RESUMO
Folate receptor (FR) has been proposed as a promising target for tumor drug targeting. The aim of this study was to increase the chemo-sensitivity of FR-positive cells to doxorubicin by folate-directed enzyme prodrug therapy (FDEPT). Folate conjugated penicillin-G amidase was prepared and its ability to hydrolyze N-(phenylacetyl) doxorubicin was measured by HPLC. Fluorescence and confocal image analysis revealed that Folate-PGA can be specifically delivered into FR-positive HeLa and SKOV3 tumor cells. In vitro cytotoxity assays, IC50 was reduced with N-(phenylacetyl) doxorubicin versus doxorubicin for HeLa (3.1-fold reduction; p<0.001) and SKOV3 (3.3-fold reduction; p<0.001) when Folate-PGA was specifically bound to the cells. Complete activation was confirmed in HeLa and SKOV3 cells pretreated with free folic acid (1 mM), where the combination of N-(phenylacetyl) doxorubicin with Folate-PGA did not show any significant cell toxicity to the IC50 of doxorubicin. Pharmacokinetic clearance and biodistribution studies in vivo showed that 125I-Folate-PGA was cleared from blood within 24 h and had significantly higher tumor uptake compared to 125I-PGA (p<0.05). These results demonstrate that the FDEPT approach may be a potential promising strategy to improve chemotherapy-resistant cancers therapeutic ratio and warranted future studies.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Ácido Fólico/farmacologia , Penicilina Amidase/farmacologia , Pró-Fármacos/farmacologia , Animais , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Receptores de Folato com Âncoras de GPI , Ácido Fólico/química , Ácido Fólico/farmacocinética , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Penicilina Amidase/química , Penicilina Amidase/farmacocinética , Receptores de Superfície Celular/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
IL-8 was radiolabeled with 125I via Bolten-Hunter agent and the distribution of 125I-IL-8 in mice was determined in order to understand IL-8 behaviors in vivo. The percentage of 125I-IL-8 in blood, heart, liver, lung, kidneys, bone and spleen was obtained. The half-clearance of fast phase T1/2 alpha and slow phase T1/2 beta were 0.32 h and 8.01 h respectively. Most of 125I-IL-8 was excluded by kidneys.
