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Zarandi M, Cai R, Kovacs M, Popovics P, Szalontay L, Cui T, Sha W, Jaszberenyi M, Varga J, Zhang X, Block NL, Rick FG, Halmos G, Schally AV. Synthesis and structure-activity studies on novel analogs of human growth hormone releasing hormone (GHRH) with enhanced inhibitory activities on tumor growth. Peptides 2017; 89:60-70. [PMID: 28130121 DOI: 10.1016/j.peptides.2017.01.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/10/2017] [Accepted: 01/23/2017] [Indexed: 12/21/2022]
Abstract
The syntheses and biological evaluations of new GHRH analogs of Miami (MIA) series with greatly increased anticancer activity are described. In the design and synthesis of these analogs, the following previous substitutions were conserved: D-Arg2, Har9, Abu15, and Nle27. Most new analogs had Ala at position 8. Since replacements of both Lys12 and Lys21 with Orn increased resistance against enzymatic degradation, these modifications were kept. The substitutions of Arg at both positions 11 and 20 by His were also conserved. We kept D-Arg28, Har29 -NH2 at the C-terminus or inserted Agm or 12-amino dodecanoic acid amide at position 30. We incorporated pentafluoro-Phe (Fpa5), instead of Cpa, at position 6 and Tyr(Me) at position 10 and ω-amino acids at N-terminus of some analogs. These GHRH analogs were prepared by solid-phase methodology and purified by HPLC. The evaluation of the activity of the analogs on GH release was carried out in vitro on rat pituitaries and in vivo in male rats. Receptor binding affinities were measured in vitro by the competitive binding analysis. The inhibitory activity of the analogs on tumor proliferation in vitro was tested in several human cancer cell lines such as HEC-1A endometrial adenocarcinoma, HCT-15 colorectal adenocarcinoma, and LNCaP prostatic carcinoma. For in vivo tests, various cell lines including PC-3 prostate cancer, HEC-1A endometrial adenocarcinoma, HT diffuse mixed β cell lymphoma, and ACHN renal cell carcinoma cell lines were xenografted into nude mice and treated subcutaneously with GHRH antagonists at doses of 1-5μg/day. Analogs MIA-602, MIA-604, MIA-610, and MIA-640 showed the highest binding affinities, 30, 58, 48, and 73 times higher respectively, than GHRH (1-29) NH2. Treatment of LNCaP and HCT-15 cells with 5μM MIA-602 or MIA-690 decreased proliferation by 40%-80%. In accord with previous tests in various human cancer lines, analog MIA-602 showed high inhibitory activity in vivo on growth of PC-3 prostate cancer, HT-mixed β cell lymphoma, HEC-1A endometrial adenocarcinoma and ACHN renal cell carcinoma. Thus, GHRH analogs of the Miami series powerfully suppress tumor growth, but have only a weak endocrine GH inhibitory activity. The suppression of tumor growth could be induced in part by the downregulation of GHRH receptors levels.
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Affiliation(s)
- Marta Zarandi
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Renzhi Cai
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Magdolna Kovacs
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Petra Popovics
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Luca Szalontay
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Tengjiao Cui
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Wei Sha
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Division of Hematology/Oncology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Sylvester Comprehensive Cancer Center, Miami, FL, United States
| | - Miklos Jaszberenyi
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Jozsef Varga
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States
| | - XianYang Zhang
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Norman L Block
- South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Sylvester Comprehensive Cancer Center, Miami, FL, United States; Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Ferenc G Rick
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Urology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL, United States
| | - Gabor Halmos
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States
| | - Andrew V Schally
- Endocrine, Polypeptide, and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, United States; South Florida VA Foundation for Research and Education, Miami, FL, United States; Department of Pathology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Division of Hematology/Oncology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States; Sylvester Comprehensive Cancer Center, Miami, FL, United States.
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Deller MC, Kong L, Rupp B. Protein stability: a crystallographer's perspective. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2016; 72:72-95. [PMID: 26841758 PMCID: PMC4741188 DOI: 10.1107/s2053230x15024619] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 12/21/2015] [Indexed: 12/18/2022]
Abstract
Protein stability is a topic of major interest for the biotechnology, pharmaceutical and food industries, in addition to being a daily consideration for academic researchers studying proteins. An understanding of protein stability is essential for optimizing the expression, purification, formulation, storage and structural studies of proteins. In this review, discussion will focus on factors affecting protein stability, on a somewhat practical level, particularly from the view of a protein crystallographer. The differences between protein conformational stability and protein compositional stability will be discussed, along with a brief introduction to key methods useful for analyzing protein stability. Finally, tactics for addressing protein-stability issues during protein expression, purification and crystallization will be discussed.
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Affiliation(s)
- Marc C Deller
- Stanford ChEM-H, Macromolecular Structure Knowledge Center, Stanford University, Shriram Center, 443 Via Ortega, Room 097, MC5082, Stanford, CA 94305-4125, USA
| | - Leopold Kong
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Building 8, Room 1A03, 8 Center Drive, Bethesda, MD 20814, USA
| | - Bernhard Rupp
- Department of Forensic Crystallography, k.-k. Hofkristallamt, 91 Audrey Place, Vista, CA 92084, USA
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Hao CH, Han QH, Shan ZJ, Hu JT, Zhang N, Zhang XP. Effects of different interchain linkers on biological activity of an anti-prostate cancer single-chain bispecific antibody. Theor Biol Med Model 2015; 12:14. [PMID: 26246000 PMCID: PMC4527239 DOI: 10.1186/s12976-015-0010-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 07/14/2015] [Indexed: 11/30/2022] Open
Abstract
Background A single-chain bispecific antibody (scBsAb; an engineered antibody), has promising clinical applications. Nonetheless, the effect of different interchain linkers on its activity is poorly understood. Methods Gene synthesis was used to splice the anti-γ-seminoprotein single-chain antibody (anti-γ-Sm scFv) gene with the anti-CD3 single-chain antibody (anti-CD3 scFv) gene via different interchain peptide linkers. The Phyre2 software was used to predict spatial configuration of different scBsAbs. Eukaryotic expression vectors carrying scBsAbs were constructed by molecular cloning techniques and these plasmids were transfected into HeLa cells with liposomes. scBsAbs were purified by Ni2+-NTA agarose and analysed for antigen binding by an enzyme-linked immunosorbent assay (ELISA). Blood pharmacokinetics and inhibition of prostate tumour growth in nude mice were analysed in in vivo experiments. Results Bioinformatics analysis and prediction showed that none of the three linkers, Fc, 205C’, and HSA, had a significant effect on protein folding of anti-γ-Sm scFv or anti-CD3 scFv. Nevertheless, the spatial structures of the three linkers were noticeably different. Anti-γ-Sm × anti-CD3 scBsAb with an Fc, 205C’, or HSA linker was successfully constructed, and these antibodies had similar protein expression levels. ELISA showed that all the three scBsAbs bound to Jurkat cells and the LNCaP membrane antigen, although binding of (205C’)scBsAb was weaker than that of the two parental scFvs (P < 0.05). In contrast, binding strength of (HSA)scBsAb and (Fc)scBsAb was close to that of the parental scFvs (P > 0.05). Pharmacokinetic analysis showed that the half-clearance time of the elimination phase (T1/2β) for (HSA)scBsAb was the longest: up to 4.4 h. Compared with γ-Sm ScFv, the three scBsAbs all had a much stronger inhibitory effect on the growth of prostate cancer (P < 0.05), but there were no significant differences among the three scBsAbs (P > 0.05). Conclusions HSA is the optimal linker for the anti-γ-Sm × anti-CD3 scBsAb and may improve antigen-binding affinity of antibodies and prolong physiological retention time. Interchain linkers affect the function of scBsAbs; these effects may have important implications for construction of antibodies.
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Affiliation(s)
- Chao-hui Hao
- Department of Urology, Zhengzhou People's Hospital, No.33 Huanghe Road, Jinshui District, Zhengzhou, 450003, People's Republic of China.
| | - Qian-he Han
- Department of Urology, Zhengzhou People's Hospital, No.33 Huanghe Road, Jinshui District, Zhengzhou, 450003, People's Republic of China.
| | - Zhong-jie Shan
- Department of Urology, Zhengzhou People's Hospital, No.33 Huanghe Road, Jinshui District, Zhengzhou, 450003, People's Republic of China.
| | - Jian-ting Hu
- Department of Urology, Zhengzhou People's Hospital, No.33 Huanghe Road, Jinshui District, Zhengzhou, 450003, People's Republic of China.
| | - Nan Zhang
- Department of Urology, Zhengzhou People's Hospital, No.33 Huanghe Road, Jinshui District, Zhengzhou, 450003, People's Republic of China.
| | - Xue-pei Zhang
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, No.1 East Jianshe Road, Erqi District, Zhengzhou, 450052, People's Republic of China.
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