RESUMO
Vincristine (VCR) is one of the most widely prescribed medications for treating solid tumors and acute lymphoblastic leukemia (ALL) in children and adults. However, its major dose-limiting toxicity is peripheral neuropathy that can disrupt curative therapy. Peripheral neuropathy can also persist into adulthood, compromising quality of life of childhood cancer survivors. Reducing VCR-induced neurotoxicity without compromising its anticancer effects would be ideal. Here, we show that low expression of NHP2L1 is associated with increased sensitivity of primary leukemia cells to VCR, and that concomitant administration of VCR with inhibitors of NHP2L1 increases VCR cytotoxicity in leukemia cells, prolongs survival of ALL xenograft mice, but decreases VCR effects on human-induced pluripotent stem cell-derived neurons and mitigates neurotoxicity in mice. These findings offer a strategy for increasing VCR's antileukemic effects while reducing peripheral neuropathy in patients treated with this widely prescribed medication.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Doenças do Sistema Nervoso Periférico/prevenção & controle , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Ribonucleoproteínas Nucleares Pequenas/antagonistas & inibidores , Vincristina/efeitos adversos , Adolescente , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Células Cultivadas , Criança , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Leucêmica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Células-Tronco Pluripotentes Induzidas , Masculino , Camundongos , Neurônios , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Cultura Primária de Células , Ribonucleoproteínas Nucleares Pequenas/genética , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Vincristina/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto JovemRESUMO
PURPOSE: Werner's syndrome (WS) is a recessive disorder of premature onset of processes associated with aging. Defective DNA repair has been reported after exposure of cells isolated from WS patients to DNA-damaging agents. The germline 4330T>C (Cys1367Arg) variant in the WS gene (WRN) has been associated with protection from age-related diseases, suggesting it has a functional role. We studied whether the 4330T>C variant confers altered drug sensitivity in vitro. METHODS: 4330T>C was genotyped in 372 human lymphoblastoid cell lines (LCLs) from unrelated healthy Caucasian individuals using a TaqMan-based method. The study was powered to detect the effect of the 4330T>C genotypes after exposure to camptothecin (based upon preliminary data). The effect of the 4330T>C variant on the cytotoxicity of etoposide, carboplatin, cisplatin and daunorubicin was also tested. WRN expression in 57 LCLs was measured by microarray. RESULTS: No significant difference between the IC50 of the cells was observed among genotypes (P = 0.46) after exposure to camptothecin. No association was also observed for etoposide, carboplatin, cisplatin, and daunorubicin (ANOVA, P > 0.05). WRN expression also did not vary across genotypes (ANOVA, P = 0.37). CONCLUSION: These results suggest that this nonsynonymous variant has relatively normal function at the cellular level.
Assuntos
Linfócitos B/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Exodesoxirribonucleases/genética , Compostos de Platina/farmacologia , Polimorfismo de Nucleotídeo Único/genética , RecQ Helicases/genética , Inibidores da Topoisomerase , Síndrome de Werner/genética , Antibióticos Antineoplásicos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Camptotecina/farmacologia , Carboplatina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cisplatino/farmacologia , Daunorrubicina/farmacologia , Etoposídeo/farmacologia , Genótipo , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Helicase da Síndrome de WernerRESUMO
Chemotherapeutic alkylnitrosoureas (BCNU, CCNU, streptozotocin) and alkyltriazenes (DTIC, temozolomide) produce a cytotoxic lesion at the O(6)-position of guanine. The DNA repair protein, O(6)-alkylguanine-DNA alkyltransferase removes damage from the O(6)-position in a single-step mechanism without co-factors. There is extensive evidence that this protein is one of the most important factors contributing to alkylnitrosourea and alkyltriazene treatment failure. There is an inverse correlation between the level of this protein and the sensitivity of cells to the cytotoxic effects of O(6)-alkylating agents. Attempts have been made to modulate AGT activity using anti-sense technology, methylating agents, O(6)-alkylguanines, and O(6)-benzylguanine analogs. O(6)-Benzylguanine and its analogs are clearly the most potent direct inactivators of the AGT protein. The mechanism involves O(6)-benzylguanine acting as a low-molecular weight substrate with transfer of the benzyl group to the cysteine residue within the active site of the repair protein. Pretreatment of cells with non-toxic doses of O(6)-benzylguanine results in an increase in the sensitivity to O(6)-alkylating agents. Animal studies revealed that the therapeutic index of BCNU increased when administered in combination with O(6)-benzylguanine. This drug is currently in phase I clinical trials. Evidence from animal studies indicates that myelosuppression may be the dose-limiting toxicity, thus, efforts are aimed at improving the therapeutic index by the stable expression of O(6)-benzylguanine-resistant AGT proteins into targeted normal tissue such as bone marrow. The successful modulation of alkyltransferases brings on an exciting new era for alkylnitrosoureas and alkyltriazenes.