Simultaneous expression of flotillin-1, flotillin-2, stomatin and caveolin-1 in non-small cell lung cancer and soft tissue sarcomas.

BACKGROUND

At the present time, there is a lack of data about the involvement of flotillins and stomatin in the development of non-small cell lung cancer (NSCLC) and soft tissue sarcomas (STS). Moreover, changes in expression of members of different families of the microdomain-forming proteins (caveolins and SPFH-domain containing family) are usually investigated independently of each other. In this study we performed a combined analysis of flotillins, stomatin, and caveolin-1 expression in these pathologies and evaluated correlations between generated data and clinicopathological characteristics of the specimens.

METHODS

The protein and mRNA expression was analyzed by Western blotting and real-time PCR, respectively, in tissue specimens of patients undergoing surgery for non-small cell lung cancer and soft tissue sarcomas. Association between expression of studied proteins and patient clinicopathological characteristics or outcome was evaluated.

RESULTS

Stomatin protein expression was down-regulated in 80% of NSCLC samples and this decrease significantly associated with presence of lymph node metastases. Flotillin-2 protein expression was up-regulated in the majority of NSCLC samples whereas caveolin-1α expression was decreased. We revealed a strong correlation between STOM and FLOT-1 mRNA expression in both pathologies, although the gene expression changes were diverse.

CONCLUSIONS

Our data demonstrate for the first time that expression of stomatin, a poorly studied microdomain-forming protein, significantly changes in human tumors, thus pointing to its importance in the progression of NSCLC. We also suggest the existence of some relationship between the expression of these proteins.