title: Effects of tumor necrosis factor-related apoptosis-inducing ligand alone and in combination with chemotherapeutic agents on patients' colon tumors grown in SCID mice.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to induce apoptosis in a variety of malignant cell lines, but it shows little or no toxicity in most normal cells. We examined the response of three human colon tumors to TRAIL alone and in combination with chemotherapy, using SCID mice engrafted with intact patient surgical specimens. These tumors, taken from fresh surgical specimens, contained the heterogeneous tumor cell population characteristic of patient tumors and showed differential sensitivity to TRAIL alone. We also investigated the effect of TRAIL in combination with chemotherapy, using one tumor that showed moderate sensitivity to TRAIL alone. Combining TRAIL with either 5-fluorouracil (5-FU) or CPT-11 (irinotecan hydrochloride) produced a greatly enhanced antitumor effect over that of either agent alone, with 50% of the animals achieving complete tumor regression with a combination of TRAIL and CPT-11. By histological analysis, tumors treated with TRAIL plus either 5-FU or CPT-11 were seen to consist mainly of connective tissue and fibrotic areas with only a few scattered tumor cells encapsulated in the connective tissue. Several markers were assessed to investigate the basis for the observed therapeutic effect, and significant induction of apoptosis was observed in tumors treated with curative combinations. Cytoplasmic and cell surface expression of the TRAIL receptors DR4 and DR5 was observed in this patient's tumor by immunohistochemistry. Tumors treated with CPT-11 showed increased membrane expression of DR5, suggesting that CPT-11 may increase sensitivity to TRAIL by up-regulation of DR5. These results obtained in a relevant preclinical model support the idea that the use of TRAIL in combination with either 5-FU or CPT-11 may be an effective strategy in controlling human colon cancer.
authors.affiliation: First Department of Surgery, Tottori University School of Medicine, Yonago 683, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Naka
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugamura
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Hylander
authors.forename: Michael B
authors.initials: MB
authors.lastname: Widmer
authors.forename: Youcef M
authors.initials: YM
authors.lastname: Rustum
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Repasky
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D004357:Drug Synergism; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D007150:Immunohistochemistry; D000077146:Irinotecan; D008562:Membrane Glycoproteins / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D016513:Mice, SCID; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D051017:Apoptosis Regulatory Proteins; D008562:Membrane Glycoproteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; C505640:Tnfrsf10b protein, mouse; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000077146:Irinotecan; D005472:Fluorouracil; D002166:Camptothecin