QUANTITATIVE ASSESSMENT OF BETA-III TUBULIN EXPRESSION IN LUNG ADENOCARCINOMA AND SQUAMOUS CELL CARCINOMA

Abstract

Background. Beta-III tubulin (TUBB3) is a tumor-specific isoform of the microtubule protein beta-tubulin. TUBB3 is considered to be a marker of adverse prognosis and tumor resistance to therapy with taxanes and Vinka alkaloids. Association between TUBB3 expression and histological type of the tumor has not been studied properly yet. Objective. The expression level of TUBB3 in non-small cell lung cancer biopsy specimens has been measured on 2 groups of patients with adenocarcinoma and squamous cell carcinoma. Materials and methods. The samples with adenocarcinoma (n = 43) and squamous cell carcinoma (n = 39) were converted to suspension, filtered, fixed with 4 % formaldehyde, stained with monoclonal antibodies for TUBB3 and DyLight 650-conjugated secondary antibodies to mouse IgG and analyzed by flow-cytometry. The method was developed in N.N. Blokhin Russian Cancer Research Center. Results. The average level of TUBB3 expression in the adenocarcinoma group is higher than in the squamous cell carcinoma group (33.1 ± 12.4 % of cells expressing the marker in adenocarcinoma vs. 26.0 ± 13.6 % in squamous cell carcinoma; differences were statistically significant). The average level of TUBB3 expression in adenocarcinoma is 29.7 ± 8.1 % in female and is 34.9 ± 13.9 % in male (differences statistically insignificant). Since the group of patients with adenocarcinoma was presented by both men and women, while the group of patients with squamous cell carcinoma was only men, from the analysis was excluded all female patients. Differences between the groups remained statistically significant. Conclusion. TUBB3 expression in tumor tissue does not depend on the gender, at least among patients with adenocarcinoma of the lung, and at the same time, the level of TUBB3 in adenocarcinoma tissue is higher in comparison with squamous cell carcinoma tissue.