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Efficacy of the hypoxia-activated prodrug evofosfamide (TH-302) in nasopharyngeal carcinoma in vitro and in vivo
BACKGROUND: Tumor hypoxia is considered an important factor in metastasis and disease relapse. Evofosfamide is a hypoxia-activated prodrug that selectively targets the hypoxic regions of solid tumors. As hypoxia-inducible factor-1α (HIF-1α) is overexpressed in nasopharyngeal carcinoma (NPC) tissues,...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5993153/ https://www.ncbi.nlm.nih.gov/pubmed/29764490 http://dx.doi.org/10.1186/s40880-018-0285-0 |
Sumario: | BACKGROUND: Tumor hypoxia is considered an important factor in metastasis and disease relapse. Evofosfamide is a hypoxia-activated prodrug that selectively targets the hypoxic regions of solid tumors. As hypoxia-inducible factor-1α (HIF-1α) is overexpressed in nasopharyngeal carcinoma (NPC) tissues, we performed the present study to evaluate the efficacy profile of evofosfamide in NPC. METHODS: We evaluated the efficacy of evofosfamide as a single agent or combined with cisplatin (DDP) in the NPC cell lines CNE-2, HONE-1 and HNE-1, and in nude mouse xenograft tumor models. RESULTS: Evofosfamide exhibited hypoxia-selective cytotoxicity in NPC cell lines, with 50% inhibition concentration (IC(50)) values of 8.33 ± 0.75, 7.62 ± 0.67, and 0.31 ± 0.07 μmol/L under hypoxia in CNE-2, HONE-1 and HNE-1 cells, respectively. The sensitization ranged from ninefold to greater than 300-fold under hypoxia compared with normoxia controls. The combination of evofosfamide with DDP had a synergistic effect on cytotoxicity in the NPC cell lines by combination index values assessment. Cell cycle G2 phase was arrested after treated with 0.05 μmol/L evofosfamide under hypoxia. Histone H2AX phosphorylation (γH2AX) (a marker of DNA damage) expression increased while HIF-1α expression suppressed after evofosfamide treatment under hypoxic conditions. In the HNE-1 NPC xenograft models, evofosfamide exhibited antitumor activity both as a single agent and combined with DDP. Hypoxic regions in xenograft tissue were reduced after both evofosfamide monotherapy and combined therapy with DDP. CONCLUSIONS: Our results present preclinical evidence for targeting the selective hypoxic portion of NPC by evofosfamide as a single agent and combined with DDP and provide rationale for the potential clinical application of evofosfamide for the treatment of nasopharyngeal carcinoma. |
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