Relapses remain a major concern in acute leukemia. It is well known that leukemia stem cells(LSCs) hide in hematopoietic niches and escape to the immune system surveillance through the outgrowth of poorly immunogenic ...Relapses remain a major concern in acute leukemia. It is well known that leukemia stem cells(LSCs) hide in hematopoietic niches and escape to the immune system surveillance through the outgrowth of poorly immunogenic tumor-cell variants and the suppression of the active immune response. Despitethe introduction of new reagents and new therapeutic approaches, no treatment strategies have been able to definitively eradicate LSCs. However, recent adoptive immunotherapy in cancer is expected to revolutionize our way to fight against this disease, by redirecting the immune system in order to eliminate relapse issues. Initially described at the onset of the 90's, chimeric antigen receptors(CARs) are recombinant receptors transferred in various T cell subsets, providing specific antigens binding in a non-major histocompatibility complex restricted manner, and effective on a large variety of human leukocyte antigen-divers cell populations. Once transferred, engineered T cells act like an expanding "living drug" specifically targeting the tumor-associated antigen, and ensure long-term antitumor memory. Over the last decades, substantial improvements have been made in CARs design. CAR T cells have finally reached the clinical practice and first clinical trials have shown promising results. In acute lymphoblastic leukemia, high rate of complete and prolonged clinical responses have been observed after anti-CD19 CAR T cell therapy, with specific but manageable adverse events. In this review, our goal was to describe CAR structures and functions, and to summarize recent data regarding pre-clinical studies and clinical trials in acute leukemia.展开更多
Leukemia stem cells(LSCs),which constitute a minority of the tumor bulk,are functionally defined on the basis of their ability to transfer leukemia into an immunodeficient recipient animal.The presence of LSCs has bee...Leukemia stem cells(LSCs),which constitute a minority of the tumor bulk,are functionally defined on the basis of their ability to transfer leukemia into an immunodeficient recipient animal.The presence of LSCs has been demonstrated in acute lymphoblastic leukemia(ALL),of which ALL with Philadelphia chromosome-positive(Ph+).The use of imatinib,a tyrosine kinase inhibitor(TKI),as part of front-line treatment and in combination with cytotoxic agents,has greatly improved the proportions of complete response and molecular remission and the overall outcome in adults with newly diagnosed Ph+ ALL.New challenges have emerged with respect to induction of resistance to imatinib via Abelson tyrosine kinase mutations.An important recent addition to the arsenal against Ph+ leukemias in general was the development of novel TKIs,such as nilotinib and dasatinib.However,in vitro experiments have suggested that TKIs have an antiproliferative but not an antiapoptotic or cytotoxic effect on the most primitive ALL stem cells.None of the TKIs in clinical use target the LSC.Second generation TKI dasatinib has been shown to have a more profound effect on the stem cell compartment but the drug was still unable to kill the most primitive LSCs.Allogeneic stem cell transplantation(SCT) remains the only curative treatment available for these patients.Several mechanisms were proposed to explain the resistance of LSCs to TKIs in addition to mutations.Hence,TKIs may be used as a bridge to SCT rather than monotherapy or combination with standard chemotherapy.Better understanding the biology of Ph+ ALL will open new avenues for effective management.In this review,we highlight recent findings relating to the question of LSCs in Ph+ ALL.展开更多
AIM: To evaluate quantitatively and qualitatively the different CD34+cell subsets after priming by chemotherapy granulocyte colony-stimulating factor(± G-CSF)in patients with acute myeloid leukemia.METHODS: Perip...AIM: To evaluate quantitatively and qualitatively the different CD34+cell subsets after priming by chemotherapy granulocyte colony-stimulating factor(± G-CSF)in patients with acute myeloid leukemia.METHODS: Peripheral blood and bone marrow sampleswere harvested in 8 acute myeloid leukemia patients during and after induction chemotherapy. The CD34/CD38 cell profile was analyzed by multi-parameter flow cytometry. Adhesion profile was made using CXC chemokine receptor 4(CXCR4)(CD184), VLA-4(CD49d/CD29) and CD47.RESULTS: Chemotherapy ± G-CSF mobilized immature cells(CD34+CD38 population), while the more mature cells(CD34+CD38lowand CD34+CD38+populations) decreased progressively after treatment. Circulating CD34+cells tended to be more sensitive to chemotherapy after priming with G-CSF. CD34+cell mobilization was correlated with a gradual increase in CXCR4 and CD47expression, suggesting a role in cell protection and the capacity of homing back to the marrow.CONCLUSION: Chemotherapy ± G-CSF mobilizes into the circulation CD34+bone marrow cells, of which, the immature CD34+CD38-cell population. Further manipulations of these interactions may be a means with which to control the trafficking of leukemia stem cells to improve patients' outcomes.展开更多
Normal and abnormal hematopoiesis is working as a complex adaptive system. From this perspective, the development and the behavior of hematopoietic cell lineages appear as a balance between normal and abnormal hematop...Normal and abnormal hematopoiesis is working as a complex adaptive system. From this perspective, the development and the behavior of hematopoietic cell lineages appear as a balance between normal and abnormal hematopoiesis in the setting of a functioning or malfunctioning microenvironment under the control of the immune system and the influence of hereditary and environmental events.展开更多
AIM To evaluate the importance of the CD34+CD38-cell population when compared to the CD34+CD38+/low and CD34+CD38+/high leukemic cell sub-populations and to determine its correlations with leukemia characteristics and...AIM To evaluate the importance of the CD34+CD38-cell population when compared to the CD34+CD38+/low and CD34+CD38+/high leukemic cell sub-populations and to determine its correlations with leukemia characteristics and known prognostic factors, as well as with response to therapy and survival.METHODS Two hundred bone marrow samples were obtained at diagnosis from 200 consecutive patients with newly diagnosed acute myeloid leukemia(AML) were studied between September 2008 and December 2010 at our Institution(Hematology Department, Lyon, France). The CD34/CD38 cell profile was analyzed by multiparameter flowcytometry approach using 8 C panels and FACS CANTO and Diva software(BD Bioscience).RESULTS We analyzed CD34 and CD38 expression in bone marrow samples of 200 AML patients at diagnosis, and investigated the prognostic value of the most immature CD34+CD38-population. Using a cut-off value of 1% of CD34+CD38-from total "bulk leukemic cells" we found that a high(> 1%) level of CD34+CD38-blasts at diagnosis was correlated with advanced age, adverse cytogenetics as well as with a lower rate of complete response after induction and shorter disease-free survival. In a multivariate analysis considering age, leukocytosis, the % of CD34+ blasts cells and the standardized cytogenetic and molecular risk subgroups, a percentage of CD34+CD38-leukemic cells > 1% was an independent predictor of DFS [HR = 2.8(1.02-7.73), P = 0.04] and OS [HR = 2.65(1.09-6.43), P = 0.03].CONCLUSION Taken together, these results show that a CD34/CD38 "backbone" for leukemic cell analysis by multicolour flowcytometry at diagnosis provides useful prognostic information.展开更多
Determination of minimal residual disease (MRD) remains crucial for the follow-up after therapy in chronic lymphocytic leukemia (CLL) patients. Chimerism was assessed by short tandem repeat (STR)-PCR and single nucleo...Determination of minimal residual disease (MRD) remains crucial for the follow-up after therapy in chronic lymphocytic leukemia (CLL) patients. Chimerism was assessed by short tandem repeat (STR)-PCR and single nucleotide polymorphisms (SNP)-PCR, and MRD by a multicolor flow cytometric approach in 12 consecutive patients with CLL after they received allogeneic stem cell transplantation (SCT). Overall, 11 patients achieved MRD flow negativity [10 had full donor chimerism (FDC) and one had mixed chimerism (MC)]. Only one patient remained with MRD flow positivity and displayed MC. Fifty-six samples were concomitantly studied by both chimerism and MRD flow. A significant correlation was observed between MRD flow data and chimerism in both PB and BM by using a mixed effect linear regression (p < 0.001). Flow cytometry approach of MRD can be easily combined with chimerism during the follow-up post-allogeneic SCT. Both techniques appeared complementary for guiding post-transplant immunomodulation.展开更多
The most popular view of hematopoietic cell lineage organization is that of complex reactive or adaptative systems.Leukemia contains a subpopulation of cells that display characteristics of stem cells.These cells main...The most popular view of hematopoietic cell lineage organization is that of complex reactive or adaptative systems.Leukemia contains a subpopulation of cells that display characteristics of stem cells.These cells maintain tumor growth.The properties of leukemia stem cells indicate that current conventional chemotherapy, directed against the bulk of the tumor,will not be effective.Leukemia stem cells are quiescent and do not respond to cell cycle-specific cytotoxic agents used to treat leukemia and thus contribute to treatment failure. New strategies are required that specifically target this malignant stem cell population.展开更多
While the modern era of leukemia chemotherapy began recently,the recognition of leukemias has been mainly recorded in the second part of the nineteenth century. This brief historic review reports the first description...While the modern era of leukemia chemotherapy began recently,the recognition of leukemias has been mainly recorded in the second part of the nineteenth century. This brief historic review reports the first descriptions of the disease and the major advances in its history from its roots to the beginning of the twentieth century. Although most treatments for leukemia were ineffective until the middle of the twentieth century,it seemed of interest to review some pertinent exemples of the evolution in the knowledge of this disease(relied upon chronology as an organizing framework,while stressing the importance of themes),since our current knowledge about leukemia is still mainly based on the first accounts of scientific and medical discovery. Early in the nineteenth century,a small number of cases of patients with uncommon or peculiar alterations of the blood were published. Of the cases,four might suggest symptoms of chronic leukemia. The first published case was the detailed report prepared by John Hughes Bennett in the "Edinburgh Medical and Surgical Journal " October 1845. Leukemia gradually became accepted as a distinct disease and published case reports grew in number. Concomitantly,clinical and pathological description of the disease became more detailed.展开更多
文摘Relapses remain a major concern in acute leukemia. It is well known that leukemia stem cells(LSCs) hide in hematopoietic niches and escape to the immune system surveillance through the outgrowth of poorly immunogenic tumor-cell variants and the suppression of the active immune response. Despitethe introduction of new reagents and new therapeutic approaches, no treatment strategies have been able to definitively eradicate LSCs. However, recent adoptive immunotherapy in cancer is expected to revolutionize our way to fight against this disease, by redirecting the immune system in order to eliminate relapse issues. Initially described at the onset of the 90's, chimeric antigen receptors(CARs) are recombinant receptors transferred in various T cell subsets, providing specific antigens binding in a non-major histocompatibility complex restricted manner, and effective on a large variety of human leukocyte antigen-divers cell populations. Once transferred, engineered T cells act like an expanding "living drug" specifically targeting the tumor-associated antigen, and ensure long-term antitumor memory. Over the last decades, substantial improvements have been made in CARs design. CAR T cells have finally reached the clinical practice and first clinical trials have shown promising results. In acute lymphoblastic leukemia, high rate of complete and prolonged clinical responses have been observed after anti-CD19 CAR T cell therapy, with specific but manageable adverse events. In this review, our goal was to describe CAR structures and functions, and to summarize recent data regarding pre-clinical studies and clinical trials in acute leukemia.
文摘Leukemia stem cells(LSCs),which constitute a minority of the tumor bulk,are functionally defined on the basis of their ability to transfer leukemia into an immunodeficient recipient animal.The presence of LSCs has been demonstrated in acute lymphoblastic leukemia(ALL),of which ALL with Philadelphia chromosome-positive(Ph+).The use of imatinib,a tyrosine kinase inhibitor(TKI),as part of front-line treatment and in combination with cytotoxic agents,has greatly improved the proportions of complete response and molecular remission and the overall outcome in adults with newly diagnosed Ph+ ALL.New challenges have emerged with respect to induction of resistance to imatinib via Abelson tyrosine kinase mutations.An important recent addition to the arsenal against Ph+ leukemias in general was the development of novel TKIs,such as nilotinib and dasatinib.However,in vitro experiments have suggested that TKIs have an antiproliferative but not an antiapoptotic or cytotoxic effect on the most primitive ALL stem cells.None of the TKIs in clinical use target the LSC.Second generation TKI dasatinib has been shown to have a more profound effect on the stem cell compartment but the drug was still unable to kill the most primitive LSCs.Allogeneic stem cell transplantation(SCT) remains the only curative treatment available for these patients.Several mechanisms were proposed to explain the resistance of LSCs to TKIs in addition to mutations.Hence,TKIs may be used as a bridge to SCT rather than monotherapy or combination with standard chemotherapy.Better understanding the biology of Ph+ ALL will open new avenues for effective management.In this review,we highlight recent findings relating to the question of LSCs in Ph+ ALL.
文摘AIM: To evaluate quantitatively and qualitatively the different CD34+cell subsets after priming by chemotherapy granulocyte colony-stimulating factor(± G-CSF)in patients with acute myeloid leukemia.METHODS: Peripheral blood and bone marrow sampleswere harvested in 8 acute myeloid leukemia patients during and after induction chemotherapy. The CD34/CD38 cell profile was analyzed by multi-parameter flow cytometry. Adhesion profile was made using CXC chemokine receptor 4(CXCR4)(CD184), VLA-4(CD49d/CD29) and CD47.RESULTS: Chemotherapy ± G-CSF mobilized immature cells(CD34+CD38 population), while the more mature cells(CD34+CD38lowand CD34+CD38+populations) decreased progressively after treatment. Circulating CD34+cells tended to be more sensitive to chemotherapy after priming with G-CSF. CD34+cell mobilization was correlated with a gradual increase in CXCR4 and CD47expression, suggesting a role in cell protection and the capacity of homing back to the marrow.CONCLUSION: Chemotherapy ± G-CSF mobilizes into the circulation CD34+bone marrow cells, of which, the immature CD34+CD38-cell population. Further manipulations of these interactions may be a means with which to control the trafficking of leukemia stem cells to improve patients' outcomes.
文摘Normal and abnormal hematopoiesis is working as a complex adaptive system. From this perspective, the development and the behavior of hematopoietic cell lineages appear as a balance between normal and abnormal hematopoiesis in the setting of a functioning or malfunctioning microenvironment under the control of the immune system and the influence of hereditary and environmental events.
文摘AIM To evaluate the importance of the CD34+CD38-cell population when compared to the CD34+CD38+/low and CD34+CD38+/high leukemic cell sub-populations and to determine its correlations with leukemia characteristics and known prognostic factors, as well as with response to therapy and survival.METHODS Two hundred bone marrow samples were obtained at diagnosis from 200 consecutive patients with newly diagnosed acute myeloid leukemia(AML) were studied between September 2008 and December 2010 at our Institution(Hematology Department, Lyon, France). The CD34/CD38 cell profile was analyzed by multiparameter flowcytometry approach using 8 C panels and FACS CANTO and Diva software(BD Bioscience).RESULTS We analyzed CD34 and CD38 expression in bone marrow samples of 200 AML patients at diagnosis, and investigated the prognostic value of the most immature CD34+CD38-population. Using a cut-off value of 1% of CD34+CD38-from total "bulk leukemic cells" we found that a high(> 1%) level of CD34+CD38-blasts at diagnosis was correlated with advanced age, adverse cytogenetics as well as with a lower rate of complete response after induction and shorter disease-free survival. In a multivariate analysis considering age, leukocytosis, the % of CD34+ blasts cells and the standardized cytogenetic and molecular risk subgroups, a percentage of CD34+CD38-leukemic cells > 1% was an independent predictor of DFS [HR = 2.8(1.02-7.73), P = 0.04] and OS [HR = 2.65(1.09-6.43), P = 0.03].CONCLUSION Taken together, these results show that a CD34/CD38 "backbone" for leukemic cell analysis by multicolour flowcytometry at diagnosis provides useful prognostic information.
文摘Determination of minimal residual disease (MRD) remains crucial for the follow-up after therapy in chronic lymphocytic leukemia (CLL) patients. Chimerism was assessed by short tandem repeat (STR)-PCR and single nucleotide polymorphisms (SNP)-PCR, and MRD by a multicolor flow cytometric approach in 12 consecutive patients with CLL after they received allogeneic stem cell transplantation (SCT). Overall, 11 patients achieved MRD flow negativity [10 had full donor chimerism (FDC) and one had mixed chimerism (MC)]. Only one patient remained with MRD flow positivity and displayed MC. Fifty-six samples were concomitantly studied by both chimerism and MRD flow. A significant correlation was observed between MRD flow data and chimerism in both PB and BM by using a mixed effect linear regression (p < 0.001). Flow cytometry approach of MRD can be easily combined with chimerism during the follow-up post-allogeneic SCT. Both techniques appeared complementary for guiding post-transplant immunomodulation.
文摘The most popular view of hematopoietic cell lineage organization is that of complex reactive or adaptative systems.Leukemia contains a subpopulation of cells that display characteristics of stem cells.These cells maintain tumor growth.The properties of leukemia stem cells indicate that current conventional chemotherapy, directed against the bulk of the tumor,will not be effective.Leukemia stem cells are quiescent and do not respond to cell cycle-specific cytotoxic agents used to treat leukemia and thus contribute to treatment failure. New strategies are required that specifically target this malignant stem cell population.
文摘While the modern era of leukemia chemotherapy began recently,the recognition of leukemias has been mainly recorded in the second part of the nineteenth century. This brief historic review reports the first descriptions of the disease and the major advances in its history from its roots to the beginning of the twentieth century. Although most treatments for leukemia were ineffective until the middle of the twentieth century,it seemed of interest to review some pertinent exemples of the evolution in the knowledge of this disease(relied upon chronology as an organizing framework,while stressing the importance of themes),since our current knowledge about leukemia is still mainly based on the first accounts of scientific and medical discovery. Early in the nineteenth century,a small number of cases of patients with uncommon or peculiar alterations of the blood were published. Of the cases,four might suggest symptoms of chronic leukemia. The first published case was the detailed report prepared by John Hughes Bennett in the "Edinburgh Medical and Surgical Journal " October 1845. Leukemia gradually became accepted as a distinct disease and published case reports grew in number. Concomitantly,clinical and pathological description of the disease became more detailed.
