title: Epidermal growth factor receptor-mediated tissue transglutaminase overexpression couples acquired tumor necrosis factor-related apoptosis-inducing ligand resistance and migration through c-FLIP and MMP-9 proteins in lung cancer cells.
abstract: Acquired chemoresistance not only blunts anticancer therapy but may also promote cancer cell migration and metastasis. Our previous studies have revealed that acquired tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance in lung cancer cells is associated with Akt-mediated stabilization of cellular caspase 8 and Fas-associated death domain (FADD)-like apoptosis regulator-like inhibitory protein (c-FLIP) and myeloid cell leukemia 1 (Mcl-1). In this report, we show that cells with acquired TRAIL resistance have significantly increased capacities in migration and invasion. By gene expression screening, tissue transglutaminase (TGM2) was identified as one of the genes with the highest expression increase in TRAIL-resistant cells. Suppressing TGM2 dramatically alleviated TRAIL resistance and cell migration, suggesting that TGM2 contributes to these two phenotypes in TRAIL-resistant cells. TGM2-mediated TRAIL resistance is likely through c-FLIP because TGM2 suppression significantly reduced c-FLIP but not Mcl-1 expression. The expression of matrix metalloproteinase 9 (MMP-9) was suppressed when TGM2 was inhibited, suggesting that TGM2 potentiates cell migration through up-regulating MMP-9 expression. We found that EGF receptor (EGFR) was highly active in the TRAIL-resistant cells, and suppression of EGFR dramatically reduced TGM2 expression. We further determined JNK and ERK, but not Akt and NF-κB, are responsible for EGFR-mediated TGM2 expression. These results identify a novel pathway that involves EGFR, MAPK (JNK and ERK), and TGM2 for acquired TRAIL resistance and cell migration in lung cancer cells. Because TGM2 couples TRAIL resistance and cell migration, it could be a molecular target for circumventing acquired chemoresistance and metastasis in lung cancer.
authors.affiliation: Molecular Biology and Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA.
authors.forename: Zi
authors.initials: Z
authors.lastname: Li
authors.forename: Xiuling
authors.initials: X
authors.lastname: Xu
authors.forename: Lang
authors.initials: L
authors.lastname: Bai
authors.forename: Wenshu
authors.initials: W
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Lin
mesh_terms: D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D066246:ErbB Receptors / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D019204:GTP-Binding Proteins; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D011503:Transglutaminases / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C000717608:TGM2 protein, human; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4; D020780:Matrix Metalloproteinase 9; D019204:GTP-Binding Proteins