Expression of selected miRNA, RARβ and FHIT genes in BALf of squamous cell lung cancer (squamous-cell carcinoma, SCC) patients: a pilot study.

Two suppressor genes which often undergo epigenetic silencing during the early stages of lung carcinogenesis are those encoding retinoic acid receptor-β (RARβ) and Fhit protein (FHIT). RARβ expression is regulated by miRNA-34a and miRNA-141, and FHIT expression by miRNA-143 and miRNA-217. The aim of the study was to assess how selected miRNAs regulate the expression of their targeted genes in bronchoalveolar lavage fluid (BALf), obtained from patients with SCC of the lung. It also examines the relationship between the genetic findings and the clinical and pathomorphological features of the tumor. A total of 50 BALf samples were taken: 25 from patients with SCC and 25 from healthy donors. The expression (RQ) of the selected genes was analyzed by qPCR, as well as the miRNA level, with a particular emphasis on the relationship between the expression of the genes themselves and their corresponding miRNAs; in addition, the expression of the genes and miRNAs were compared with the pathomorphological features of the tumor and the clinical features of patients. Analysis of the RQ values showed downregulation of RARß, FHIT and miRNA-34a and increased expression of miRNA-141, miRNA-143 and miRNA-217 in all BALf samples (P > 0.05). No correlation was found between the expression of the selected genes and corresponding miRNAs, history of smoking, cancer stage, age and sex of the patients. The presence of the selected genes and miRNAs in BALf material does not seem to have diagnostic potential in patients with SCC; however, the results should be verified on a larger group of patients.