Figure 4.

PTPµ peptide SBK4 demarcates glioblastoma cells at the tumor edge. (A) Surgically resected human GBM tumor edge section was labeled with TR-conjugated SBK4 peptide. Arrows in the phase image indicate the approximate position of the margin between GBM and normal brain tissue. (B) PTPµ mAb blocks SBK2 and SBK4 peptide binding to human glioblastoma tissue. Preincubation of a PTPµ extracellular antibody raised against the MAM domain (BK2) specifically blocked SBK2-TR and SBK4-TR peptide binding to GBM tumor tissue sections.