Non-MTC IGH-CCND1 Breakpoints in Mantle Cell Lymphoma Are Associated with CpG Sites and AID Hotspots

Abstract Abstract 398 Most t(11;14)(q13;q32) breakpoints in mantle cell lymphoma (MCL) are scattered across a large genomic region centromeric to the CCND1 gene on chromosome 11q13. However, few t(11;14) breakpoints outside the major translocation cluster (MTC) have been sequenced. We report our analysis of 56 IGH-CCND1 fusion sequences from 32 non-MTC cases of MCL. Our analysis reveals remarkable breakpoint diversity at both CCND1 and IGH loci. The CCND1 breakpoints are located from 2 kb to 331 kb from the CCND1 gene, including 12 breakpoints (38%) in the 220kb region centromeric to the MTC, which is itself located 110 kb centromeric to the CCND1 gene. Twenty-one cases had a JH coding end breakpoint on the der(14) chromosome and a DH coding end breakpoint on the der(11). Two cases had der(14) and der(11) breakpoints derived from the coding and signal ends of the same JH or DH gene segment; one case had a JH/DH breakpoint on the der(14) and a VH breakpoint on the der(11); and one case had a breakpoint in the JH region located >100 bases from the nearest RSS motif, suggesting a RAG-independent break at IGH. No der(11) breakpoint could be amplified in eight cases. In sixteen cases (50%), one or both CCND1 breakpoints were within 4 bases of a CpG dinucleotide, a feature characteristic of translocation breakpoints in many human B cell lymphomas. Three CpG-associated “microclusters” were identified, i.e. breakpoints in two different tumors located at or near the same CpG site. Breakpoints in the sixteen (50%) “non-CpG” cases showed a significant association with AID hotspot motifs at the CCND1 locus. In addition, the non-CpG breakpoints were more likely to: 1) be located telomeric to the MTC, 2) involve 3' JH and 5' DH gene segments, and 3) be associated with immunoglobulin lambda light chain restriction; features that suggest occurrence at a late stage of pre-B cell maturation. In contrast, the CpG-associated breakpoints were: 1) more likely to be centromeric to the MTC, 2) not biased in their JH or DH segment usage, and 3) associated with kappa light chain restriction; features suggesting occurrence in an earlier pre-B cell or pro-B cell. Our results implicate AID in chromosomal breakage at both CpG and non-CpG sites within the CCND1 locus and suggest that AID and RAG collude to generate the chromosomal breaks underlying the t(11;14). Our findings also suggest that IGH-CCND1 rearrangements can occur at different stages of pre-B cell maturation. This study provides novel insights into the mechanism and developmental timing of the t(11;14) in human MCL, features that are likely to be relevant to a broad range of human lymphomas. Disclosures: Greisman: Signature Genomics, LLC: Patents & Royalties. Yi:Signature Genomics, LLC: Patents & Royalties.

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Immunoglobulin VH gene mutational analysis suggests that blastic variant of mantle cell lymphoma derives from different stages of B-cell maturation

Leukemia Research ◽

10.1016/s0145-2126(99)00156-3 ◽

2000 ◽

Vol 24 (1) ◽

pp. 27-31 ◽

Cited By ~ 15

Author(s):

Terézia László ◽

Mónika Nagy ◽

Gábor Kelényi ◽

András Matolcsy

Keyword(s):

B Cell ◽

Mantle Cell Lymphoma ◽

Mutational Analysis ◽

Cell Lymphoma ◽

Cell Maturation ◽

B Cell Maturation ◽

Mantle Cell ◽

Vh Gene

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Concomitant Chronic Lymphocytic Leukemia and Mantle Cell Lymphoma Discovered by Flow Cytometry

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa161.278 ◽

2020 ◽

Vol 154 (Supplement_1) ◽

pp. S127-S127

Author(s):

K M Erickson ◽

D Lynch

Keyword(s):

Flow Cytometry ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Mantle Cell Lymphoma ◽

Light Chain ◽

Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Cell Populations ◽

Light Chain Restriction ◽

Mantle Cell

Abstract Casestudy: Chronic lymphocytic leukemia (CLL) accounts for about 30% of all lymphoid neoplasms and is the most common adult blood cancer in the Western world. Mantle cell lymphoma (MCL) accounts for only about 6% of all B-cell lymphomas in Western countries. MCL and CLL are both CD5 positive B-cell lymphoproliferative disorders. It is necessary to distinguish these two entities as MCL is a more aggressive disease, and requires specific treatment. MCL and CLL can occur in one patient at the same time and is often termed a composite lymphoma. We present an 84-year-old female with a history of endometrial cancer who was found to have splenomegaly and lymphadenopathy. Flow cytometry was performed upon her peripheral blood specimen which demonstrated two distinct populations of abnormal light chain restricted B-cell populations. One population demonstrated kappa light chain restriction and was positive for CD45, CD19, CD20, CD5, CD38, FMC-7, and CD22, representing MCL. The other population showed dim lambda light chain restriction that was also positive for CD45, CD19, dim CD20, CD5, and CD23, representing CLL. FISH studies demonstrated t(11;14), and four common deletions or chromosome aneuploidy associated with CLL. These findings confirmed the dual populations of CLL and MCL. This is an interesting case because it is a very rare combination with only a few cases having been reported with two distinct cell populations in one patient at the same time.

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Concomitant Chronic Lymphocytic Leukemia and Mantle Cell Lymphoma Discovered by Flow Cytometry

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa161.043 ◽

2020 ◽

Vol 154 (Supplement_1) ◽

pp. S23-S23

Author(s):

K M Erickson ◽

D Lynch

Keyword(s):

Flow Cytometry ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Mantle Cell Lymphoma ◽

Light Chain ◽

Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Cell Populations ◽

Light Chain Restriction ◽

Mantle Cell

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UBR5 HECT domain mutations identified in mantle cell lymphoma control maturation of B cells

Blood ◽

10.1182/blood.2019002102 ◽

2020 ◽

Vol 136 (3) ◽

pp. 299-312

Author(s):

Samantha A. Swenson ◽

Tyler J. Gilbreath ◽

Heather Vahle ◽

R. Willow Hynes-Smith ◽

Jared H. Graham ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Mantle Cell Lymphoma ◽

Malignant Transformation ◽

Cell Lymphoma ◽

Cell Maturation ◽

Hect Domain ◽

B Cell Maturation ◽

Mantle Cell

Abstract Coordination of a number of molecular mechanisms including transcription, alternative splicing, and class switch recombination are required to facilitate development, activation, and survival of B cells. Disruption of these pathways can result in malignant transformation. Recently, next-generation sequencing has identified a number of novel mutations in mantle cell lymphoma (MCL) patients including mutations in the ubiquitin E3 ligase UBR5. Approximately 18% of MCL patients were found to have mutations in UBR5, with the majority of mutations within the HECT domain of the protein that can accept and transfer ubiquitin molecules to the substrate. Determining if UBR5 controls the maturation of B cells is important to fully understand malignant transformation to MCL. To elucidate the role of UBR5 in B-cell maturation and activation, we generated a conditional mutant disrupting UBR5′s C-terminal HECT domain. Loss of the UBR5 HECT domain leads to a block in maturation of B cells in the spleen and upregulation of proteins associated with messenger RNA splicing via the spliceosome. Our studies reveal a novel role of UBR5 in B-cell maturation by stabilization of spliceosome components during B-cell development and suggests UBR5 mutations play a role in MCL transformation.

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E3 Ligase UBR5 HECT domain mutations in lymphoma control maturation of B cells via alternative splicing

10.1101/732180 ◽

2019 ◽

Author(s):

Samantha A. Swenson ◽

Tyler J. Gilbreath ◽

Heather Vahle ◽

R. Willow Hynes-Smith ◽

Jared H. Graham ◽

...

Keyword(s):

Alternative Splicing ◽

B Cells ◽

B Cell ◽

Cell Lymphoma ◽

B Cell Development ◽

Cell Maturation ◽

Hect Domain ◽

B Cell Maturation ◽

Mantle Cell

ABSTRACTCoordination of a number of molecular mechanisms including transcription, alternative splicing, and class switch recombination are required to facilitate development, activation, and survival of B cells. Disruption of these pathways can result in malignant transformation. Recently, next generation sequencing has identified a number of novel mutations in mantle cell lymphoma (MCL) patients including the ubiquitin E3 ligase UBR5. Approximately 18% of MCL patients were found to have mutations in UBR5 with the majority of mutations within the HECT domain of the protein which can accept and transfer ubiquitin molecules to the substrate. Determining if UBR5 controls the maturation of B cells is important to fully understand malignant transformation to MCL. To elucidate the role of UBR5 in B cell maturation and activation we generated a conditional mutant disrupting UBR5’s C-terminal HECT domain. Loss of the UBR5 HECT domain leads to a block in maturation of B cells in the spleen and up-regulation of proteins associated with mRNA splicing via the spliceosome. Our studies reveal a novel role of UBR5 in B cell maturation by regulating alternative splicing of key transcripts during B cell development and suggests UBR5 mutations may promote mantle cell lymphoma initiation.KEY POINTSUtilizing a novel mouse model mimicking MCL patient mutations, the loss of UBR5’s HECT domain causes alterations in B cell development.UBR5 mutations lead to stabilization of UBR5 and aberrant splicing.

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A Systemic Review of CD5-Negative Mantle Cell Lymphoma Identifies Potential Clinical and Biological Implications

Blood ◽

10.1182/blood.v128.22.3048.3048 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3048-3048 ◽

Cited By ~ 2

Author(s):

Arshia Soleimani ◽

Georges Tanios ◽

Hana Safah ◽

Nakhle S. Saba

Keyword(s):

B Cell ◽

Cyclin D1 ◽

Mantle Cell Lymphoma ◽

Light Chain ◽

Cell Lymphoma ◽

Ki 67 ◽

Female Ratio ◽

Mantle Cell ◽

Leukemic Phase ◽

Male To Female

Abstract Introduction: Mantle cell lymphoma (MCL) is an aggressive subtype of non-Hodgkin lymphoma (NHL) with a median survival of 3 to 5 years. MCL is characterized by the translocation t(11;14)(q13;32) which results in the overexpression of cyclin-D1 and ultimately an uninhibited G1/S cell cycle transition. MCL has a distinctive immunophenotype among B-cell NHL, characterized by a strong expression of the pan B-cell markers CD19 and CD20, absence of CD10 and CD23, overexpression of the anti-apoptotic protein BCL2, and aberrant expression of the T-cell marker CD5. However, up to 10% of MCL lack CD5 expression and remain ill-characterized. Whether this absence of CD5 expression impacts MCL biology and clinical course remains unknown. We performed a systematic review of all reported cases of CD5-negative MCL and analyzed their biological and clinical characteristics. Patients and methods: A systematic literature search was performed and included studies published from 1st June 1994 to 1st June 2016 in PubMed, Embase, and Web of Science. We used the key words CD5 negative, CD5-, mantle cell lymphoma, and MCL. Data was tabulated regarding the following 16 variables: t(11;14)(q13;q32), cyclin-D1, CD5, CD10, CD19, CD20, CD23, BCL2, BCL6, Ki-67 (higher or lower than 30%), IGHV mutation status (mutated IGHV >3% discordance with germline), male to female ratio, light chain expression (kappa or lambda), presence of a leukemic phase, stage, and overall survival (OS). Data was reported as percent and total number of cases with available data of each variable. Results and discussion: 68 out of 470 screened articles included CD5-negative MCL cases. After exclusion of duplicates, 50 sources (46 full articles and 4 abstracts) were included. Data of 222 cases of CD5-negative MCL were collected. To a degree, reviewed cases of CD-5 negative MCL shared similarities to classic MCL. Both sub-types had a median age at diagnosis of approximately 65 and presented as stage IV disease 70% of the time. Both subtypes overexpressed cyclin-D1 (100%, 222/222), possessed the t(11;14)(q13;q32) (93%, 49/53: 49 of 53 cases with available data on the translocation), were CD-19 positive (100%,18/18), CD20-positive (100%, 58/58), BCL2-positive (97%, 34/35), CD10-negative (93%, 42/45), and CD23-negative (95%,56/59). Presence or absence of leukemic phase was reported in 16 cases, 8 of those were positive for circulating MCL cells (50%). The proliferation marker Ki-67 was reported in 22 cases, 7 (32%) of which were >30%. CD5-negative MCL deviated from the classic MCL presentation in a number of clinical and biological variables. Most importantly, the median OS of 47 cases with available follow-up was greater than 16 years (Figure 1), which compared very favorably to the historic survival of 3 to 5 years in classic MCL. Interestingly, the number of affected males was less than expected in the CD5-negative group. Male-to-female ratio was 2:1 (74 males and 36 females of 110 cases with available gender data), which is lower than the expected 3:1 ratio. From a biological standpoint, the CD5-negative MCL cohort had more kappa than lambda-restricted cases (62%, 13 of 21 available light chain data), and more mutated than unmutated IGHV (61% mutated, 11 of 18 cases with available IGHV data). Classically, lambda-restricted MCL and unmutated IGHV are more commonly seen and were associated with worse clinical outcomes. In addition, we observed BCL6 expression in 23% of CD5-negative MCL cases, which is higher than expected (6 of 26 cases with BCL6 available data). Conclusions: To our knowledge this is the most comprehensive review of CD5-negative MCL. Lack of CD5 expression was associated with important clinical and biological differences compared to classic MCL. The higher survival observed in our analysis suggest that CD5 can potentially be incorporated in identifying a subset of a more indolent MCL that might benefit from a watch and wait approach. Currently, treatment in MCL can be differed in a subset of patients with an indolent presentation characterized by leukemic-only disease with absence of lymphadenopathy, mutated IGHV, and lack of SOX11 expression. SOX11 data was not available in our cohort, and only 18 patients had available IGHV mutation data. While the exact role of CD5 in MCL remains unknown, our findings highlight the need for a deeper investigation of CD5-negative MCL at the genetic, phenotypic, and clinical levels. Disclosures No relevant conflicts of interest to declare.

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