Increased EGFR mRNA Expression Levels in Non-Small Cell Lung Cancer

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Epidermal growth factor receptor (EGFR) plays a crucial role in cancer development.
• EGFR mutations and expression levels are important biomarkers for predicting response to targeted therapies in non-small cell lung cancer (NSCLC).
• Understanding population-specific variations in EGFR is essential for personalized medicine.

Purpose of the Study:

• To investigate the frequency of EGFR gene mutations (exon 19 and L858R) in the Turkish population.
• To quantify EGFR mRNA and protein expression levels in NSCLC patients.
• To assess the correlation between EGFR parameters and response to EGFR tyrosine kinase inhibitors (TKIs).

Main Methods:

• Analysis of EGFR mutations in exon 19 and exon 21 (L858R) using sequencing and PCR.
• Quantification of EGFR mRNA expression via relative quantitative reverse transcription PCR.
• Detection of EGFR protein levels using immunohistochemistry on paraffin-embedded tumor tissues.

Main Results:

• No EGFR mutations in exon 19 or L858R were detected in the 34 NSCLC patients.
• Overexpression of EGFR mRNA was observed in 47% of patients, and EGFR protein overexpression in 44%.
• No significant correlation was found between demographic/clinical factors and EGFR mRNA/protein overexpression.

Conclusions:

• EGFR mutations in exon 19 and L858R are rare in the Turkish NSCLC population.
• EGFR mRNA expression is significantly increased compared to existing literature, while protein expression is similar.
• Elevated EGFR mRNA levels, in the absence of activating mutations, may serve as a predictive biomarker for TKI response in this population.