RESUMO
A 78-year-old woman was examined in the outpatient department with a chief complaint of swelling of the left breast. Examination confirmed a 10 cm mass in the left breast as along with edema and redness of the skin, following which a diagnosis of invasive micropapillary carcinoma was made after biopsy. The CT imaging showed left chest wall invasion, multiple axillary lymph node metastases, and left carcinomatous pleuritis. Since this a case of advanced breast cancer, we initiated treatment with bevacizumab plus paclitaxel. After 8 months, her medication was changed to eribulin, owing to progression of the cancer, which continued even up to 4 months. We then initiated abemaciclib plus letrozole therapy as the third treatment. We observed tumor reduction and clearing of pleural effusion with no serious adverse events, and continued her therapy for 11 months before the cancer progressed. We report a case of chemotherapy-resistant breast cancer and carcinomatous pleuritis in an older adult patient for which abemaciclib plus letrozole therapy was effective.
Assuntos
Neoplasias da Mama , Pleurisia , Humanos , Feminino , Idoso , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Letrozol/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Paclitaxel , Bevacizumab , Pleurisia/tratamento farmacológico , Pleurisia/etiologiaRESUMO
A 69-year-old woman admitted to our hospital with the lump in the left breast. Further examination was performed for the lesion, and it was diagnosed as invasive ductal carcinoma. Partial resection and sentinel lymph node biopsy were performed. Pathological diagnosis was metaplastic carcinoma with squamous metaplasia. As the adjuvant treatment, docetaxel and cyclophosphamide(TC)therapy and radiotherapy was performed. Following the treatment of those, tegafur-uracil was administered for 2 years. Three years after the surgery, an isolated lung metastasis was revealed by CT. Capecitabine and cyclophosphamide(XC)therapy was administered, but not effective. Stereotactic body radiation therapy(SBRT)was performed for the lesion. As a result, the metastatic lesion was obscured. Drug therapy was stopped due to adverse events, and she is observed by no medication. Thirty-six months after SBRT and 78 months after the surgery, the patient is alive without recurrence. SBRT could be an effective treatment strategy for the oligometastais of the lung.
Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , Radiocirurgia , Idoso , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/terapia , Recidiva Local de Neoplasia , TegafurRESUMO
BACKGROUND: Application of next-generation DNA sequencing (NGS) has recently become increasingly common in the field of clinical oncology in several countries around the world. In Japan also, a system for applying NGS to routine clinical practice is gradually being established. During this process, we introduced in Japan the tumor-profiling MSK-IMPACT (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets) assay. METHODS: We present here our initial experience with the use of MSK-IMPACT in 68 patients selected from two institutions in Japan between June 2016 and October 2017. RESULTS: MSK-IMPACT sequencing was successful and yielded results in specimens obtained from 64 of the 68 patients, representing an overall assay success rate of 94.1%. The top three cancer types tested were endometrial cancer (17.2%), pancreatic cancer (15.6%) and colorectal cancer (12.5%). Evaluation of the clinical actionability of the genetic alterations revealed that 25.0% of patients (n = 16) harbored at least one actionable alteration. However, enrolling the patients in a genomically matched clinical trial was difficult, mainly because most clinical trials are limited to tumors arising from a specific organ/site. One patient with microsatellite instability-high status, as determined by MSK-IMPACT, was treated with pembrolizumab and showed partial response. CONCLUSIONS: Although tumor profiling by NGS and administration of genomically matched therapy is a promising strategy, because of its high cost, we need to consider how we can fit it into the Japanese medical system. Towards this end, we believe that it is important to share our initial experience for furthering precision medicine in Japan.
Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias/genética , Neoplasias/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Rearranjo Gênico/genética , Genes Neoplásicos , Genômica , Humanos , Japão , Metástase Linfática/diagnóstico por imagem , Masculino , Instabilidade de Microssatélites , Mutação/genética , Estadiamento de Neoplasias , Medicina de Precisão , Regiões Promotoras Genéticas/genética , Adulto JovemRESUMO
A 56-year-old women underwent retroperitoneal leiomyosarcoma resection in December 2011. In July 2015, CT showed multiple liver metastases, and she received first-line chemotherapy treatment with doxorubicin. After 2 courses of doxorubicin, her performance status deteriorated; therefore, she was treated with pazopanib as second-line chemotherapy. PFS with pazopanib was 5 months and that with eribulin was 2.5 months. She was then treated with trabectedin as fourth-line chemotherapy from July 2016. The liver metastases reduced, and the disease was controlled for 1 year and 6 months following administration of trabectedin. We continue to treat this patient with trabectedin, and no serious side effects have been observed.
Assuntos
Antineoplásicos Alquilantes , Leiomiossarcoma , Tetra-Hidroisoquinolinas , Trabectedina , Antineoplásicos Alquilantes/uso terapêutico , Dioxóis , Feminino , Humanos , Leiomiossarcoma/tratamento farmacológico , Pessoa de Meia-Idade , Trabectedina/uso terapêutico , Resultado do TratamentoRESUMO
Tropomyosin-related kinase(TRK)fusion proteins are oncogenic drivers in multiple tumors in adults and children.Larotrectinib, an orally administered selective TRK inhibitor approved in the US, exhibits inhibitory activity against tumors harboring TRK fusions and is well tolerated.Here, we report the case of an 8-year-old female child with recurrence of an NTRK fusion low-grade sarcoma treated with larotrectinib monotherapy.The patient previously underwent resection of low-grade sarcoma in the right brachialis at 6 years of age, but local recurrence occurred after 16 months.As re-operation likely required amputation, larotrectinib was commenced at a dose of 100 mg BID.Complete radiographic remission was achieved after 3 months.There were no adverse events attributed to larotrectinib treatment.After dosing for 6 months, we performed local resection, confirming pathological complete remission.The drug was stopped, and the patient showed no evidence of relapse at 4 months after resection.In this case, larotrectinib was obtained using Single Patient Expanded Access under the FDA.In this paper, we also discuss the issues faced while accessing unapproved drugs in the precision medicine era in Japan.
Assuntos
Recidiva Local de Neoplasia , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Sarcoma , Criança , Feminino , Fusão Gênica , Humanos , Japão , Lamina Tipo A , Receptor trkA , Sarcoma/tratamento farmacológicoRESUMO
A 60-year-old woman was admitted to our hospital with anemia and thrombocytopenia. Serum testing showed platelet-associated IgG elevation and she was positive on the direct and indirect Coombs tests. Together with bone marrow examination, these findings indicated a diagnosis of Evans syndrome. At diagnosis, she also had an IgM-κ type of monoclonal gammopathy of unknown significance. Initially, we administered steroids and her hemolytic anemia showed improvement. In contrast, only transient recovery of platelet counts was observed and her platelet counts rapidly decreased after steroid dose reduction. Thus, we treated her with a TPO-agonist, romiplostim. During the clinical course, she showed gradual serum IgM elevation. We thus performed another bone marrow biopsy and diagnosed her as having Waldenström's macroglobulinemia (WM). We started treatment with rituximab for WM. Together with the serum IgM reduction, she showed marked improvement of thrombocytopenia. This is a very rare case of WM initially presenting as autoimmune hemolytic anemia and immunethrombocytopenia associated with IgG class auto-antibody. Our experience suggests the usefulness of rituximab and romiplostim for the treatment of immunethrombocytopenia associated with WM.
Assuntos
Anemia Hemolítica Autoimune/tratamento farmacológico , Anticorpos Monoclonais Murinos/uso terapêutico , Imunossupressores/uso terapêutico , Receptores Fc/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Trombocitopenia/tratamento farmacológico , Trombopoetina/uso terapêutico , Macroglobulinemia de Waldenstrom/tratamento farmacológico , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/etiologia , Anticorpos Monoclonais Murinos/administração & dosagem , Combinação de Medicamentos , Feminino , Humanos , Imunossupressores/administração & dosagem , Pessoa de Meia-Idade , Receptores Fc/administração & dosagem , Proteínas Recombinantes de Fusão/administração & dosagem , Rituximab , Trombocitopenia/diagnóstico , Trombocitopenia/etiologia , Trombopoetina/administração & dosagem , Macroglobulinemia de Waldenstrom/complicações , Macroglobulinemia de Waldenstrom/patologiaRESUMO
Adult T cell lymphoma-leukemia (ATL) is a highly aggressive disease and allogeneic hematopoietic transplantation (allo-HSCT) is the only therapeutic option for achieving a cure. However, some ATL patients cannot undergo HSCT. One of the important reasons for restricting HSCT in ATL is the high incidence of pulmonary complications associated with ATL including opportunistic infections, infiltration of ATL cells, and HTLV-1 associated bronchopneumonopathy. Herein, we report an ATL case with pulmonary infiltration of ATL cells successfully treated with allo-HSCT after improvement of pulmonary function with administration of the anti-CCR4 antibody mogamulizumab. To our knowledge, this is the first ATL case showing improvement of pulmonary invasion of ATL cells after treatment with mogamulizumab. In addition, this case suggests that mogamulizumab treatment might be useful as a bridge to allo-HSCT in ATL patients.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Transplante de Células-Tronco Hematopoéticas , Vírus Linfotrópico T Tipo 1 Humano , Leucemia-Linfoma de Células T do Adulto/terapia , Transplante Homólogo/efeitos adversos , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Leucemia-Linfoma de Células T do Adulto/diagnóstico , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Bendamustine is one of the new key drugs for patients with indolent lymphoma. Bendamustine, together with rituximab, significantly improves the treatment outcomes of these patients. In addition, previous clinical studies have shown the complication rate of severe infection in bendamustine-containing regimens to be relatively low as compared to those of conventional chemotherapeutic regimens such as CHOP. However, some clinical case reports have raised the possibility that bendamustine may abrogate the immune responses of patients and trigger opportunistic infections including cytomegalovirus reactivation. Herein, we report three indolent lymphoma cases becoming positive on cytomegalovirus antigenemia assay during bendamustine monotherapy. All events occurred after more than three courses of treatment with bendamustine. One patient showed decreased CD4 positive T lymphocytes before the development of cytomegalovirus antigenemia. All three patients were successfully treated with valganciclovir. Although the precise risk is unknown, it should be noted that bendamustine can potentially cause reactivation of/infection with cytomegalovirus and physicians should pay attention to the possibility of this infection during treatment with bendamustine-containing regimens.
Assuntos
Infecções por Citomegalovirus/induzido quimicamente , Infecções por Citomegalovirus/complicações , Linfoma de Células B/complicações , Linfoma de Células B/tratamento farmacológico , Compostos de Mostarda Nitrogenada/administração & dosagem , Compostos de Mostarda Nitrogenada/efeitos adversos , Infecções Oportunistas/induzido quimicamente , Infecções Oportunistas/complicações , Adulto , Idoso , Antígenos Virais/sangue , Antivirais/uso terapêutico , Cloridrato de Bendamustina , Biomarcadores/sangue , Contagem de Linfócito CD4 , Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/tratamento farmacológico , Feminino , Ganciclovir/análogos & derivados , Ganciclovir/uso terapêutico , Humanos , Linfoma de Células B/imunologia , Masculino , Pessoa de Meia-Idade , Compostos de Mostarda Nitrogenada/farmacologia , Infecções Oportunistas/diagnóstico , Infecções Oportunistas/tratamento farmacológico , Resultado do Tratamento , Valganciclovir , Ativação Viral/efeitos dos fármacosRESUMO
Meningeal carcinomatosis is a condition in which cancer cells diffusely metastasize to the cerebral pia mater in the cerebrospinal membrane or cerebrospinal cavity. It causes a wide array of symptoms according to the site of metastasis. The prognosis is poor, especially in metastasis from solid tumors. This study reports a case of meningeal carcinomatosis caused by advanced gastric cancer, manifested by headache and vision loss. The patient was a 69-year-old man who underwent head computed tomography (CT) and magnetic resonance imaging (MRI) for persistent headaches. No abnormal findings were found; however, his vision declined, convulsions occurred, and cerebrospinal fluid (CSF) cytology showed poorly differentiated adenocarcinoma. Therefore, meningeal carcinomatosis was diagnosed. The patient died after receiving FOLFOX therapy to relieve symptoms and prolong his life. An autopsy showed no invasion of the optic nerve or surrounding tissues. As the frequency of complications of meningeal carcinomatosis in solid cancers is rare, it is crucial to actively suspect and make an early diagnosis.
Assuntos
Adenocarcinoma , Carcinomatose Meníngea , Neoplasias Gástricas , Masculino , Humanos , Idoso , Carcinomatose Meníngea/tratamento farmacológico , Carcinomatose Meníngea/complicações , Carcinomatose Meníngea/diagnóstico , Detecção Precoce de Câncer , Adenocarcinoma/complicações , Neoplasias Gástricas/patologia , Acuidade VisualRESUMO
Spontaneous rupture of the spleen is a rare but important complication in hematological malignancies. Without splenectomy, the mortality rate of these patients is nearly 100%. We present a blastic plasmacytoid dendritic cell neoplasm case with this complication. Nine days after initiation of chemotherapy, the patient had increased epigastric pain and a drop in hemoglobin. CT scan showed an enlarged spleen surrounded by hemorrhage. Spontaneous rupture of the spleen was diagnosed. Although the patient had severe bone marrow suppression due to chemotherapy, emergency splenectomy was performed and the patient recovered.
Assuntos
Células Dendríticas/patologia , Neoplasias Hematológicas/tratamento farmacológico , Ruptura Espontânea/cirurgia , Esplenectomia , Ruptura Esplênica/cirurgia , Adulto , Humanos , Masculino , Radiografia , Esplenectomia/métodos , Ruptura Esplênica/diagnóstico por imagem , Resultado do TratamentoRESUMO
Rearrangements of the mixed lineage leukemia MLL gene at chromosome 11q23 are common chromosomal abnormalities in human leukemia. MLL fused with numerous partner genes causes different leukemia phenotypes that depend on the function of partner genes. MLLT3-MLL is generated by translocation t(9;11), which primarily induces acute myeloid leukemia in humans, whereas MLLT3-MLL induces ALL or biphenotypic leukemia in mice. The microenvironment that surrounds leukemia cells plays a central role in this process. We report a patient with mixed phenotype acute leukemia with MLLT3-MLL. This patient, a 44-year-old woman, initially exhibited extramedullary leukemia with multiple tumors and subsequently developed bone marrow disease. The leukemia cells exhibited myeloid (CD13 and MPO) and B cell (CD19 and CD79a) phenotypes. Chromosomal analysis and RT-PCR assay revealed tumor cells with the MLLT3-MLL fusion gene. We treated this patient with a drug regimen for AML (Ara-C plus anthracycline), and complete remission was obtained. This report describes the fourth case of mixed phenotypic leukemia with extramedullary disease. The extramedullary circumstance may underlie the biphenotypic features of these patients.
Assuntos
Rearranjo Gênico/genética , Leucemia Mieloide Aguda/genética , Proteína de Leucina Linfoide-Mieloide/genética , Fatores de Transcrição/metabolismo , Translocação Genética/genética , Adulto , Feminino , Humanos , Leucemia Mieloide Aguda/diagnóstico , FenótipoRESUMO
BACKGROUND/AIM: The efficacy of retreatment with immune checkpoint inhibitors (ICIs) in programmed death-ligand 1 (PD-L1) positive metastatic or recurrent triple-negative breast cancer (mTNBC) remains unknown. We report a case of a patient with recurrent triple-negative breast cancer who was successfully treated with two different ICIs in combination with chemotherapy. CASE REPORT: A 60-year-old female patient was treated with neoadjuvant chemotherapy consisting of epirubicin + cyclophosphamide (EC) followed by docetaxel (DTX). The tumor shrank with EC, but progressed with DTX. One year after the surgery, the patient presented with multiple lung metastases. The patient received combination therapy with atezolizumab and nab-paclitaxel and achieved a partial response (PR). However, the disease progressed after 6 months. She received eribulin as second-line chemotherapy for 4.5 months, and her treatment was changed to pembrolizumab, carboplatin, and gemcitabine as third-line chemotherapy. The tumor immediately reduced and disappeared after three cycles of this treatment and achieved PR. CONCLUSION: This case illustrated that retreatment with ICIs was effective.
RESUMO
A 67-year-old woman with refractory multiple myeloma was admitted to our hospital for salvage therapy. She developed fever several days after chemotherapy was initiated and complained of chest pain. Since abnormal electrocardiogram was demonstrated. Emergency coronary angiography was performed, but the coronary artery did not demonstrate stenosis. Thereafter, the patient was diagnosed as having takotsubo cardiomyopathy. Hydragogue and nitric acid preparation transiently improved chest symptoms, but high fever persisted despite antibiotic and antifungal agents. She died on the 9th day after the initiation of chemotherapy. Physicians need to be aware that cardiomyopathy may develop as a severe side effect of chemotherapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Mieloma Múltiplo/complicações , Cardiomiopatia de Takotsubo/etiologia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Evolução Fatal , Feminino , Humanos , Melfalan/administração & dosagem , Melfalan/efeitos adversos , Mieloma Múltiplo/tratamento farmacológico , Prednisolona/administração & dosagem , Prednisolona/efeitos adversos , Terapia de Salvação/efeitos adversos , Vincristina/administração & dosagem , Vincristina/efeitos adversosRESUMO
PURPOSE: TP53 signature has a robust predictive performance for prognosis in early-stage breast cancer, but the experiment that reported this relied on public microarray data and fresh-frozen samples. Before TP53 signature can be used in a clinical setting, a simple and low-cost diagnostic system using formalin-fixed paraffin-embedded (FFPE) samples is needed. New treatments based on the biological characteristics of TP53 signature are expected to follow. EXPERIMENTAL DESIGN: TP53 signature was evaluated in 174 FFPE early breast cancer specimens using digital quantification via the nCounter technique (NanoString). Patients were classified as TP53 signature mutant type (n = 64) or wild type (n = 110). Predictive power of TP53 signature was compared with those of other gene expression signatures in 153 fresh-frozen samples of the same cohort by RNA-seq. The molecular features of TP53 signature were elucidated using TCGA omics data and RNA-seq data to explore new therapeutic strategies for patients with TP53 signature mutant type. RESULTS: TP53 signature was a strong predictor of prognosis and was also more accurate than other gene expression signatures and independent of other clinicopathological factors. TCGA data analysis showed that risk score of TP53 signature was an index of chromosomal and genomic instability and that TP53 signature mutant type was associated with higher PD-L1 expression, variation in copy numbers, and numbers of somatic mutations. CONCLUSIONS: TP53 signature as diagnosed using the nCounter system is not only a robust predictor of prognosis but also a potential predictor of responsiveness to immune checkpoint inhibitors.
RESUMO
Adenosine monophosphate-activated protein kinase (AMPK) is a sensor for cellular energy status. When the cellular energy level is decreased, AMPK is activated and functions to suppress energy-consuming processes, including protein synthesis. Recently, AMPK has received attention as an attractive molecular target for cancer therapy. Several studies have revealed that the activation of AMPK by chemical stimulators, such as metformin, induces apoptosis in a variety of hematologic malignant cells. From another perspective, these results suggest that the function of AMPK is impaired in hematologic tumor cells. However, the precise mechanisms by which this impairment occurs are not well understood. In melanoma cells, oncogenic BRAF constitutively activates the extracellular signal-regulated kinase (ERK) pathway and phosphorylates liver kinase B1, an upstream activator of 5' adenosine monophosphate-activated protein kinase (AMPK), resulting in the inactivation of liver kinase B1 and AMPK. In this study, we analyzed whether ERK is involved in the suppression of AMPK activity using established and primary human leukemia cells. We found an inverse correlation between the intensity of ERK activity and the degree of AMPK activation after stimulation with either glucose deprivation or metformin. We also found that the inhibition of ERK activity by U0126 restored AMPK activation after metformin treatment. Furthermore, a combined treatment with metformin and U0126 enhanced the antileukemic activity of metformin. Importantly, metformin induced ERK activation by suppressing the protein levels of dual specificity phosphatase 6, a negative regulator of ERK. This crosstalk between AMPK and ERK could diminish the antileukemic activity of metformin. Taken together, our present observations suggest a novel therapeutic strategy for improving the efficacy of metformin in treating leukemia.
Assuntos
Proteínas Quinases Ativadas por AMP/fisiologia , Leucemia Mieloide Aguda/patologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/fisiologia , Proteínas de Neoplasias/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Quinases Proteína-Quinases Ativadas por AMP , Proteínas Quinases Ativadas por AMP/genética , Adulto , Idoso , Antineoplásicos/farmacologia , Apoptose , Butadienos/farmacologia , Linhagem Celular Tumoral , Interações Medicamentosas , Fosfatase 6 de Especificidade Dupla/fisiologia , Ativação Enzimática , Retroalimentação Fisiológica , Feminino , Glucose/farmacologia , Humanos , Leucemia Mieloide Aguda/enzimologia , Leucemia Mielomonocítica Aguda/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metformina/farmacologia , Pessoa de Meia-Idade , Nitrilas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Interferência de RNA , RNA Interferente Pequeno/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Células Tumorais CultivadasRESUMO
We report a case of anaplastic large cell lymphoma (ALCL) with involvement of bone marrow, exhibiting extreme leukocytosis leading to death due to multi-organ failure within 1 week after admission. The patient had a history of rheumatoid arthritis, and had severe pneumonia at admission. To elucidate the basis for the observed extreme neutrophilia, we analysed the levels of several cytokines in serum samples taken from the patient at diagnosis. The patient exhibited an extreme increase in interleukin-17 (IL-17), one of the major regulatory cytokines for inflammation and neutrophil migration. Interestingly, a recent study revealed that anaplastic lymphoma kinase (ALK)-positive ALCL cells produce IL-17. IL-17 also contributes to treatment resistance in multiple types of cancer. Given these previous findings, our case may suggest a possible link between overproduction of IL-17 and an aggressive ALCL phenotype. Further studies will be required to determine whether serum IL-17 levels serve as a useful prognostic marker for ALCL.
Assuntos
Leucocitose/complicações , Linfoma Anaplásico de Células Grandes/complicações , Neutrófilos/patologia , Idoso de 80 Anos ou mais , Medula Óssea/patologia , Progressão da Doença , Evolução Fatal , Feminino , Fator Estimulador de Colônias de Granulócitos/sangue , Humanos , Interleucina-17/sangue , Leucocitose/sangue , Leucocitose/diagnóstico , Linfoma Anaplásico de Células Grandes/sangue , Linfoma Anaplásico de Células Grandes/diagnósticoRESUMO
The hypoxic microenvironment of the bone marrow, known as the hypoxic niche, supports hematopoietic stem cell quiescence and maintains long-term repopulation activity. Hypoxia also affects the expansion of progenitor cells and enhances erythropoiesis and megakaryopoiesis. In contrast to the known effects of hypoxia on normal hematopoiesis, the effects of the hypoxic environment of the bone marrow on the pathogenesis of myeloproliferative neoplasms (MPNs) have not been well studied. In the present study, we investigated the role of the hypoxic environment in the pathophysiology of MPNs, focusing on JAK2V617F, a major driver of mutation in Philadelphia-negative MPNs. We found that the activity of JAK2V617F was suppressed in hypoxic conditions not only in JAK2V617F-positive leukemia cells, but also in primary peripheral blood mononuclear cells from patients with polycythemia vera. Concomitant with the inhibition of JAK2V617F activity, hypoxia increased the expression of p27/KIP1, the primary negative regulator of the cell cycle, and inhibited cell cycle progression in JAK2V617F-positive leukemia cell lines. The spontaneous erythroid colony formation of primary cells from polycythemia vera patients was also suppressed under hypoxic conditions. We also revealed that the hypoxia-induced overproduction of reactive oxygen species played a crucial role in the inhibition of JAK2V617F through the oxidation and inhibition of SHP-2, a protein tyrosine phosphatase that contains SH-2, which is required for JAK2 activation. In conclusion, a hypoxic environment may modulate JAK2-positive MPN cell fate and disease progression through the suppression of SHP-2 function and the subsequent suppression of JAK2V617F activity.
Assuntos
Neoplasias Hematológicas/enzimologia , Janus Quinase 2/metabolismo , Leucócitos Mononucleares/enzimologia , Mutação de Sentido Incorreto , Proteínas de Neoplasias/metabolismo , Policitemia Vera/enzimologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Idoso , Idoso de 80 Anos ou mais , Substituição de Aminoácidos , Hipóxia Celular/genética , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Ativação Enzimática/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Humanos , Janus Quinase 2/genética , Leucócitos Mononucleares/patologia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Policitemia Vera/genética , Policitemia Vera/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Espécies Reativas de Oxigênio/metabolismoAssuntos
Leucemia Eritroblástica Aguda , Idoso , Antineoplásicos/uso terapêutico , Transfusão de Eritrócitos , Humanos , Leucemia Eritroblástica Aguda/diagnóstico , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/patologia , Leucemia Eritroblástica Aguda/terapia , Masculino , Indução de RemissãoRESUMO
The introduction of rituximab, an anti-CD20 monoclonal antibody, has dramatically improved the treatment outcomes of patients with B cell lymphoma. Nevertheless, the clinical response to rituximab varies, and a subpopulation of patients does not respond well to this antibody. Although several molecular events have been shown to be involved in the mechanism of action of rituximab, recent studies have demonstrated that intracellular signaling pathways and the direct effects of rituximab on cell membrane components are responsible for the antilymphoma action of this drug. In the present study, we demonstrated that rituximab activated Syk and Akt, molecules with antiapoptotic functions, in several CD20-positive lymphoma cell lines. Notably, rituximab activated Syk and Akt in all the tested primary lymphoma samples from six patients. Our results show that the cholesterol levels in lymphoma cell membranes have a crucial role in the regulation of Syk and Akt. The depletion of cholesterol from the cell membrane completely blocked rituximab-induced Syk and Akt activation. Simvastatin, an inhibitor of cholesterol synthesis, also abrogated rituximab-mediated Syk and Akt activation. Finally, we report that rituximab inhibited the apoptosis induced by chemotherapeutic drugs, which was observed solely in Akt-activated cells. This work demonstrates for the first time that rituximab paradoxically works to suppress apoptosis under certain conditions in a manner that is dependent on the cell membrane cholesterol level. Our observations provide novel insights and suggest that the cell membrane cholesterol level represents a new biomarker for predicting patient response to rituximab. Furthermore, the modulation of lipid rafts could provide a new strategy for enhancing the antilymphoma action of rituximab.