为了确定比较基因组杂交（CGH）是否会检测出中期或鱼类分析未发现的染色体材料的损失；并将细胞遗传学结果与该疾病的临床，形态和免疫表型特征相关联，以及基因表达的cDNA微阵列分析，以及新疗法的结果。 > 120名患者进入研究的数据显示，使用G带状的中期分析，只有30％的病例中，克隆染色体异常，并证明E的自卑。大肠杆菌脂多糖作为白血病细胞的有丝分裂原。带有五个探针面板的相间鱼已经证实或扩大了异常克隆患者的G频段发现，并且在迄今已通过G-Banding进行了“正常”或不太了解的10名患者中发现了异常。从2002年到2005年，我们对先前进入研究的患者分离的DNA进行了回顾性的CGH，并对新患者的DNA进行了前瞻性。 CGH在检测亚显微镜缺失方面的敏感性不如相互相互作用，但发现未被鱼类探索的区域的收益和损失。结合G带，鱼和CGH，我们能够在90％以上的B-CLL患者中找到分子细胞遗传学异常。此外，与两个探针的双重杂交以及多个患者的顺序分析表明，诊断时存在某些异常，并且在转化时有其他异常。现在，细胞遗传学结果与诊断和转化时的临床和其他实验室特征相关，以及对基因表达和治疗结果的cDNA微阵列分析。该项目有可能产生有关临床细胞遗传学诊断技术的新信息，以证明B-CLL患者的新临床病理亚群，并确定对B-CLL起始或进展至关重要的遗传重排。