Cyr61 expression confers resistance to apoptosis in breast cancer MCF-7 cells by a mechanism of NF-κB-dependent XIAP up-regulation
Journal
Journal of Biological Chemistry
Journal Volume
279
Journal Issue
23
Pages
24015-24023
Date Issued
2004
Author(s)
Abstract
The aggressiveness of a tumor is partly attributed to its resistance to chemotherapeutic agent-induced apoptosis. Cysteine-rich 61 (Cyr61), from the CCN gene family, is a secreted and matrix-associated protein, which is involved in many cellular activities such as growth and differentiation. Here we established a cell model system to examine whether stable expression of Cyr61 in MCF-7 cells can confer resistance to apoptosis and identify possible participating mechanisms. We showed that stable cell lines overexpressing Cyr61 had acquired a remarkable resistance to apoptosis induced by paclitaxel, adriamycin, and β-lapachone. Most interesting, gel shift and reporter assays showed that the Cyr61-overexpressing cells had significantly increased NF-κB activity compared with neo control cells. Blockage of NF-κB activity in Cyr61-expressing cells by transfecting with a dominant negative (DN)-IκB or with an NF-κB decoy rendered them more susceptible to anti-cancer drugs-induced apoptosis. In addition, several NF-κB-regulated anti-apoptotic genes were examined, and we found that only XIAP showed a significant 3-4-fold increase in mRNA and protein in Cyr61-overexpressing cells but not in neo control cells. Treatment with inhibitor of apoptosis protein (XIAP)-specific antisense, but not sense, oligonucleotides abolished the apoptosis resistance of the Cyr61-overexpressing cells. At the same time, transfection of these stable cells with DN-IκB to block NF-κB activity also effectively reduced the elevated XIAP level. Function-neutralizing antibodies to αvβ3, and αvβ5 could inhibit Cyr61-mediated NF-κB activation as well as XIAP expression. Taken together, our data suggested that Cyr61 plays an important role in resistance to chemotherapeutic agent-induced apoptosis in human breast cancer MCF-7 cells by a mechanism involving the activation of the integrins/NF-κB/XIAP signaling pathway.
SDGs
Other Subjects
Chemical activation; Gels; Genes; Proteins; RNA; Tumors; Anti-apoptotic genes; Apoptosis; Biochemistry; alphavbeta5 integrin; antisense oligonucleotide; beta lapachone; cysteine rich protein 61; doxorubicin; I kappa B; immunoglobulin enhancer binding protein; integrin; messenger RNA; neutralizing antibody; paclitaxel; unclassified drug; vitronectin receptor; X linked inhibitor of apoptosis; apoptosis; article; breast cancer; cancer resistance; CCN gene; cell differentiation; cell growth; cell strain MCF 7; controlled study; gene; gene overexpression; genetic transfection; human; human cell; priority journal; protein expression; signal transduction; Active Transport, Cell Nucleus; Antibiotics, Antineoplastic; Antineoplastic Agents, Phytogenic; Apoptosis; Blotting, Western; Breast Neoplasms; Cell Division; Cell Line, Tumor; Cell Nucleus; Cell Survival; DNA; Doxorubicin; Flow Cytometry; Genes, Dominant; Genes, Reporter; Humans; Immediate-Early Proteins; Integrin alphaVbeta3; Integrins; Intercellular Signaling Peptides and Proteins; Microscopy, Fluorescence; Models, Biological; Naphthoquinones; NF-kappa B; Oligonucleotides, Antisense; Paclitaxel; Promoter Regions (Genetics); Proteins; Receptors, Vitronectin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Time Factors; Transfection; Up-Regulation; X-Linked Inhibitor of Apoptosis Protein; Mink cell focus-forming virus
Type
journal article