Functional role of α4β1 and α5β1 integrin fibronectin receptors expressed on adriamycin-resistant MCF-7 human mammary carcinoma cells

✍ Scribed by Anna Nista; Carlo Leonetti; Giovanni Bernardini; Manlio Mattioni; Angela Santoni

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: French
• Weight: 337 KB
• Volume: 72
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19970703)72:1<133::aid-ijc19>3.0.co;2-k

✦ Synopsis

Cytofluorimetric and reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that adriamycinresistant (ADR R ), but not sensitive (WT), MCF-7 human mammary carcinoma cell lines express a4b1 and a5b1 integrins. ADR R cells adhere to fibronectin (FN), and only a5b1 is involved in cell adhesion to this glycoprotein, while a4b1 mediates cell binding to the cellular counter-receptor VCAM-1. Proliferation assays showed that FN, but not VCAM-1, delivers a mitogenic signal to quiescent ADR R MCF-7 cells. The activating signal is mediated by a5b1, since cell proliferation is inhibited in the presence of RGD peptide or specific antibody. Cell cycle analysis demonstrated that cell/FN interaction induces the re-entry of ADR R MCF-7 into S phase, and prevents them from undergoing serum deprivation-induced apoptosis. Our data suggest that the presence of a5b1 on the resistant cells enables them to draw advantage from FN for both cell growth and survival. Int.