Rhabdomyosarcomas (RMS) are a heterogeneous group of mesodermal tumors, the most common sub-types are embryonal (eRMS) and alveolar (aRMS) rhabdomyosarcoma. Immunohistochemical analysis revealed c-Myb expression in both eRMS and aRMS. c-Myb has been reported to be often associated with malignant human cancers. We therefore investigated the c-Myb role in RMS using cellular models of RMS. Specific suppression of c-Myb by a lentiviral vector expressing doxycycline (Dox)-inducible c-Myb shRNA inhibited proliferation, colony formation, and migration of the eRMS cell line (RD), but not of the aRMS cell line (RH30). Upon c-Myb knockdown in eRMS cells, cells accumulated in G0/G1 phase, the invasive behaviour of cells was repressed, and elevated levels of myosin heavy chain, marker of muscle differentiation, was detected. Next, we used an RD-based xenograft model to investigate the role of c-Myb in eRMS tumorigenesis in vivo. We found that Dox administration did not result in efficient suppression of c-Myb in growing tumors. However, when c-Myb-deficient RD cells were implanted into SCID mice, we observed inefficient tumor grafting and attenuation of tumor growth during the initial stages of tumor expansion. The presented study suggests that c-Myb could be a therapeutic target in embryonal rhabdomyosarcoma assuming that its expression is ablated.

Czech Centre for Phenogenomics Institute of Molecular Genetics of the Czech Academy of Sciences Prague 14220 Czech Republic

Laboratory of Transgenic Models of Diseases Institute of Molecular Genetics of the Czech Academy of Sciences Prague 14220 Czech Republic

Microscopy Centre LM and EM Institute of Molecular Genetics of the Czech Academy of Sciences Prague 14220 Czech Republic

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Cormier JN, Pollock RE. Soft tissue sarcomas. CA Cancer J Clin. 2004;54:94–109. doi: 10.3322/canjclin.54.2.94. PubMed DOI

Sebire NJ, Malone M. Myogenin and MyoD1 expression in paediatric rhabdomyosarcomas. J Clin Pathol. 2003;56:412–416. doi: 10.1136/jcp.56.6.412. PubMed DOI PMC

Clark J, et al. Expression of members of the myf gene family in human rhabdomyosarcomas. Br J Cancer. 1991;64:1039–1042. doi: 10.1038/bjc.1991.461. PubMed DOI PMC

Tenente, I. M. PubMed PMC

Parham DM. Pathologic classification of rhabdomyosarcomas and correlations with molecular studies. Mod Pathol. 2001;14:506–514. doi: 10.1038/modpathol.3880339. PubMed DOI

Kumar S, Perlman E, Harris CA, Raffeld M, Tsokos M. Myogenin is a specific marker for rhabdomyosarcoma: an immunohistochemical study in paraffin-embedded tissues. Mod Pathol. 2000;13:988–993. doi: 10.1038/modpathol.3880179. PubMed DOI

Heerema-McKenney A, et al. Diffuse myogenin expression by immunohistochemistry is an independent marker of poor survival in pediatric rhabdomyosarcoma: a tissue microarray study of 71 primary tumors including correlation with molecular phenotype. Am J Surg Pathol. 2008;32:1513–1522. doi: 10.1097/PAS.0b013e31817a909a. PubMed DOI

Xia SJ, Pressey JG, Barr FG. Molecular pathogenesis of rhabdomyosarcoma. Cancer Biol Ther. 2002;1:97–104. doi: 10.4161/cbt.51. PubMed DOI

Barr FG. Gene fusions involving PAX and FOX family members in alveolar rhabdomyosarcoma. Oncogene. 2001;20:5736–5746. doi: 10.1038/sj.onc.1204599. PubMed DOI

Sokolowski E, Turina CB, Kikuchi K, Langenau DM, Keller C. Proof-of-concept rare cancers in drug development: the case for rhabdomyosarcoma. Oncogene. 2014;33:1877–1889. doi: 10.1038/onc.2013.129. PubMed DOI

Mucenski ML, et al. A functional c-myb gene is required for normal murine fetal hepatic hematopoiesis. Cell. 1991;65:677–689. doi: 10.1016/0092-8674(91)90099-K. PubMed DOI

Metcalf D, et al. Anomalous megakaryocytopoiesis in mice with mutations in the c-Myb gene. Blood. 2005;105:3480–3487. doi: 10.1182/blood-2004-12-4806. PubMed DOI

Ramsay RG, Gonda TJ. MYB function in normal and cancer cells. Nat Rev Cancer. 2008;8:523–534. doi: 10.1038/nrc2439. PubMed DOI

Lieu YK, Reddy EP. Conditional c-myb knockout in adult hematopoietic stem cells leads to loss of self-renewal due to impaired proliferation and accelerated differentiation. Proc Natl Acad Sci USA. 2009;106:21689–21694. doi: 10.1073/pnas.0907623106. PubMed DOI PMC

Malaterre J, et al. c-Myb is required for progenitor cell homeostasis in colonic crypts. Proc Natl Acad Sci USA. 2007;104:3829–3834. doi: 10.1073/pnas.0610055104. PubMed DOI PMC

Malaterre J, et al. c-Myb is required for neural progenitor cell proliferation and maintenance of the neural stem cell niche in adult brain. Stem Cells. 2008;26:173–181. doi: 10.1634/stemcells.2007-0293. PubMed DOI

Giacomazzi G, et al. MicroRNAs promote skeletal muscle differentiation of mesodermal iPSC-derived progenitors. Nat Commun. 2017;8:1249. doi: 10.1038/s41467-017-01359-w. PubMed DOI PMC

Lefebvre C, et al. A human B-cell interactome identifies MYB and FOXM1 as master regulators of proliferation in germinal centers. Mol Syst Biol. 2010;6:377. doi: 10.1038/msb.2010.31. PubMed DOI PMC

Lorenzo PI, et al. Identification of c-Myb Target Genes in K562 Cells Reveals a Role for c-Myb as a Master Regulator. Genes Cancer. 2011;2:805–817. doi: 10.1177/1947601911428224. PubMed DOI PMC

Mansour MR, et al. Oncogene regulation. An oncogenic super-enhancer formed through somatic mutation of a noncoding intergenic element. Science. 2014;346:1373–1377. doi: 10.1126/science.1259037. PubMed DOI PMC

Capellera-Garcia S, et al. Defining the Minimal Factors Required for Erythropoiesis through Direct Lineage Conversion. Cell Rep. 2016;15:2550–2562. doi: 10.1016/j.celrep.2016.05.027. PubMed DOI PMC

Fuglerud BM, et al. A c-Myb mutant causes deregulated differentiation due to impaired histone binding and abrogated pioneer factor function. Nucleic Acids Res. 2017;45:7681–7696. doi: 10.1093/nar/gkx364. PubMed DOI PMC

Bengtsen M, et al. c-Myb Binding Sites in Haematopoietic Chromatin Landscapes. PLoS One. 2015;10:e0133280. doi: 10.1371/journal.pone.0133280. PubMed DOI PMC

Stenman G, Andersson MK, Andren Y. New tricks from an old oncogene: gene fusion and copy number alterations of MYB in human cancer. Cell Cycle. 2010;9:2986–2995. doi: 10.4161/cc.9.15.12515. PubMed DOI PMC

Kaspar P, et al. c-Myb inhibits myoblast fusion. PLoS One. 2013;8:e76742. doi: 10.1371/journal.pone.0076742. PubMed DOI PMC

Kaspar P, et al. The Expression of c-Myb Correlates with the Levels of Rhabdomyosarcoma-specific Marker Myogenin. Sci Rep. 2015;5:15090. doi: 10.1038/srep15090. PubMed DOI PMC

Hinson AR, et al. Human rhabdomyosarcoma cell lines for rhabdomyosarcoma research: utility and pitfalls. Front Oncol. 2013;3:183. doi: 10.3389/fonc.2013.00183. PubMed DOI PMC

Drabsch Y, et al. Mechanism of and requirement for estrogen-regulated MYB expression in estrogen-receptor-positive breast cancer cells. Proc Natl Acad Sci USA. 2007;104:13762–13767. doi: 10.1073/pnas.0700104104. PubMed DOI PMC

Gewirtz AM, et al. G1/S transition in normal human T-lymphocytes requires the nuclear protein encoded by c-myb. Science. 1989;245:180–183. doi: 10.1126/science.2665077. PubMed DOI

Nakata Y, et al. c-Myb contributes to G2/M cell cycle transition in human hematopoietic cells by direct regulation of cyclin B1 expression. Mol Cell Biol. 2007;27:2048–2058. doi: 10.1128/MCB.01100-06. PubMed DOI PMC

Mokhtari Z, et al. Automated characterization and parameter-free classification of cell tracks based on local migration behavior. PLoS One. 2013;8:e80808. doi: 10.1371/journal.pone.0080808. PubMed DOI PMC

Hettmer S, Wagers AJ. Muscling in: Uncovering the origins of rhabdomyosarcoma. Nat Med. 2010;16:171–173. doi: 10.1038/nm0210-171. PubMed DOI

Waldron T, et al. c-Myb and its target Bmi1 are required for p190BCR/ABL leukemogenesis in mouse and human cells. Leukemia. 2012;26:644–653. doi: 10.1038/leu.2011.264. PubMed DOI PMC

Manzotti G, et al. Expression of p89(c-Mybex9b), an alternatively spliced form of c-Myb, is required for proliferation and survival of p210BCR/ABL-expressing cells. Blood Cancer J. 2012;2:e71. doi: 10.1038/bcj.2012.16. PubMed DOI PMC

De Dominici M, et al. Targeting CDK6 and BCL2 Exploits the “MYB Addiction” of Ph(+) Acute Lymphoblastic Leukemia. Cancer Res. 2018;78:1097–1109. doi: 10.1158/0008-5472.CAN-17-2644. PubMed DOI PMC

Marshall AD, Grosveld GC. Alveolar rhabdomyosarcoma - The molecular drivers of PAX3/7-FOXO1-induced tumorigenesis. Skelet Muscle. 2012;2:25. doi: 10.1186/2044-5040-2-25. PubMed DOI PMC

Rubin BP, et al. Evidence for an unanticipated relationship between undifferentiated pleomorphic sarcoma and embryonal rhabdomyosarcoma. Cancer Cell. 2011;19:177–191. doi: 10.1016/j.ccr.2010.12.023. PubMed DOI PMC

Nanni P, et al. Opposing control of rhabdomyosarcoma growth and differentiation by myogenin and interleukin 4. Mol Cancer Ther. 2009;8:754–761. doi: 10.1158/1535-7163.MCT-08-0678. PubMed DOI