Journal article
Potentiation of irinotecan sensitivity by Se-methylselenocysteine in an in vivo tumor model is associated with downregulation of cyclooxygenase-2, inducible nitric oxide synthase, and hypoxia-inducible factor 1α expression, resulting in reduced angiogenesis
Oncogene, Vol.25(17), pp.2509-2519
2006
DOI: 10.1038/sj.onc.1209073
PMID: 16518418
Abstract
Until recently, the use of Se-methylselenocysteine (MSC) as selective modulator of the antitumor activity and selectivity of anticancer drugs including irinotecan, a topoisomerase I poison, had not been evaluated. Therapeutic synergy between MSC and irinotecan was demonstrated by our laboratory in mice bearing human squamous cell carcinoma of the head and neck tumors. In FaDu xenografts, a poorly differentiated tumor-expressing mutant p53, the cure rate was increased from 30% with irinotecan alone to 100% with the combination of irinotecan and MSC. Cellular exposure to cytotoxic concentration of SN-38, the active metabolite of irinotecan (0.1 microM) alone and in combination with noncytotoxic concentration of MSC (10 microM) did not result in additional enhancement of chk2 phosphorylation and downregulation of specific DNA replication-associated proteins, cdc6, MCM2, cdc25A, nor increase in PARP cleavage, caspase activation and the 30-300 kb DNA fragmentation induced by SN-38 treatment. MSC did not alter significantly markers associated with apoptosis, nor potentiate irinotecan-induced apoptosis. These results indicate that apoptosis is unlikely to be one of the main mechanism associated with the observed in vivo therapeutic synergy. In contrast, significant downregulation of cyclooxygenase-2 (COX-2) expression and activity was observed in the cells exposed to SN-38 in combination with MSC compared to SN-38 alone. Moreover, the inhibition of PGE(2) production was also observed in the cells treated with the combination as compared with SN-38 alone. Analysis of tumor tissues at 24 h after treatment with synergistic modality of irinotecan and MSC revealed significant downregulation of COX-2, inducible nitric oxide synthase (iNOS) and hypoxia-induced factor-1alpha expression (HIF 1alpha). Moreover, decreased microvessel density was observed after irinotecan treatment with the addition of MSC. These results suggest that observed therapeutic synergy correlates with the inhibition of neoangiogenesis through the downregulation of COX-2, iNOS and HIF-1alpha expression.
Details
- Title: Subtitle
- Potentiation of irinotecan sensitivity by Se-methylselenocysteine in an in vivo tumor model is associated with downregulation of cyclooxygenase-2, inducible nitric oxide synthase, and hypoxia-inducible factor 1α expression, resulting in reduced angiogenesis
- Creators
- M. B Yin - Roswell Park Cancer InstituteZ. R LI - Roswell Park Cancer InstituteK Toth - Roswell Park Cancer InstituteS Cao - Roswell Park Cancer InstituteF. A Durrani - Roswell Park Cancer InstituteG Hapke - Roswell Park Cancer InstituteA Bhattacharya - Roswell Park Cancer InstituteR. G Azrak - Roswell Park Cancer InstituteC Frank - Roswell Park Cancer InstituteY. M Rustum - Roswell Park Cancer Institute
- Resource Type
- Journal article
- Publication Details
- Oncogene, Vol.25(17), pp.2509-2519
- Publisher
- Nature Publishing
- DOI
- 10.1038/sj.onc.1209073
- PMID
- 16518418
- ISSN
- 0950-9232
- eISSN
- 1476-5594
- Language
- English
- Date published
- 2006
- Academic Unit
- Hematology, Oncology, and Blood & Marrow Transplantation; Internal Medicine
- Record Identifier
- 9984360053102771
Metrics
11 Record Views