Abstract
Indomethacin-induced G(1) arrest and apoptosis of human colorectal cancer (CRC) cells is associated with a dose-dependent decrease in beta-catenin protein levels. Beta-catenin plays a pivotal role in the WNT signalling pathway and its expression is frequently dysregulated at early stages of colorectal carcinogenesis. The objective of this study was to investigate the effect of indomethacin on catenin expression and downstream WNT signalling events in human CRC cells. Beta-catenin, gamma-catenin and T-cell factor (TCF) target gene (cyclin D1, c-MYC and PPARdelta) expression was studied following indomethacin treatment of SW480 and HCT116 cells. Cyclin D1 was used as a model TCF target gene for analysis of beta-catenin-TCF-4 DNA binding and trans-activation. Indomethacin treatment was associated with a specific decrease in beta-catenin (but not gamma-catenin) expression. Resulting TCF target gene expression was gene specific (cyclin D1, decreased; c-MYC, increased; PPARdelta, no significant change). Cyclin D1 promoter analysis revealed that indomethacin disrupted formation of a beta-catenin-TCF-4-DNA complex. Indomethacin-induced G(1) arrest and apoptosis is associated with specific beta-catenin down-regulation in human CRC cells in vitro. Differential expression of TCF target genes following indomethacin treatment implies complex effects on multiple genes which play an important role in colorectal carcinogenesis.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Acetylcysteine / analogs & derivatives*
-
Acetylcysteine / pharmacology
-
Blotting, Western
-
Colorectal Neoplasms / genetics
-
Colorectal Neoplasms / metabolism*
-
Cyclin D1 / genetics
-
Cyclin D1 / metabolism
-
Cytoskeletal Proteins / genetics
-
Cytoskeletal Proteins / metabolism*
-
DNA / genetics
-
DNA / metabolism
-
Desmoplakins
-
Dose-Response Relationship, Drug
-
Down-Regulation / drug effects*
-
Electrophoretic Mobility Shift Assay
-
Gene Expression Regulation, Neoplastic / drug effects*
-
Humans
-
Indomethacin / pharmacology*
-
Interleukin-2 / genetics*
-
Isoenzymes / metabolism
-
Nitrobenzenes / pharmacology
-
Promoter Regions, Genetic / genetics
-
Protein Kinase C / metabolism
-
Protein Kinase C beta
-
Proto-Oncogene Proteins c-myc / genetics
-
RNA, Messenger / genetics
-
RNA, Messenger / metabolism
-
Receptors, Cytoplasmic and Nuclear / genetics
-
Sulfonamides / pharmacology
-
Trans-Activators*
-
Transcription Factors / genetics
-
Tumor Cells, Cultured
-
beta Catenin
-
gamma Catenin
Substances
-
CTNNB1 protein, human
-
Cytoskeletal Proteins
-
Desmoplakins
-
Interleukin-2
-
Isoenzymes
-
JUP protein, human
-
Nitrobenzenes
-
Proto-Oncogene Proteins c-myc
-
RNA, Messenger
-
Receptors, Cytoplasmic and Nuclear
-
Sulfonamides
-
Trans-Activators
-
Transcription Factors
-
beta Catenin
-
gamma Catenin
-
N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide
-
lactacystin
-
Cyclin D1
-
DNA
-
Protein Kinase C
-
Protein Kinase C beta
-
Acetylcysteine
-
Indomethacin