Integrin β1, Osmosensing, and Chemoresistance in Mouse Ehrlich Carcinoma Cells

• Published in: Cellular physiology and biochemistry Vol. 36; no. 1; pp. 111 - 132
• Main Authors: Sørensen, Belinda Halling, Rasmussen, Line Jee Hartmann, Broberg, Bjørn Sindballe, Klausen, Thomas Kjær, Sauter, Daniel Peter Rafael, Lambert, Ian Henry, Aspberg, Anders, Hoffmann, Else Kay
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Cell Physiol Biochem Press GmbH & Co KG 2015
• Subjects: Animals; Antineoplastic Agents - pharmacology; Apoptosis; Carcinoma, Ehrlich Tumor - genetics; Carcinoma, Ehrlich Tumor - metabolism; Carcinoma, Ehrlich Tumor - pathology; Caspases - metabolism; Cell Adhesion - drug effects; Cell Line, Tumor; Cell Proliferation - drug effects; Cell Size - drug effects; Cisplatin; Cisplatin - pharmacology; Deoxycytidine - analogs & derivatives; Deoxycytidine - pharmacology; Drug Resistance, Neoplasm; Ehrlich Ascites Tumor Cells; Fibronectins - metabolism; Gemcitabine; Hypotonic cell swelling; Integrin; Integrin beta1 - genetics; Integrin beta1 - metabolism; Mice; Multi-drug-resistance; Original Paper; Osmosis; Taurine - metabolism; Ehrlich Ascites Tumor Cells; Integrin; Gemcitabine; Multi-drug-resistance; Cisplatin; Hypotonic cell swelling
• ISSN: 1015-8987; 1421-9778
• DOI: 10.1159/000374057

Background/Aims: Altered expression of the integrin family of cell adhesion receptors has been associated with initiation, progression, and metastasis of solid tumors as well as in the development of chemoresistance. Here, we investigated the role of integrins, in particular integrin β 1 , in cell volume regulation and drug-induced apoptosis in adherent and non-adherent Ehrlich ascites cell lines. Methods: Adhesion phenotypes were verified by colorimetric cell-adhesion-assay. Quantitative real-time PCR and western blot were used to compare expression levels of integrin subunits. Small interfering RNA was used to silence integrin β 1 expression. Regulatory volume decrease (RVD) after cell swelling was studied with calcein-fluorescence-self-quenching and Coulter counter analysis. Taurine efflux was estimated with tracer technique. Caspase assay was used to determine apoptosis. Results: We show that adherent cells have stronger fibronectin binding and a significantly increased expression of integrin α 5 , α v , and β 1 at mRNA and protein level, compared to non-adherent cells. Knockdown of integrin β 1 reduced RVD of the adherent but not of the non-adherent cells. Efflux of taurine was unaffected. In contrast to non-adherent, adherent cells exhibited chemoresistance to chemotherapeutic drugs (cisplatin and gemcitabine). However, knockdown of integrin β 1 promoted cisplatin-induced caspase activity in adherent cells. Conclusion: Our data identifies integrin β 1 as a part of the osmosensing machinery and regulator of cisplatin resistance in adherent Ehrlich cells.