1
|
Miyazaki A, Tsuda Y, Fukushima S, Yokoi T, Vántus T, Bökönyi G, Szabó E, Horváth A, Kéri G, Okada Y. Synthesis of Somatostatin Analogues Containing C-Terminal Adamantane and Their Antiproliferative Properties. J Med Chem 2008; 51:5121-4. [DOI: 10.1021/jm701599w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna Miyazaki
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Yuko Tsuda
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Shoji Fukushima
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Toshio Yokoi
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Tibor Vántus
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Gyöngyi Bökönyi
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Edit Szabó
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Anikó Horváth
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - György Kéri
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| | - Yoshio Okada
- Faculty of Pharmaceutical Sciences, Department of Medicinal Chemistry, Kobe Gakuin University, Nishi-ku, Kobe, 651-2180, Japan, and Pathobiochemistry Research Group of Hungarian Academy of Science and Semmelweis University, H-1088 Budapest, Hungary
| |
Collapse
|
2
|
Hrabák A, Bökönyi G, Orfi L, Bajor T, Kéri G. Comparison of the cytotoxic effects of receptor tyrosine kinase inhibitors on macrophage functions; possible side effects in the immune defense. Immunol Lett 2006; 107:169-75. [PMID: 17098294 DOI: 10.1016/j.imlet.2006.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Accepted: 09/25/2006] [Indexed: 10/24/2022]
Abstract
Certain receptor tyrosine kinase (RTK) inhibitors reduced the phagocytic capacity of rat macrophages, without influencing the binding of bacteria to macrophage surface. The NO production of elicited rat macrophages was also decreased due to the inhibition of the expression of NOS II. The most potent inhibitory compound was PD166326 (6-(2,6-dichloro-phenyl)-2-(4-hydroxy-phenylamino)-8-methyl-8H-pyrido[2,3-d]pyrimidin-7-one) belonging to a family of RTK inhibitors of broad spectra. These impairing effects could be explained by the apoptosis inducing property of the inhibitor, evidenced by the destroyed mitochondrial membrane potential. The MTT cell viability test indicated a slight, but significant injury of macrophages. In addition to this compound, two other tested RTK inhibitors caused less marked impairment of macrophage functions, while four compounds were not efficient on macrophages at all. Nevertheless, these damaging effects of the inhibitors did not reduce the anti-tumor effect of the RTK inhibitors on COS 7 cells as evidenced by MTT test and apoptosis study. However, these side effects may be important when RTK inhibitors are selected against tumor growth, indicating that certain inhibitors may impair the immune defense during therapeutical application.
Collapse
Affiliation(s)
- András Hrabák
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary.
| | | | | | | | | |
Collapse
|
3
|
Szende B, Horváth A, Bökönyi G, Kéri G. Effect of a novel somatostatin analogue combined with cytotoxic drugs on human tumour xenografts and metastasis of B16 melanoma. Br J Cancer 2003; 88:132-6. [PMID: 12556972 PMCID: PMC2376778 DOI: 10.1038/sj.bjc.6600668] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A novel somatostatin analogue, TT-232 (which inhibits the proliferation of various cell cultures and transplantable mouse tumours), was examined regarding its effect on human melanoma and lymphoma xenografts as a single treatment or in combination with DTIC (dacarbazine) and etoposide. TT-232 inhibited the growth of HT-18 melanoma xenografts, a dose of 5 mg kg(-1) being the most effective. Combination of 1 mg kg(-1) TT-232 with 30 or 60 mg kg(-1) DTIC (administered daily) resulted in a stronger inhibitory effect compared to TT-232 or DTIC as a single modality. Antimetastatic effect of TT-232 treatment combined with DTIC was studied using the B16 mouse melanoma muscle - lung metastasis model. The number of lung metastases of B16 melanoma could be decreased by the daily administration of 1 mg kg(-1) TT-232 or 60 mg kg(-1), but not of 30 mg kg(-1) DTIC. TT-232, combined with 30 or 60 mg kg(-1) DTIC decreased the lung metastasis number significantly lower than the control. Nearly 50% growth inhibition of HT-58 lymphoma was achieved by daily treatment with 1 mg kg(-1) TT-232. 5 mg kg(-1) etoposide, administered daily, resulted in a similar effect. The combination of 1 mg kg(-1) TT-232 and 5 mg kg(-1) etoposide was significantly more effective than TT-232 or etoposide as a single treatment. The very strong tumour growth inhibitory effect of 10 mg kg(-1) etoposide could even be increased by combination with TT-232. These experimental data suggest that TT-232 may be an effective new tool in the combination chemotherapy of malignant tumours like melanoma and lymphoma.
Collapse
Affiliation(s)
- B Szende
- 1st Department of Pathology and Experimental Cancer Research, Semmelweis University and Molecular Pathology Research Group Joint Research Organisation of the Hungarian Academy of Sciences, and Semmelweis University Budapest, Hungary.
| | | | | | | |
Collapse
|
4
|
Szende B, Okada Y, Tsuda Y, Horvath A, Bökönyi G, Okamoto S, Wanaka K, Kéri G. A novel plasmin-inhibitor inhibits the growth of human tumor xenografts and decreases metastasis number. In Vivo 2002; 16:281-6. [PMID: 12494864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The novel plasmin inhibitor YO-2, which also exerts an apoptosis-inducing effect on various human tumor cell cultures, was examined regarding its tumor growth inhibitory and antimetastatic action. The tumor growth inhibitory effect of YO-2 was studied using HT-29 human colon carcinoma, HT-18 human melanoma and HT-58 human B cell lymphoma inoculated as xenografts into immuno-deprived mice. Antimetastatic activity was tested on the B16 mouse melanoma muscle-lung model. YO-2 inhibited the growth of all xenografts in the range of 40-50%, when administered s.c. at a dose of 2.0 mg/kg (HT-29, HT-58) or orally at a dose of 0.4 mg/kg (HT-18). YO-2 decreased the number of lung metastasis found in mice inoculated i.m. with B16 melanoma, 4 mg/kg being the most effective. Since YO-2 is the only plasmin inhibitor having antihemorrhagic and also antitumor effect, this compound could be rationally used in combination therapy of neoplastic disease, especially when hemorrhage aggravates the course of the disease.
Collapse
Affiliation(s)
- Béla Szende
- 1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Molecular Pathology Research Group of Hungarian Academy of Sciences, Budapest, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Vántus T, Kéri G, Krivickiene Z, Valius M, Steták A, Keppens S, Csermely P, Bauer PI, Bökönyi G, Declercq W, Vandenabeele P, Merlevede W, Vandenheede JR. The somatostatin analogue TT-232 induces apoptosis in A431 cells: sustained activation of stress-activated kinases and inhibition of signalling to extracellular signal-regulated kinases. Cell Signal 2001; 13:717-25. [PMID: 11602182 DOI: 10.1016/s0898-6568(01)00194-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
TT-232 is a somatostatin analogue containing a five-residue ring structure. The present report describes TT-232-induced signalling events in A431 cells, where a 4-h preincubation with the peptide irreversibly induced a cell death program, which involves DNA-laddering and the appearance of shrunken nuclei, but is unrelated to somatostatin signalling. Early intracellular signals of TT-232 include a transient two-fold activation of the extracellular signal-regulated kinase (ERK2) and a strong and sustained activation of the stress-activated protein kinases c-Jun NH(2)-terminal kinase (JNK)/SAPK and p38MAPK. Blocking the signalling to ERK or p38MAPK activation had no effect on the TT-232-induced cell killing. At the commitment time for inducing cell death, TT-232 decreased EGFR-tyrosine phosphorylation and prevented epidermial growth factor (EGF)-induced events like cRaf-1 and ERK2 activation. Signalling to ERK activation by FCS, phorbol 12-myristate 13-acetate (PMA) and platelet-derived growth factor (PDGF) was similarly blocked. Our data suggest that TT-232 triggers an apoptotic type of cell death, concomitant with a strong activation of JNK and a blockade of cellular ERK2 activation pathways.
Collapse
Affiliation(s)
- T Vántus
- Peptide Biochemistry Research Group, Department of Medical Biochemistry, Budapest H-1088, Hungary
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Hollósy F, Idei M, Csorba G, Szabó E, Bökönyi G, Seprödi A, Mészáros G, Szende B, Kéri G. Activation of caspase-3 protease during the process of ursolic acid and its derivative-induced apoptosis. Anticancer Res 2001; 21:3485-91. [PMID: 11848513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The apoptosis-inducing effect of the triterpene saponins, namely, ursolic acid and its natural derivative, methyl-ursolate beta-D-glucoside on A431 human epidermoid carcinoma cells was studied. The cells treated with 5-50 microg/ml of ursolic acid resulted in a dose- and time-dependent decrease in cell number, due to an increase of apoptotic cells as evidenced by MTT assay together with morphological changes. The highest dose (50 microg/ml) of ursolic acid resulted in approximately 90% inhibition in tumor cell growth after 96 hours of treatment and 60% of apoptosis after 48 hours. To the contrary, when the same treatment was carried out with methyl-ursolate beta-D-glucoside, after 96 hours of treatment the percentage of cell growth inhibition was found to be only 30% at the dose of 50 microg/ml and the value of apoptosis did not exceed 10%. Similarly to these results, ursolic acid effectively induced proteolytic activation of caspase-3 protease in a dose-dependent manner while its derivative showed only weak activity in this enzyme assay. The addition of DEVD-CHO prior to ursolic acid and methyl-ursolate beta-D-glucoside treatment effectively prevented the loss of triterpenes-induced viability. In summary, the triterpene saponins investigated contain an apoptotic-inducing activity in A431 cells and in the case of ursolic acid it is associated with proteolytic activation of caspase-3 and/or other similar caspases. Our results also indicated that methylation of COOH-28 together with the glycosylation of C3 of ursolic acid have a strong impact on its antitumor activity.
Collapse
Affiliation(s)
- F Hollósy
- Hungarian Academy of Sciences, Peptidbiochemical Research Group in Semmelweis University Budapest.
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Koncz G, Tóth GK, Bökönyi G, Kéri G, Pecht I, Medgyesi D, Gergely J, Sármay G. Co-clustering of Fcgamma and B cell receptors induces dephosphorylation of the Grb2-associated binder 1 docking protein. Eur J Biochem 2001; 268:3898-906. [PMID: 11453982 DOI: 10.1046/j.1432-1327.2001.02295.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immunoreceptor tyrosine-based inhibitory motif (ITIM) of human type IIb Fcgamma receptor (FcgammaRIIb) is phosphorylated on its tyrosine upon co-clustering with the B cell receptor (BCR). The phosphorylated ITIM (p-ITIM) binds to the SH2 domains of polyphosphoinositol 5-phosphatase (SHIP) and the tyrosine phosphatase, SHP-2. We investigated the involvement of the molecular complex composed of the phosphorylated SHIP and FcgammaRIIb in the activation of SHP-2. As a model compound, we synthesized a bisphosphopeptide, combining the sequences of p-ITIM and the N-terminal tyrosine phosphorylated motif of SHIP with a flexible spacer. This compound bound to the recombinant SH2 domains of SHP-2 with high affinity and activated the phosphatase in an in vitro assay. These data suggest that the phosphorylated FcgammaRII-SHIP complexes formed in the intact cells may also activate SHP-2. Grb2-associated binder 1 (Gab1) is a multisite docking protein, which becomes tyrosine-phosphorylated in response to various types of signaling, including BCR. In turn it binds to the SH2 domains of SHP-2, SHIP and the p85 subunit of phosphatidyl inositol 3-kinase (PtdIns3-K) and may regulate their activity. Gab1 is a potential substrate of SHP-2, thus its binding to FcgammaRIIb may modify the Gab1-bound signaling complex. We show here that Gab1 is part of the multiprotein complex assembled by FcgammaRIIb upon its co-clustering with BCR. Gab1 may recruit SH2 domain-containing molecules to the phosphorylated FcgammaRIIb. SHP-2, activated upon the binding to FcgammaRIIb-SHIP complex, partially dephosphorylates Gab1, resulting in the release of PtdIns3-K and ultimately in the inhibition of downstream activation pathways in BCR/FcgammaRIIb co-aggregated cells.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing
- Adaptor Proteins, Vesicular Transport
- Amino Acid Motifs
- Antigens, CD/metabolism
- Intracellular Signaling Peptides and Proteins
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases
- Phosphopeptides/metabolism
- Phosphoproteins/metabolism
- Phosphoric Monoester Hydrolases/metabolism
- Protein Binding
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatase, Non-Receptor Type 6
- Protein Tyrosine Phosphatases/metabolism
- Proteins/metabolism
- Receptors, Antigen, B-Cell/metabolism
- Receptors, IgG/metabolism
- SH2 Domain-Containing Protein Tyrosine Phosphatases
- Shc Signaling Adaptor Proteins
- Signal Transduction
- Src Homology 2 Domain-Containing, Transforming Protein 1
Collapse
Affiliation(s)
- G Koncz
- Research Group of the Hungarian Academy of Science at the Department of Immunology, Loránd Eötvös University, Göd, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
The mode of cytoprotective action of the monoamine oxydase B inhibitor (-)-deprenyl was studied using A-2058 human melanoma cells in culture. Serum deprivation caused apoptosis of the cultured cells, which could be decreased by administration of 10(-9) - 10(-13)M (-)-deprenyl. The known metabolites of (-)-deprenyl, (-)-desmethyl-deprenyl, (-)- and (+)-methylamphetamine failed to exert the same effect. The anti-apoptotic activity of (-)-deprenyl was prevented by the simultaneous application of the microsomal drug-metabolizing enzyme inhibitor SKF-525A. These results show that (-)-deprenyl needs metabolic conversion in order to be anti-apoptotic, but the effective metabolite is still unknown. On the other hand, higher dose (10(-13)M) of (-)-deprenyl, (-)-desmethyl-deprenyl, (-)- and (+)-methylamphetamine induced apoptosis in the non-serum-deprived A-2058 cell culture. SKF-525A did not prevent the apoptosis-inducing effect of (-)-deprenyl, which means that no metabolic changes are needed for this activity. High dose (10(-3)M) of (-)-deprenyl induced very high Caspase 3 activity in non-serum-deprived A-2058 cell culture, low doses (10(-9) - 10(-3) M) of (-)-deprenyl maintained Caspase 3 activity on control level in case of serum-deprivation.
Collapse
Affiliation(s)
- B Szende
- 1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary.
| | | | | | | | | | | |
Collapse
|
9
|
Hollósy F, Mészáros G, Bökönyi G, Idei M, Seprödi A, Szende B, Kéri G. Cytostatic, cytotoxic and protein tyrosine kinase inhibitory activity of ursolic acid in A431 human tumor cells. Anticancer Res 2000; 20:4563-70. [PMID: 11205305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The effect of the tritepene, ursolic acid, on the proliferation of A431 human epidermoid carcinoma cells was studied. According to our investigations, ursolic acid is a potent inhibitor of A431 cell growth. Ursolic acid markedly reduced A431 cell growth in a time- and dose-dependent manner. We found a good correlation between the results of direct cell counting and the MTT test. During long periods of drug exposure, ursolic acid exhibited both cytotoxic and cytostatic activity. The effect was partially reversible on drug removal. The greatest cytotoxicity was observed both in the trypan blue test and in the MTT test at 50 mM. Investigations on tyrosine kinase inhibition were performed by biochemical and cellular assays on A431 cells. Ursolic acid inhibited tyrosine kinase activity of A431 cells in biochemical assay in a dose-dependent manner with an IC50 of 24 mM. In cellular assay, when A431 cells were pretreated with ursolic acid for 24, 48 and 168 hours at various concentrations (5, 10, 20, 30 and 50 mM), lower values of IC50 were measured: 6.8 microM for 24 hours, 5.2 mM for 48 hours and 1.4 mM for 168 hours. The results suggest that ursolic acid exerts an antiproliferative effect through the inhibition of tyrosine kinase enzymes.
Collapse
Affiliation(s)
- F Hollósy
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis Medical University, Budapest, H-1085 Hungary.
| | | | | | | | | | | | | |
Collapse
|
10
|
Kunvári M, Páska C, László M, Orfi L, Kövesdi I, Eros D, Bökönyi G, Kéri G, Gyurján I. [Biological activity and structure of antitumor compounds from Plantago media L]. Acta Pharm Hung 1999; 69:232-9. [PMID: 10652790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Tyrosine kinase inhibition and tumor growth inhibition activity of verbascoside and homoplantaginin are described. Both molecules proved to be equally significant inhibitors of isolated EGF-R tyrosine kinases, nevertheless their in vitro antiproliferative activity was variable in cellular assays. Their different inhibitory efficacies could be interpreted on the basis of conformational analysis and lipophilicity evaluation.
Collapse
Affiliation(s)
- M Kunvári
- Eötvös Loránd Tudományegyetem, Növényszervezettani Tanszék, Budapest
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Kéri G, Erchegyi J, Horváth A, Mezõ I, Idei M, Vántus T, Balogh A, Vadász Z, Bökönyi G, Seprõdi J, Teplán I, Csuka O, Tejeda M, Gaál D, Szegedi Z, Szende B, Roze C, Kalthoff H, Ullrich A. A tumor-selective somatostatin analog (TT-232) with strong in vitro and in vivo antitumor activity. Proc Natl Acad Sci U S A 1996; 93:12513-8. [PMID: 8901613 PMCID: PMC38023 DOI: 10.1073/pnas.93.22.12513] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We report a series of new in vitro and in vivo data proving the selective antitumor activity of our somatostatin structural derivative, TT-232. In vitro, it inhibited the proliferation of 20 different human tumor cell lines in the range of 50-95% and induced a very strong apoptosis. In vivo TT-232 was effective on transplanted animal tumors (Colon 26, B16 melanoma, and S180 sarcoma) and on human tumor xenografts. Treatment of MDA-MB-231 human breast cancer xenografted in mice with low submaximal doses of TT-232 [0.25 and 0.5 mg/kg of body weight (b.w.)] caused an average 80% decrease in the tumor volume resulting in 30% tumor-free animals surviving for longer than 200 days. Treatment of prostate tumor (PC-3) xenografted animals with 20 mg/kg of b.w. of TT-232 for 3 weeks resulted in 60% decrease in tumor volume and 100% survival even after 60 days, while 80% of nontreated animals perished. We have demonstrated that TT-232 did not bind to the membrane preparation of rat pituitary and cortex and had no antisecretory activity. TT-232 was not toxic at a dose of 120 mg/kg of b.w. in mice. Long-term incubation (24 h) of tumor cells with TT-232 caused significant inhibition of tyrosine kinases in good correlation with the apoptosis-inducing effect. The level of p53 or KU86 did not change following TT-232 treatment, suggesting a p53-independent apoptotic effect. Preincubation of human breast cancer cells (MDA-MB-453) with TT-232 for 2 h decreased the growth factor receptor autophosphorylation. All of these data suggest that TT-232 is a promising and selective antitumor agent.
Collapse
Affiliation(s)
- G Kéri
- Joint Research Organization, Hungarian Academy of Sciences, Budapest, Hungary
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Kéri G, Mezô I, Vadász Z, Horváth A, Idei M, Vántus T, Balogh A, Bökönyi G, Bajor T, Teplán I. Structure-activity relationship studies of novel somatostatin analogs with antitumor activity. Pept Res 1993; 6:281-8. [PMID: 7903057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A series of new somatostatin analogs were synthesized in order to study the relative importance of specific substitutions in relation to selectivity between their endocrine and antitumor effects. Substitutions were carried out in all positions, except for Lys in position 5. Peptides were tested for their ability to inhibit in vitro and in vivo GH release, proliferation of the MCF 7 breast carcinoma cell line and tyrosine kinase activity in the HT 29 human colon carcinoma cell line. Selective biological activity was achieved in GH release and antitumor activity by the different amino acid substitutions. One of the analogs, with a five-residue ring (D-Phe-Cys-Tyr-D-Trp-Lys-Cys-Thr-NH2, TT-232), was unique. It had no GH release inhibitory activity, but did have strong tyrosine kinase inhibitory and antiproliferative effects.
Collapse
Affiliation(s)
- G Kéri
- Semmelweis University Medical School, Hungary
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Kéri G, Balogh A, Horváth A, Mezö I, Vadász Z, Bökönyi G, Bajor T, Vántus T, Teplán I, Horváth J. Novel antitumor peptide hormones and their effect on signal transduction. J Steroid Biochem Mol Biol 1992; 43:105-10. [PMID: 1356011 DOI: 10.1016/0960-0760(92)90193-m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A series of novel gonadotropin releasing hormone (GnRH) and Somatostatin analogs have been developed in our laboratory and were screened for antiproliferative and signal transduction inhibitory effect. Our GnRH analog Folligen, had significant antitumor activity on DMBA induced mammary carcinomas in rats without blocking ovarian functions. The direct effect of Folligen and Buserelin has been compared on the human breast cancer cell line MDA-MB-231. Folligen was found to be more effective in inhibiting cell proliferation and significant differences were found in the signal transduction pathways activated by these analogs. Our novel Somatostatin analogs were screened for tyrosine kinase inhibition and for antiproliferative effect on human colon tumor cells and for growth hormone (GH) release inhibition in vitro and in vivo. The analog TT-2-50 was significantly more active inhibiting GH release in superfused rat pituitary cells and in vivo than native Somatostatin and it strongly inhibited tyrosine kinase and proliferation while it stimulated protein kinase C activity.
Collapse
Affiliation(s)
- G Kéri
- Semmelweis University Medical School, 1st Institute of Biochemistry, Budapest, Hungary
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Kéri G, Gulyás T, Horváth A, Szöke B, Bökönyi G, Teplán I. Synthesis and characterization of a novel gonadotropin hormone releasing hormone analog which stimulates reproductive functions in fish and mammals. Pept Res 1990; 3:142-7. [PMID: 1966865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A novel gonadotropin hormone releasing hormone analog, (D-Phe6,Gln8,des-Gly10)GnRH ethylamide, has been developed in our laboratory which stimulates not only ovulation but also follicular maturation in various kinds of fish and mammals. A large-scale liquid phase synthesis has been worked out for this analog. The synthetic product was characterized for structure and purity by various physicochemical methods. Though its structure was derived from the native chicken type I sequence, this peptide was one of the most effective analogs among those reported so far in the literature for artificial propagation of fish. The peptide was effective both during and out of spawning season. It was also potent in treating various sexual disorders such as anestrous, inactive ovaries and follicular cysts in cows.
Collapse
Affiliation(s)
- G Kéri
- 1st Institute of Biochemistry, Semmelweis University Medical School, Budapest, Hungary
| | | | | | | | | | | |
Collapse
|