EGFR^vIII: An Oncogene with Ambiguous Role

Figure 3

Hypotheses concerning the presence and role of EGFR^vIII-positive cells in tumors, on the example of glioblastoma. (a) One of the hypotheses states that EGFR^vIII is expressed on the surface of cancer stem cells (CSCs). In such a case, EGFR^vIII-positive CSCs should be also detected in recurrent GB tumors [164]. Nevertheless, failure to detect such cells may be due to the exposure of primary tumor to therapeutic compounds. (b) Another hypothesis states that EGFR^vIII-positive cells are only crucial during the early stages of carcinogenesis. It is supported by reports demonstrating loss of expression of this mutated oncogene in approx. 30% of patients with EGFR^vIII-positive primary tumors [119, 165]. (c) Cells expressing EGFR^vIII are also reported in recurrent tumors when primary GB was EGFR^vIII-negative [119, 165].

(a)

(b)

(c)