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Naeem A, Harish V, Coste S, Parasido EM, Choudhry MU, Kromer LF, Ihemelandu C, Petricoin EF, Pierobon M, Noon MS, Yenugonda VM, Avantaggiati M, Kupfer GM, Fricke S, Rodriguez O, Albanese C. Regulation of Chemosensitivity in Human Medulloblastoma Cells by p53 and the PI3 Kinase Signaling Pathway. Mol Cancer Res 2022; 20:114-126. [PMID: 34635507 PMCID: PMC8738155 DOI: 10.1158/1541-7786.mcr-21-0277] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/06/2021] [Accepted: 10/04/2021] [Indexed: 01/07/2023]
Abstract
In medulloblastoma, p53 expression has been associated with chemoresistance and radiation resistance and with poor long-term outcomes in the p53-mutated sonic hedgehog, MYC-p53, and p53-positive medulloblastoma subgroups. We previously established a direct role for p53 in supporting drug resistance in medulloblastoma cells with high basal protein expression levels (D556 and DAOY). We now show that p53 genetic suppression in medulloblastoma cells with low basal p53 protein expression levels (D283 and UW228) significantly reduced drug responsiveness, suggesting opposing roles for low p53 protein expression levels. Mechanistically, the enhanced cell death by p53 knockdown in high-p53 cells was associated with an induction of mTOR/PI3K signaling. Both mTOR inhibition and p110α/PIK3CA induction confirmed these findings, which abrogated or accentuated the enhanced chemosensitivity response in D556 cells respectively while converse was seen in D283 cells. Co-treatment with G-actin-sequestering peptide, thymosin β4 (Tβ4), induced p-AKTS473 in both p53-high and p53-low cells, enhancing chemosensitivity in D556 cells while enhancing chemoresistance in D283 and UW228 cells. IMPLICATIONS: Collectively, we identified an unexpected role for the PI3K signaling in enhancing cell death in medulloblastoma cells with high basal p53 expression. These studies indicate that levels of p53 immunopositivity may serve as a diagnostic marker of chemotherapy resistance and for defining therapeutic targeting.
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Affiliation(s)
- Aisha Naeem
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC.,Health Research Governance Department, Ministry of Public Health, Doha, Qatar
| | - Varsha Harish
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Sophie Coste
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Erika M. Parasido
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Muhammad Umer Choudhry
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Lawrence F. Kromer
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC
| | - Chukuemeka Ihemelandu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Emanuel F. Petricoin
- George Mason University, Center for Applied Proteomics and Molecular Medicine, Manassas, Virginia
| | - Mariaelena Pierobon
- George Mason University, Center for Applied Proteomics and Molecular Medicine, Manassas, Virginia
| | | | | | - Maria Avantaggiati
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Gary M. Kupfer
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC.,Department of Pediatrics, Georgetown University Medical Center, Washington, DC
| | - Stanley Fricke
- Department of Radiology, Georgetown University Medical Center, Washington, DC.,Center for Translational Imaging, Georgetown University Medical Center, Washington, DC
| | - Olga Rodriguez
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC.,Center for Translational Imaging, Georgetown University Medical Center, Washington, DC
| | - Chris Albanese
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC.,Department of Radiology, Georgetown University Medical Center, Washington, DC.,Center for Translational Imaging, Georgetown University Medical Center, Washington, DC.,Corresponding Author: Chris Albanese, Department of OncologyGeorgetown University Medical Center, Lombardi Cancer Center, NRB W417, Washington, DC 20007. Phone: 202-687-3305; E-mail:
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2
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Valencia-Cervantes J, Huerta-Yepez S, Aquino-Jarquín G, Rodríguez-Enríquez S, Martínez-Fong D, Arias-Montaño JA, Dávila-Borja VM. Hypoxia increases chemoresistance in human medulloblastoma DAOY cells via hypoxia‑inducible factor 1α‑mediated downregulation of the CYP2B6, CYP3A4 and CYP3A5 enzymes and inhibition of cell proliferation. Oncol Rep 2018; 41:178-190. [PMID: 30320358 PMCID: PMC6278548 DOI: 10.3892/or.2018.6790] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 09/17/2018] [Indexed: 02/06/2023] Open
Abstract
Medulloblastomas are among the most frequently diagnosed pediatric solid tumors, and drug resistance remains as the principal cause of treatment failure. Hypoxia and the subsequent activation of hypoxia-inducible factor 1α (HIF-1α) are considered key factors in modulating drug antitumor effectiveness, but the underlying mechanisms in medulloblastomas have not yet been clearly understood. The aim of the present study was to determine whether hypoxia induces resistance to cyclophosphamide (CPA) and ifosfamide (IFA) in DAOY medulloblastoma cells, whether the mechanism is dependent on HIF-1α, and whether involves the modulation of the expression of cytochromes P450 (CYP)2B6, 3A4 and 3A5 and the control of cell proliferation. Monolayer cultures of DAOY medulloblastoma cells were exposed for 24 h to moderate (1% O2) or severe (0.1% O2) hypoxia, and protein expression was evaluated by immunoblotting. Cytotoxicity was studied with the MTT assay and by Annexin V/PI staining and flow cytometry. Cell proliferation was determined by the trypan-blue exclusion assay and cell cycle by propidium iodide staining and flow cytometry. Hypoxia decreased CPA and IFA cytotoxicity in medulloblastoma cells, which correlated with a reduction in the protein levels of CYP2B6, CYP3A4 and CYP3A5 and inhibition of cell proliferation. These responses were dependent on hypoxia-induced HIF-1α activation, as evidenced by chemical inhibition of its transcriptional activity with 2-methoxyestradiol (2-ME), which enhanced the cytotoxic activity of CPA and IFA and increased apoptosis. Our results indicate that by stimulating HIF-1α activity, hypoxia downregulates the expression of CYP2B6, CYP3A4 and CYP3A5, that in turn leads to decreased conversion of CPA and IFA into their active forms and thus to diminished cytotoxicity. These results support that the combination of HIF-1α inhibitors and canonical antineoplastic agents provides a potential therapeutic alternative against medulloblastoma.
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Affiliation(s)
- Jesús Valencia-Cervantes
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico
| | - Sara Huerta-Yepez
- Oncology Disease Research Unit, Children's Hospital of Mexico 'Federico Gomez', Mexico City 06720, Mexico
| | - Guillermo Aquino-Jarquín
- Laboratory of Research on Genomics, Genetics and Bioinformatics, Haemato‑Oncology Building, Children's Hospital of Mexico 'Federico Gomez', Mexico City 06720, Mexico
| | - Sara Rodríguez-Enríquez
- Department of Biochemistry,National Institute of Cardiology 'Ignacio Chavez', Mexico City 14080, Mexico
| | - Daniel Martínez-Fong
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico
| | - José-Antonio Arias-Montaño
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico
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Hatton BA, Ellison DW, Gajjar A, Kool M, Fero M, Olson JM. Prognostic value and functional consequences of cell cycle inhibitor p27Kip1 loss in medulloblastoma. Biomark Res 2013; 1:14. [PMID: 24252239 PMCID: PMC4177552 DOI: 10.1186/2050-7771-1-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/17/2013] [Indexed: 11/28/2022] Open
Abstract
Background The cyclin-dependent kinase inhibitor p27Kip1 functions during normal cerebellar development and has demonstrated tumor suppressor functions in mouse models of medulloblastoma. Because P27 loss is associated with increased proliferation, we assessed whether P27 absence in surgical medulloblastoma specimens correlated with response to therapy in pediatric patients enrolled in two large studies. Additionally, we examined the functional consequence of p27Kip1 loss in the SmoA1 medulloblastoma model to distinguish whether p27Kip1 reduces tumor initiation or slows tumor progression. Findings Analysis of 87 well-characterized patient samples identified a threshold of P27 staining at which significant P27 loss correlated with poor patient outcome. The same criteria, applied to a second test set of tissues from 141 patients showed no difference in survival between patients with minimal P27 staining and others, suggesting that P27 levels alone are not a sufficient prognostic indicator for identifying standard-risk patients that may fail standard therapy. These findings were in contrast to prior experiments completed using a mouse medulloblastoma model. Analysis of cerebellar tumor incidence in compound mutant mice carrying the activated Smoothened (SmoA1) allele that were heterozygous or nullizygous for p27Kip1 revealed that p27Kip1 loss did not alter the frequency of tumor initiation. Tumors haploinsufficient or nullizygous for p27Kip1 were, however, more invasive and displayed a higher proliferative index, suggesting p27Kip1 loss may contribute to SmoA1 medulloblastoma progression. Conclusions These studies revealed P27 loss affects medulloblastoma progression rather than initiation and that this putative biomarker should not be used for stratifying children with medulloblastoma to risk-based therapeutic regimens.
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Affiliation(s)
- Beryl A Hatton
- Clinical Research Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Mailstop D4-100, PO Box 19024, Seattle, WA 98109, USA.
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4
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Moschovi M, Alexiou GA, Patereli A, Siozos G, Sfakianos G, Prodromou N, Stefanaki K. Immunohistochemical expression of cell-cycle regulators in pediatric embryonal brain tumors. J Neurooncol 2012; 109:529-34. [PMID: 22763761 DOI: 10.1007/s11060-012-0920-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 06/19/2012] [Indexed: 11/30/2022]
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Moschovi M, Koultouki E, Stefanaki K, Sfakianos G, Tourkantoni N, Prodromou N, Alexiou GA. Prognostic significance of angiogenesis in relation to Ki-67, p-53, p-27, and bcl-2 expression in embryonal tumors. Pediatr Neurosurg 2011; 47:241-7. [PMID: 22309998 DOI: 10.1159/000335398] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 11/24/2011] [Indexed: 02/02/2023]
Abstract
AIM We investigated the angiogenesis and density of newly formed blood vessels in embryonal tumors in relation to Ki-67, bcl-2, p-53 and p-27 expression. METHODS Forty-five children with embryonal tumors were enrolled in the study. Forty patients had a medulloblastoma (MB) and 5 patients had atypical teratoid/rhabdoid tumor (AT/RT). RESULTS In MB, the 5-year PFS and OS was 62.5 and 70%, respectively. Patients with Ki-67 index >50%, bcl-2 index >30% and higher density of new vessels were associated with worse survival. In the multivariate analysis, Ki-67 index was identified as a factor with independent prognostic power. In AT/RTs, high density of new vessels (>25 HRF) was observed in 3 patients and Ki-67 index over 25% was found in 4 patients. CONCLUSION Increased Ki-67, bcl-2 and density of new vessels are of prognostic value for the disease outcome in MB.
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Affiliation(s)
- Maria Moschovi
- Hematology-Oncology Unit, First Department of Pediatrics, University of Athens, Athens, Greece
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6
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Geng Y, Walls KC, Ghosh AP, Akhtar RS, Klocke BJ, Roth KA. Cytoplasmic p53 and activated Bax regulate p53-dependent, transcription-independent neural precursor cell apoptosis. J Histochem Cytochem 2009; 58:265-75. [PMID: 19901272 DOI: 10.1369/jhc.2009.954024] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The prodeath effects of p53 are typically mediated via its transcriptional upregulation of proapoptotic Bcl-2 family members, including PUMA, Noxa, and/or Bax. We previously reported that staurosporine (STS), a broad-spectrum kinase inhibitor and prototypical apoptosis-inducing agent, produced p53-dependent, Bax-dependent, neural precursor cell (NPC) apoptosis, but that this effect occurred independently of new gene transcription and PUMA expression. To further characterize the mechanism by which p53 regulates NPC death, we used primary cerebellar NPCs derived from wild-type, p53-deficient, and Bax-deficient neonatal mice and the mouse cerebellar neural stem cell line, C17.2. We found that STS rapidly increased p53 cytoplasmic immunoreactivity in neuritic-like processes in C17.2 cells, which preceded Bax activation and caspase-3 cleavage. Confocal microscopy analysis of STS-treated cells revealed partial colocalization of p53 with the mitochondrial marker pyruvate dehydrogenase as well as with conformationally altered "activated" Bax, suggesting an interaction between these proapoptotic molecules in triggering apoptotic death. Nucleophosmin (NPM), a CRM1-dependent nuclear chaperone, also exhibited partial colocalization with both activated Bax and p53 following STS treatment. These observations suggest that cytoplasmic p53 can trigger transcription-independent NPC apoptosis through its potential interaction with NPM and activated Bax.
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Affiliation(s)
- Ying Geng
- Department of Pathology, University of Alabama at Birmingham, USA
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7
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Pellegata NS, Quintanilla-Martinez L, Keller G, Liyanarachchi S, Höfler H, Atkinson MJ, Fend F. Human pheochromocytomas show reduced p27Kip1 expression that is not associated with somatic gene mutations and rarely with deletions. Virchows Arch 2007; 451:37-46. [PMID: 17554557 DOI: 10.1007/s00428-007-0431-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 05/03/2007] [Accepted: 05/03/2007] [Indexed: 01/24/2023]
Abstract
Pheochromocytomas are neuroendocrine tumors arising in the neural crest-derived chromaffin cells of the adrenal gland or in extra-adrenal sympathetic ganglia (paragangliomas). In a rat model of multiple endocrine neoplasia (MEN), absence of functional p27Kip1 protein predisposes to pheochromocytoma and paraganglioma development. As no data is available regarding the involvement of p27Kip1 in human pheochromocytoma and/or paraganglioma, we set out to determine the expression pattern of p27Kip1 in those tumor types. A panel of 25 pheochromocytomas and 23 paragangliomas was collected. Two pheochromocytomas were from MEN2 patients. The paragangliomas included 15 tumors that developed at the carotid bifurcation, three in the jugulo-tympanic area, and five at other sites. Except for the MEN2 cases, all others were apparently sporadic. Immunohistochemistry for p27Kip1 and the proliferation marker Ki67 was performed. We found that p27Kip1 expression is reduced/lost in 56% of pheochromocytomas, but only in 18.1% of paragangliomas. Downregulation of p27Kip1 was not associated with increased proliferation. Cases showing reduced/lost p27Kip1 expression were screened for the presence of somatic mutations in CDKN1B (p27Kip1) and for allelic imbalance at the p27Kip1 locus. Three cases had allelic imbalance but none had mutations. In conclusion, pheochromocytomas display extreme reduction/loss of p27Kip1 expression at high frequency.
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Affiliation(s)
- Natalia S Pellegata
- Institute of Pathology, GSF-National Research Center for Environment and Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.
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8
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Adesina AM, Nguyen Y, Mehta V, Takei H, Stangeby P, Crabtree S, Chintagumpala M, Gumerlock MK. FOXG1 dysregulation is a frequent event in medulloblastoma. J Neurooncol 2007; 85:111-22. [PMID: 17522785 DOI: 10.1007/s11060-007-9394-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 04/17/2007] [Indexed: 01/10/2023]
Abstract
Medulloblastomas represent 20% of malignant brain tumors of childhood. Although, they show multiple, non-random genomic alterations, no common, early genetic event involving all histologic types of medulloblastomas have been described. Nineteen medulloblastomas were analyzed using chromosomal comparative genomic hybridization (cCGH). Nine tumors with the most frequent number of genetic changes were further analyzed using bacterial artificial chromosome array CGH (aCGH). With aCGH, the frequency of gains and losses were higher than with cCGH. Chromosome 2p gains spanning 2p11-2p25 including N-myc locus, 2p24.1 were detected in 5/9 (55%) tumors while 14q12 gains were detected in 6/9 (67%) tumors. The 14q12 locus overlapped with the FOXGI gene locus. Quantitative real time PCR showed a 2-7-fold copy gain for FOXG1 in all the nine tumors. Protein expression was demonstrated by immunohistochemistry in all histologic types. The expression of FOXG1 and p21cip1 showed an inverse relationship. FOXG1 copy gain (>2 to 21 folds) was seen in 93% (55/59) of a validating set of tumors and showed a positive correlation with protein expression (Spearman's rank order correlation coefficient = 0.276; P = 0.038) representing the first report of FOXG1 dysregulation in medulloblastoma. Modulation of FOXG1 expression in DAOY cell line using siRNA showed a modest decrease in proliferation with a 2-fold upregulation of p21cip1. Current reports indicate that FOXG1 represses TGF-beta induced expression of p21cip1 and cytostasis, and forms a transcriptional repressor complex with Notch signaling induced hes1. Our findings are consistent with a role for FOXG1 in the inhibition of TGF-beta induced cytostasis in medulloblastoma.
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Affiliation(s)
- Adekunle M Adesina
- Department of Pathology, Texas Children's Cancer Center, Baylor College of Medicine, One Baylor Plaza, Rm. 286A, Houston, TX 77030, USA.
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Abstract
Central nervous system (CNS) neoplasms can be diagnostically challenging, due to remarkably wide ranges in histologic appearance, biologic behavior, and therapeutic approach. Nevertheless, accurate diagnosis is the critical first step in providing optimal patient care. As with other oncology-based specialties, there is a rapidly expanding interest and enthusiasm for identifying and utilizing new biomarkers to enhance the day-to-day practice of surgical neuropathology. In this regard, the field is primed by recent advances in basic research, elucidating the molecular mechanisms of tumorigenesis and progression in the most common adult and pediatric brain tumors. Thus far, few have made the transition into routine clinical practice, the most notable example being 1p and 19q testing in oligodendroglial tumors. However, the field is rapidly evolving and many other biomarkers are likely to emerge as useful ancillary diagnostic, prognostic, or therapeutic aids. The goal of this article is to highlight the most common genetic alterations currently implicated in CNS tumors, focusing most on those that are either already in common use in ancillary molecular diagnostics testing or are likely to become so in the near future.
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Affiliation(s)
- Christine E Fuller
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN 38105, and Division of Neuropathology, Washington University School of Medicine, St. Louis, MO, USA.
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Rickert CH, Paulus W. Prognosis-related histomorphological and immunohistochemical markers in central nervous system tumors of childhood and adolescence. Acta Neuropathol 2005; 109:69-92. [PMID: 15647946 DOI: 10.1007/s00401-004-0959-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Accepted: 10/11/2004] [Indexed: 10/26/2022]
Abstract
Brain tumors account for approximately 20% of all childhood cancers, and are the leading cause of cancer morbidity and mortality among children. Although numerous demographic, clinical and therapeutic parameters have been identified over the past few years that have significant prognostic bearing for some pediatric brain tumors, predicting the clinical course and outcome among children with central nervous system tumors is still difficult. A survey of publications on prognosis-related histopathological and immunohistochemical features among pediatric brain tumors revealed 172 series, of which 91 presented statistically significant outcome-associated parameters as defined by a P value of less than 0.05. Most investigations revealing significant prognosis-related markers were performed on medulloblastomas (30 publications), ependymomas (25) and astrocytic tumors (18). In total, 16 cohorts consisted of more than 100 cases (5 on ependymomas, 3 each on medulloblastomas and astrocytic tumors). On the other hand, there were also 13 series with fewer than 20 cases (5 on medulloblastomas). Potentially prognostic histopathological markers vary among different entities and consist of assessment of necroses, mitoses, differentiation, vascular proliferation, and growth pattern, whereas immunohistochemical features include proliferation markers (Ki-67, MIB-1), expression of oncogenes/tumor suppressor genes and their proteins (TP53, c-erbB2), growth factor and hormonal receptors (VEGF, EGFR, HER2, HER4, ErbB-2), cell cycle genes (p27, p14ARF) and cell adhesion molecules, as well as factors potentially related to therapeutic resistance (DNA topoisomerase IIalpha, metallothionein, P-glycoprotein, tenascin). This review discusses the prognostic potential of histopathological and immunohistochemical markers that can be investigated by the practicing neuropathologist as part of the routine diagnostic workload, and scrutinizes their benefit for predicting therapy response and patient outcome among children with brain tumors.
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Rickert CH. Prognosis-Related Molecular Markers in Pediatric Central Nervous System Tumors. J Neuropathol Exp Neurol 2004; 63:1211-24. [PMID: 15624758 DOI: 10.1093/jnen/63.12.1211] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In the wake of recent progress in understanding the genetic pathways involved in the development of brain tumors, a major goal is to correlate molecular data with clinical outcome, survival, and response to treatment modalities. This is of particular importance among the pediatric population. Reliable prognostic factors could potentially permit a tailoring of therapy in that only patients with the most aggressive tumors would receive the most intense treatments. A survey of publications about prognosis-related molecular features among pediatric brain tumors revealed 74 series, of which 46 presented statistically significant outcome-associated parameters as defined by a p value <0.05. Most investigations revealing significant prognosis-related features were performed on medulloblastomas (34 publications), followed by astrocytic tumors (6 publications) and ependymomas (5 publications). Promising approaches and molecular markers include gene expression profiles, DNA ploidy, loss of heterozygosity and chromosomal aberrations as detected by CGH and FISH (1q, 17p, 17q), as well as oncogenes/ tumor suppressor genes and their proteins (TP53, PTEN, c-erbB2, N-myc, c-myc), growth factor and hormonal receptors (PDGFRA, VEGF, EGFR, HER2, HER4, ErbB-2, hTERT, TrkC), cell cycle genes (p27) and cell adhesion molecules, as well as factors potentially related to therapeutic resistance (multi-drug resistance, DNA topoisomerase IIalpha, metallothionein, P-glycoprotein, tenascin). This review discusses the predictive potential of molecular markers for clinical outcome and their influence on therapeutic decision-making among children with brain tumors.
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Affiliation(s)
- Christian H Rickert
- Institute of Neuropathology, Department of Pediatric Hematology and Oncology, Münster University Hospital, Germany.
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Ellison D. Classifying the medulloblastoma: insights from morphology and molecular genetics. Neuropathol Appl Neurobiol 2002; 28:257-82. [PMID: 12175339 DOI: 10.1046/j.1365-2990.2002.00419.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Significant advances in the treatment of the medulloblastoma (MB) have been made in the last 30 years, reducing mortality by 2-fold. Further improvements in the cure rate require an increased understanding of the biology of MBs, and this will translate into refinements in their classification. Scrutiny of the cytological variation found among MBs has recently led to the concept of the anaplastic MB, which overlaps the large-cell variant and appears to share its poor prognosis. In contrast, the MB with extensive nodularity, a distinctive nodular/desmoplastic variant occurring in infants, has a better outcome than most MBs in these young patients. Building on cytogenetic studies that have drawn attention to abnormalities on chromosome 17 in over a third of MBs, research shows non-random losses on chromosomes 8, 9, 10, 11 and 16, and gains on chromosomes 1, 7 and 9. Overexpression of ErbB2 receptors and losses on chromosome 17p have been proposed as independent indicators of aggressive behaviour, while high TrkC receptor expression indicates a favourable outcome. There is a strong association between anaplastic/large-cell tumours and MYC amplification, which has previously been linked with aggressive disease, but associations between abnormalities on chromosome 17 and anaplastic/large-cell MBs and between abnormalities in the shh/PTCH pathway and the desmoplastic variant are more controversial. Classification of the MB histopathologically and according to profiles of molecular abnormalities will help both to rationalize approaches to therapy, increasing the cure rate and reducing long-term side-effects, and to suggest novel treatments.
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Affiliation(s)
- D Ellison
- Northern Institute for Cancer Research, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne, UK.
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Korshunov A, Savostikova M, Ozerov S. Immunohistochemical markers for prognosis of average-risk pediatric medulloblastomas. The effect of apoptotic index, TrkC, and c-myc expression. J Neurooncol 2002; 58:271-9. [PMID: 12187960 DOI: 10.1023/a:1016226319068] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Medulloblastomas (MB) are the most common central nervous system malignancies in children. Numerous publications describe certain efforts to identify predictive value of various patterns of MB pathology and immunohistochemistry but received data appear to be controversial. In the present study, the apoptotic index (AI) and immunoexpression of TrkC, and c-myc proteins were investigated in biopsy samples from 68 MB with an average clinical risk to determine their prognostic utility in this tumor category. The number of cases with AI > 1.5% was significantly greater in the group of tumors in patients with recurrent MB and the mean AI was significantly higher in this group -4.7% vs. 1.1%. Furthermore, the number of tumors with AI > 1.5% was greater in the group of tumors in deceased patients and the mean Al was also higher in this group -4.6% vs. 1.2%. Immunoreactivity of the c-myc and TrkC did not show any differences between groups of patients with various clinical outcomes. A close association between Al as a continuous variable and the progression-free and overall survival was found. We found no any differences in survival times for c-myc and TrkC immunoreactivity. Multivariate revealed analysis that AI is a single significant prognostic factor for MB survival. Perhaps, investigations of c-myc and TrkC mRNA levels should be useful for clinical purposes, but in order to introduce these biomolecular markers in clinical protocols its distinct prognostic significance needs to be proved by prospective studies.
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Affiliation(s)
- Andrey Korshunov
- Department of Neuropathology, Neurosurgical NN Burdenko Institute, Moscow, Russia.
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Eberhart CG, Kaufman WE, Tihan T, Burger PC. Apoptosis, neuronal maturation, and neurotrophin expression within medulloblastoma nodules. J Neuropathol Exp Neurol 2001; 60:462-9. [PMID: 11379821 DOI: 10.1093/jnen/60.5.462] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Nodular/desmoplastic medulloblastomas are a well-established histopathological subtype containing reticulin-free nodules or "pale islands' that are comprised of cells with round "neurocytic" nuclei and abundant cytoplasm. Significant neuronal maturation occurs within nodules. We used immunohistochemistry to evaluate neuronal differentiation in the nodules of 6 of these tumors. The neuronal markers NeuN, synaptophysin, and MAP-2 were identified in the "pale islands" of all 6 nodular medulloblastomas examined, and high and medium molecular weight nonphosphorylated neurofilaments were detected in 2 of the 6 cases. We also observed collections of apoptotic cells within nodules. Given the known role of neurotrophin signaling in neuronal maturation and apoptosis, we analyzed immunohistochemically the distribution of neurotrophin receptors TrkA and TrkC and their primary ligands NGF and NT3 in 14 nodular medulloblastomas. TrkA and TrkC were detected in 13 and 10 cases, respectively, and were predominantly localized within nodules. NGF and NT3 were distributed diffusely with some nodular accentuation. The localized expression of Trk receptors within nodules of desmoplastic medulloblastomas suggests neurotrophin signaling is involved in the apoptosis and neuronal differentiation in medulloblastomas. We also examined expression of p53 and BCL-2 in these tumors; both were prominent in internodular regions but only weakly expressed within nodules. Trk receptors, p53, and BCL-2 are all expressed during development of the normal cerebellum. Interestingly, the immunohistochemical expression profile of these proteins in the differentiating nodules of medulloblastomas is in many ways similar to their expression in the developing cerebellum. Thus similar signaling pathways may be operational in cerebellar development and medulloblastoma tumor differentiation.
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Affiliation(s)
- C G Eberhart
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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