title: Targeting FLIP and Mcl-1 using a combination of aspirin and sorafenib sensitizes colon cancer cells to TRAIL.
abstract: The multikinase inhibitor sorafenib is highly effective against certain types of cancer in the clinic and prevents colon cancer cell proliferation in vitro. Non-steroidal anti-inflammatory drugs, such as acetylsalicylic acid (aspirin), have shown activity against colon cancer cells. The aims of this study were to determine whether the combination of aspirin with sorafenib has enhanced anti-proliferative effects and increases recombinant human tumour necrosis factor-related apoptosis-inducing ligand (rhTRAIL)-induced apoptosis in the human SW948, Lovo, Colo205, Colo320, Caco-2 and HCT116 colon cancer cell lines. In four cell lines, aspirin strongly stimulated the anti-proliferative effects of sorafenib (∼four-fold enhancement) by inducing cell cycle arrest. Furthermore, combining low doses of aspirin (≤ 5 mm) and sorafenib (≤ 2.5 µm) greatly sensitized TRAIL-sensitive and TRAIL-resistant colon cancer cells to rhTRAIL, much more potently than either drug combined with rhTRAIL. The increase in rhTRAIL sensitivity was due to inhibition of FLIP and Mcl-1 protein expression following aspirin and sorafenib co-treatment, as confirmed by knock-down studies. Next, the clinical relevance of targeting FLIP and Mcl-1 in colon cancer was examined. Using immunohistochemistry, we found that Mcl-1 expression was significantly increased in colon adenoma and carcinoma patient material compared to healthy colonic epithelium, similar to the enhanced FLIP expression we recently observed in colon cancer. These results underscore the potential of combining low doses of aspirin with sorafenib to inhibit proliferation and target the anti-apoptotic proteins FLIP and Mcl-1 in colon cancer cells.
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Centre Groningen, The Netherlands.
authors.forename: Bodvael
authors.initials: B
authors.lastname: Pennarun
authors.forename: Jan H
authors.initials: JH
authors.lastname: Kleibeuker
authors.forename: Wytske
authors.initials: W
authors.lastname: Boersma-van Ek
authors.forename: Frank A E
authors.initials: FA
authors.lastname: Kruyt
authors.forename: Harry
authors.initials: H
authors.lastname: Hollema
authors.forename: Elisabeth G E
authors.initials: EG
authors.lastname: de Vries
authors.forename: Steven
authors.initials: S
authors.lastname: de Jong
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001241:Aspirin / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004359:Drug Therapy, Combination; D055785:Gene Knockdown Techniques; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D010671:Phenylurea Compounds / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011994:Recombinant Proteins; D000077157:Sorafenib; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism / Q000494:pharmacology*; D014410:Tumor Stem Cell Assay
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D010671:Phenylurea Compounds; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C434062:TNIP2 protein, human; D009536:Niacinamide; D000077157:Sorafenib; D001241:Aspirin