N-Cadherin And Vimentin Expression In Small Rounded-Shaped Cells Of Non-Functioning Human Pituitary Adenomas

It has been suggested that pituitary macroadenomas present an epithelial-mesenchymal transition (EMT) related with the invasive behavior. This process is characterized by the expression of vimentin and N-cadherin. Accordingly, in a genomic study of non-functioning pituitary macroadenomas (NFPM), an increase in the expression of CDH2 gene was observed. The aim of the present study was to analyze the presence of N-cadherin and vimentin in tissues and cultured cells from NFPM. In order to correlate the cytoskeleton organization with a cell invasion type, the shape and cytoskeletal organization of the cultured cells were determined. In ten NFPM, we analyzed the presence of vimentin and N-cadherin by immunohistochemistry. In the corresponding primary cultures, the distribution of vimentin, beta 4 integrin subunit, N-cadherin, tubulin, and actin filaments were also analyzed. We found that all the NFPM expressed vimentin and N-cadherin. Analyzing the cell size, a significant decrease with respect to normal tissue was observed. In vitro the cells exhibited a small, rounded shape with actin cortical rings and also disorganized microtubules, with different organization patterns of vimentin and N-cadherin. These observations sustain an aggressive comportment and suggest they acquired an amoeboid behavior. These cells showed different organization patterns of vimentin and N-cadherin. Considering these pituitary adenoma cells have lost their secretory phenotype, our observations support the overall change in the physiology of these cells. The NFPM studied expressed the EMT markers vimentin and N-cadherin, suggesting they acquire mesenchymal characteristics, and the small size coincided with that observed in small aggressive cancer cells.