[1632] Evaluation of 18 miRNAs in Non-Small Cell Lung Carcinoma According to Its Clinical Stage

A Quera, A Navarro, A Huerta, R Marrades, N Vinolas, M Monzo, J Ramirez. Hospital Clinic, Barcelona, Spain; Facultat Medicina UB, Barcelona, Spain

Background: microRNA (miRNA) are small molecules of RNA that act as negative regulators in proteic synthesis. They are encoded in intronic or intergenic regions. Its function is performed in the cytoplasm where they bind specific messenger RNAs and downregulate its translation. They do participate in the regulation of multiple biologic processes, with cancer among them.
Design: Aim: To determine the expression of miRNA in normal lung tissue as well as in neoplasic tissue. To analyze the relationship among them in different stages of tumoral disease according to the TNM. Methods: We analyzed 62 bronchial biopsies (31 tumoral and 31 normal) obtained from fibrobronchoscopy corresponding to 31 patients with non-small cell lung carcinoma (NSCLC). We determined the expression of 18 miRNA by real time RT-PCR and performed the analysis of data with SPSS.
Results: The hierarchical clustering of miRNA expression showed statistically significant differences between the following groups: Tumoral tissue vs. normal tissue: There is an underexpression of let-7c and overexpression of miR 17-5p, miR 19a and miR-221, that are involved in carcinogenesis and cell proliferation. NSCLC stage I vs. all other stages: We found underexpression of miRNA of the let-7 family (let-7a, let-7c amd let-7e) (p=0.015) and overexpression of miR 17-5p, miR 19a and miR-221. NSCLC stage IV vs. all others: We found an overexpression of miR 21, miR 491 and miR 502 (miRNAs involved in the diminution of apoptosis and cellular polarization).
Conclusions: The results indicate that miRNA expression profiles are diagnostic and prognostic markers of NSCLC. The miRNA studies give us information about both the biology of these tumors and the staging. These miRNAs may be good targets for new therapeutic strategies. With the support of: FIS060087, SEPAR06, CIBER DE ENFERMEDADES RESPIRATORIAS 06/06/0028
Category: Pulmonary

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 221, Tuesday Afternoon