Expression of Epidermal Growth Factor Receptor variant III in laryngeal carcinoma tissues

Abstract

Objectives Epidermal Growth Factor Receptor variant III (EGFRvIII) has been believed to be an attractive tumor-specific candidate for molecular targeting therapy. However, there is little literature dealing with this variant of EGFR expressed in laryngeal carcinomas. In the present study, we try to evaluate the expression of EGFRvIII, as well as EGFR, in laryngeal carcinoma tissues and its correlation with clinicopathological features. Methods Real-time polymerase chain reaction (real-time PCR) with TaqMan probes was applied to detect the expression for EGFR and EGFRvIII mRNA in the 39 pairs of samples of laryngeal carcinoma tissues and microscopically normal laryngeal mucosal tissues adjacent to the tumor. 2 −ΔΔCT method was used to obtain the relative quantity of target mRNA expression. The correlation between EGFRvIII expression and its clinicopathological features was analyzed by Pearson's chi-squared test. Results Among the 39 pairs of samples of laryngeal carcinoma tissues and microscopically normal laryngeal mucosal tissues adjacent to the tumor, the level of EGFR mRNA of the former (0.030 ± 0.076) was higher than that of the latter (0.011 ± 0.046) ( P < 0.01). EGFRvIII mRNA was detected only in six samples of laryngeal carcinoma tissues. While, as control, in 39 samples of microscopically normal laryngeal mucosal tissues, EGFRvIII mRNA was hardly detected. As analyzing the correlation between expression of EGFRvIII and EGFR, we found the positive rate of EGFRvIII expression was higher in samples with relative EGFR mRNA value ≥0.025 than those of EGFR mRNA <0.025. The difference between them was statistically significant ( P < 0.05). Conclusions Expression of EGFRvIII in laryngeal carcinoma was confirmed in this study. It is tumor-specific and tends to be more frequent in EGFR-over expressing tumor tissues and poorly differentiated ones, which may in part contribute to the malignant phenotype.