J Cancer 2017; 8(1):146-151. doi:10.7150/jca.16108
Low Incidence along with Low mRNA Levels of EGFRvIII in Prostate and Colorectal Cancers Compared to Glioblastoma
1. Department of Research and Development, Celther Polska, Ltd., Milionowa 23, 93-193 Lodz, Poland;
2. Department of Tumor Biology, Medical University of Lodz, Zeligowskiego 7/9, 90-752 Lodz, Poland;
3. Clinical Department of Neurosurgery, The Voivodal Specialistic Hospital in Olsztyn, Zolnierska 18, 10-561 Olsztyn, Poland.
Peciak J, Stec WJ, Treda C, Ksiazkiewicz M, Janik K, Popeda M, Smolarz M, Rosiak K, Hulas-Bigoszewska K, Och W, Rieske P, Stoczynska-Fidelus E. Low Incidence along with Low mRNA Levels of EGFRvIII in Prostate and Colorectal Cancers Compared to Glioblastoma. J Cancer 2017; 8(1):146-151. doi:10.7150/jca.16108. Available from http://www.jcancer.org/v08p0146.htm
Background: The presence as well as the potential role of EGFRvIII in tumors other than glioblastoma still remains a controversial subject with many contradictory data published. Previous analyses, however, did not consider the level of EGFRvIII mRNA expression in different tumor types. Methods: Appropriately designed protocol for Real-time quantitative reverse-transcription PCR (Real-time qRT-PCR) was applied to analyze EGFRvIII and EGFRWT mRNA expression in 155 tumor specimens. Additionally, Western Blot (WB) analysis was performed for selected samples. Stable cell lines showing EGFRvIII expression (CAS-1 and DK-MG) were analyzed by means of WB, immunocytochemistry (ICC) and fluorescence in situ hybridization (FISH). Results: Our analyses revealed EGFRvIII expression in 27.59% of glioblastomas (8/29), 8.11% of colorectal cancers (3/37), 6.52% of prostate cancers (3/46) and none of breast cancers (0/43). Despite the average relative expression of EGFRvIII varying greatly among tumors of different tissues (approximately 800-fold) or even within the same tissue group (up to 8000-fold for GB), even the marginal expression of EGFRvIII mRNA can be detrimental to cancer progression, as determined by the analysis of stable cell lines endogenously expressing the oncogene.
Conclusion: EGFRvIII plays an unquestionable role in glioblastomas with high expression of this oncogene. Our data suggests that EGFRvIII importance should not be underestimated even in tumors with relatively low expression of this oncogene.
Keywords: EGFRvIII, prostate cancer, colorectal cancer, breast cancer, glioblastoma, Real-time quantitative reverse-transcription PCR.