SRPX Emerges as a Potential Tumor Marker in the Extracellular Vesicles of Glioblastoma

Elisabet Ampudia-Mesias, Samia El-Hadad, Charles Scott Cameron, Adelheid Wöhrer, Thomas Ströbel, Nurten Saydam, Okay Saydam

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Extracellular vesicles (EVs) may be used as a non-invasive screening platform to discover markers associated with early diagnosis, prognosis, and treatment response. Such an approach is invaluable for diseases such as glioblastoma, for which only a few non-invasive diagnostic or prognostic markers are available. We used mass spectrometry to analyze proteomics profiles of EVs derived from four glioblastoma cell lines and human primary astrocytes (HPAs) and found that SRPX is the only protein enriched in the majority of glioblastoma EVs that was absent in the HPA-derived EVs. Then, we evaluated the relationship between SRPX protein expression and tumor grade using immunohistochemical staining (IHC) and performed colony formation and viability assays to analyze the possible function of SRPX in glioblastoma. SRPX mRNA and protein expression were associated with tumor grade. Moreover, temozolomide (TMZ)-resistant tumor tissues showed highly positive SRPX staining, compared to all other tumor grades. Additionally, glioblastoma cells displayed enhanced SRPX gene expression when exposed to TMZ. Knockdown of SRPX gene expression via siRNA inhibited cell viability. Taken together, the results of this study suggest that SRPX can be used as a novel tumor marker for diagnostic and prognostic purposes and can also be a therapeutic target for glioblastomas.

Original languageEnglish (US)
Article number1984
Issue number8
StatePublished - Apr 1 2022

Bibliographical note

Funding Information:
Acknowledgments: This work was supported, in part, by UMN, Medical School Start-Up (OS). This work was supported by the resources and staff at the University of Minnesota University Imaging Centers (UIC). SCR_020997.

Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.


  • EVs
  • SRPX
  • glioblastoma
  • proteomics

PubMed: MeSH publication types

  • Journal Article


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