Two novel sugar-conjugated 5-fluorocytosine(5-FC)antineoplastic compounds were designed and synthesized to improve the selective drug uptake by targeting the tumor-specific glucose transporter(GLUT).The antitumor acti...Two novel sugar-conjugated 5-fluorocytosine(5-FC)antineoplastic compounds were designed and synthesized to improve the selective drug uptake by targeting the tumor-specific glucose transporter(GLUT).The antitumor activity of these compounds was evaluated in four different human cancer cell lines:A549(human lung cancer cell line),HT29(human colorectal cancer cell line),H460(human lung cancer cell line),and PC3(human prostate cancer cell line).The sugar conjugates exhibited cytotoxicity similar to or higher than 5-FC and 1-hexylcarbamoyl-5-FC in A549,HT29,H460,and PC3.Furthermore,GLUT-mediated transport of the glycoconjugate was investigated with GLUT inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing HT29 cell line.The cell-killing potency of 5-FC glycoconjugate was found to depend significantly on the GLUT inhibitor,and the cellular uptake of molecules was regulated by GLUT-mediated transport.All the results demonstrate the potential advantages of glycoconjugation for Warburg effect-targeted drug design.展开更多
5-Fluorocytosine (5-FC) is used for the treatment of several infections. It is extremely important to monitor blood level concentration for maximum activity to avoid its side effects. A simple, faster, and more accura...5-Fluorocytosine (5-FC) is used for the treatment of several infections. It is extremely important to monitor blood level concentration for maximum activity to avoid its side effects. A simple, faster, and more accurate analytical method is developed and validated using high-performance liquid chromatography with UV detection in a very low-volume serum sample. Exactly 50 μL of serum was precipitated with 5% trichloroacetic acid. After mixing and centrifugation, 20 μL of supernatant was injected into the HPLC column. Detection was performed at 280 nm. The method is very specific and free from interfering substances due to different drugs and their different circulating metabolites. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.50 μg/L and 1.0 μg/L, respectively. The method was linear in the range of 5 - 150 μg/L in the serum sample. In method comparison, the correlation coefficient r<sup>2</sup> was 0.999 and the percentage recovery was 90% - 105% on four levels of the quality control samples. Within run and between run precision was found to be less than 2.2% at four different concentrations (5, 25, 50, and 100 μg/L). A simple, faster, and more accurate HPLC-UV method is developed which is very useful for monitoring 5-FC concentration in low volume serum samples without evaporation step and ion exchange chromatography within minutes.展开更多
Cytosine Deaminase (CD) from Aspergillus parasiticus was purified and characterized. Time course for maximal CD production (50 μmol/min/mg) was at 72 hrs. The enzyme was purified 387.73 folds with an overall yield of...Cytosine Deaminase (CD) from Aspergillus parasiticus was purified and characterized. Time course for maximal CD production (50 μmol/min/mg) was at 72 hrs. The enzyme was purified 387.73 folds with an overall yield of 13%. The CD had pH optimum of 7.2, a temperature optimum of 40℃ - 45℃, activation of energy (Ea) of 8.4 KJ/mol and a t1/2 of 1.10 hr. A. parasiticus CD stoichiometrically deaminated Cyto-sine and 5-fluorocytosine (5-FC) with the KM values of 0.19mM and 0.30 mM respectively. Studies on the effect of pH on KM and Vmax gave pKa1 of 5.8 and pKa2 of 6.3 with enthalpy of ionization of 43.01 KJ/mole suggesting histidine in the active site. The enzyme was strongly inhibited by Ca2+, Co2+, Zn2+ and Hg2+ and completely inhibited by Cu2+ and Fe2+ at 50 mM. Therefore, A. parasiticus CD can be compared with CDs from other sources that are used in suicide gene therapy.展开更多
基金supported by the National Natural Science Foundation of China (No. 21772144 and No. 21801184)Tianjin Municipal Applied Basic and Key Research Scheme, China (No. 18JCQNIC06400)
文摘Two novel sugar-conjugated 5-fluorocytosine(5-FC)antineoplastic compounds were designed and synthesized to improve the selective drug uptake by targeting the tumor-specific glucose transporter(GLUT).The antitumor activity of these compounds was evaluated in four different human cancer cell lines:A549(human lung cancer cell line),HT29(human colorectal cancer cell line),H460(human lung cancer cell line),and PC3(human prostate cancer cell line).The sugar conjugates exhibited cytotoxicity similar to or higher than 5-FC and 1-hexylcarbamoyl-5-FC in A549,HT29,H460,and PC3.Furthermore,GLUT-mediated transport of the glycoconjugate was investigated with GLUT inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing HT29 cell line.The cell-killing potency of 5-FC glycoconjugate was found to depend significantly on the GLUT inhibitor,and the cellular uptake of molecules was regulated by GLUT-mediated transport.All the results demonstrate the potential advantages of glycoconjugation for Warburg effect-targeted drug design.
文摘5-Fluorocytosine (5-FC) is used for the treatment of several infections. It is extremely important to monitor blood level concentration for maximum activity to avoid its side effects. A simple, faster, and more accurate analytical method is developed and validated using high-performance liquid chromatography with UV detection in a very low-volume serum sample. Exactly 50 μL of serum was precipitated with 5% trichloroacetic acid. After mixing and centrifugation, 20 μL of supernatant was injected into the HPLC column. Detection was performed at 280 nm. The method is very specific and free from interfering substances due to different drugs and their different circulating metabolites. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.50 μg/L and 1.0 μg/L, respectively. The method was linear in the range of 5 - 150 μg/L in the serum sample. In method comparison, the correlation coefficient r<sup>2</sup> was 0.999 and the percentage recovery was 90% - 105% on four levels of the quality control samples. Within run and between run precision was found to be less than 2.2% at four different concentrations (5, 25, 50, and 100 μg/L). A simple, faster, and more accurate HPLC-UV method is developed which is very useful for monitoring 5-FC concentration in low volume serum samples without evaporation step and ion exchange chromatography within minutes.
文摘Cytosine Deaminase (CD) from Aspergillus parasiticus was purified and characterized. Time course for maximal CD production (50 μmol/min/mg) was at 72 hrs. The enzyme was purified 387.73 folds with an overall yield of 13%. The CD had pH optimum of 7.2, a temperature optimum of 40℃ - 45℃, activation of energy (Ea) of 8.4 KJ/mol and a t1/2 of 1.10 hr. A. parasiticus CD stoichiometrically deaminated Cyto-sine and 5-fluorocytosine (5-FC) with the KM values of 0.19mM and 0.30 mM respectively. Studies on the effect of pH on KM and Vmax gave pKa1 of 5.8 and pKa2 of 6.3 with enthalpy of ionization of 43.01 KJ/mole suggesting histidine in the active site. The enzyme was strongly inhibited by Ca2+, Co2+, Zn2+ and Hg2+ and completely inhibited by Cu2+ and Fe2+ at 50 mM. Therefore, A. parasiticus CD can be compared with CDs from other sources that are used in suicide gene therapy.
