Abstract
Most patients with glioblastoma (GBM) die within 2 years. A major therapeutic goal is to target GBM stem cells (GSCs), a subpopulation of cells that contribute to treatment resistance and recurrence. Since their discovery in 2003, GSCs have been isolated using single-surface markers, such as CD15, CD44, CD133, and α6 integrin. It remains unknown how these single-surface marker–defined GSC populations compare with each other in terms of signaling and function and whether expression of different combinations of these markers is associated with different functional capacity. Using mass cytometry and fresh operating room specimens, we found 15 distinct GSC subpopulations in patients, and they differed in their MEK/ERK, WNT, and AKT pathway activation status. Once in culture, some subpopulations were lost and previously undetectable ones materialized. GSCs that highly expressed all 4 surface markers had the greatest self-renewal capacity, WNT inhibitor sensitivity, and in vivo tumorigenicity. This work highlights the potential signaling and phenotypic diversity of GSCs. Larger patient sample sizes and antibody panels are required to confirm these findings.
Authors
Luciano Galdieri, Arijita Jash, Olga Malkova, Diane D. Mao, Patrick DeSouza, Yunli E. Chu, Amber Salter, Jian L. Campian, Kristen M. Naegle, Cameron W. Brennan, Hiroaki Wakimoto, Stephen T. Oh, Albert H. Kim, Milan G. Chheda
Figure 4
GSC populations are lost and gained in culture, and CD15hiCD44hiCD133hi α6 integrinhi (quadruple high) cells and CD44hiCD133hi cells derived from patient 4 are the most clonogenic.
