Abstract
Recently, we developed a powerful cytotoxic analogue of bombesin AN-215, in which the bombesin-like carrier peptide Gln–Trp–Ala–Val–Gly–His–Leu–Ψ(CH2-NH)–Leu–NH2 (RC-3094) is conjugated to a potent derivative of doxorubicin, 2-pyrrolinodoxorubicin (AN-201). Small-cell lung carcinomas (SCLCs) are known to express high levels of bombesin receptors. We evaluated whether these receptors could be used for targeting cytotoxic bombesin analogue to H-69 SCLC cells. H-69 cells were xenografted into male nude mice, which then received an intravenous injection of AN-215, cytotoxic radical AN-201, the carrier peptide RC-3094 alone or unconjugated mixture of RC-3094 and AN-201. The levels of mRNA for bombesin receptor subtypes were evaluated by reverse transcription-polymerase chain reaction. In vitro, both the analogue AN-215 and the radical AN-201 showed strong antiproliferative effects on H-69 cells, AN-215 requiring more time to exert its action at 10–8M concentration than AN-201. In vivo, the growth of H-69 SCLC tumours was significantly inhibited by the treatment with 200 nmol kg–1 of AN-215, while equimolar doses of the cytotoxic radical AN-201 or the mixture of AN-201 and the carrier peptide were toxic and produced only a minor tumour inhibition as compared with control groups. mRNA for bombesin receptor subtypes 2 (BRS-2) and 3 (BRS-3) was detected in H-69 tumours. The mRNA levels for BRS-3, but not for BRS-2, were lower in the AN-215-treated tumours as compared with controls. Our results demonstrate that the cytotoxic bombesin analogue AN-215 could be considered for targeted therapy of tumours, such as SCLC, that express bombesin receptors. © 1999 Cancer Research Campaign
Keywords: tumour inhibition, cancer therapy, hormone analogues, tumour targeting, doxorubicin, bombesin receptor, hGRPR, hNMBR, RT-PCR
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- Cuttitta F., Carney D. N., Mulshine J., Moody T. W., Fedorko J., Fischler A., Minna J. D. Bombesin-like peptides can function as autocrine growth factors in human small-cell lung cancer. 1985 Aug 29-Sep 4Nature. 316(6031):823–826. doi: 10.1038/316823a0. [DOI] [PubMed] [Google Scholar]
- Draoui M., Chung P., Park M., Birrer M., Jakowlew S., Moody T. W. Bombesin stimulates c-fos and c-jun mRNAs in small cell lung cancer cells. Peptides. 1995;16(2):289–292. doi: 10.1016/0196-9781(94)00173-1. [DOI] [PubMed] [Google Scholar]
- Fathi Z., Corjay M. H., Shapira H., Wada E., Benya R., Jensen R., Viallet J., Sausville E. A., Battey J. F. BRS-3: a novel bombesin receptor subtype selectively expressed in testis and lung carcinoma cells. J Biol Chem. 1993 Mar 15;268(8):5979–5984. [PubMed] [Google Scholar]
- Koppán M., Halmos G., Arencibia J. M., Lamharzi N., Schally A. V. Bombesin/gastrin-releasing peptide antagonists RC-3095 and RC-3940-II inhibit tumor growth and decrease the levels and mRNA expression of epidermal growth factor receptors in H-69 small cell lung carcinoma. Cancer. 1998 Oct 1;83(7):1335–1343. doi: 10.1002/(sici)1097-0142(19981001)83:7<1335::aid-cncr10>3.0.co;2-5. [DOI] [PubMed] [Google Scholar]
- Mantey S. A., Weber H. C., Sainz E., Akeson M., Ryan R. R., Pradhan T. K., Searles R. P., Spindel E. R., Battey J. F., Coy D. H. Discovery of a high affinity radioligand for the human orphan receptor, bombesin receptor subtype 3, which demonstrates that it has a unique pharmacology compared with other mammalian bombesin receptors. J Biol Chem. 1997 Oct 10;272(41):26062–26071. doi: 10.1074/jbc.272.41.26062. [DOI] [PubMed] [Google Scholar]
- Moody T. W., Carney D. N., Cuttitta F., Quattrocchi K., Minna J. D. High affinity receptors for bombesin/GRP-like peptides on human small cell lung cancer. Life Sci. 1985 Jul 15;37(2):105–113. doi: 10.1016/0024-3205(85)90413-8. [DOI] [PubMed] [Google Scholar]
- Moody T. W., Cuttitta F. Growth factor and peptide receptors in small cell lung cancer. Life Sci. 1993;52(14):1161–1173. doi: 10.1016/0024-3205(93)90098-n. [DOI] [PubMed] [Google Scholar]
- Nagalla S. R., Barry B. J., Creswick K. C., Eden P., Taylor J. T., Spindel E. R. Cloning of a receptor for amphibian [Phe13]bombesin distinct from the receptor for gastrin-releasing peptide: identification of a fourth bombesin receptor subtype (BB4). Proc Natl Acad Sci U S A. 1995 Jun 20;92(13):6205–6209. doi: 10.1073/pnas.92.13.6205. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagy A., Armatis P., Cai R. Z., Szepeshazi K., Halmos G., Schally A. V. Design, synthesis, and in vitro evaluation of cytotoxic analogs of bombesin-like peptides containing doxorubicin or its intensely potent derivative, 2-pyrrolinodoxorubicin. Proc Natl Acad Sci U S A. 1997 Jan 21;94(2):652–656. doi: 10.1073/pnas.94.2.652. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagy A., Armatis P., Schally A. V. High yield conversion of doxorubicin to 2-pyrrolinodoxorubicin, an analog 500-1000 times more potent: structure-activity relationship of daunosamine-modified derivatives of doxorubicin. Proc Natl Acad Sci U S A. 1996 Mar 19;93(6):2464–2469. doi: 10.1073/pnas.93.6.2464. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Orosz A., Schrett J., Nagy J., Bartha L., Schön I., Nyéki O. New short-chain analogs of a substance-P antagonist inhibit proliferation of human small-cell lung-cancer cells in vitro and in vivo. Int J Cancer. 1995 Jan 3;60(1):82–87. doi: 10.1002/ijc.2910600112. [DOI] [PubMed] [Google Scholar]
- Pastan I., FitzGerald D. Recombinant toxins for cancer treatment. Science. 1991 Nov 22;254(5035):1173–1177. doi: 10.1126/science.1683495. [DOI] [PubMed] [Google Scholar]
- Pinski J., Schally A. V., Halmos G., Szepeshazi K., Groot K., O'Byrne K., Cai R. Z. Effects of somatostatin analogue RC-160 and bombesin/gastrin-releasing peptide antagonists on the growth of human small-cell and non-small-cell lung carcinomas in nude mice. Br J Cancer. 1994 Nov;70(5):886–892. doi: 10.1038/bjc.1994.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Plonowski A., Schally A. V., Nagy A., Sun B., Szepeshazi K. Inhibition of PC-3 human androgen-independent prostate cancer and its metastases by cytotoxic somatostatin analogue AN-238. Cancer Res. 1999 Apr 15;59(8):1947–1953. [PubMed] [Google Scholar]
- Plumb J. A., Milroy R., Kaye S. B. Effects of the pH dependence of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan absorption on chemosensitivity determined by a novel tetrazolium-based assay. Cancer Res. 1989 Aug 15;49(16):4435–4440. [PubMed] [Google Scholar]
- Schally A. V., Nagy A. Cancer chemotherapy based on targeting of cytotoxic peptide conjugates to their receptors on tumors. Eur J Endocrinol. 1999 Jul;141(1):1–14. doi: 10.1530/eje.0.1410001. [DOI] [PubMed] [Google Scholar]
- Spindel E. R., Giladi E., Segerson T. P., Nagalla S. Bombesin-like peptides: of ligands and receptors. Recent Prog Horm Res. 1993;48:365–391. doi: 10.1016/b978-0-12-571148-7.50017-8. [DOI] [PubMed] [Google Scholar]
- Szepeshazi K., Milovanovic S., Lapis K., Groot K., Schally A. V. Growth inhibition of estrogen independent MXT mouse mammary carcinomas in mice treated with an agonist or antagonist of LH-RH, an analog of somatostatin, or a combination. Breast Cancer Res Treat. 1992;21(3):181–192. doi: 10.1007/BF01975001. [DOI] [PubMed] [Google Scholar]
- Toi-Scott M., Jones C. L., Kane M. A. Clinical correlates of bombesin-like peptide receptor subtype expression in human lung cancer cells. Lung Cancer. 1996 Nov;15(3):341–354. doi: 10.1016/0169-5002(95)00597-8. [DOI] [PubMed] [Google Scholar]