Increased c-MYC Expression Associated with Active IGH Locus Rearrangement: An Emerging Role for c-MYC in Chronic Lymphocytic Leukemia

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1.  What is the prevalence rate of CLL among france population.

2. Is there any specific reason why CLL most frequently observed among elder patients.

3. What is the rate of OS, PFS, DFS OF CLL in your population group.

4. Is there any molecular methods to diagnose CLL cells in the blood.

5. What are the treatment regimes given to the patients diagnose with CLL.

6.  c-MYC regulates B-cell proliferation and survival depending on the developmental stage, explain this mechanism in detail and include a figure of this mechanism.

 7.  c-MYC can be used as therapeutic target for CLL treatment, kindly include this section.

Comments on the Quality of English Language

It seems fine.

Author Response

Reviewer 1

Thank you very much for taking the time to review our manuscript. Please find the detailed responses below and the corresponding revisions/corrections  in the re-submitted files. All changes made in the revised manuscript (Please see the attachment) have been highlighted in yellow and the lines are indicated in the responses to the comments.

1.What is the prevalence rate of CLL among france population.

In France, FILO is a Cooperative Group dedicated to conducting research on CLL. Thanks to the work of the FILO-CLL group, access to biomedical, epidemiological, clinical, pharmacological, and biological data related to the disease in France is possible. For instance, a publication by this group (Quinquenel et al., Hemasphere, 2020) [1] reported that in 2018, the estimated number of new incident cases of CLL in France was 4,674, based on data from the French cancer registry published in 2019 [2].

2. Is there any specific reason why CLL most frequently observed among elder patients.

Based on data from the French cancer registry in 2018 [2], published in 2019, it was observed that the increase in incidence with age applies to all mature B cell lymphomas and myelomas, not just CLL.

Molecular mechanisms underlie the increase incidence of B cell lymphoma with age. The presence of somatic mutations in a number of genes previously associated with myeloid pathologies known as clonal hematopoiesis of indeterminate potential (CHIP) is associated with an increased risk of transformation into malignant hematologic disorders, including both myeloid and lymphoid malignancies. CHIP mutations increase with age, thereby raising the risk of lymphoid cancers, including CLL [3,4].

3. What is the rate of OS, PFS, DFS OF CLL in your population group.

Regarding the patient cohort described in the Al Jamal et al. [5] study, we can provide the following details: the overall survival (OS) was 106 months (97 months for the CLL Sµ-3’RRrec^high group and 107 months for the Sµ-3’RRrec^Low group). As for the overall treatment-free survival (TFS), it was 50 months. Specifically, the CLL Sµ-3’RRrec^high subgroup had a TFS of 14 months, while the Sµ-3’RRrec^Low subgroup had a TFS of 56 months. We are unable to provide data regarding PFS and DFS for this cohort.

4. Is there any molecular methods to diagnose CLL cells in the blood.

Currently, the diagnosis of CLL is based on cytology, flow cytometry, and the calculation of the Matutes score

5. What are the treatment regimes given to the patients diagnose with CLL.

Up to 2020, immunochemotherapy was the backbone of first-line treatment (Quinquenel et al., Hemasphere, 2020)[1]. Based on fludarabine eligibility, the reference treatment was fludarabine, cyclophosphamide and rituximab combinaison (FCR) with 6 or 4 monthly cycles depending on age. In FCR-ineligible patients, immunotherapy remained the gold standard using the combinaison of bendamustine and rituximab or chlorambucil and obinutuzumab. The presence of a significant TP53 alteration contraindicates to immunochemotherapy, making search test mandatatory before any treatment. When TP53 is altered, continuous ibrutinib treatment was the gold standard. Current guidelines recommend targeted therapies as first-line treatment, mainly BTK inhibitors and venetoclax alone, in combination or combined with obinutuzumab. FCR is no longer proposed as first-line treatment.

The patient cohort from the Al Jamal et al. [5] was treated according to the 2020 guidelines: of the 48 patients, 29% (12 patients) did not receive any treatment, while 70% (31 patients) were treated. Among the treated patients, 8 were eligible for FCR (2 CLL Sµ-3’RRrec^high and 6 Sµ-3’RRrec^Low). Of the 16 patients ineligible for FCR, 15 received another form of immunochemotherapy, and 1 patient received obinutuzumab plus venetoclax. Seven patients were treated with continuous ibrutinib: 4 had TP53 alterations, and 3 were treated according to recent recommendations.

We added this paragraph lines 243-250 in the section “MYC and the treatment for CLL” of the revised manuscript.

6. c-MYC regulates B-cell proliferation and survival depending on the developmental stage, explain this mechanism in detail and include a figure of this mechanism.

c-MYC plays a crucial role in regulating B-cell proliferation and survival, but its effects vary depending on the B-cell’s developmental stage.

In the early stages of B-cell development, c-MYC promotes the proliferation of progenitor B cells. During these stages, c-MYC is activated by external signals such as IL-7. During this early phase, c-MYC activation must be tightly controlled to maintain genomic integrity. Cells with unsuccessful rearrangements or unchecked MYC activity undergo apoptosis. This mechanism ensures that only B cells with functional rearrangements survive. In pro-B cells, c-MYC regulates the cell cycle, driving pro-B cell proliferation and promoting V(D)J recombinations. In pre-B cells, c-MYC promotes pre-B cell expansion, allowing the cells to divide before Ig light chain V(D)J recombination.

As B cells mature and leave the bone marrow, MYC expression turns off.

Once B cells recognize antigens MYC expression is induced after BCR engagement to drive the rapid proliferation necessary for an effective immune response. Once in the germinal center (GC), MYC is induced in centroblasts in the dark zone of the GC, where proliferation and somatic hypermutation occur to produce high-affinity antibodies. While c-MYC drives proliferation, it also induces a vulnerability to apoptosis due to its ability to upregulate pro-apoptotic factors like P53. To balance this, c-MYC activation often coincides with survival signals that prevent apoptosis. c-MYC promotes cell survival by activating anti-apoptotic pathways. This is primarily mediated through proteins like BCL-2, which inhibit apoptosis, allowing cells to survive even under stress or genomic instability.

We have added a table of MYC expression in B lymphocytes with the legend synthesizing the answer above. This addition is made lines 112-120 of the revised manuscript.

7. c-MYC can be used as therapeutic target for CLL treatment, kindly include this section.

Recently, MYC has been identified as a potential therapeutic target in CLL. Targeting the PHB-eIF4F complex inhibits MYC translation, resulting in reduced proliferation and survival of CLL cells. These results suggest that disruption of the PHB-eIF4F interaction could represent a promising therapeutic strategy for CLL patients by down-regulating MYC activity and modifying the malignant phenotype [6]. Furthermore, MYC orchestrates metabolic reprogramming in CLL cells, and the study by Simon-Molas et al. [7] shows that it is possible to target MYC-mediated metabolic alterations to improve therapeutic outcomes in CLL.

We have added this paragraph lines 259-264 of the revised manuscript.

Bibliography

1. Quinquenel, A.; Aurran-Schleinitz, T.; Clavert, A.; Cymbalista, F.; Dartigeas, C.; Davi, F.; Guibert, S. de; Delmer, A.; Dilhuydy, M.-S.; Feugier, P.; et al. Diagnosis and Treatment of Chronic Lymphocytic Leukemia: Recommendations of the French CLL Study Group (FILO). HemaSphere 2020, 4, e473, doi:10.1097/HS9.0000000000000473.
2. SPF Estimations nationales de l’incidence et de la mortalité par cancer en France métropolitaine entre 1990 et 2018 - Hémopathies malignes : Étude à partir des registres des cancers du réseau Francim Available online: https://www.santepubliquefrance.fr/import/estimations-nationales-de-l-incidence-et-de-la-mortalite-par-cancer-en-france-metropolitaine-entre-1990-et-2018-hemopathies-malignes-etude-a-pa (accessed on 23 October 2024).
3. Niroula, A.; Sekar, A.; Murakami, M.A.; Trinder, M.; Agrawal, M.; Wong, W.J.; Bick, A.G.; Uddin, M.M.; Gibson, C.J.; Griffin, G.K.; et al. Distinction of Lymphoid and Myeloid Clonal Hematopoiesis. Nature medicine 2021, 27, 1921, doi:10.1038/s41591-021-01521-4.
4. Brown, D.W.; Cato, L.D.; Zhao, Y.; Nandakumar, S.K.; Bao, E.L.; Gardner, E.J.; Hubbard, A.K.; DePaulis, A.; Rehling, T.; Song, L.; et al. Shared and Distinct Genetic Etiologies for Different Types of Clonal Hematopoiesis. Nat Commun 2023, 14, 5536, doi:10.1038/s41467-023-41315-5.
5. Al Jamal, I.; Parquet, M.; Guiyedi, K.; Aoufouchi, S.; Le Guillou, M.; Rizzo, D.; Pollet, J.; Dupont, M.; Boulin, M.; Faumont, N.; et al. IGH 3’RR Recombination Uncovers a Non-Germinal Center Imprint and c-MYC-Dependent IGH Rearrangement in Unmutated Chronic Lymphocytic Leukemia. Haematologica 2024, 109, 466–478, doi:10.3324/haematol.2023.282897.
6. Largeot, A.; Klapp, V.; Viry, E.; Gonder, S.; Botana, I.F.; Blomme, A.; Benzarti, M.; Pierson, S.; Duculty, C.; Marttila, P.; et al. Inhibition of MYC Translation through Targeting of the Newly Identified PHB-EIF4F Complex as a Therapeutic Strategy in CLL. Blood 2023, 141, 3166, doi:10.1182/blood.2022017839.
7. Simon-Molas, H.; Montironi, C.; Kabanova, A.; Eldering, E. Metabolic Reprogramming in the CLL TME; Potential for New Therapeutic Targets. Seminars in Hematology 2024, 61, 155–162, doi:10.1053/j.seminhematol.2024.02.001.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The article "Increased c-MYC expression associated to active IGH locus rearrangement: an emerging role of c-MYC in Chronic Lymphocytic Leukemia" nicely reviewed the functional significance of c-MYC dysregulation in CLL biology. It is a well-written review, and is informative for readers who concerned about hematologic malignancies.

Comment

One topic that the authors can add is that the impact of c-MYC dysregulation along with different treatment, such as purine analogue, BTK inhibitors, and monoclonal antibody for CD20, etc.

Author Response

Reviewer 2

Thank you very much for taking the time to review our manuscript. Please find the detailed responses below and the corresponding revisions/corrections  in the re-submitted files. All changes made in the revised manuscript (Please see the attachment) have been highlighted in yellow and the lines are indicated in the responses to the comments.

The article "Increased c-MYC expression associated to active IGH locus rearrangement: an emerging role of c-MYC in Chronic Lymphocytic Leukemia" nicely reviewed the functional significance of c-MYC dysregulation in CLL biology. It is a well-written review, and is informative for readers who concerned about hematologic malignancies.

Comment

One topic that the authors can add is that the impact of c-MYC dysregulation along with different treatment, such as purine analogue, BTK inhibitors, and monoclonal antibody for CD20, etc.

MYC exhibits prognostic significance in chronic lymphocytic leukemia (CLL) concerning two types of 8q24 abnormalities: translocations involving MYC and genomic gains. MYC translocations are infrequent found in less than 1% of CLL cases, while gains of one or more copies of the MYC gene occur in 5-6% of CLL cases. The poor prognosis associated with these alterations correlates with an aggressive clinical course and reduced overall survival (OS) [1]. Additionally, MYC gain may be associated with del(17p), which further exacerbates the prognosis [2]. However, alterations in MYC do not yield specific treatment recommendations, and their impact on therapeutic outcomes remains inadequately characterized. The potential role of MYC activation in mediating drug resistance, particularly to BTK inhibitors, is currently unknown.

We have added this paragraph in the section exploring MYC in the CLL treatment, lines 251-258.

Bibliography:

1. Nguyen-Khac, F.; Balogh, Z.; Chauzeix, J.; Veronese, L.; Chapiro, E. Cytogenetics in the Management of Chronic Lymphocytic Leukemia: Guidelines from the Groupe Francophone de Cytogénétique Hématologique (GFCH). Current Research in Translational Medicine 2023, 71, 103410, doi:10.1016/j.retram.2023.103410.
2. Nguyen-Khac, F. “Double-Hit” Chronic Lymphocytic Leukemia, Involving the TP53 and MYC Genes. Front. Oncol. 2022, 11, 826245, doi:10.3389/fonc.2021.826245.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The review entitled: “Increased c-MYC expression associated to active IGH locus rearrangement: an emerging role of c-MYC in Chronic Lymphocytic Leukemia” (ID: cancers-3280983) by Guiyedi et al. evaluates the role of c-MYC on CLL.

Albeit the review is well written and of special interest, comments should be addressed to further improve the manuscript.

Comments:

1.    Discussion on page 8: As mentioned within the aim of the review, please provide more information about potential clinical implications of c-MYC, what are exact recommendation for the clinicians.

2.    Discussion/Conclusion: Please provide a kind of outlook concerning the next important steps for future studies e.g. c-MYC and the role for potential therapies or decision making in CLL patients.  

Author Response

Reviewer 3

Thank you very much for taking the time to review our manuscript. Please find the detailed responses below and the corresponding revisions/corrections  in the re-submitted files. All changes made in the revised manuscript (Please see the attachment) have been highlighted in yellow and the lines are indicated in the responses to the comments.

The review entitled: “Increased c-MYC expression associated to active IGH locus rearrangement: an emerging role of c-MYC in Chronic Lymphocytic Leukemia” (ID: cancers-3280983) by Guiyedi et al. evaluates the role of c-MYC on CLL.

Albeit the review is well written and of special interest, comments should be addressed to further improve the manuscript.

Comments:

1. Discussion on page 8: As mentioned within the aim of the review, please provide more information about potential clinical implications of c-MYC, what are exact recommendation for the clinicians.

MYC exhibits prognostic significance in chronic lymphocytic leukemia (CLL) concerning two types of 8q24 abnormalities: translocations involving MYC and genomic gains. MYC translocations are infrequent found in less than 1% of CLL cases, while gains of one or more copies of the MYC gene occur in 5-6% of CLL cases. The poor prognosis associated with these alterations correlates with an aggressive clinical course and reduced overall survival (OS) [1]. Additionally, MYC gain may be associated with del(17p), which further exacerbates the prognosis [2]. However, alterations in MYC do not yield specific treatment recommendations, and their impact on therapeutic outcomes remains inadequately characterized. The potential role of MYC activation in mediating drug resistance, particularly to BTK inhibitors, is currently unknown.

We have added this paragraph in the section exploring MYC in the CLL treatment, lines 251-258.

2. Discussion/Conclusion: Please provide a kind of outlook concerning the next important steps for future studies e.g. c-MYC and the role for potential therapies or decision making in CLL patients.

Future studies could address how high levels of c-MYC modulates chromatin architecture and impacts cellular transcriptional control in CLL. This modulation affects long-range genomic interactions, enabling the cell to coordinate the expression of genes located far apart on the genome, thereby facilitating changes in transcriptional programs. In the context of neoplastic transformation, this chromatin reorganization likely contributes to the deregulated gene expression that underpins cancer aggressiveness. Thus, the identification of MYC-specific alterations in gene expression in CLL could participate to the development of targeted therapies.  

We have added this to the conclusion, lines 368 to 373.

Bibliography

1. Nguyen-Khac, F.; Balogh, Z.; Chauzeix, J.; Veronese, L.; Chapiro, E. Cytogenetics in the Management of Chronic Lymphocytic Leukemia: Guidelines from the Groupe Francophone de Cytogénétique Hématologique (GFCH). Current Research in Translational Medicine 2023, 71, 103410, doi:10.1016/j.retram.2023.103410.
2. Nguyen-Khac, F. “Double-Hit” Chronic Lymphocytic Leukemia, Involving the TP53 and MYC Genes. Front. Oncol. 2022, 11, 826245, doi:10.3389/fonc.2021.826245.

Author Response File: Author Response.docx