title: Enhanced anti-colorectal cancer effects of carfilzomib combined with CPT-11 via downregulation of nuclear factor-κB in vitro and in vivo.
abstract: Upregulation of nuclear factor-κB (NF-κB) in colorectal carcinoma (CRC) accelerates tumor growth, whereas, irinotecan (CPT-11)-induced NF-κB activation reduces chemosensitivity and weakens the anti-colorectal cancer function itself, while proteasome inhibitors can inhibit NF-κB and improve the effect of chemotherapy. Carfilzomib (CFZ) is a novel proteasome inhibitor that has been recently approved by the FDA and is in clinical use for the treatment of multiple myeloma, but little is known about its activity against CRC. The aim of the present study was to explore whether CFZ alone or in combination with CPT-11 is effective in CRC treatment. We evaluated the novel therapeutic ability and mechanism of action of CFZ in CRC in vitro and in vivo. SW620 cells were incubated with CFZ alone or in combination with CPT-11. Cell proliferation was assessed by WST-1 and clonogenic assays, the cytotoxic interaction was assessed with a combination index (CI). Cell cycle progression was analysed with flow cytometry. Cell apoptosis was evaluated by detecting the Annexin V/propidium iodide (PI) ratio, caspase 3 and CD95 expression, and with TUNEL staining. Cell migration and invasion was determined with a wound-healing assay and a Transwell matrix penetration assay. A CRC xenograft model was established to monitor tumor growth. EMSA was used to analyse NF-κB activation and western blot analysis was used to detect the protein levels of related signaling factors. CFZ significantly inhibited the growth of SW620 cells, and had synergistic inhibitory effects with CPT-11 on survival and colony formation; possibly by inhibition of NF-κB activation, MEK/ERK and PI3K/AKT pathway factor dephosphorylation and survivin downregulation. Co-administration of CFZ and CPT-11 induced G2/M arrest, increased p21WAF1/CIP, and decreased mutant p53 and cdc25c expression. Induction of apoptosis was accompanied by marked increases in PARP cleavage, caspase 3 activation, an increase of CD95 and p-p38, and ATF3 activation. Combination treatment lowered the invasive and migration ability of SW620 cells, reduced MMP and increased TIMP protein expression. Finally, co-administration of CFZ and CPT-11 suppressed tumor growth and increased apoptosis compared with single-agent treatment in SW620 xenograft models correlated with NF-κB downregulation. Carfilzomib alone or in combination with CPT-11 is effective against colorectal cancer through inhibition of multiple mechanisms related to NF-κB, and could be a potential novel therapy for CRC.
authors: Graduate School of Education, Fujian Medical University, Fuzhou, P.R. China.
authors: Weiwei
authors: W
authors: Tang
authors: Graduate School of Education, Fujian Medical University, Fuzhou, P.R. China.
authors: Guangjian
authors: G
authors: Su
authors: Graduate School of Education, Fujian Medical University, Fuzhou, P.R. China.
authors: Jieyu
authors: J
authors: Li
authors: Graduate School of Education, Fujian Medical University, Fuzhou, P.R. China.
authors: Jinrong
authors: J
authors: Liao
authors: Laboratory of Immuno-Oncology, Fujian Provincial Cancer Hospital, Fuzhou, P.R. China.
authors: Shuping
authors: S
authors: Chen
authors: Laboratory of Immuno-Oncology, Fujian Provincial Cancer Hospital, Fuzhou, P.R. China.
authors: Chuanzhong
authors: C
authors: Huang
authors: Laboratory of Immuno-Oncology, Fujian Provincial Cancer Hospital, Fuzhou, P.R. China.
authors: Fang
authors: F
authors: Liu
authors: Graduate School of Education, Fujian Medical University, Fuzhou, P.R. China.
authors: Qiang
authors: Q
authors: Chen
authors: Graduate School of Education, Fujian Medical University, Fuzhou, P.R. China.
authors: Yunbin
authors: Y
authors: Ye
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004357:Drug Synergism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D066298:In Vitro Techniques; D000077146:Irinotecan; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental; D009842:Oligopeptides / Q000008:administration & dosage* / Q000627:therapeutic use; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays; D000097782:NF-kappaB-Inducing Kinase
chemical_list: D000970:Antineoplastic Agents; D002166:Camptothecin; D000077146:Irinotecan; D009842:Oligopeptides; D017346:Protein Serine-Threonine Kinases; D000097782:NF-kappaB-Inducing Kinase; C524865:carfilzomib