Characterization of Non-Small Cell Lung Cancer Tissue by Quantitative Assessment of Class III β-Tubulin Expression

Background. The cytoskeletal protein β-tubulin class III (Tubb3) is associated with tumor resistance to taxanes and vinca alkaloids, as well as with the metastatic potential of neoplasm, however, data from immunohistochemical analysis of Tubb3 expression in non-small cell lung cancer (NSCLC) tissue are few and contradictory. Purpose. Characterization of the level and intensity of Tubb3 expression in NSCLC tissue and analysis of the identified parameters correlation with clinically significant characteristics of the disease. Methods. Quantitative assessment of the level and intensity of Tubb3 expression in 120 surgical samples of NSCLC was carried out by immunofluorescence method associated with flow cytometry. Primary rabbit monoclonal antibodies specific to Tubb3 and secondary anti-rabbit antibodies conjugated with fluorescent dye DyLight650 (ab98510, UK) were used. The expression of the marker was assessed by two parameters: the level of expression measured as the percentage of the cells expressing Tubb3 and the intensity of expression in conventional units (CU) represented as the ratio of the geometric mean fluorescence intensity in the experimental and control samples (cells incubated with secondary antibodies only). Results. 1. Tubb3 expression was detected in all NSCLC samples studied. The median level and intensity of Tubb3 expression was 30.5% and 2.0 CU with significant differences (up to 10 times) in the quantitative values of both parameters in different patients. 2. The distribution of the studied tumors in terms of the level and intensity of Tubb3 expression differs from normal (P