1
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The CMG helicase and cancer: a tumor "engine" and weakness with missing mutations. Oncogene 2023; 42:473-490. [PMID: 36522488 PMCID: PMC9948756 DOI: 10.1038/s41388-022-02572-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
The replicative Cdc45-MCM-GINS (CMG) helicase is a large protein complex that functions in the DNA melting and unwinding steps as a component of replisomes during DNA replication in mammalian cells. Although the CMG performs this important role in cell growth, the CMG is not a simple bystander in cell cycle events. Components of the CMG, specifically the MCM precursors, are also involved in maintaining genomic stability by regulating DNA replication fork speeds, facilitating recovery from replicative stresses, and preventing consequential DNA damage. Given these important functions, MCM/CMG complexes are highly regulated by growth factors such as TGF-ß1 and by signaling factors such as Myc, Cyclin E, and the retinoblastoma protein. Mismanagement of MCM/CMG complexes when these signaling mediators are deregulated, and in the absence of the tumor suppressor protein p53, leads to increased genomic instability and is a contributor to tumorigenic transformation and tumor heterogeneity. The goal of this review is to provide insight into the mechanisms and dynamics by which the CMG is regulated during its assembly and activation in mammalian genomes, and how errors in CMG regulation due to oncogenic changes promote tumorigenesis. Finally, and most importantly, we highlight the emerging understanding of the CMG helicase as an exploitable vulnerability and novel target for therapeutic intervention in cancer.
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Sethi B, Kumar V, Jayasinghe TD, Dong Y, Ronning DR, Zhong HA, Coulter DW, Mahato RI. Targeting BRD4 and PI3K signaling pathways for the treatment of medulloblastoma. J Control Release 2023; 354:80-90. [PMID: 36599397 PMCID: PMC9974792 DOI: 10.1016/j.jconrel.2022.12.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/17/2022] [Accepted: 12/28/2022] [Indexed: 01/06/2023]
Abstract
Medulloblastoma (MB) is a malignant pediatric brain tumor which shows upregulation of MYC and sonic hedgehog (SHH) signaling. SHH inhibitors face acquired resistance, which is a major cause of relapse. Further, direct MYC oncogene inhibition is challenging, inhibition of MYC upstream insulin-like growth factor/ phosphatidylinositol-4,5-bisphosphate 3-kinase (IGF/PI3K) is a promising alternative. While PI3K inhibition activates resistance mechanisms, simultaneous inhibition of bromodomain-containing protein 4 (BRD4) and PI3K can overcome resistance. We synthesized a new molecule 8-(2,3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-2-morpholino-4H-chromen-4-one (MDP5) that targets both BRD4 and PI3K pathways. We used X-ray crystal structures and a molecular modeling approach to confirm the interactions between MDP5 with bromo domains (BDs) from both BRD2 and BRD4, and molecular modeling for PI3K binding. MDP5 was shown to inhibit target pathways and MB cell growth in vitro and in vivo. MDP5 showed higher potency in DAOY cells (IC50 5.5 μM) compared to SF2523 (IC50 12.6 μM), and its IC50 values in HD-MB03 cells were like SF2523. Treatment of MB cells with MDP5 significantly decreased colony formation, increased apoptosis, and halted cell cycle progression. Further, MDP5 was well tolerated in NSG mice bearing either xenograft or orthotopic MB tumors at the dose of 20 mg/kg, and significantly reduced tumor growth and prolonged animal survival.
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Affiliation(s)
- Bharti Sethi
- Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Virender Kumar
- Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Thilina D Jayasinghe
- Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Yuxiang Dong
- Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Donald R Ronning
- Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Haizhen A Zhong
- Department of Chemistry, the University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE 68182, USA
| | - Donald W Coulter
- Department of Pediatrics, the University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Ram I Mahato
- Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA.
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Deciphering the Role of p53 and TAp73 in Neuroblastoma: From Pathogenesis to Treatment. Cancers (Basel) 2022; 14:cancers14246212. [PMID: 36551697 PMCID: PMC9777536 DOI: 10.3390/cancers14246212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Neuroblastoma (NB) is an embryonic cancer that develops from neural crest stem cells, being one of the most common malignancies in children. The clinical manifestation of this disease is highly variable, ranging from spontaneous regression to increased aggressiveness, which makes it a major therapeutic challenge in pediatric oncology. The p53 family proteins p53 and TAp73 play a key role in protecting cells against genomic instability and malignant transformation. However, in NB, their activities are commonly inhibited by interacting proteins such as murine double minute (MDM)2 and MDMX, mutant p53, ΔNp73, Itch, and Aurora kinase A. The interplay between the p53/TAp73 pathway and N-MYC, a known biomarker of poor prognosis and drug resistance in NB, also proves to be decisive in the pathogenesis of this tumor. More recently, a strong crosstalk between microRNAs (miRNAs) and p53/TAp73 has been established, which has been the focused of great attention because of its potential for developing new therapeutic strategies. Collectively, this review provides an updated overview about the critical role of the p53/TAp73 pathway in the pathogenesis of NB, highlighting encouraging clues for the advance of alternative NB targeted therapies.
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Chen C, Lan MS. Interplay: The Essential Role between INSM1 and N-Myc in Aggressive Neuroblastoma. BIOLOGY 2022; 11:biology11101376. [PMID: 36290282 PMCID: PMC9598261 DOI: 10.3390/biology11101376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/24/2022]
Abstract
Simple Summary Neuroblastoma (NB) is a cancer that starts in certain very early forms of nerve cells of the sympathetic nervous system, most often found in an embryo or fetus. Symptoms may include bone pain, an abdominal mass, frequent urination, limping, anemia, spinal cord weakness, or bruising of the eye area. N-Myc is a key driver of high-risk NB. An elevated expression of N-Myc often predicts a poorer prognosis, in both time to tumor progression and overall survival rate. We discovered a transcription factor, insulinoma-associated-1 (INSM1), as the downstream target gene of N-Myc. INSM1 has emerged as a novel NB biomarker that plays a critical role in facilitating NB tumor cell development. Both N-Myc and INSM1 demonstrate high clinical relevance to NB. Therefore, further understanding the association of INSM1 and N-Myc functions in aggressive NB should be beneficial for future NB treatment. Abstract An aggressive form of neuroblastoma (NB), a malignant childhood cancer derived from granule neuron precursors and sympathoadrenal lineage, frequently comprises MYCN amplification/elevated N-Myc expression, which contributes to the development of neural crest-derived embryonal malignancy. N-Myc is an oncogenic driver in NB. Persistent N-Myc expression during the maturation of SA precursor cells can cause blockage of the apoptosis and induce abnormal proliferation, resulting in NB development. An insulinoma-associated-1 (INSM1) zinc-finger transcription factor has emerged as an NB biomarker that plays a critical role in facilitating tumor cell growth and transformation. INSM1 plays an essential role in sympathoadrenal cell differentiation. N-Myc activates endogenous INSM1 through an E2-box of the INSM1 proximal promoter, whereas INSM1 enhances N-Myc stability via RAC-α-serine/threonine protein kinase (AKT) phosphorylation in NB. The ectopic expression of INSM1 stimulates NB tumor growth in contrast to the knockdown of INSM1 that inhibits NB cell proliferation. The clinical pathological result and bioinformatics analysis show that INSM1 is a strong diagnostic and a prognostic biomarker for the evaluation of NB progression. The INSM1/N-Myc expression shows high clinical relevance in NB. Therefore, targeting the INSM1/N-Myc-associated signaling axis should be a feasible approach to identifying new drugs for the suppression of NB tumor growth.
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Affiliation(s)
| | - Michael S. Lan
- Correspondence: ; Tel.: +1-504-568-2437; Fax: +1-504-568-8500
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Molecular switch from MYC to MYCN expression in MYC protein negative Burkitt lymphoma cases. Blood Cancer J 2019; 9:91. [PMID: 31748534 PMCID: PMC6868231 DOI: 10.1038/s41408-019-0252-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/29/2019] [Accepted: 08/19/2019] [Indexed: 12/21/2022] Open
Abstract
MYC is the most altered oncogene in human cancer, and belongs to a large family of genes, including MYCN and MYCL. Recently, while assessing the degree of correlation between MYC gene rearrangement and MYC protein expression in aggressive B-cell lymphomas, we observed few Burkitt lymphoma (BL) cases lacking MYC protein expression despite the translocation involving the MYC gene. Therefore, in the present study we aimed to better characterize such cases. Our results identified two sub-groups of MYC protein negative BL: one lacking detectable MYC protein expression but presenting MYCN mRNA and protein expression; the second characterized by the lack of both MYC and MYCN proteins but showing MYC mRNA. Interestingly, the two sub-groups presented a different pattern of SNVs affecting MYC gene family members that may induce the switch from MYC to MYCN. Particulary, MYCN-expressing cases show MYCN SNVs at interaction interface that stabilize the protein associated with loss-of-function of MYC. This finding highlights MYCN as a reliable diagnostic marker in such cases. Nevertheless, due to the overlapping clinic, morphology and immunohistochemistry (apart for MYC versus MYCN protein expression) of both sub-groups, the described cases represent bona fide BL according to the current criteria of the World Health Organization.
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Han H, Jain AD, Truica MI, Izquierdo-Ferrer J, Anker JF, Lysy B, Sagar V, Luan Y, Chalmers ZR, Unno K, Mok H, Vatapalli R, Yoo YA, Rodriguez Y, Kandela I, Parker JB, Chakravarti D, Mishra RK, Schiltz GE, Abdulkadir SA. Small-Molecule MYC Inhibitors Suppress Tumor Growth and Enhance Immunotherapy. Cancer Cell 2019; 36:483-497.e15. [PMID: 31679823 PMCID: PMC6939458 DOI: 10.1016/j.ccell.2019.10.001] [Citation(s) in RCA: 242] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 08/19/2019] [Accepted: 09/30/2019] [Indexed: 01/16/2023]
Abstract
Small molecules that directly target MYC and are also well tolerated in vivo will provide invaluable chemical probes and potential anti-cancer therapeutic agents. We developed a series of small-molecule MYC inhibitors that engage MYC inside cells, disrupt MYC/MAX dimers, and impair MYC-driven gene expression. The compounds enhance MYC phosphorylation on threonine-58, consequently increasing proteasome-mediated MYC degradation. The initial lead, MYC inhibitor 361 (MYCi361), suppressed in vivo tumor growth in mice, increased tumor immune cell infiltration, upregulated PD-L1 on tumors, and sensitized tumors to anti-PD1 immunotherapy. However, 361 demonstrated a narrow therapeutic index. An improved analog, MYCi975 showed better tolerability. These findings suggest the potential of small-molecule MYC inhibitors as chemical probes and possible anti-cancer therapeutic agents.
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Affiliation(s)
- Huiying Han
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Atul D Jain
- Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA
| | - Mihai I Truica
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Javier Izquierdo-Ferrer
- Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA
| | - Jonathan F Anker
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Barbara Lysy
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Vinay Sagar
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Yi Luan
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Zachary R Chalmers
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Kenji Unno
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Hanlin Mok
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Rajita Vatapalli
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Young A Yoo
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Yara Rodriguez
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Irawati Kandela
- Center for Developmental Therapeutics, Northwestern University, Evanston, IL 60208, USA
| | - J Brandon Parker
- Division of Reproductive Science in Medicine, Department of OB/GYN, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Debabrata Chakravarti
- Division of Reproductive Science in Medicine, Department of OB/GYN, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago IL 60611, USA
| | - Rama K Mishra
- Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago IL 60611, USA
| | - Gary E Schiltz
- Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA; The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago IL 60611, USA
| | - Sarki A Abdulkadir
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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The roles played by the MYCN, Trk, and ALK genes in neuroblastoma and neural development. Surg Today 2019; 49:721-727. [PMID: 30848386 DOI: 10.1007/s00595-019-01790-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 01/20/2019] [Indexed: 12/23/2022]
Abstract
Neuroblastoma is one of the most frequent, yet distinctive and challenging childhood tumors. The uniqueness of this tumor depends on its biological markers, which classify neuroblastomas into favorable and unfavorable, with 5-year survival rates ranging from almost 100-30%. In this review, we focus on some biological factors that play major roles in neuroblastoma: MYCN, Trk, and ALK. The MYCN and Trk family genes have been studied for decades and are known to be crucial for the tumorigenesis and progression of neuroblastoma. ALK gene mutations have been recognized recently to be responsible for familial neuroblastomas. Each factor plays an important role in normal neural development, regulating cell proliferation or differentiation by activating several signaling pathways, and interacting with each other. These factors have been studied not only as prognostic factors, but also as targets of neuroblastoma therapy, and some clinical trials are ongoing. We review the basic aspects of MYCN, Trk, and ALK in both neural development and in neuroblastoma.
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Chen C, Breslin MB, Lan MS. INSM1 increases N-myc stability and oncogenesis via a positive-feedback loop in neuroblastoma. Oncotarget 2017; 6:36700-12. [PMID: 26456864 PMCID: PMC4742205 DOI: 10.18632/oncotarget.5485] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/18/2015] [Indexed: 12/12/2022] Open
Abstract
Insulinoma associated-1 (IA-1/INSM1) gene is exclusively expressed during early embryonic development, but has been found to be re-expressed at high levels in neuroendocrine tumors including neuroblastoma. Using over-expression and knockdown experiments in neuroblastoma cells, we showed that INSM1 is critical for cell proliferation, BME-coated invasion, and soft agar colony formation. Here, we identified INSM1 as a novel target gene activated by N-myc in N-myc amplified neuroblastoma cells. The Sonic hedgehog signaling pathway induced INSM1 by increasing N-myc expression. INSM1 activated PI3K/AKT/GSK3β pathways to suppress N-myc phosphorylation (Thr-58) and inhibited degradation of N-myc. Inversely, N-myc protein bound to the E2-box region of the INSM1 promoter and activated INSM1 expression. The invasion assay and the xenograft nude mouse tumor model revealed that the INSM1 factor facilitated growth and oncogenesis of neuroblastoma. The current data supports our hypothesis that a positive-feedback loop of sonic hedgehog signaling induced INSM1 through N-myc and INSM1 enhanced N-myc stability contributing to the transformation of human neuroblastoma.
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Affiliation(s)
- Chiachen Chen
- The Research Institute for Children, Children's Hospital, New Orleans, LA 70118, USA.,Laboratory of Diana Helis Henry Medical Research Foundation, New Orleans, LA 70119, USA
| | - Mary B Breslin
- The Research Institute for Children, Children's Hospital, New Orleans, LA 70118, USA.,Laboratory of Diana Helis Henry Medical Research Foundation, New Orleans, LA 70119, USA.,Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Michael S Lan
- The Research Institute for Children, Children's Hospital, New Orleans, LA 70118, USA.,Laboratory of Diana Helis Henry Medical Research Foundation, New Orleans, LA 70119, USA.,Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.,Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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9
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Venturutti L, Russo RIC, Rivas MA, Mercogliano MF, Izzo F, Oakley RH, Pereyra MG, De Martino M, Proietti CJ, Yankilevich P, Roa JC, Guzmán P, Cortese E, Allemand DH, Huang TH, Charreau EH, Cidlowski JA, Schillaci R, Elizalde PV. MiR-16 mediates trastuzumab and lapatinib response in ErbB-2-positive breast and gastric cancer via its novel targets CCNJ and FUBP1. Oncogene 2016; 35:6189-6202. [PMID: 27157613 PMCID: PMC5832962 DOI: 10.1038/onc.2016.151] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 02/26/2016] [Accepted: 03/24/2016] [Indexed: 12/11/2022]
Abstract
ErbB-2 amplification/overexpression accounts for an aggressive breast cancer (BC) subtype (ErbB-2-positive). Enhanced ErbB-2 expression was also found in gastric cancer (GC) and has been correlated with poor clinical outcome. The ErbB-2-targeted therapies trastuzumab (TZ), a monoclonal antibody, and lapatinib, a tyrosine kinase inhibitor, have proved highly beneficial. However, resistance to such therapies remains a major clinical challenge. We here revealed a novel mechanism underlying the antiproliferative effects of both agents in ErbB-2-positive BC and GC. TZ and lapatinib ability to block extracellular signal-regulated kinases 1/2 and phosphatidylinositol-3 kinase (PI3K)/AKT in sensitive cells inhibits c-Myc activation, which results in upregulation of miR-16. Forced expression of miR-16 inhibited in vitro proliferation in BC and GC cells, both sensitive and resistant to TZ and lapatinib, as well as in a preclinical BC model resistant to these agents. This reveals miR-16 role as tumor suppressor in ErbB-2-positive BC and GC. Using genome-wide expression studies and miRNA target prediction algorithms, we identified cyclin J and far upstream element-binding protein 1 (FUBP1) as novel miR-16 targets, which mediate miR-16 antiproliferative effects. Supporting the clinical relevance of our results, we found that high levels of miR-16 and low or null FUBP1 expression correlate with TZ response in ErbB-2-positive primary BCs. These findings highlight a potential role of miR-16 and FUBP1 as biomarkers of sensitivity to TZ therapy. Furthermore, we revealed miR-16 as an innovative therapeutic agent for TZ- and lapatinib-resistant ErbB-2-positive BC and GC.
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Affiliation(s)
- L Venturutti
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - RI Cordo Russo
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - MA Rivas
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - MF Mercogliano
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - F Izzo
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - RH Oakley
- Department of Health and Human Services, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, USA
| | - MG Pereyra
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
- Servicio de Anatomía Patológica, Hospital General de Agudos ‘Juan A Fernández’, Buenos Aires, Argentina
| | - M De Martino
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - CJ Proietti
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - P Yankilevich
- Instituto de Investigación en Biomedicina de Buenos Aires, CONICET—Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - JC Roa
- Departamento de Anatomía Patológica (BIOREN), Universidad de La Frontera, Temuco, Chile
- Departamento de Anatomía Patológica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago de Chile, Chile
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Católica de Chile, Santiago de Chile, Santiago, Chile
| | - P Guzmán
- Departamento de Anatomía Patológica (BIOREN), Universidad de La Frontera, Temuco, Chile
| | - E Cortese
- Servicio de Ginecología, Hospital Aeronáutico Central, Buenos Aires, Argentina
| | - DH Allemand
- Unidad de Patología Mamaria, Hospital General de Agudos ‘Juan A Fernández’, Buenos Aires, Argentina
| | - TH Huang
- Department of Molecular Medicine/Institute of Biotechnology, Cancer Therapy and Research Center, University of Texas, San Antonio, TX, USA
| | - EH Charreau
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - JA Cidlowski
- Department of Health and Human Services, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, USA
| | - R Schillaci
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - PV Elizalde
- Laboratory of Molecular Mechanisms of Carcinogenesis, Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
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MEK inhibitors as a novel therapy for neuroblastoma: Their in vitro effects and predicting their efficacy. J Pediatr Surg 2016; 51:2074-2079. [PMID: 27686482 DOI: 10.1016/j.jpedsurg.2016.09.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 09/12/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND A recent study reported that relapsed neuroblastomas had frequent RAS-ERK pathway mutations. We herein investigated the effects and pathways of MEK inhibitors, which inhibit the RAS-ERK pathway, as a new molecular-targeted therapy for refractory neuroblastomas. METHOD Five neuroblastoma cell lines were treated with trametinib (MEK inhibitor) or CH5126766 (RAF/MEK inhibitor). Growth inhibition was analyzed using a cell viability assay. ERK phosphorylation and the MYCN expression were analyzed by immunoblotting or immunohistochemistry. RAS/RAF mutations were identified by direct sequencing or through the COSMIC database. RESULTS Both MEK inhibitors showed growth inhibition effects on cells with ERK phosphorylation, but almost no effect on cells without. In immunoblotting analyses, ERK phosphorylation and MYCN expression were suppressed in ERK active cells by these drugs. Furthermore, phosphorylated-ERK immunohistochemistry corresponded to the drug responses. Regarding the relationship between RAS/Raf mutations and ERK phosphorylation, ERK was phosphorylated in one cell line (NLF) without RAS/Raf mutations. CONCLUSION MEK inhibitors are a promising molecular-targeted therapeutic option for ERK active neuroblastomas. The efficacy of MEK inhibitors corresponds to ERK phosphorylation, while RAS/RAF mutations are not always detected in drug-sensitive cells. Phosphorylated-ERK immunohistochemistry is thus a useful method to analyze ERK activity and predict the therapeutic effects of MEK inhibitors.
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11
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Dorstyn L, Puccini J, Nikolic A, Shalini S, Wilson CH, Norris MD, Haber M, Kumar S. An unexpected role for caspase-2 in neuroblastoma. Cell Death Dis 2014; 5:e1383. [PMID: 25144718 PMCID: PMC4454317 DOI: 10.1038/cddis.2014.342] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 07/11/2014] [Indexed: 12/12/2022]
Abstract
Caspase-2 has been implicated in various cellular functions, including cell death by apoptosis, oxidative stress response, maintenance of genomic stability and tumor suppression. The loss of the caspase-2 gene (Casp2) enhances oncogene-mediated tumorigenesis induced by E1A/Ras in athymic nude mice, and also in the Eμ-Myc lymphoma and MMTV/c-neu mammary tumor mouse models. To further investigate the function of caspase-2 in oncogene-mediated tumorigenesis, we extended our studies in the TH-MYCN transgenic mouse model of neuroblastoma. Surprisingly, we found that loss of caspase-2 delayed tumorigenesis in the TH-MYCN neuroblastoma model. In addition, tumors from TH-MYCN/Casp2−/− mice were predominantly thoracic paraspinal tumors and were less vascularized compared with tumors from their TH-MYCN/Casp2+/+ counterparts. We did not detect any differences in the expression of neuroblastoma-associated genes in TH-MYCN/Casp2−/− tumors, or in the activation of Ras/MAPK signaling pathway that is involved in neuroblastoma progression. Analysis of expression array data from human neuroblastoma samples showed a correlation between low caspase-2 levels and increased survival. However, caspase-2 levels correlated with clinical outcome only in the subset of MYCN-non-amplified human neuroblastoma. These observations indicate that caspase-2 is not a suppressor in MYCN-induced neuroblastoma and suggest a tissue and context-specific role for caspase-2 in tumorigenesis.
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Affiliation(s)
- L Dorstyn
- 1] Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia [2] Department of Medicine, University of Adelaide, Adelaide, SA 5005, Australia
| | - J Puccini
- Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia
| | - A Nikolic
- Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia
| | - S Shalini
- Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia
| | - C H Wilson
- Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia
| | - M D Norris
- Children's Cancer Institute Australia for Medical Research, Lowy Cancer Research Centre, UNSW, Sydney, NSW 2052, Australia
| | - M Haber
- Children's Cancer Institute Australia for Medical Research, Lowy Cancer Research Centre, UNSW, Sydney, NSW 2052, Australia
| | - S Kumar
- 1] Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia [2] Department of Medicine, University of Adelaide, Adelaide, SA 5005, Australia
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Beltran H. The N-myc Oncogene: Maximizing its Targets, Regulation, and Therapeutic Potential. Mol Cancer Res 2014; 12:815-22. [PMID: 24589438 DOI: 10.1158/1541-7786.mcr-13-0536] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
N-myc (MYCN), a member of the Myc family of basic-helix-loop-helix-zipper (bHLHZ) transcription factors, is a central regulator of many vital cellular processes. As such, N-myc is well recognized for its classic oncogenic activity and association with human neuroblastoma. Amplification and overexpression of N-myc has been described in other tumor types, particularly those of neural origin and neuroendocrine tumors. This review outlines N-myc's contribution to normal development and oncogenic progression. In addition, it highlights relevant transcriptional targets and mechanisms of regulation. Finally, the clinical implications of N-Myc as a biomarker and potential as a target using novel therapeutic approaches are discussed.
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Affiliation(s)
- Himisha Beltran
- Author's Affiliation: Weill Cornell Medical College, New York, New York
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Wittmann W, Schimmang T, Gunhaga L. Progressive effects of N-myc deficiency on proliferation, neurogenesis, and morphogenesis in the olfactory epithelium. Dev Neurobiol 2014; 74:643-56. [PMID: 24376126 PMCID: PMC4237195 DOI: 10.1002/dneu.22162] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/27/2013] [Accepted: 12/18/2013] [Indexed: 12/03/2022]
Abstract
N-myc belongs to the myc proto-oncogene family, which is
involved in numerous cellular processes such as proliferation, growth, apoptosis, and
differentiation. Conditional deletion of N-myc in the mouse nervous system
disrupted brain development, indicating that N-myc plays an essential role during
neural development. How the development of the olfactory epithelium and neurogenesis within are
affected by the loss of N-myc has, however, not been determined. To address these
issues, we examined an N-mycFoxg1Cre conditional mouse line, in which
N-myc is depleted in the olfactory epithelium. First changes in
N-myc mutants were detected at E11.5, with reduced proliferation and neurogenesis
in a slightly smaller olfactory epithelium. The phenotype was more pronounced at E13.5, with a
complete lack of Hes5-positive progenitor cells, decreased proliferation, and
neurogenesis. In addition, stereological analyses revealed reduced cell size of post-mitotic neurons
in the olfactory epithelium, which contributed to a smaller olfactory pit. Furthermore, we observed
diminished proliferation and neurogenesis also in the vomeronasal organ, which likewise was reduced
in size. In addition, the generation of gonadotropin-releasing hormone neurons was severely reduced
in N-myc mutants. Thus, diminished neurogenesis and proliferation in combination
with smaller neurons might explain the morphological defects in the N-myc depleted
olfactory structures. Moreover, our results suggest an important role for N-myc in
regulating ongoing neurogenesis, in part by maintaining the Hes5-positive
progenitor pool. In summary, our results provide evidence that N-myc deficiency in
the olfactory epithelium progressively diminishes proliferation and neurogenesis with negative
consequences at structural and cellular levels. © 2013 The Authors. Developmental
Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 74: 643–656, 2014
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Affiliation(s)
- Walter Wittmann
- Umeå Centre for Molecular Medicine, Umeå University, 901 87, Umeå, Sweden
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Shung CY, Ota S, Zhou ZQ, Keene DR, Hurlin PJ. Disruption of a Sox9-β-catenin circuit by mutant Fgfr3 in thanatophoric dysplasia type II. Hum Mol Genet 2012; 21:4628-44. [PMID: 22843502 DOI: 10.1093/hmg/dds305] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mutations in fibroblast growth factor (FGF) receptors are responsible for a variety of skeletal birth defects, but the underlying mechanisms responsible remain unclear. Using a mouse model of thanatophoric dysplasia type II in which FGFR3(K650E) expression was directed to the appendicular skeleton, we show that the mutant receptor caused a block in chondrocyte differentiation specifically at the prehypertrophic stage. The differentiation block led to a severe reduction in hypertrophic chondrocytes that normally produce vascular endothelial growth factor, which in turn was associated with poor vascularization of primary ossification centers and disrupted endochondral ossification. We show that the differentiation block and defects in joint formation are associated with persistent expression of the chondrogenic factor Sox9 and down-regulation of β-catenin levels and activity in growth plate chondrocytes. Consistent with these in vivo results, FGFR3(K650E) expression was found to increase Sox9 and decrease β-catenin levels and transcriptional activity in cultured mesenchymal cells. Coexpression of Fgfr3(K650E) and Sox9 in cells resulted in very high levels of Sox9 and cooperative suppression of β-catenin-dependent transcription. Fgfr3(K650E) had opposing effects on Sox9 and β-catenin protein stability with it promoting Sox9 stabilization and β-catenin degradation. Since both Sox9 overexpression and β-catenin deletion independently blocks hypertrophic differentiation of chondrocytes and cause chondrodysplasias similar to those caused by mutations in FGFR3, our results suggest that dysregulation of Sox9 and β-catenin levels and activity in growth plate chondrocytes is an important underlying mechanism in skeletal diseases caused by mutations in FGFR3.
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Affiliation(s)
- Chia-Yi Shung
- Shriners Hospitals for Children Portland, Portland, OR 97239, USA
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