The Detection of EGFR Mutation Status with Immunocytochemistry in Circulating Tumor Cells Using Mutation Specific Antibodies
J Yu, CH Hu, DQ Li, XM Zhou, MJ Comb. Cell Signaling Technologg, Danvers, MA; The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; The Second Xiangya Hospital, Changsha, Hunan, China
Background: The somatic mutations in the EGFR gene are found in a subset of lung cancer and are associated with sensitivity to the EGFR tyrosine kinase inhibitors (TKI). Detecting the gene mutations or mutant protein has provided clinicians useful information for the selection of the treatment to this subset of lung cancer patients. The purpose of this study is to develop a fast and reliable clinical assay to detect the status of EGFR mutations without patient tumor tissue.
Design: We used fluorescence immunocytochemistry with mutation-specific antibodies in circulating tumor cells (CTC) or the cells from pleural effusion. This assay detects the proteins of most common EGFR mutations, exon 19 deletion and L858R point mutation, which represent about 90% of EGFR mutations in NSCLC.
Results: We used NSCLC cell lines to verify that the mutation-specific antibodies can specifically detect EGFR mutations and the EpCAM antibody was selectively labeled at the epithelial cells by fluorescence immunocytochemistry.
Next, we tested the cancer cell lines enriched from mixed with blood.
Finally, we confirmed the assay from the cells recovered from the blood or pleural effusion of late stage NSCLC patients.
Conclusions: Fluorescence immunocytochemistry with mutation-specific antibodies to detect EGFR mutations on the tumor cells from blood or pleural effusion is a reliable, easily accessible and cost efficient assay for patient selective to target therapy, especially in the late stage NSCLC patients without tumor tissue or the patients treated by TKI for following up the response.
Category: Pan-genomic/Pan-proteomic Approaches to Diseases
Monday, March 22, 2010 1:00 PM
Poster Session II # 228, Monday Afternoon