Acta Neuropathologica

, Volume 123, Issue 5, pp 727–738

A prognostic gene expression signature in infratentorial ependymoma

  • Khalida Wani
  • Terri S. Armstrong
  • Elizabeth Vera-Bolanos
  • Aditya Raghunathan
  • David Ellison
  • Richard Gilbertson
  • Brian Vaillant
  • Stewart Goldman
  • Roger J. Packer
  • Maryam Fouladi
  • Ian Pollack
  • Tom Mikkelsen
  • Michael Prados
  • Antonio Omuro
  • Riccardo Soffietti
  • Alicia Ledoux
  • Charmaine Wilson
  • Lihong Long
  • Mark R. Gilbert
  • Ken Aldape
  • For the Collaborative Ependymoma Research Network
Original Paper

DOI: 10.1007/s00401-012-0941-4

Cite this article as:
Wani, K., Armstrong, T.S., Vera-Bolanos, E. et al. Acta Neuropathol (2012) 123: 727. doi:10.1007/s00401-012-0941-4

Abstract

Patients with ependymoma exhibit a wide range of clinical outcomes that are currently unexplained by clinical or histological factors. Little is known regarding molecular biomarkers that could predict clinical behavior. Since recent data suggest that these tumors display biological characteristics according to their location (cerebral vs. infratentorial vs. spinal cord), rather than explore a broad spectrum of ependymoma, we focused on molecular alterations in ependymomas arising in the infratentorial compartment. Unsupervised clustering of available gene expression microarray data revealed two major subgroups of infratentorial ependymoma. Group 1 tumors over expressed genes that were associated with mesenchyme, Group 2 tumors showed no distinct gene ontologies. To assess the prognostic significance of these gene expression subgroups, real-time reverse transcriptase polymerase chain reaction assays were performed on genes defining the subgroups in a training set. This resulted in a 10-gene prognostic signature. Multivariate analysis showed that the 10-gene signature was an independent predictor of recurrence-free survival after adjusting for clinical factors. Evaluation of an external dataset describing subgroups of infratentorial ependymomas showed concordance of subgroup definition, including validation of the mesenchymal subclass. Importantly, the 10-gene signature was validated as a predictor of recurrence-free survival in this dataset. Taken together, the results indicate a link between clinical outcome and biologically identified subsets of infratentorial ependymoma and offer the potential for prognostic testing to estimate clinical aggressiveness in these tumors.

Keywords

Infratentorial ependymoma Expression profiling Gene expression signature Prognostic genes Microarray Biomarker 

Supplementary material

401_2012_941_MOESM1_ESM.docx (46 kb)
Supplementary Tables 1 (DOCX 46 kb)
401_2012_941_MOESM2_ESM.tif (282 kb)
Supplementary Fig. 1 Overall experimental approach for the study. The number of microarray samples from each site is indicated. INDT: Instituto Nazionale Dei Tumori; UCD: University of Colorado at Denver; SJCRH: St. Jude Children’s Research Hospital; VCU: Virginia Commonwealth University. (TIFF 282 kb)
401_2012_941_MOESM3_ESM.tif (673 kb)
Supplementary Fig. 2 Comparison of the transcriptomal Groups 1 and 2 with the Johnson et al posterior fossa subgroups G, H and I. Group 1 tumors are similar to subgroup H and I tumors in their gene expression profile while group 2 tumors resemble subgroup G. (TIFF 673 kb)
401_2012_941_MOESM4_ESM.tif (5.8 mb)
Supplementary Fig. 3 Expression of TOP2A and its correlation with metagene score and patient survival. a) Immunohistochemical staining for TOP2A showing a negative and positive case. b) Box-whisker plot showing the association of TOP2A staining and metagene score. High TOP2A immunostaining score corresponded with a low metagene score (unfavorable response group) while low TOP2A immunostaining was seen in the high metagene score group (favorable group).The Fisher’s exact test, two-tailed, was used for statistical significance calculation. c-d) Kaplan-Meier survival curves showing a worse progression-free and overall survival in the group of cases that had high levels of TOP2A protein expression as detected by immunohistochemistry. (TIFF 5918 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Khalida Wani
    • 1
  • Terri S. Armstrong
    • 13
    • 14
  • Elizabeth Vera-Bolanos
    • 13
  • Aditya Raghunathan
    • 1
  • David Ellison
    • 2
  • Richard Gilbertson
    • 3
  • Brian Vaillant
    • 12
  • Stewart Goldman
    • 4
  • Roger J. Packer
    • 5
  • Maryam Fouladi
    • 6
  • Ian Pollack
    • 7
  • Tom Mikkelsen
    • 8
  • Michael Prados
    • 9
  • Antonio Omuro
    • 10
  • Riccardo Soffietti
    • 11
  • Alicia Ledoux
    • 1
  • Charmaine Wilson
    • 1
  • Lihong Long
    • 1
  • Mark R. Gilbert
    • 13
  • Ken Aldape
    • 1
  • For the Collaborative Ependymoma Research Network
  1. 1.Department of PathologyThe University of Texas MD Anderson Cancer CenterHoustonUSA
  2. 2.Department of PathologySt Jude Children’s Research HospitalMemphisUSA
  3. 3.Department of Developmental NeurobiologySt Jude Children’s Research HospitalMemphisUSA
  4. 4.Department of Neuro-OncologyChildren’s Memorial HospitalChicagoUSA
  5. 5.Center for Neuroscience and Behavioral MedicineBrain Tumor Institute, Children’s National Medical Center for Neuroscience Research (CNR)Washington, DCUSA
  6. 6.Department of Neuro-OncologyCincinnati Children’s Hospital Medical CenterCincinnatiUSA
  7. 7.Department of Neurological SurgeryChildren’s Hospital of Pittsburgh, University of Pittsburgh School of MedicinePittsburghUSA
  8. 8.Department of NeurosurgeryHenry Ford West Bloomfield HospitalWest BloomfieldUSA
  9. 9.Department of NeurosurgeryUniversity of California, San FranciscoSan FranciscoUSA
  10. 10.Department of Neuro-OncologyMemorial Sloan-Kettering Cancer CenterNew YorkUSA
  11. 11.Department of Neuro-Oncology, Medical SchoolUniversity of TorinoTurinItaly
  12. 12.Department of NeurosurgeryMethodist Neurological InstituteHoustonUSA
  13. 13.Department of Neuro-OncologyThe University of Texas MD Anderson Cancer CenterHoustonUSA
  14. 14.Department of Family HealthThe University of Texas Health Science Centre School of NursingHoustonUSA