Conclusion
Four immunophenotypes were found in GBM vessels, corresponding to endotheliocytes, Pcs, Tcs, and a mixed Pc/Tc immunophenotype. These and forthcoming improvements in our understanding of the origin and function of Tcs, including their relationship with Pcs, are necessary steps in oncology. Study of these cell types (Tcs, Pcs) and their roles in brain tumor oncogenesis will likely enable improved targeted therapies and support development of new forms of anti-neoplastic drugs.
Methods
Samples from 15 GBM, 10 diffuse astrocytoma, as well as 5 control samples were studied. We used immunohistochemistry (IHC) with antibodies (Abs) to GFAP, Ki-67, CD117, NeuroD1, NG2, CD34, and SMA. Confocal laser scanning microscopy (CLSM) of 4 glioma tissue cultures and 4 GBM sections was performed with GFAP, CD117, CD34/connexin43, NeuroD1/connexin43, CD34/NG2 and CD13/CD117 Abs. Electron microscopy (EM) of GBM was performed in 4 cases.
Objective
Morphological study of Tc and Pc roles in GBM. Materials and
Results
The presence of Tcs and Pcs was shown in GBM (IHC, EM, CLSM) and glioma cultures (CLSM). The Tc immunophenotype was CD117+/CD34+/connexin43+/NeuroD1+. The Pc immunophenotype was SMA+/NG2+/CD13+. The number of Tcs in GBM specimens was 10 times higher than in astrocytoma. We also identified CD13/CD117 and CD34/NG2 co-expressing cells in GBM blood vessels.