Recently hydrophilic poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) was used for BS-RNase modification to prevent its degradation in bloodstream or fast elimination. Polymer-conjugated BS-RNase preparations proved to be cytotoxic after intravenous or intraperitoneal application, whereas native BS-RNase was ineffective. Here RNase A unimer was conjugated with two HPMA polymers (classic and star) and their antitumor effects both in vitro and in vivo were compared with those of BS-RNase polymers. Surprisingly, the antitumor effect of RNase A conjugates was also pronounced. The RNase A conjugates (classic and star) injected intravenously to mice bearing melanoma tumor caused a significant reduction in tumor volume following ten doses of 5 and 1 mg/kg, respectively. Despite the antitumor activity observed in vivo, the in vitro tested cytotoxic activity of RNase A did not differ from that caused by native RNase A while native BS-RNase (50 microg/ml) totally inhibited DNA synthesis in treated cells. The experiments with 125I-labeled preparations demonstrated concentration-dependent internalization of native BS-RNase by tumor cells within an hour, whereas the polymer conjugate (S-BS) was not internalized. On the contrary, the in vivo experiments showed that whereas 40% of S-BS conjugate persisted in bloodstream for 24h after administration, 98% of the native BS-RNase was already eliminated. Improved antitumor activities of PHPMA-modified RNases in vivo might be ascribed to their prolonged retention in bloodstream, better proteolytic stability and resistance to the action of the ribonuclease inhibitor.

• MeSH
• antitumorózní látky aplikace a dávkování   chemie   terapeutické užití   MeSH
• endoribonukleasy aplikace a dávkování   chemie   terapeutické užití   MeSH
• injekce intraperitoneální MeSH
• injekce intravenózní MeSH
• konformace proteinů MeSH
• kyseliny polymethakrylové aplikace a dávkování   chemie   MeSH
• lidé MeSH
• lymfocyty metabolismus   MeSH
• melanom experimentální farmakoterapie   patologie   MeSH
• molekulární struktura MeSH
• myši nahé MeSH
• myši MeSH
• nádorové buňky kultivované metabolismus   MeSH
• nosiče léků MeSH
• pankreatická ribonukleasa aplikace a dávkování   chemie   terapeutické užití   MeSH
• radioizotopy jodu MeSH
• skot MeSH
• vazebná místa fyziologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• způsoby aplikace léků MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• Duxon MeSH Prohlížeč
• endoribonukleasy MeSH
• kyseliny polymethakrylové MeSH
• nosiče léků MeSH
• pankreatická ribonukleasa MeSH
• radioizotopy jodu MeSH
• ribonuclease SPL MeSH Prohlížeč

Bovine seminal ribonuclease (BS-RNase) exerts a potent cytotoxic activity when administered intratumorally (i.t.) to the nude mice bearing human tumors. The ineffective treatment with intravenous (i.v.) or intraperitoneal (i.p.) administration led us to the synthesis of polymeric conjugates with BS-RNase to prevent it from degradation in the blood vessel. Hydrophilic poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) was used for BS-RNase modification and a PHPMA-BS-RNase conjugates were prepared. Classic conjugate (P-BS) with BS-RNase bound to the polymer by its oligopeptide site chains was prepared by aminolytic reaction of the polymer precursor bearing reactive ester groups situated in the side chains of polymer, while star-like conjugate (S-BS) was synthesized by the reaction of PHPMA containing end-chain reactive group with BS-RNase in aqueous buffer solution at pH 8. In contrast to the total ineffectiveness of free BS-RNase administered i.v. at a daily dose 10 mg/kg, application of P-BS and S-BS conjugates at doses 2 mg/kg and 0.5 mg/kg caused significant inhibition of the growth of human melanoma in nude mice. On the base of these results the effect of i.v. administered S-BS on the metastatic process and the survival of C57Bl/6 inbred mice inoculated with B16 melanoma cells was investigated. Sixty per cent of mice treated with S-BS (0.5 mg/kg/day) survived 100 days without metastatic foci when the experiment terminated. The average survival time of the treated groups was 75.5 days compared to 32.7 days in the control group. BS-RNase conjugated to water soluble polymers appears to be the first BS RNase preparation which exerts anticancer and antimetastatic activity following its intravenous administration.

• MeSH
• antitumorózní látky aplikace a dávkování   terapeutické užití   toxicita   MeSH
• endoribonukleasy aplikace a dávkování   terapeutické užití   toxicita   MeSH
• injekce intraperitoneální MeSH
• injekce intravenózní MeSH
• kyseliny polymethakrylové MeSH
• lidé MeSH
• melanom experimentální farmakoterapie   patologie   sekundární   MeSH
• melanom farmakoterapie   patologie   sekundární   MeSH
• metastázy nádorů prevence a kontrola   MeSH
• myši inbrední C57BL MeSH
• myši nahé MeSH
• myši MeSH
• nosiče léků MeSH
• skot MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• Duxon MeSH Prohlížeč
• endoribonukleasy MeSH
• kyseliny polymethakrylové MeSH
• nosiče léků MeSH
• ribonuclease SPL MeSH Prohlížeč

This paper reports on the antitumor activity of BS RNase on human melanoma and mouse seminoma. Human melanoma cells established in culture were extremely susceptible to BS RNase, administered in concentrations ranging from 1-100 microg/ml. Concentrations of BS RNase over 10 microg/ml caused complete inhibition of cell growth. Bovine pancreatic ribonuclease (RNase A), a prototype of the ribonuclease superfamily, did not exert any effect under these conditions. Based on our previous results, athymic mice bearing human melanoma or mouse seminoma were treated with intratumoral administration of BS RNase (12.5 mg/kg b.w.). This dose was injected for five consecutive days excluding weekends. The intratumoral administration of BS RNase to nude mice bearing human melanoma showed a significant antitumor effect. There were no tumors seen in eighty percent of mice treated for three weeks, and tumors in the other mice diminished significantly. After some delay the tumors started to regrow. Prolonging of the treatment to five weeks had a similar effect. The effect of BS RNase on mouse seminoma was well pronounced. Five to seven doses of BS RNase were sufficient to eliminate tumors in all treated mice. However, as in the previous experiment, the growth of tumor tissue later reappeared.

• MeSH
• antitumorózní látky terapeutické užití   MeSH
• endoribonukleasy terapeutické užití   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• melanom farmakoterapie   MeSH
• myši nahé MeSH
• myši MeSH
• nádorové buňky kultivované MeSH
• pankreatická ribonukleasa terapeutické užití   MeSH
• seminom farmakoterapie   MeSH
• testikulární nádory farmakoterapie   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• endoribonukleasy MeSH
• pankreatická ribonukleasa MeSH
• ribonuclease SPL MeSH Prohlížeč

Unlike the bovine pancreatic ribonuclease (RNAase A), bovine seminal ribonuclease (BS RNAase) displays various biological activities including antitumor cytotoxicity. To learn more about its antitumor activity, we investigated BS RNAase effect on athymic nude mice bearing various tumors. BS RNAase (250 micrograms per mouse per day) was administered to the mice with prostate carcinoma for three weeks by three different routes (intraperitoneally--i.p., subcutaneously--s.c., and intratumorally-i.t.). Administration i.p. was ineffective, while s.c. administration reduced significantly size of tumors and i.t. administration abolished half of the tumors in treated mice. The i.t. administration of BS RNase to nude mice bearing melanoma showed even better results. Eighty % of mice were without tumors and in the other mice the tumors were significantly diminished. The best antitumor effect was obtained in case of seminoma. All mice bearing this tumor were cured after ten doses of BS RNAase.

• MeSH
• antitumorózní látky aplikace a dávkování   terapeutické užití   MeSH
• endoribonukleasy aplikace a dávkování   terapeutické užití   MeSH
• experimentální nádory farmakoterapie   MeSH
• léky antitumorózní - screeningové testy MeSH
• melanom farmakoterapie   MeSH
• myši nahé MeSH
• myši MeSH
• nádory prostaty farmakoterapie   MeSH
• seminom farmakoterapie   MeSH
• skot MeSH
• transplantace heterologní MeSH
• transplantace nádorů MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• endoribonukleasy MeSH
• ribonuclease SPL MeSH Prohlížeč