RESUMO
Iron is an essential nutrient, acting as a catalyst for metabolic reactions that are fundamental to cell survival and proliferation. Iron complexed to transferrin is delivered to the metabolism after endocytosis via the CD71 surface receptor. We found that transformed cells from a murine PTEN-deficient T-cell lymphoma model and from T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/T-LL) cell lines overexpress CD71. As a consequence, the cells developed an addiction toward iron whose chelation by deferoxamine (DFO) dramatically affected their survival to induce apoptosis. Interestingly, DFO displayed synergistic activity with three ALL-specific drugs: dexamethasone, doxorubicin, and L-asparaginase. DFO appeared to act through a reactive oxygen species-dependent DNA damage response and potentiated the action of an inhibitor of the PARP pathway of DNA repair. Our results demonstrate that targeting iron metabolism could be an interesting adjuvant therapy for acute lymphoblastic leukemia.
Assuntos
Quelantes de Ferro/farmacologia , Ferro/metabolismo , Linfoma de Células T/genética , Linfoma de Células T/metabolismo , PTEN Fosfo-Hidrolase/deficiência , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Apoptose/efeitos dos fármacos , Asparaginase/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quimioterapia Adjuvante , Dano ao DNA , Desferroxamina/farmacologia , Modelos Animais de Doenças , Sinergismo Farmacológico , Expressão Gênica , Humanos , Quelantes de Ferro/uso terapêutico , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/mortalidade , Camundongos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/mortalidade , Espécies Reativas de Oxigênio/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismoRESUMO
The membrane-bound carbonic anhydrase isoforms CAIX and CAXII, underpin a pH-regulating system that enables hypoxic tumor cell survival. Here, we observed for the first time an upregulation of CAXII in T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LL) cells. First we showed that CAXII is overexpressed in thymocytes from tPTEN-/- mice suffering of T lymphoma and that its pharmacological inhibition decreased cell proliferation and induced apoptosis. The same results were observed with the SupT1 human T cell lymphoma line. In addition we observed an upregulation of CAXII in human T-ALL samples supporting the case that CAXII may represent a new therapeutic target for T-ALL/LL.