MYBL1

Gene Summary

Gene:MYBL1; MYB proto-oncogene like 1
Aliases: AMYB, A-MYB
Location:8q13.1
Summary:-
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:myb-related protein A
Source:NCBIAccessed: 15 March, 2017

Ontology:

What does this gene/protein do?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 15 March 2017 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 15 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: MYBL1 (cancer-related)

Zamani-Ahmadmahmudi M, Aghasharif S, Ilbeigi K
Prognostic efficacy of the human B-cell lymphoma prognostic genes in predicting disease-free survival (DFS) in the canine counterpart.
BMC Vet Res. 2017; 13(1):17 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Canine B-cell lymphoma is deemed an ideal model of human non-Hodgkin's lymphoma where the lymphomas of both species share similar clinical features and biological behaviors. However there are some differences between tumor features in both species. In the current study, we sought to evaluate the prognostic efficacy of human B-cell lymphoma prognostic gene signatures in canine B-cell lymphoma.
METHODS: The corresponding probe sets of 36 human B-cell lymphoma prognostic genes were retrieved from 2 canine B-cell lymphoma microarray datasets (GSE43664 and GSE39365) (76 samples), and prognostic probe sets were thereafter detected using the univariate and multivariate Cox proportional-hazard model and the Kaplan-Meier analysis. The two datasets were employed both as training sets and as external validation sets for each other. Results were confirmed using quantitative real-time PCR (qRT-PCR) analysis.
RESULTS: In the univariate analysis, CCND1, CCND2, PAX5, CR2, LMO2, HLA-DQA1, P53, CD38, MYC-N, MYBL1, and BIRCS5 were associated with longer disease-free survival (DFS), while CD44, PLAU, and FN1 were allied to shorter DFS. However, the multivariate Cox proportional-hazard analysis confirmed CCND1 and BIRCS5 as prognostic genes for canine B-cell lymphoma. qRT-PCR used for verification of results indicated that expression level of CCND1 was significantly higher in B-cell lymphoma patients with the long DFS than ones with the short DFS, while expression level of BIRCS5 wasn't significantly different between two groups.
CONCLUSION: Our results confirmed CCND1 as important gene that can be used as a potential predictor in this tumor type.

Pinto A, Howitt B
Uterine Adenosarcoma.
Arch Pathol Lab Med. 2016; 140(3):286-90 [PubMed] Related Publications
Müllerian adenosarcoma is an uncommon biphasic tumor composed of malignant stromal and benign epithelial components. Morphologically, adenosarcoma is characterized by a broad leaflike architecture, reminiscent of phyllodes tumors of the breast. Periglandular cuffing of the stromal cells around the compressed or cystically dilated glands is characteristic. The mesenchymal component is typically a low-grade spindle cell sarcoma, whereas the epithelial counterpart is commonly endometrioid with frequent squamous or mucinous metaplasia and may, in some circumstances, show mild to moderate atypia. In all cases, it is important to assess for the presence of sarcomatous overgrowth and myometrial invasion, which are the prognostic factors. In this brief review, we present the clinical, histopathologic, and immunohistochemical features of adenosarcoma, as well as updates on the molecular biology of this neoplasm.

Zhao S, Dong X, Shen W, et al.
Machine learning-based classification of diffuse large B-cell lymphoma patients by eight gene expression profiles.
Cancer Med. 2016; 5(5):837-52 [PubMed] Free Access to Full Article Related Publications
Gene expression profiling (GEP) had divided the diffuse large B-cell lymphoma (DLBCL) into molecular subgroups: germinal center B-cell like (GCB), activated B-cell like (ABC), and unclassified (UC) subtype. However, this classification with prognostic significance was not applied into clinical practice since there were more than 1000 genes to detect and interpreting was difficult. To classify cancer samples validly, eight significant genes (MYBL1, LMO2, BCL6, MME, IRF4, NFKBIZ, PDE4B, and SLA) were selected in 414 patients treated with CHOP/R-CHOP chemotherapy from Gene Expression Omnibus (GEO) data sets. Cutoffs for each gene were obtained using receiver-operating characteristic curves (ROC) new model based on the support vector machine (SVM) estimated the probability of membership into one of two subgroups: GCB and Non-GCB (ABC and UC). Furtherly, multivariate analysis validated the model in another two cohorts including 855 cases in all. As a result, patients in the training and validated cohorts were stratified into two subgroups with 94.0%, 91.0%, and 94.4% concordance with GEP, respectively. Patients with Non-GCB subtype had significantly poorer outcomes than that with GCB subtype, which agreed with the prognostic power of GEP classification. Moreover, the similar prognosis received in the low (0-2) and high (3-5) IPI scores group demonstrated that the new model was independent of IPI as well as GEP method. In conclusion, our new model could stratify DLBCL patients with CHOP/R-CHOP regimen matching GEP subtypes effectively.

Gonda TJ, Ramsay RG
Adenoid Cystic Carcinoma Can Be Driven by MYB or MYBL1 Rearrangements: New Insights into MYB and Tumor Biology.
Cancer Discov. 2016; 6(2):125-7 [PubMed] Related Publications
A majority of adenoid cystic carcinomas (AdCC)-rare tumors of the salivary gland and some other organs-have recently been found to be driven by chromosomal translocations resulting in MYB-NFIB fusions. Brayer and colleagues and Mitani and colleagues have now reported that AdCCs can alternatively be driven by similar rearrangements involving a second MYB family gene, MYBL1, and that these two drivers act in remarkably similar ways.

Argyris PP, Wetzel SL, Greipp P, et al.
Clinical utility of myb rearrangement detection and p63/p40 immunophenotyping in the diagnosis of adenoid cystic carcinoma of minor salivary glands: a pilot study.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2016; 121(3):282-9 [PubMed] Related Publications
OBJECTIVES: MYB rearrangement is observed in approximately 28% to 86% of adenoid cystic carcinomas (ACCs). Also, ACC features a p63+/p40+ immunophenotype in greater than 90% of cases, compared with p63+/p40- polymorphous low-grade adenocarcinoma (PLGA). Our aim was to investigate the incidence of (1) MYB rearrangement and (2) p63/p40 immunoreactivity in ACC and PLGA of minor salivary glands (MSGs).
STUDY DESIGN: Seven cases of ACC as well as five of PLGA were evaluated by using a MYB (6 q23.3) break-apart fluorescence in situ hybridization (FISH) probe. In addition, all cases were immunohistochemically stained with p63 and p40 antibodies.
RESULTS: All five successfully hybridized ACCs featured MYB rearrangement, whereas PLGAs did not show MYB rearrangement. Interestingly, one case of PLGA demonstrated a single intact copy of MYB in greater than 88% of the neoplastic cells. All ACCs exhibited consistent p63+/p40+ staining, whereas PLGAs demonstrated a p63+/p40- immunophenotype.
CONCLUSIONS: (1) MYB rearrangement is encountered in ACCs but not PLGAs of MSGs; (2) MYB aberrations, for example, monosomy or deletion, can be seen in PLGAs; (3) combined p63/p40 immunostaining can be used to differentiate ACC from PLGA in incisionally biopsied specimens; and (4) performance of either FISH or p63/p40 immunohistochemistry is expected to be able to confirm the diagnosis of ACC or PLGA in small intraoral biopsies, since both techniques appeared to be diagnostically accurate in this pilot study.

Mitani Y, Liu B, Rao PH, et al.
Novel MYBL1 Gene Rearrangements with Recurrent MYBL1-NFIB Fusions in Salivary Adenoid Cystic Carcinomas Lacking t(6;9) Translocations.
Clin Cancer Res. 2016; 22(3):725-33 [PubMed] Free Access to Full Article Related Publications
PURPOSE: Adenoid cystic carcinoma (ACC) is an indolent salivary gland malignancy, characterized by t(6;9) translocations and MYB-NFIB gene fusions in approximately 50% of the tumors. The genetic alterations underlying t(6;9)-negative and t(6;9)-positive/MYB-NFIB fusion-negative ACC remain unknown. To uncover the genetic alterations in ACC lacking the canonical translocation and fusion transcript and identify new abnormalities in translocation positive tumors.
EXPERIMENTAL DESIGN: We performed whole-genome sequencing in 21 salivary ACCs and conducted targeted molecular analyses in a validation set (81 patients). Microarray gene-expression data were also analyzed to explore the biologic differences between fusion positive and negative tumors.
RESULTS: We identified a novel MYBL1-NFIB gene fusion as a result of t(8;9) translocation and multiple rearrangements in the MYBL1 gene in 35% of the t(6;9)-negative ACCs. All MYBL1 alterations involved deletion of the C-terminal negative regulatory domain and were associated with high MYBL1 expression. Reciprocal MYB and MYBL1 expression was consistently found in ACCs. In addition, 5'-NFIB fusions that did not involve MYB/MYBL1 genes were identified in a subset of t(6;9)-positive/fusion-negative tumors. We also delineated distinct gene-expression profiles in ACCs associated with the length of the MYB or MYBL1 fusions, suggesting a biologic importance of the C-terminal part of these fusions.
CONCLUSIONS: Our study defines new molecular subclasses of ACC characterized by MYBL1 rearrangements and 5'-NFIB gene fusions.

Brayer KJ, Frerich CA, Kang H, Ness SA
Recurrent Fusions in MYB and MYBL1 Define a Common, Transcription Factor-Driven Oncogenic Pathway in Salivary Gland Adenoid Cystic Carcinoma.
Cancer Discov. 2016; 6(2):176-87 [PubMed] Free Access to Full Article Related Publications
UNLABELLED: Adenoid cystic carcinoma (ACC), the second most common malignancy of salivary glands, is a rare tumor with a bleak prognosis for which therapeutic targets are unavailable. We used RNA sequencing (RNA-seq) to analyze low-quality RNA from archival, formaldehyde-fixed, paraffin-embedded samples. In addition to detecting the most common ACC translocation, t(6;9) fusing the MYB proto-oncogene to NFIB, we also detected previously unknown t(8;9) and t(8;14) translocations fusing the MYBL1 gene to the NFIB and RAD51B genes, respectively. RNA-seq provided information about gene fusions, alternative RNA splicing, and gene expression signatures. Interestingly, tumors with MYB and MYBL1 translocations displayed similar gene expression profiles, and the combined MYB and MYBL1 expression correlated with outcome, suggesting that the related MYB proteins are interchangeable oncogenic drivers in ACC. Our results provide important details about the biology of ACC and illustrate how archival tissue samples can be used for detailed molecular analyses of rare tumors.
SIGNIFICANCE: Using RNA-seq to perform whole-transcriptome analysis of archival ACC tumor samples, we identified novel, recurrent gene fusions, detected alternative RNA splicing, and established gene expression signatures that provide detailed information about the biology of ACC tumors.

Roden AC, Greipp PT, Knutson DL, et al.
Histopathologic and Cytogenetic Features of Pulmonary Adenoid Cystic Carcinoma.
J Thorac Oncol. 2015; 10(11):1570-5 [PubMed] Related Publications
INTRODUCTION: A significant portion of adenoid cystic carcinoma (ACC) cases are characterized by a t(6;9)(q22-23;p23-24) translocation that originates a MYB-NFIB fusion oncogene. The MYB-NFIB fusion oncoprotein activates transcription of MYB-mediated pathways that impact cell cycle control, DNA repair, and apoptosis. This translocation seems highly specific for ACC. Moreover, therapies targeting MYB-activated pathways to treat ACC are being explored. Pulmonary ACC (PACC) has not been thoroughly studied for rearrangements of the MYB gene.
METHODS: Mayo Clinic Rochester surgical pathology archives (1972-2011) were searched for PACC. All cases were reviewed and classified according to the predominant histologic pattern (cribriform, solid, and tubular) by two surgical pathologists. Fluorescence in situ hybridization (FISH) was employed using a break-apart strategy to detect MYB rearrangement (at 6q23.3). Medical records were studied.
RESULTS: Forty cases of PACC were studied; tissue blocks were available for FISH analysis in 35 cases. Six cases failed to hybridize. In 12 of 29 cases (41%), the MYB gene region was disrupted, whereas 17 cases (59%) showed no evidence of rearrangement. FISH studies performed on other histologic subtypes of lung cancer (10 squamous cell carcinomas, 10 adenocarcinomas, and 10 small-cell carcinomas) failed to show MYB rearrangement. There was no significant difference in MYB rearrangement status with respect to predominant histologic pattern, clinical features, or clinical outcome.
CONCLUSIONS: A MYB rearrangement was identified in 41% of PACC and was 100% specific. FISH studies for MYB may be of diagnostic utility in PACC, particularly on small biopsy specimens. MYB rearrangement in PACC does not seem to be associated with clinical features or prognosis.

Rettig EM, Tan M, Ling S, et al.
MYB rearrangement and clinicopathologic characteristics in head and neck adenoid cystic carcinoma.
Laryngoscope. 2015; 125(9):E292-9 [PubMed] Free Access to Full Article Related Publications
OBJECTIVES: Salivary gland adenoid cystic carcinoma (ACC) is rare, aggressive, and challenging to treat. Many ACCs have a t(6;9) chromosomal translocation resulting in a MYB-NFIB fusion gene, but the clinical significance is unclear. The purposes of this study were to describe the clinicopathologic factors impacting survival and to determine the prevalence and clinical significance of MYB-NFIB fusion.
STUDY DESIGN: Case series.
METHODS: Medical records of patients treated for ACC of the head and neck from 1974 to 2011 were reviewed and clinicopathologic data recorded. Fluorescence in situ hybridization (FISH) was used to detect MYB rearrangement in archival tumor tissue as a marker of MYB-NFIB fusion.
RESULTS: One hundred fifty-eight patients were included, with median follow-up 75.1 months. Median overall survival was 171.5 months (95% confidence interval [CI] = 131.9-191.6), and median disease-free survival was 112.0 months (95% CI = 88.7-180.4). Advanced stage was associated with decreased overall survival (adjusted ptrend  < 0.001), and positive margins were associated with decreased disease-free survival (adjusted hazard ratio [aHR] = 8.80, 95% CI = 1.25-62.12, P = 0.029). Ninety-one tumors were evaluable using FISH, and 59 (65%) had evidence of a MYB-NFIB fusion. MYB-NFIB positive tumors were more likely than MYB-NFIB negative tumors to originate in minor salivary glands (adjusted prevalence ratios = 1.51, 95% CI = 1.07-2.12, P = 0.019). MYB-NFIB tumor status was not significantly associated with disease-free or overall survival (hazard ratio [HR] = 1.53, 95% CI = 0.77-3.02, P = 0.22 and HR = 0.91, 95% CI = 0.46-1.83, P = 0.80, respectively, for MYB-NFIB positive compared with MYB-NFIB negative tumors).
CONCLUSION: Stage and margin status were important prognostic factors for ACC. Tumors with evidence of MYB-NFIB fusion were more likely to originate in minor salivary glands, but MYB-NFIB tumor status was not significantly associated with prognosis.
LEVEL OF EVIDENCE: 4.

Xu Q, Tan C, Ni S, et al.
Identification and validation of a two-gene expression index for subtype classification and prognosis in Diffuse Large B-Cell Lymphoma.
Sci Rep. 2015; 5:10006 [PubMed] Free Access to Full Article Related Publications
The division of diffuse large B-cell lymphoma (DLBCL) into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes based on gene expression profiling has proved to be a landmark in understanding the pathogenesis of the disease. This study aims to identify a novel biomarker to facilitate the translation of research into clinical practice. Using a training set of 350 patients, we identified a two-gene expression signature, "LIMD1-MYBL1 Index", which is significantly associated with cell-of-origin subtypes and clinical outcome. This two-gene index was further validated in two additional dataset. Tested against the gold standard method, the LIMD1-MYBL1 Index achieved 81% sensitivity, 89% specificity for ABC group and 81% sensitivity, 87% specificity for GCB group. The ABC group had significantly worse overall survival than the GCB group (hazard ratio = 3.5, P = 0.01). Furthermore, the performance of LIMD1-MYBL1 Index was satisfactory compared with common immunohistochemical algorithms. Thus, the LIMD1-MYBL1 Index had considerable clinical value for DLBCL subtype classification and prognosis. Our results might prompt the further development of this two-gene index to a simple assay amenable to routine clinical practice.

Ding J, Dirks WG, Ehrentraut S, et al.
BCL6--regulated by AhR/ARNT and wild-type MEF2B--drives expression of germinal center markers MYBL1 and LMO2.
Haematologica. 2015; 100(6):801-9 [PubMed] Free Access to Full Article Related Publications
Genetic heterogeneity is widespread in tumors, but poorly documented in cell lines. According to immunoglobulin hypermutation analysis, the diffuse large B-cell lymphoma cell line U-2932 comprises two subpopulations faithfully representing original tumor subclones. We set out to identify molecular causes underlying subclone-specific expression affecting 221 genes including surface markers and the germinal center oncogenes BCL6 and MYC. Genomic copy number variations explained 58/221 genes differentially expressed in the two U-2932 clones. Subclone-specific expression of the aryl-hydrocarbon receptor (AhR) and the resulting activity of the AhR/ARNT complex underlaid differential regulation of 11 genes including MEF2B. Knock-down and inhibitor experiments confirmed that AhR/ARNT regulates MEF2B, a key transcription factor for BCL6. AhR, MEF2B and BCL6 levels correlated not only in the U-2932 subclones but in the majority of 23 cell lines tested, indicting overexpression of AhR as a novel mechanism behind BCL6 diffuse large B-cell lymphoma. Enforced modulation of BCL6 affected 48/221 signature genes. Although BCL6 is known as a transcriptional repressor, 28 genes were up-regulated, including LMO2 and MYBL1 which, like BCL6, signify germinal center diffuse large B-cell lymphoma. Supporting the notion that BCL6 can induce gene expression, BCL6 and the majority of potential targets were co-regulated in a series of B-cell lines. In conclusion, genomic copy number aberrations, activation of AhR/ARNT, and overexpression of BCL6 are collectively responsible for differential expression of more than 100 genes in subclones of the U-2932 cell line. It is particularly interesting that BCL6 - regulated by AhR/ARNT and wild-type MEF2B - may drive expression of germinal center markers in diffuse large B-cell lymphoma.

Tao D, Pan Y, Lu H, et al.
B-myb is a gene implicated in cell cycle and proliferation of breast cancer.
Int J Clin Exp Pathol. 2014; 7(9):5819-27 [PubMed] Free Access to Full Article Related Publications
B-myb belongs to the myb family of transcription factors that include A-myb and c-myb. While A-myb and c-myb are tissue-specific, B-myb is broadly expressed in rapidly dividing cells of developing adult mammals. Results of our study showed that increased B-myb expression of was associated with the progression of breast cancer and that B-myb protein levels were significantly elevated in matched metastases. High B-myb levels also predict shorter overall survival of breast cancer patients. Moreover, B-myb stimulated transcription of target genes that promoted entry into the S and M-phases of the cell cycle, cell proliferation, migration and invasion in breast cancer. Taken together, our results strongly demonstrated that B-myb had a critical role in both cell cycle progression and tumorigenesis, and might serve as a novel potential target in the diagnosis and/or treatment of human breast cancer.

Howitt BE, Sholl LM, Dal Cin P, et al.
Targeted genomic analysis of Müllerian adenosarcoma.
J Pathol. 2015; 235(1):37-49 [PubMed] Related Publications
Müllerian adenosarcoma (MA) is a rare mixed mesenchymal tumour of the female genital tract, composed of malignant stroma and benign-appearing epithelium. Sarcomatous overgrowth (SO) is the only established histological variable associated with higher stage and shorter survival. Specific molecular or immunohistochemistry (IHC) tools for the diagnosis of MA are lacking. Our goal was to study genomic mutations and copy number variations (CNVs) in MA to understand better its pathobiology, and develop specific diagnostic and prognostic tools. DNA was extracted from 20 samples of MA from 18 subjects (12 without SO and 6 with SO), including two in which areas of both typical MA histology and SO were independently tested. Samples were analysed using a targeted next-generation sequencing assay interrogating exonic sequences of 275 cancer genes for mutations and CNVs as well as 91 introns across 30 genes for cancer-associated rearrangements. The mean number of mutations in MA with SO (mean 9.7; range 3-14) did not differ significantly from that in MA without SO (mean 9.6; range 5-16). MA with SO had significantly higher mean numbers of gene-level CNVs (24.6) compared to MA without SO (5; p = 0.0002). The most frequent amplification involved MDM2 and CDK4 (5/18; 28%), accompanied by focal CDK4 and MDM2 and diffuse HMGA2 expression using immunohistochemistry. MYBL1 amplification was seen in 4/18 (22%), predominantly in SO. Alterations in PIK3CA/AKT/PTEN pathway members were seen in 13/18 (72%). Notably, TP53 mutations were uncommon, present in only two cases with SO. Three out of 18 (17%) had mutations in ATRX, all associated with SO. No chromosomal rearrangements were identified. We have identified a number of recurrent genomic alterations in MA, including some associated with SO. Although further investigation of these findings is needed, confirmation of one or more may lead to new mechanistic insights and novel markers for this often difficult-to-diagnose tumour.

Nobusawa S, Hirato J, Yokoo H
Molecular genetics of ependymomas and pediatric diffuse gliomas: a short review.
Brain Tumor Pathol. 2014; 31(4):229-33 [PubMed] Related Publications
Here, we review the recent literature on molecular discoveries in ependymomas and pediatric diffuse gliomas. Ependymomas can now be categorized into three location-related subgroups according to their biological profile: posterior fossa ependymomas, group A (PFA) and B (PFB), and supratentorial ependymomas. Although no recurrently mutated genes were found throughout these groups of ependymomas, PFA exhibited a CpG island methylator phenotype, PFB was associated with extensive chromosomal aberrations, and the C11orf95-RELA fusion gene was frequently observed in supratentorial ependymomas. Meanwhile, it has now become apparent that pediatric diffuse gliomas have a distinct genetic status from their adult counterparts, even though they share an indistinguishable histology. In pediatric low-grade diffuse gliomas, an intragenic duplication of the portion of FGFR1 encoding the tyrosine kinase domain (TKD) and rearrangements of MYB/MYBL1 were found recurrently and mutually exclusively. As for non-brainstem high-grade tumors, in addition to H3F3A, TP53, and ATRX mutations, which were frequently observed in older children, recurrent fusions involving NTRK1, NTRK2, and NTRK3 were reported in infants younger than 3 years of age. Moreover, in diffuse intrinsic pontine gliomas (DIPG), recurrent somatic mutations of ACVR1 were found in association with HIST1H3B mutations.

Yong ZW, Zaini ZM, Kallarakkal TG, et al.
Genetic alterations of chromosome 8 genes in oral cancer.
Sci Rep. 2014; 4:6073 [PubMed] Free Access to Full Article Related Publications
The clinical relevance of DNA copy number alterations in chromosome 8 were investigated in oral cancers. The copy numbers of 30 selected genes in 33 OSCC patients were detected using the multiplex ligation-dependent probe amplification (MLPA) technique. Amplifications of the EIF3E gene were found in 27.3% of the patients, MYC in 18.2%, RECQL4 in 15.2% and MYBL1 in 12.1% of patients. The most frequent gene losses found were the GATA4 gene (24.2%), FGFR1 gene (24.2%), MSRA (21.2) and CSGALNACT1 (12.1%). The co-amplification of EIF3E and RECQL4 was found in 9% of patients and showed significant association with alcohol drinkers. There was a significant association between the amplification of EIF3E gene with non-betel quid chewers and the negative lymph node status. EIF3E amplifications did not show prognostic significance on survival. Our results suggest that EIF3E may have a role in the carcinogenesis of OSCC in non-betel quid chewers.

Liu LY, Chang LY, Kuo WH, et al.
A supervised network analysis on gene expression profiles of breast tumors predicts a 41-gene prognostic signature of the transcription factor MYB across molecular subtypes.
Comput Math Methods Med. 2014; 2014:813067 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: MYB is predicted to be a favorable prognostic predictor in a breast cancer population. We proposed to find the inferred mechanism(s) relevant to the prognostic features of MYB via a supervised network analysis.
METHODS: Both coefficient of intrinsic dependence (CID) and Galton Pierson's correlation coefficient (GPCC) were combined and designated as CIDUGPCC. It is for the univariate network analysis. Multivariate CID is for the multivariate network analysis. Other analyses using bioinformatic tools and statistical methods are included.
RESULTS: ARNT2 is predicted to be the essential gene partner of MYB. We classified four prognostic relevant gene subpools in three breast cancer cohorts as feature types I-IV. Only the probes in feature type II are the potential prognostic feature of MYB. Moreover, we further validated 41 prognosis relevant probes to be the favorable prognostic signature. Surprisingly, two additional family members of MYB are elevated to promote poor prognosis when both levels of MYB and ARNT2 decline. Both MYBL1 and MYBL2 may partially decrease the tumor suppressive activities that are predicted to be up-regulated by MYB and ARNT2.
CONCLUSIONS: The major prognostic feature of MYB is predicted to be determined by the MYB subnetwork (41 probes) that is relevant across subtypes.

Hudson JB, Collins BT
MYB gene abnormalities t(6;9) in adenoid cystic carcinoma fine-needle aspiration biopsy using fluorescence in situ hybridization.
Arch Pathol Lab Med. 2014; 138(3):403-9 [PubMed] Related Publications
CONTEXT: Fine-needle aspiration (FNA) biopsy of salivary gland neoplasms can have a variety of overlapping appearances. Basaloid neoplasms can be a diagnostic challenge, and FNA cytomorphology alone cannot always provide a definitive diagnosis.
OBJECTIVE: To examine the incidence and potential utility of detecting a MYB translocation by fluorescence in situ hybridization (FISH) in adenoid cystic carcinomas (AdCCs) and pleomorphic adenoma FNA smears with known surgical outcomes.
DESIGN: Patients who underwent FNA biopsy for surgically confirmed AdCCs and pleomorphic adenomas were identified. Fluorescence in situ hybridization, using commercially available fluorescent-labeled probes, hybridizing to MYB-telomeric and MYB-centromeric, was used to identify the MYB gene and to evaluate it for abnormalities and translocation. Using a fluorescent microscope, 4',6-diamidino-2-phenylindole (DAPI)-stained, nonoverlapping cells were counted, and 10% or greater abnormal cells were considered positive.
RESULTS: The 10 AdCC and 13 pleomorphic adenoma FNA cases had FISH evaluations performed; 50% (5 of 10) of the AdCC cases showed a MYB abnormality by FISH; 40% (4 of 10) AdCCs showed a positive break-apart signal in most cells (48%-84%). One case (10%) of AdCC showed a trisomy MYB signal pattern without the break-apart translocation pattern. Of the 13 pleomorphic adenomas, none (0%) of the cases showed a MYB translocation or abnormality by FISH. MYB FISH abnormalities showed a 100% positive predictive value, 50% sensitivity, and 100% specificity, when differentiating AdCC from pleomorphic adenoma.
CONCLUSIONS: MYB gene abnormalities were present in 50% (5 of 10) of the AdCC cases. This corresponds to the reported prevalence in formalin-fixed, paraffin-embedded tissue for AdCC surgical resections. Using FISH testing for detecting MYB gene abnormalities in the salivary gland of FNA biopsies has the potential to provide additional, helpful ancillary information in diagnosing AdCC.

Amaro AA, Esposito AI, Mirisola V, et al.
Endocrine disruptor agent nonyl phenol exerts an estrogen-like transcriptional activity on estrogen receptor positive breast cancer cells.
Curr Med Chem. 2014; 21(5):630-40 [PubMed] Related Publications
Several substances widely dispersed in the environment including hormones, industrial by-products and pollutants exert hormone like activity affecting steroid-responsive physiological systems. These compounds, named endocrine disruptors, are suspected to affect the mammalian reproductive system. However it is still unclear whether these substances are able to elicit estrogen like activity at the low concentrations encountered in the environment. Here we compare the effects of the endocrine disruptor nonylphenol with the effects elicited by 17-β-estradiol on gene transcription in the human breast cancer cell line MCF7. The correlation of the nonylphenol induced gene expression alterations with a reference profile of estradiol treated cells shows that nonylphenol at a concentration of 100 nM exerts a significant effect on estrogen responsive gene transcription in MCF7 cells. Most of the genes regulated by 17-β-estradiol respond to the nonylphenol in the same direction though to a much lesser extent. Molecular modeling of the potential interaction of nonylphenol with the estrogen receptor α shows that nonylphenol is likely to bind to the estrogen receptor α.

Haeri M, Li Y, Li Y, et al.
Insertional activation of myb by F-MuLV in SCID mice induces myeloid leukemia.
Int J Oncol. 2013; 43(1):169-76 [PubMed] Related Publications
Identification of retrovirus integration sites is a powerful method to identify cancer-related genes. This approach led to the discovery of the Friend murine leukemia virus (F-MuLV) integration site-1 (fli-1). Viral insertion at the fli-1 locus induces erythroleukemia in susceptible strains of mice. Our recent data demonstrated that, F-MuLV-infected SCID mice, in contrast to wt CB17 controls, developed a non‑erythroleukemic leukemia without viral integration at the fli-1 locus. Using ligation-mediated polymerase chain reaction (LM-PCR) approach we identified a total of 15 viral integration sites in F-MuLV-infected SCID mice. One of the identified insertion sites was located about 62 kb upstream of the myeloblastosis (myb) gene. While integration within or surrounding the myb gene has been reported before for murine leukemia viruses, the location of the viral integration site identified in F-MuLV‑infected SCID mice is novel and has never been reported. Using PCR analysis we showed that viral integration at the myb locus occurs with a frequency of 35% and therefore is considered as a common integration site. Integration of F-MuLV in this locus resulted in upregulation of the MYB protein. Flow cytometry analysis and methylcellulose culture of leukemic cells isolated from tumors with viral integration close to the myb indicated tumors of myeloid origin. Our findings indicate that, in contrast to wt CB17 mice, F-MuLV-infected SCID mice display viral integration within myeloid specific gene loci that result in the development of myelogenous leukemia.

Ramkissoon LA, Horowitz PM, Craig JM, et al.
Genomic analysis of diffuse pediatric low-grade gliomas identifies recurrent oncogenic truncating rearrangements in the transcription factor MYBL1.
Proc Natl Acad Sci U S A. 2013; 110(20):8188-93 [PubMed] Free Access to Full Article Related Publications
Pediatric low-grade gliomas (PLGGs) are among the most common solid tumors in children but, apart from BRAF kinase mutations or duplications in specific subclasses, few genetic driver events are known. Diffuse PLGGs comprise a set of uncommon subtypes that exhibit invasive growth and are therefore especially challenging clinically. We performed high-resolution copy-number analysis on 44 formalin-fixed, paraffin-embedded diffuse PLGGs to identify recurrent alterations. Diffuse PLGGs exhibited fewer such alterations than adult low-grade gliomas, but we identified several significantly recurrent events. The most significant event, 8q13.1 gain, was observed in 28% of diffuse astrocytoma grade IIs and resulted in partial duplication of the transcription factor MYBL1 with truncation of its C-terminal negative-regulatory domain. A similar recurrent deletion-truncation breakpoint was identified in two angiocentric gliomas in the related gene v-myb avian myeloblastosis viral oncogene homolog (MYB) on 6q23.3. Whole-genome sequencing of a MYBL1-rearranged diffuse astrocytoma grade II demonstrated MYBL1 tandem duplication and few other events. Truncated MYBL1 transcripts identified in this tumor induced anchorage-independent growth in 3T3 cells and tumor formation in nude mice. Truncated transcripts were also expressed in two additional tumors with MYBL1 partial duplication. Our results define clinically relevant molecular subclasses of diffuse PLGGs and highlight a potential role for the MYB family in the biology of low-grade gliomas.

Zhang J, Wu G, Miller CP, et al.
Whole-genome sequencing identifies genetic alterations in pediatric low-grade gliomas.
Nat Genet. 2013; 45(6):602-12 [PubMed] Free Access to Full Article Related Publications
The most common pediatric brain tumors are low-grade gliomas (LGGs). We used whole-genome sequencing to identify multiple new genetic alterations involving BRAF, RAF1, FGFR1, MYB, MYBL1 and genes with histone-related functions, including H3F3A and ATRX, in 39 LGGs and low-grade glioneuronal tumors (LGGNTs). Only a single non-silent somatic alteration was detected in 24 of 39 (62%) tumors. Intragenic duplications of the portion of FGFR1 encoding the tyrosine kinase domain (TKD) and rearrangements of MYB were recurrent and mutually exclusive in 53% of grade II diffuse LGGs. Transplantation of Trp53-null neonatal astrocytes expressing FGFR1 with the duplication involving the TKD into the brains of nude mice generated high-grade astrocytomas with short latency and 100% penetrance. FGFR1 with the duplication induced FGFR1 autophosphorylation and upregulation of the MAPK/ERK and PI3K pathways, which could be blocked by specific inhibitors. Focusing on the therapeutically challenging diffuse LGGs, our study of 151 tumors has discovered genetic alterations and potential therapeutic targets across the entire range of pediatric LGGs and LGGNTs.

Liu M, Fan J, Wang S, et al.
Transcriptional profiling of Chinese medicinal formula Si-Wu-Tang on breast cancer cells reveals phytoestrogenic activity.
BMC Complement Altern Med. 2013; 13:11 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Si-Wu-Tang (SWT), comprising the combination of four herbs, Paeoniae, Angelicae, Chuanxiong and Rehmanniae, is one of the most popular traditional oriental medicines for women's diseases. In our previous study, the microarray gene expression profiles of SWT on breast cancer cell line MCF-7 were found similar to the effect of β-estradiol (E2) on MCF-7 cells in the Connectivity Map database.
METHODS: Further data analysis was conducted to find the main similarities and differences between the effects of SWT and E2 on MCF-7 gene expression. The cell proliferation assay on MCF-7 (ER-positive) and MDA-MB-231 (ER-negative) cells were used to examine such estrogenic activity. The estrogenic potency of SWT was further confirmed by estrogen-responsive element (ERE) luciferase reporter assay in MCF-7 cells.
RESULTS: Many estrogen regulated genes strongly up-regulated by E2 were similarly up-regulated by SWT, e.g., GREB1, PGR and EGR3. Of interest with regard to safety of SWT, the oncogenes MYBL1 and RET were strongly induced by E2 but not by SWT. Quantitative RT-PCR analysis revealed a highly concordant expression change in selected genes with data obtained by microarrays. Further supporting SWT's estrogenic activity, in MCF-7 but not in MDA-MB-231 cells, SWT stimulated cell growth at lower concentrations (< 3.0 mg/ml), while at high concentrations, it inhibits the growth of both cell lines. The growth inhibitory potency of SWT was significantly higher in MDA-MB-231 than in MCF-7 cells. The SWT-induced cell growth of MCF-7 could be blocked by addition of the estrogen receptor antagonist tamoxifen. In addition, SWT was able to activate the ERE activity at lower concentrations. The herbal components Angelicae, Chuanxiong and Rehmanniae at lower concentrations (< 3.0 mg/ml) also showed growth-inducing and ERE-activating activity in MCF-7 cells.
CONCLUSIONS: These results revealed a new mechanism to support the clinical use of SWT for estrogen related diseases and possibly for cancer prevention. This study also demonstrated the feasibility of using microarray transcriptional profiling to discover phytoestrogenic components that are present in natural products.

Quelen C, Lippert E, Struski S, et al.
Identification of a transforming MYB-GATA1 fusion gene in acute basophilic leukemia: a new entity in male infants.
Blood. 2011; 117(21):5719-22 [PubMed] Related Publications
Acute basophilic leukemia (ABL) is a rare subtype of acute leukemia with clinical features and symptoms related to hyperhistaminemia because of excessive growth of basophils. No known recurrent cytogenetic abnormality is associated with this leukemia. Rare cases of t(X;6)(p11;q23) translocation have been described but these were sporadic. We report here 4 cases of ABL with a t(X;6)(p11;q23) translocation occurring in male infants. Because of its location on chromosome 6q23, MYB was a good candidate gene. Our molecular investigations, based on fluorescence in situ hybridization and rapid amplification of cDNA ends, revealed that the translocation generated a MYB-GATA1 fusion gene. Expression of MYB-GATA1 in mouse lineage-negative cells committed them to the granulocyte lineage and blocked at an early stage of differentiation. Taken together, these results establish, for the first time, a link between a recurrent chromosomal translocation and the development of this particular subtype of infant leukemia.

Zhou Y, Ness SA
Myb proteins: angels and demons in normal and transformed cells.
Front Biosci (Landmark Ed). 2011; 16:1109-31 [PubMed] Free Access to Full Article Related Publications
A key regulator of proliferation, differentiation and cell fate, the c-Myb transcription factor regulates the expression of hundreds of genes and is in turn regulated by numerous pathways and protein interactions. However, the most unique feature of c-Myb is that it can be converted into an oncogenic transforming protein through a few mutations that completely change its activity and specificity. The c-Myb protein is a myriad of interactions and activities rolled up in a protein that controls proliferation and differentiation in many different cell types. Here we discuss the background and recent progress that have led to a better understanding of this complex protein, and outline the questions that have yet to be answered.

Duhagon MA, Hurt EM, Sotelo-Silveira JR, et al.
Genomic profiling of tumor initiating prostatospheres.
BMC Genomics. 2010; 11:324 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The cancer stem cell (CSC) hypothesis proposes that a population of tumor cells bearing stem cell properties is responsible for the origin and maintenance of tumors. Normal and cancer stem cells possess the ability to grow in vitro as self-renewing spheres, but the molecular basis of this phenotype remains largely unknown. We intended to establish a comprehensive culture system to grow prostatospheres (PSs) from both cancer cell lines and patient tumors. We then used gene expression microarrays to gain insight on the molecular pathways that sustain the PS tumor initiating cell (TIC) phenotype.
RESULTS: Traditional stem cell medium (SCM) supplemented with KnockoutSR (KO) allows the propagation of monoclonal PSs from cell lines and primary cells. PSs display gene expression and tumorigenicity hallmarks of TICs. Gene expression analysis defined a gene signature composed of 66 genes that characterize LNCaP and patient PSs. This set includes novel prostate TIC growth factors (NRP1, GDF1, JAG1), proteins implicated in cell adhesion and cytoskeletal maintenance, transcriptional regulators (MYCBP, MYBL1, ID1, ID3, FOS, ELF3, ELF4, KLF2, KLF5) and factors involved in protein biosynthesis and metabolism. Meta-analysis in Oncomine reveals that some of these genes correlate with prostate cancer status and/or progression. Reporter genes and inhibitors indicate that the Notch pathway contributes to prostatosphere growth.
CONCLUSIONS: We have developed a model for the culture of PSs, and provide a genomic profile that support CSCs identity. This signature identifies novel markers and pathways that are predicted to correlate with prostate cancer evolution.

Thorner AR, Hoadley KA, Parker JS, et al.
In vitro and in vivo analysis of B-Myb in basal-like breast cancer.
Oncogene. 2009; 28(5):742-51 [PubMed] Free Access to Full Article Related Publications
A defining feature of basal-like breast cancer, a breast cancer subtype with poor clinical prognosis, is the high expression of 'proliferation signature' genes. We identified B-Myb, a MYB family transcription factor that is often amplified and overexpressed in many tumor types, as being highly expressed in the proliferation signature. However, the roles of B-Myb in disease progression, and its mammary-specific transcriptional targets, are poorly understood. Here, we showed that B-Myb expression is a significant predictor of survival and pathological complete response to neoadjuvant chemotherapy in breast cancer patients. We also identified a significant association between the G/G genotype of a nonsynonymous B-Myb germline variant (rs2070235, S427G) and an increased risk of basal-like breast cancer [OR 2.0, 95% CI (1.1-3.8)]. In immortalized, human mammary epithelial cell lines, but not in basal-like tumor lines, cells ectopically expressing wild-type B-Myb or the S427G variant showed increased sensitivity to two DNA topoisomerase IIalpha inhibitors, but not to other chemotherapeutics. In addition, microarray analyses identified many G2/M genes as being induced in B-Myb overexpressing cells. These results confirm that B-Myb is involved in cell cycle control, and that its dysregulation may contribute to increased sensitivity to a specific class of chemotherapeutic agents. These data provide insight into the influence of B-Myb in human breast cancer, which is of potential clinical importance for determining disease risk and for guiding treatment.

O'Neil J, Tchinda J, Gutierrez A, et al.
Alu elements mediate MYB gene tandem duplication in human T-ALL.
J Exp Med. 2007; 204(13):3059-66 [PubMed] Free Access to Full Article Related Publications
Recent studies have demonstrated that the MYB oncogene is frequently duplicated in human T cell acute lymphoblastic leukemia (T-ALL). We find that the human MYB locus is flanked by 257-bp Alu repeats and that the duplication is mediated somatically by homologous recombination between the flanking Alu elements on sister chromatids. Nested long-range PCR analysis indicated a low frequency of homologous recombination leading to MYB tandem duplication in the peripheral blood mononuclear cells of approximately 50% of healthy individuals, none of whom had a MYB duplication in the germline. We conclude that Alu-mediated MYB tandem duplication occurs at low frequency during normal thymocyte development and is clonally selected during the molecular pathogenesis of human T-ALL.

Lacoste V, Nicot C, Gessain A, et al.
In primary effusion lymphoma cells, MYB transcriptional repression is associated with v-FLIP expression during latent KSHV infection while both v-FLIP and v-GPCR become involved during the lytic cycle.
Br J Haematol. 2007; 138(4):487-501 [PubMed] Related Publications
Primary effusion lymphoma (PEL) is a rare, distinct subtype of non-Hodgkin lymphoma, which is associated with Kaposi sarcoma-associated herpesvirus (KSHV) infection. Although MYB levels are high in most neoplastic B cells, we found that, unexpectedly, both PEL cells and uncultured PEL patients' samples contained very low levels of MYB mRNA when compared to B-cell leukaemia samples obtained from KSHV(-) patients. These results were further confirmed at the protein level. Both latent viral FLICE inhibitory protein (v-FLIP) and early lytic viral G protein coupled receptor (v-GPCR) KSHV proteins were found to activate nuclear factor (NF)-kappaB and transrepress a MYB promoter reporter construct. In contrast, a dominant negative inhibitor of NF-kappaB (IkappaB-alpha) mutant prevented v-FLIP and v-GPCR from inhibiting MYB functions while a v-GPCR mutant that was impaired for NF-kappaB activation could not repress the MYB construct. Transduction of a v-FLIP expressing vector or stable transfection of v-GPCR both resulted in a marked downregulation of the endogenous MYB protein expression. However, MYB expression transactivated the lytic switch Replication and Transcription Activator (RTA) promoter in transient transfection assays. Taken together, our results demonstrate that, contrary to a number of other haematological malignancies, MYB expression is not required for PEL cell proliferation. Repressing MYB expression also helps in maintaining the virus in latency.

Chen Y, Guo Y, Ge X, et al.
Elevated expression and potential roles of human Sp5, a member of Sp transcription factor family, in human cancers.
Biochem Biophys Res Commun. 2006; 340(3):758-66 [PubMed] Related Publications
In this report, we describe the expression and function of human Sp5, a member of the Sp family of zinc finger transcription factors. Like other family members, the Sp5 protein contains a Cys2His2 zinc finger DNA binding domain at the C-terminus. Our experiments employing Gal4-Sp5 fusion proteins reveal multiple transcriptional domains, including a N-terminal activity domain, an intrinsic repressive element, and a C-terminal synergistic domain. Elevated expression of Sp5 was noted in several human tumors including hepatocellular carcinoma, gastric cancer, and colon cancer. To study the effects of the Sp5 protein on growth properties of human cancer cells and facilitate the identification of its downstream genes, we combined an inducible gene expression system with microarray analysis to screen for its transcriptional targets. Transfer of Sp5 into MCF-7 cells that expressed no detectable endogenous Sp5 protein elicited significant growth promotion activity. Several of the constitutively deregulated genes have been associated with tumorigenesis (CDC25C, CEACAM6, TMPRSS2, XBP1, MYBL1, ABHD2, and CXCL12) and Wnt/beta-Catenin signaling pathways (BAMBI, SIX1, IGFBP5, AES, and p21WAF1). This information could be utilized for further mechanistic research and for devising optimized therapeutic strategies against human cancers.

Kim KY, Lee JW, Park MS, et al.
Expression of a thioredoxin-related protein-1 is induced by prostaglandin E(2).
Int J Cancer. 2006; 118(7):1670-9 [PubMed] Related Publications
Prostaglandin E(2) (PGE(2)) plays an important role in protection of the gastric mucosa against various damaging agents and growth-inhibitory activity on tumor cells. However, the precise regulation mechanism of PGE(2) in gastric cancer cells is still unclear. In this study, we isolated a gene, which is regulated by PGE(2) in SNU-1, human gastric adenocarcinoma cells, using differential display RT-PCR (DD RT-PCR) and characterized the function of the gene induced by PGE(2). The full-length cDNA of the gene was cloned by the rapid amplification of cDNA ends method. The 1659 base pair cDNA consists of a 30-nt 5'-noncoding region, an 891-nt open reading frame and a 738-nt 3'noncoding region that includes a poly (A) signal. As a result of protein motif search, we found that it has a conserved thioredoxin-active site, Cys-Gly-Pro-Cys and a Myb-DNA binding domain repeat signature. Thus, we designated this gene product as thioredoxin-related protein-1, TRP-1. TRP-1 was expressed in a lower extent in renal, gastric and colon cancer tissues and is translated into 33 kDa protein in nuclear and cytoplasmic fractions. TRP-1 has a thioredoxin activity, which was detected using the insulin disulfide reduction assay. Another potential role of TRP-1 is repression of B-Myb activity through direct binding to B-Myb, a transcriptional factor induced at G1-S transition. Finally, TRP-1 overexpression inhibits mammalian cell proliferation and specifically predispose to G0/G1 phase arrest. In conclusion, these results imply that TRP-1 is a mammalian thioredoxin and plays as a transcriptional repressor through direct binding to the transcription factor B-Myb.

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