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Lau J, Rousseau E, Zhang Z, Uribe CF, Kuo HT, Zeisler J, Zhang C, Kwon D, Lin KS, Bénard F. Positron Emission Tomography Imaging of the Gastrin-Releasing Peptide Receptor with a Novel Bombesin Analogue. ACS OMEGA 2019; 4:1470-1478. [PMID: 30775647 PMCID: PMC6372246 DOI: 10.1021/acsomega.8b03293] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/03/2019] [Indexed: 06/09/2023]
Abstract
The gastrin-releasing peptide receptor (GRPR), a G protein-coupled receptor, is overexpressed in solid malignancies and particularly in prostate cancer. We synthesized a novel bombesin derivative, [68Ga]Ga-ProBOMB1, evaluated its pharmacokinetics and potential to image GRPR expression with positron emission tomography (PET), and compared it with [68Ga]Ga-NeoBOMB1. ProBOMB1 (DOTA-pABzA-DIG-d-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-ψ(CH2N)-Pro-NH2) was synthesized by solid-phase peptide synthesis. The polyaminocarboxylate chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was coupled to the N-terminal and separated from the GRPR-targeting sequence by a p-aminomethylaniline-diglycolic acid (pABzA-DIG) linker. The binding affinity to GRPR was determined using a cell-based competition assay, whereas the agonist/antagonist property was determined with a calcium efflux assay. ProBOMB1 was radiolabeled with 68GaCl3. PET imaging and biodistribution studies were performed in male immunocompromised mice bearing PC-3 prostate cancer xenografts. Blocking experiments were performed with coinjection of [d-Phe6,Leu-NHEt13,des-Met14]bombesin(6-14). Dosimetry calculations were performed with OLINDA software. ProBOMB1 and the nonradioactive Ga-ProBOMB were obtained in 1.1 and 67% yield, respectively. The K i value of Ga-ProBOMB1 for GRPR was 3.97 ± 0.76 nM. Ga-ProBOMB1 behaved as an antagonist for GRPR. [68Ga]Ga-ProBOMB1 was obtained in 48.2 ± 10.9% decay-corrected radiochemical yield with 121 ± 46.9 GBq/μmol molar activity and >95% radiochemical purity. Imaging/biodistribution studies showed that the excretion of [68Ga]Ga-ProBOMB1 was primarily through the renal pathway. At 1 h postinjection (p.i.), PC-3 tumor xenografts were clearly delineated in PET images with excellent contrast. The tumor uptake for [68Ga]Ga-ProBOMB1 was 8.17 ± 2.57 percent injected dose per gram (% ID/g) and 9.83 ± 1.48% ID/g for [68Ga]Ga-NeoBOMB1, based on biodistribution studies at 1 h p.i. This corresponded to tumor-to-blood and tumor-to-muscle uptake ratios of 20.6 ± 6.79 and 106 ± 57.7 for [68Ga]Ga-ProBOMB1 and 8.38 ± 0.78 and 39.0 ± 12.6 for [68Ga]Ga-NeoBOMB1, respectively. Blockade with [d-Phe6,Leu-NHEt13,des-Met14]bombesin(6-14) significantly reduced the average uptake of [68Ga]Ga-ProBOMB1 in tumors by 62%. The total absorbed dose was lower for [68Ga]Ga-ProBOMB1 in all organs except for bladder compared with [68Ga]Ga-NeoBOMB1. Our data suggest that [68Ga]Ga-ProBOMB1 is an excellent radiotracer for imaging GRPR expression with PET. [68Ga]Ga-ProBOMB1 achieved a similar uptake as [68Ga]Ga-NeoBOMB1 in tumors, with enhanced contrast and lower whole-body absorbed dose.
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Affiliation(s)
- Joseph Lau
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Etienne Rousseau
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
- Département
de Médecine Nucléaire et Radiobiologie, Université de Sherbrooke, 3001 12e Avenue Nord, J1H 5N4 Sherbrooke, Quebec, Canada
| | - Zhengxing Zhang
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Carlos F. Uribe
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Hsiou-Ting Kuo
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Jutta Zeisler
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Chengcheng Zhang
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Daniel Kwon
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
| | - Kuo-Shyan Lin
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
- Department
of Radiology, University of British Columbia, 2211 Wesbrook Mall, V6T 1Z7 Vancouver, British Columbia, Canada
| | - François Bénard
- Department
of Molecular Oncology, BC Cancer Research
Centre, 675 West 10th
Avenue, V5Z 1L3 Vancouver, British Columbia, Canada
- Department
of Radiology, University of British Columbia, 2211 Wesbrook Mall, V6T 1Z7 Vancouver, British Columbia, Canada
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Cancer treatment using peptides: current therapies and future prospects. JOURNAL OF AMINO ACIDS 2012; 2012:967347. [PMID: 23316341 PMCID: PMC3539351 DOI: 10.1155/2012/967347] [Citation(s) in RCA: 296] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/07/2012] [Indexed: 12/12/2022]
Abstract
This paper discusses the role of peptides in cancer therapy with special emphasis on peptide drugs which are already approved and those in clinical trials. The potential of peptides in cancer treatment is evident from a variety of different strategies that are available to address the progression of tumor growth and propagation of the disease. Use of peptides that can directly target cancer cells without affecting normal cells (targeted therapy) is evolving as an alternate strategy to conventional chemotherapy. Peptide can be utilized directly as a cytotoxic agent through various mechanisms or can act as a carrier of cytotoxic agents and radioisotopes by specifically targeting cancer cells. Peptide-based hormonal therapy has been extensively studied and utilized for the treatment of breast and prostate cancers. Tremendous amount of clinical data is currently available attesting to the efficiency of peptide-based cancer vaccines. Combination therapy is emerging as an important strategy to achieve synergistic effects in fighting cancer as a single method alone may not be efficient enough to yield positive results. Combining immunotherapy with conventional therapies such as radiation and chemotherapy or combining an anticancer peptide with a nonpeptidic cytotoxic drug is an example of this emerging field.
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Rick FG, Buchholz S, Schally AV, Szalontay L, Krishan A, Datz C, Stadlmayr A, Aigner E, Perez R, Seitz S, Block NL, Hohla F. Combination of gastrin-releasing peptide antagonist with cytotoxic agents produces synergistic inhibition of growth of human experimental colon cancers. Cell Cycle 2012; 11:2518-25. [PMID: 22751419 DOI: 10.4161/cc.20900] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We investigated the efficacy of a powerful antagonist of bombesin/gastrin-releasing peptide (BN/GRP) RC-3940-II administered as a single agent or in combination with cytotoxic agents on the growth of HT-29, HCT-116 and HCT-15 human colon cancer in vitro and in vivo. GRP-receptor mRNA and protein were found in all three cell lines tested. Exposure of HT-29 cells to 10 μM RC-3940-II led to an increase in the number of cells blocked in S phase and G 2/M and cells with lower G(0)/G(1) DNA content. Similar changes on the cell cycle traverse of HT-29 cells could also be seen at lower concentrations of RC-3940-II (1 μM) after pretreatment with 100 nM GRP (14-27), indicating a dose-dependent mechanism of action based on the blockage of BN/GRP induced proliferation of tumor cells at lower concentrations. Daily in vivo treatment with BN/GRP antagonist RC-3940-II decreased the volume of HT-29, HCT-116 and HCT-15 tumors xenografted into athymic nude mice by 25 to 67% (p < 0.005). Combined treatment with RC-3940-II and chemotherapeutic agents 5-FU and irinotecan resulted in a synergistic tumor growth suppression of HT-29, HCT-116 and HCT-15 xenografts by 43% to 78%. In HT-29 and HCT-116 xenografts the inhibition for the combinations of RC-3940-II and irinotecan vs. single substances (p < 0.05) was significantly greater. These findings support the use of RC-3940-II as an anticancer agent and may help to design clinical trials using RC-3940-II in combinations with cytotoxic agents.
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Affiliation(s)
- Ferenc G Rick
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA
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Stangelberger A, Schally AV, Varga JL, Zarandi M, Szepeshazi K, Armatis P, Halmos G. Inhibitory Effect of Antagonists of Bombesin and Growth Hormone-Releasing Hormone on Orthotopic and Intraosseous Growth and Invasiveness of PC-3 Human Prostate Cancer in Nude Mice. Clin Cancer Res 2005. [DOI: 10.1158/1078-0432.49.11.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Purpose: To determine whether antagonists of growth hormone-releasing hormone (GHRH) and bombesin/gastrin-releasing peptide (BN/GRP) can inhibit the orthotopic and metastatic growth of PC-3 human androgen-independent prostate cancers.
Experimental Design: The effects of administration of GHRH antagonist MZ-J-7-118, BN/GRP antagonist RC-3940-II, and their combination on the growth and metastatic spread of PC-3 tumors implanted orthotopically into nude mice were evaluated. The efficacy of this treatment on PC-3 tumors implanted intratibially and s.c. was also determined.
Results: Treatment with MZ-J-7-118, RC-3940-II, or their combination significantly inhibited the growth of PC-3 tumors implanted orthotopically, intraosseously, and s.c. The combination of the two antagonists had the greatest effect, inhibiting orthotopic tumor growth by 77%, intratibially implanted tumors by 86%, and s.c. tumors by 86%. The therapy with BN/GRP and GHRH antagonists, especially in combination, also reduced the local tumor spread and distant metastases in animals bearing orthotopic tumors. Combination therapy was likewise the most effective in reducing the incidence and severity of tibial osteolytic lesions and pathologic fractures in intraosseously implanted tumors. High-affinity binding sites for BN/GRP and GHRH were found in s.c. and orthotopic PC-3 tumor samples. MZ-J-7-118, RC-3940-II, and the combination of both compounds inhibited in vitro growth of PC-3 cells.
Conclusions: Our findings show the efficacy of BN/GRP antagonists and GHRH antagonists for the treatment of advanced prostate cancer in preclinical metastatic models. As BN/GRP antagonists are already in clinical trials and GHRH antagonists are effective in androgen-independent prostate cancer models, these analogues could be considered for the management of advanced prostate carcinoma.
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Affiliation(s)
- Anton Stangelberger
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Andrew V. Schally
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Jozsef L. Varga
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Marta Zarandi
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Karoly Szepeshazi
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Patricia Armatis
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Gabor Halmos
- 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and
- 2Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
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Bajo AM, Schally AV, Krupa M, Hebert F, Groot K, Szepeshazi K. Bombesin antagonists inhibit growth of MDA-MB-435 estrogen-independent breast cancers and decrease the expression of the ErbB-2/HER-2 oncoprotein and c-jun and c-fos oncogenes. Proc Natl Acad Sci U S A 2002; 99:3836-41. [PMID: 11891317 PMCID: PMC122610 DOI: 10.1073/pnas.052715299] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/31/2001] [Indexed: 11/18/2022] Open
Abstract
Previous studies showed that antagonists of bombesin (BN)/gastrin-releasing peptide (GRP) inhibit the growth of various cancers by interfering with the growth-stimulatory effects of BN-like peptides and down-regulating epidermal growth factor receptors on tumors. Because the overexpression of the human epidermal growth factor receptor-2 (ErbB-2/HER-2/neu) oncogene plays a role in the progression of many breast cancers, we investigated whether BN/GRP antagonists can affect HER-2 in mammary tumors. Female nude mice bearing orthotopic xenografts of MDA-MB-435 human estrogen-independent breast cancers were treated daily with BN/GRP antagonists RC-3095 (20 microg) or RC-3940-II (10 microg) for 6 weeks. The expression of BN/GRP receptors on tumors was analyzed by reverse transcription-PCR and immunoblotting. We also evaluated whether the mRNA expression for the c-jun and c-fos oncogenes is affected by the therapy. Both BN/GRP antagonists significantly inhibited growth of MDA-MB-435 cancers; RC-3095 reduced tumor volume by 40% and RC-3940-II by 65%. The GRP receptors (subtype 1) were detected in MDA-MB-435 tumors, showing that they mediate the inhibitory effect of the antagonists. Tumor inhibition was associated with a substantial reduction in the expression of mRNA and protein levels of the ErbB/HER receptor family as well as with a decrease in the expression of c-jun and c-fos oncogenes. BN/GRP antagonists RC-3940-II and RC-3095 could be considered for endocrine therapy of estrogen-independent breast cancers that express members of the ErbB/HER receptor family and the c-jun and c-fos oncogenes.
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MESH Headings
- Adult
- Animals
- Bombesin/analogs & derivatives
- Bombesin/antagonists & inhibitors
- Bombesin/pharmacology
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/pathology
- Cell Division/drug effects
- Epidermal Growth Factor/blood
- Estrogens/physiology
- Female
- Gastrins/blood
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, fos/genetics
- Genes, jun/genetics
- Humans
- Mice
- Mice, Nude
- Neoplasm Transplantation
- Peptide Fragments/pharmacology
- Proto-Oncogene Proteins c-fos/genetics
- Proto-Oncogene Proteins c-jun/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, ErbB-2/genetics
- Receptor, ErbB-2/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- Ana M Bajo
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center and Section of Experimental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
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Nagy A, Armatis P, Cai RZ, Szepeshazi K, Halmos G, Schally AV. 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; 94:652-6. [PMID: 9012839 PMCID: PMC19568 DOI: 10.1073/pnas.94.2.652] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Five peptide fragments, based on the C-terminal sequence of bombesin (BN)-(6-14) or BN-(7-14), were selected as carriers for radicals doxorubicin (DOX) and 2-pyrrolino-DOX to create hybrid cytotoxic analogs. All these compounds had a reduced peptide bond (CH2-NH or CH2-N) between positions 13 (Phe or Leu) and 14 (Phe, Leu, or Tac) (Tac = thiazolidine-4-carboxylic acid). Three pseudononapeptide carriers contained N-terminal D-Phe or D-Tpi at position 6 (Tpi = 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic acid). Two pseudooctapeptides had Gln7 at the N terminus. The conjugation of N-(9-fluorenylmethoxycarbonyl) doxorubicin (N-Fmoc-DOX)-14-O-hemiglutarate to the peptide carriers at the N terminus resulted in cytotoxic hybrids of BN-like peptides containing DOX. These hybrids could then be converted to analogs with 2-pyrrolino-DOX by a reaction with 4-iodobutyraldehyde. The ability of the carriers and the conjugates to inhibit the binding of 125I-labeled [Tyr4]BN to receptors for BN/gastrin releasing peptide (GRP) on Swiss 3T3 cells was determined. Cytotoxic conjugates of pseudooctapeptide carrier analogs displayed the highest binding affinity (KD approximately 1 nM). The cytotoxic BN analogs and their corresponding cytotoxic radicals exerted similar inhibitory effects on the in vitro growth of CFPAC-1 human pancreatic cancer, DMS-53 human lung cancer, PC-3 human prostate cancer, and MKN-45 human gastric cancer cell lines that have receptors for BN/GRP. In DMS-53 cells, the activity of 2-pyrrolino-DOX and its conjugates was approximately 2500 times higher than that of DOX and its hybrids. These highly potent cytotoxic analogs of BN have been designed as targeted anti-tumor agents for the treatment of various cancers that possess receptors for BN/GRP.
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Affiliation(s)
- A Nagy
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, New Orleans, LA, USA
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