Abstract
Some brain tumours, such as glioblastomas express high levels of receptors for bombesin/gastrin releasing peptide. We investigated whether bombesin/gastrin releasing peptide receptors found in glioblastoma cell lines can be utilised for targeting of a cytotoxic bombesin analogue, AN-215 consisting of a potent derivative of doxorubicin, 2-pyrrolino-doxorubicin (AN-201) linked to a bombesin-like peptide carrier. This study reports the effect of AN-215 on the growth of U-87MG human glioblastomas xenografted into nude mice. High affinity binding of AN-215 to U-87MG tumours was characterised by an IC50 value of 4.0 ± 0.1 nM, as determined by radioreceptor assays. mRNA analyses revealed the presence of mRNA for BN receptor subtypes 1 and 2. Treatment with AN-215 significantly (P < 0.05) extended tumour doubling time from 4.54 ± 0.2 days to 8.18 ± 1.8 days and inhibited tumour growth as demonstrated by a 69.6% reduction in final tumour volume (P < 0.001) and a 64.6% decrease in tumour weight as compared to controls. Cytotoxic radical AN-201 at the same dose was ineffective. The antitumour effect of AN-215 could be blocked by pretreatment with an excess of a bombesin antagonist, indicating that the action of this cytotoxic analogue is receptor-mediated. Our results suggest that patients with inoperable brain tumours such as malignant gliomas may benefit from targeted chemotherapy based on cytotoxic bombesin analogue AN-215.
Original language | English (US) |
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Pages (from-to) | 1322-1327 |
Number of pages | 6 |
Journal | British Journal of Cancer |
Volume | 86 |
Issue number | 8 |
DOIs | |
State | Published - Apr 22 2002 |
Keywords
- Bombesin receptor
- Doxorubicin
- RT-PCR
- Tumour targeting
ASJC Scopus subject areas
- Cancer Research
- Oncology