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Updated: Jun 6, 2026
From a 2DE-Gel Spot to Protein Function: Lesson Learned From HS1 in Chronic Lymphocytic Leukemia
Published on: October 19, 2014
13q deletion anatomy and disease progression in patients with chronic lymphocytic leukemia
H Parker1, M J J Rose-Zerilli, A Parker
1Cancer Genomics Group, Cancer Sciences Division, School of Medicine, University of Southampton, Southampton, UK.
Abstract:
Historically, genes targeted by recurrent chromosomal deletions have been identified within the smallest genomic region shared in all patients, the minimally deleted region (MDR). However, deletions this small do not occur in all patients and are a simplification of the impact larger heterogeneous deletions have during carcinogenesis. We use the example of 13q14 deletions in chronic lymphocytic leukemia to show that genes outside MDRs are associated with disease progression. Genomic profiling of 224 patients identified 205 copy number alterations on chromosome 13 in 132 cases. Deletions including DLEU2 were heterogeneous (845 Kb-96.2 Mb) and identified two breakpoint cluster regions within short interspersed nuclear elements proximal to DLEU2 and within long interspersed nuclear elements/L1 repeats distal to GUCY1B2. After defining a deletion class on the basis of size and location, we show that (a) at diagnosis, larger deletions (class II) were associated with a significantly increased risk of disease progression (odds ratio=12.3; P=0.005), (b) in progressive patients, class II deletions were enriched (P=0.02) and (c) this association was independent of IgVH mutational status, ZAP70 expression and ATM/TP53 deletion. Deletion of a 1 Mb gene cluster (48.2-49.2 Mb), including SETDB2, PHF11 and RCBTB1, was significantly associated (P<0.01) with disease progression. Here, we show that the deletion of genes outside MDRs can influence clinical outcome.
Insights
Larger deletions outside the minimally deleted region (MDR) in chromosome 13q14 are linked to chronic lymphocytic leukemia progression. These findings highlight genes beyond MDRs impacting cancer development.
Area of Science:
- Genomics
- Cancer Biology
- Hematology
Background:
- Traditionally, minimally deleted regions (MDRs) identify genes in chromosomal deletions.
- However, this approach simplifies the complex role of heterogeneous deletions in carcinogenesis.
- Chronic lymphocytic leukemia (CLL) often involves 13q14 deletions, but their full impact is not always captured by MDRs.
Purpose of the Study:
- To investigate the association between heterogeneous 13q14 deletions and disease progression in CLL.
- To identify genes outside MDRs that influence clinical outcomes in CLL patients.
- To challenge the traditional MDR-centric view of gene deletion impact in cancer.
Main Methods:
- Genomic profiling of 224 CLL patients to identify copy number alterations on chromosome 13.
- Analysis of deletion size and location, defining deletion classes.
- Statistical analysis to correlate deletion characteristics with disease progression, independent of other prognostic markers.
Main Results:
- Heterogeneous deletions involving DLEU2 were identified, with breakpoint cluster regions in interspersed nuclear elements.
- Larger deletions (class II) at diagnosis significantly increased the risk of disease progression (OR=12.3, P=0.005).
- A 1 Mb gene cluster (SETDB2, PHF11, RCBTB1) deletion strongly associated with progression (P<0.01).
Conclusions:
- Genes located outside traditional MDRs significantly influence CLL progression.
- Deletion size and location are critical factors in determining clinical outcome.
- This study redefines the understanding of chromosomal deletions in CLL pathogenesis and progression.
