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001-es BibID:	BIBFORM033597
035-os BibID:	PMID:14555524 WOS:000185830700028
Első szerző:	Letsch, Markus
Cím:	Preclinical evaluation of targeted cytotoxic luteinizing hormone-releasing hormone analogue AN-152 in androgen-sensitive and insensitive prostate cancers / Markus Letsch, Andrew V. Schally, Karoly Szepeshazi, Gabor Halmos, Attila Nagy
Dátum:	2003
Megjegyzések:	To improve conventional chemotherapy, we developed cytotoxic analogues of luteinizing hormone-releasing hormone (LH-RH), which can be targeted to prostate cancers expressing LH-RH receptors. In view of pending clinical trials on cytotoxic LH-RH analogue AN-152, containing doxorubicin (DOX) linked to [D-Lys(6])-LH-RH, we investigated the effects of AN-152 on tumor growth of s.c. implanted androgen-sensitive LNCaP and MDA-PCa-2b prostate cancers, as well as androgen-independent C4-2 prostate cancers xenografted into the tibiae of nude mice. In the C4-2 study, serum prostate-specific antigen (PSA) levels were also measured. LH-RH receptors were analyzed by reverse transcription-PCR and ligand competition assay. We also evaluated whether AN-152 can affect mRNA expression of human epidermal growth factor receptor and HER-2 and -3 oncogenes RESULTS: After 32 days of treatment with AN-152, the growth of LNCaP cancers in castrated nude mice was strongly inhibited by 83% versus intact controls (P < 0.01) and 62% versus castrated controls (P < 0.05). In animals bearing MDA-PCa-2b prostate cancers, therapy with AN-152 for 25 days resulted in a 69% inhibition of tumor growth (P < 0.01 versus controls) and was more effective (P < 0.05) than equimolar doses of DOX or microcapsules of LH-RH agonist Decapeptyl. In nude mice bearing intraosseous C4-2 prostate cancers, treatment with AN-152 decreased serum PSA levels (P < 0.01) to 10.3 +/- 3.4 ng/ml from 24.8 +/- 4 ng/ml in controls, whereas DOX had no effect on PSA. The inhibitory effects of AN-152 on C4-2 tumors was accompanied by an increase in apoptosis and a decrease in tumor proliferation. Binding sites for LH-RH and the expression of mRNA for LH-RH receptors were found on s.c. C4-2 and MDA-PCa-2b tumors. The inhibition of MDA-PCa-2b tumors by AN-152 was associated with a significant decrease in mRNA expression for epidermal growth factor receptor, HER-2, and 3. CONCLUSIONS: Our findings suggest that cytotoxic analogue AN-152 could be considered for therapeutic trials in patients with advanced prostate carcinoma.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Clinical Cancer Research. - 9 : 12 (2003), p. 4505-4513. -
További szerzők:	Schally, Andrew Victor Szepesházi Károly Halmos Gábor (1962-) (gyógyszerész, receptorfarmakológus, experimentális onkológus) Nagy Attila
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM033594
035-os BibID:	PMID:14713852 WOS:000188319300109
Első szerző:	Letsch, Markus
Cím:	Effective treatment of experimental androgen sensitive and androgen independent intraosseous prostate cancer with targeted cytotoxic somatostatin analogue AN-238 / Markus Letsch, Andrew V. Schally, Karoly Szepeshazi, Gabor Halmos, Attila Nagy
Dátum:	2004
ISSN:	0022-5347
Megjegyzések:	The targeted cytotoxic somatostatin analogue AN-238, consisting of 2-pyrrolinodoxorubicin (AN-201) linked to carrier octapeptide RC-121, is scheduled for clinical trials. To extend previous findings we tested AN-238 on human androgen sensitive MDA-PCa-2b prostate cancers grown subcutaneously and androgen independent LNCaP derived C4-2 prostate cancers xenografted into the tibiae of nude mice. MATERIALS AND METHODS: Changes in serum prostate specific antigen (PSA) levels were monitored by radioimmunoassay. Somatostatin receptors in tumor samples were characterized. RESULTS: Three intravenous injections of AN-238 at 150 nmol/kg doses inhibited the growth of subcutaneous MDA-PCa-2b tumors by 62% vs controls (p <0.05) and were more effective than equimolar doses of the radical AN-201 (p <0.05). AN-238 also decreased serum PSA levels by 62% vs controls (p <0.01). In nude mice bearing intra-osseous implanted C4-2 prostate cancers AN-238 decreased serum PSA levels by 65% compared with controls after 5 weeks of therapy (p <0.05), while AN-201 was ineffective. All AN-238 treated mice were alive at the termination of the experiment, while only 50% of controls and 60% of animals treated with AN-201 survived (p <0.01). Histological evaluation of intraosseous C4-2 tumors showed that AN-238 induced a significant increase in apoptosis (p <0.05). MDA-PCa-2b and C4-2 tumors showed high affinity binding for somatostatin and the expression of mRNA for somatostatin receptor subtypes 1, 2A and 5. CONCLUSIONS: The current study demonstrates the efficacy of the somatostatin analogue AN-238 for subcutaneous MDA-PCa-2b as well as for intraosseous C4-2 prostate cancers xenografted into nude mice. This targeted cytotoxic analogue could represent a new therapy for patients with advanced metastatic prostate carcinoma.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Journal Of Urology. - 171 : 2 (2004), p. 911-915. -
További szerzők:	Schally, Andrew Victor Szepesházi Károly Halmos Gábor (1962-) (gyógyszerész, receptorfarmakológus, experimentális onkológus) Nagy Attila
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM033541
035-os BibID:	WOS:000236362600052
Első szerző:	Zarándi Márta
Cím:	Lipopeptide antagonists of growth hormone-releasing hormone with improved antitumor activities / Marta Zarandi, Jozsef L. Varga, Andrew V. Schally, Judit E. Horvath, Gabor L. Toller, Magdolna Kovacs, Markus Letsch, Kate Groot, Patricia Armatis, Gabor Halmos
Dátum:	2006
ISSN:	0027-8424
Megjegyzések:	Antagonists of growth hormone-releasing hormone (GHRH) synthesized previously inhibit proliferation of various human cancers, but derivatisation with fatty acids could enhance their clinical efficacy. We synthesized a series of antagonists of GHRH(1-29)NH2 acylated at the N terminus with monocarboxylic or alpha,omega-dicarboxylic acids containing six to sixteen carbon atoms. These peptides are analogs of prior potent antagonists JV-1-36, JV-1-38, and JV-1-65 with phenylacetyl group at their N terminus. Several new analogs, including MZ-J-7-46 and MZA-7-30, more effectively inhibited GHRH-induced GH release in vitro in a superfused rat pituitary system than their parent compound JV-1-36 and had increased binding affinities to rat pituitary GHRH receptors, but they showed weaker inhibition of GH release in vivo than JV-1-36. All antagonists acylated with fatty acids containing 8-14 carbon atoms inhibited the proliferation of MiaPaCa-2 human pancreatic cancer cells in vitro better than JV-1-36 or JV-1-65. GHRH antagonist MZ-J-7-114 (5 mu g/day) significantly suppressed the growth of PC-3 human androgen-independent prostate cancers xenografted into nude mice and reduced serum lGF-I levels, whereas antagonist JV-1-38 had no effect at the dose of 10 mu g/day. GHRH antagonists including MZ-J-7-46 and MZ-J-7-114 acylated with octanoic acid and MZ-J-7-30 and MZ-J-7-110 acylated with 1,12-dodecanedicarboxylic acid represent relevant improvements over earlier antagonists. These and previous results suggest that this class of GHRH antagonists might be effective in the treatment of various cancers.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Proceedings of The National Academy of Sciences of The United States of America. - 103 : 12 (2006), p. 4610-4615. -
További szerzők:	Varga József L. Schally, Andrew Victor Horváth Judit E. (New Orleans) Toller Gábor L. Kovács Magdolna Letsch, Markus Groot, Kate Armatis, Patricia Halmos Gábor (1962-) (gyógyszerész, receptorfarmakológus, experimentális onkológus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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