cyclin-d1 and tolfenamic-acid

Intervention strategies in familial adenomatous polyposis (FAP) patients and other high-risk colorectal cancer (CRC) populations have highlighted a critical need for endoscopy combined with safe and effective preventive agents. We performed transcriptome profiling of colorectal adenomas from FAP patients and the polyposis in rat colon (Pirc) preclinical model, and prioritized molecular targets for prevention studies in vivo. At clinically relevant doses in the Pirc model, the drug Clotam (tolfenamic acid, TA) was highly effective at suppressing tumorigenesis both in the colon and in the small intestine, when administered alone or in combination with Sulindac. Cell proliferation in the colonic crypts was reduced significantly by TA, coincident with increased cleaved caspase-3 and decreased Survivin, β-catenin, cyclin D1 and matrix metalloproteinase 7. From the list of differentially expressed genes prioritized by transcriptome profiling, Mmp7, S100a9, Nppb and Aldh1a3 were defined as key oncogene candidates downregulated in colon tumors after TA treatment. Monthly colonoscopies revealed the rapid onset of tumor suppression by TA in the Pirc model, and the temporal changes in Mmp7, S100a9, Nppb and Aldh1a3, highlighting their value as potential early biomarkers for prevention in the clinical setting. We conclude that TA, an "old drug" repurposed from migraine, offers an exciting new therapeutic avenue in FAP and other high-risk CRC patient populations.

Topics: Adenoma; Adenomatous Polyposis Coli; Aldehyde Oxidoreductases; Animals; beta Catenin; Biomarkers, Tumor; Calgranulin B; Carcinogenesis; Caspase 3; Cell Proliferation; Colorectal Neoplasms; Cyclin D1; Down-Regulation; Gene Expression Profiling; Humans; Male; Matrix Metalloproteinase 7; Oncogenes; ortho-Aminobenzoates; Rats

The nonsteroidal anti-inflammatory drug tolfenamic acid has been shown to suppress cancer cell growth and tumorigenesis in different cancer models. However, the underlying mechanism by which tolfenamic acid exerts its antitumorigenic effect remains unclear. Previous data from our group and others indicate that tolfenamic acid alters expression of apoptosis- and cell-cycle arrest-related genes in colorectal cancer cells. Here, we show that tolfenamic acid markedly reduced the number of polyps and tumor load in APC(min)(/+) mice, accompanied with cyclin D1 downregulation in vitro and in vivo. Mechanistically, tolfenamic acid promotes endoplasmic reticulum (ER) stress, resulting in activation of the unfolded protein response (UPR) signaling pathway, of which PERK-mediated phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) induces the repression of cyclin D1 translation. Moreover, the PERK-eIF2α-ATF4 branch of the UPR pathway plays a role in tolfenamic acid-induced apoptosis in colorectal cancer cells, as silencing ATF4 attenuates tolfenamic acid-induced apoptosis. Taken together, these results suggest ER stress is involved in tolfenamic acid-induced inhibition of colorectal cancer cell growth, which could contribute to antitumorigenesis in a mouse model.

Topics: Activating Transcription Factor 4; Adenomatous Polyposis Coli Protein; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blotting, Western; Cell Transformation, Neoplastic; Colonic Polyps; Colorectal Neoplasms; Cyclin D1; eIF-2 Kinase; Endoplasmic Reticulum Stress; Humans; Immunoprecipitation; Mice; Mice, Inbred C57BL; Mice, Knockout; ortho-Aminobenzoates; Phosphorylation; Protein Serine-Threonine Kinases; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Tumor Cells, Cultured; Unfolded Protein Response