A large number of diagnosed cases of lung cancer occur in late stages and are accompanied by metastasis, which makes research into the epithelial-to-mesenchymal transition (EMT) genes relevant. The genes responsible for the EMT include E-cadherin (CDH1), which is involved in the formation of tight junctions between epithelial cells, soluble growth factors, and some transcription factors (e.g., ZEB1, ZEB2).

The aim of this study was to evaluate the expression alterations in BMI1, CDH1, SNAI1, SNAI2, ZEB1, and ZEB2 in tumors compared to histologically normal lung tissues.

The study used 50 paired RNA samples with RIN≥7 isolated from tumors, including 37 non-metastatic and 13 metastatic tumors, and normal lung tissues. The expression levels were assessed by RT-qPCR. B2M and ACTB were used as reference genes. Statistical processing of the results was performed by ANOVA using the CFX Maestro software (Bio-Rad, USA).

The expression of six genes associated with the EMT—BMI1, CDH1, SNAI1, SNAI2, ZEB1, and ZEB2—was analyzed. CDH1 expression increased in 3.63 times in tumors compared to the norm, p ≤ 0.05; moreover, in non-metastatic tumors, it increased by 3.47 times, but in metastatic tumors, it increased by 4.21 times, p ≤ 0.05. ZEB1 and ZEB2 expression decreased by 2.32 and 2.01 times, p ≤ 0.05, and their expression in metastatic tumors decreased by 3.22 and 3.01 times, p ≤ 0.05. The expression levels of BMI1, SNAI1, and SNAI2 changed by a factor of -1.51 to 1.53; however, these data were not statistically significant.

Based on the results of this study, we can conclude that E-cadherin in lung cancer promotes either the epithelial-to-mesenchymal or mesenchymal-to-epithelial transition and, consequently, metastasis. We also showed a suppression of the expression of transcription factors encoded by the ZEB1 and ZEB2. The role of BMI1, SNAI1, and SNAI2 in lung cancer is likely limited, as their expression remains largely unchanged.