RESUMO
Real-time quantitative PCR (RT-qPCR) is commonly used for follow-up of chronic myeloid leukemia (CML) patients treated with tyrosine kinase inhibitors, but its current sensitivity does not allow detection of very low BCR-ABL levels. Therefore RT-qPCR negativity is not synonymous with complete molecular response. Replicate RT-qPCR had shown increased sensitivity in tyrosine kinase inhibitor-treated patients and was, therefore, used here to evaluate whether RT-qPCR-negative post-allogeneic stem cell transplantation (SCT) patients harbor detectable disease. Samples from 12 patients were tested at 2 time points using 82 replicates of BCR-ABL RT-qPCR. One patient (38 months after SCT) had detectable transcripts at baseline and none at the follow-up test, done at a median of 107 months after SCT. This suggests cure from CML in the majority of allogeneic SCT patients who have no transcripts detectable by replicate RT-qPCR for BCR-ABL.
Assuntos
Biomarcadores Tumorais/genética , Proteínas de Fusão bcr-abl/genética , Transplante de Células-Tronco Hematopoéticas , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adulto , Aloenxertos , Resistencia a Medicamentos Antineoplásicos , Feminino , Seguimentos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide de Fase Acelerada/genética , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Neoplasia Residual , Inibidores de Proteínas Quinases/uso terapêutico , RNA Mensageiro/sangue , RNA Mensageiro/genética , RNA Neoplásico/sangue , RNA Neoplásico/genética , Recidiva , Indução de Remissão , Sensibilidade e Especificidade , Fatores de TempoAssuntos
Células da Medula Óssea/metabolismo , Eritropoetina/biossíntese , Síndromes Mielodisplásicas/metabolismo , Receptores da Transferrina/biossíntese , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea/patologia , Eritropoetina/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Prognóstico , Receptores da Transferrina/genética , Estudos RetrospectivosRESUMO
An early molecular response has a strong predictive value in chronic myeloid leukemia (CML). Recently, the halving time (velocity of early BCR-ABL1 transcript elimination) has been shown to represent an additional prognostic index. Our objective was the evaluation of the prognostic significance of the 3-month point in our population. We retrospectively collected BCR-ABL1 transcript data at different time points, events, and survival data of patients with CML treated at the Division of Hematology, San Luigi Hospital, University of Turin, Turin, Italy. Of 71 patients diagnosed from January 2005 to March 2015 in our center and treated with front-line tyrosine kinase inhibitors (imatinib, nilotinib and dasatinib), we selected those who had undergone a molecular evaluation at 3 months. The event-free survival (EFS) by the median follow-up time was the primary endpoint. The data from 50 patients with CML chronic phase were analyzed. Overall, 34 of the 50 patients (68%) had a transcript ≤ 10% at 3 months. Of those in the > 10% group, 63% had experienced an event compared with 12% in the ≤ 10% group by the median follow-up point (P < .001). The halving time threshold for discriminating between EFS was 17 days. None of the patients with a transcript > 10% at 3 months had a halving time of ≤ 17 days. Patients with BCR-ABL1 ≤ 10% and a halving time of ≤ 17 days had significantly better EFS than that of patients with BCR-ABL1 ≤ 10% and a halving time > 17 days and of patients with BCR-ABL1 > 10% (96% group 1 vs. 60% group 2 vs. 27% group 3; P < .001). Irrespective of the tyrosine kinase inhibitor used, the prognosis was significantly superior for patients with BCR-ABL1 ≤ 10% and halving time of ≤ 17 days. Our data revealed that the use of ABL1 as a control gene is reliable for the determination of the halving time in the clinical setting and highlight the importance of measuring the BCR-ABL1 transcript at CML diagnosis.
Assuntos
Proteínas de Fusão bcr-abl/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Adulto , Idoso , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Feminino , Seguimentos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
Tumor suppressor function can be modulated by subtle variation of expression levels, proper cellular compartmentalization and post-translational modifications, such as phosphorylation, acetylation and sumoylation. The non-genomic loss of function of tumor suppressors offers a challenging therapeutic opportunity. The reactivation of a tumor suppressor could indeed promote selective apoptosis of cancer cells without affecting normal cells. The identification of mechanisms that affect tumor suppressor functions is therefore essential. In this work, we show that BCR-ABL promotes the accumulation of the NFKBIA gene product, IκBα, in the cytosol through physical interaction and stabilization of the protein. Furthermore, BCR-ABL/IκBα complex acts as a scaffold protein favoring p53 nuclear exclusion. We therefore identify a novel BCR-ABL/IκBα/p53 network, whereby BCR-ABL functionally inactivates a key tumor suppressor.