Arf6, RalA, and BIRC5 protein expression in nonsmall cell lung cancer

Evaluation of tumor marker expression pattern that determines individual progression parameters is one of the major topics in molecular oncopathology research. This work represents research on expression analysis of several Ras-Ral associated signal transduction pathway proteins (Arf6, RalA, and BIRC5) in accordance with clinical criteria in nonsmall cell lung cancer patients. Using Western-blot analysis and RT-PCR Arf6, RalA, and BIRC5, expression has been analyzed in 53 nonsmall cell lung cancer samples of different origin. Arf6 protein expression was increased in 55% nonsmall cell lung cancer tumor samples in comparison with normal tissue. In the group of squamous cell lung cancer, increase of Arf6 expression was observed more often. RalA protein expression was decreased in comparison to normal tissue samples in 64% of nonsmall cell lung cancer regardless of morphological structure. Correlation between the decrease of RalA protein expression and the absence of regional metastases was revealed for squamous cell lung cancer. BIRC5 protein expression in tumor samples versus corresponding normal tissue was 1.3 times more often elevated in the squamous cell lung cancer group (in 76% tumor samples). At the same time, increase of BIRC5 expression was detected only in 63% of adenocarcinoma tumor samples. A statistically significant decrease (p = 0.015) of RalA protein expression and the increase (p = 0.049) of Arf6 protein expression in comparison with normal tissue was found in T(1-2)N(0)M(0) and T(1-2)N(1-2)M(0) groups of squamous cell lung cancer, respectively.