Na,K-ATPase subunits as markers for epithelial-mesenchymal transition in cancer and fibrosis.

Epithelial-to-mesenchymal transition (EMT) is an important developmental process, participates in tissue repair, and occurs during pathologic processes of tumor invasiveness, metastasis, and tissue fibrosis. The molecular mechanisms leading to EMT are poorly understood. Although it is well documented that transforming growth factor (TGF)-beta plays a central role in the induction of EMT, the targets of TGF-beta signaling are poorly defined.

HPAF-II, a cell culture model to study pancreatic epithelial cell structure and function.

Objectives: Epithelial cells have distinct apical and basolateral plasma membrane domains separated by tight junctions. This phenotype is essential for the directional transport functions of epithelial cells. Here we characterized a well-differentiated pancreatic epithelial cell line to establish a useful model for understanding the mechanisms involved in the regulation of junctional complexes, polarity, and disease processes in the pancreas.

Na,K-ATPase beta1-subunit increases the translation efficiency of the alpha1-subunit in MSV-MDCK cells.

The Na,K-ATPase consists of an alpha- and beta-subunit. Moloney sarcoma virus-transformed MDCK cells (MSV-MDCK) express low levels of Na,K-ATPase beta(1)-subunit. Ectopic expression of Na,K-ATPase beta(1)-subunit in these cells increased the protein levels of the alpha(1)-subunit of Na,K-ATPase.

Repression of Na,K-ATPase beta1-subunit by the transcription factor snail in carcinoma.

The Na,K-ATPase consists of two essential alpha- and beta-subunits and regulates the intracellular Na+ and K+ homeostasis. Although the alpha-subunit contains the catalytic activity, it is not active without functional beta-subunit. Here, we report that poorly differentiated carcinoma cell lines derived from colon, breast, kidney, and pancreas show reduced expression of the Na,K-ATPase beta1-subunit.

Analysis of the Na,K-ATPase alpha- and beta-subunit expression profiles of bladder cancer using tissue microarrays.

Background: The purpose of this study was to determine the clinical significance of Na,K-ATPase alpha- and beta-subunit expression in a histopathologically well-characterized group of patients representing a wide spectrum of tumor grades and disease stages with transitional cell carcinomas (TCC).

Methods: Na,K-ATPase alpha- and beta-subunit protein expression patterns were analyzed using immunohistochemistry on urothelial cancer tissue microarrays (TMA) of 146 patients diagnosed with urothelial carcinoma. For each subunit, the maximum staining intensity and the percentage of positive cells staining at the maximal intensity were analyzed.