Pathogenesis of chronic myeloid leukemia(CML)has mostly been studied with regard to the oncogenic role of BCR/ABL fusion,however,recent disclosures have declared that the challenges with the treatment of CML patients ...Pathogenesis of chronic myeloid leukemia(CML)has mostly been studied with regard to the oncogenic role of BCR/ABL fusion,however,recent disclosures have declared that the challenges with the treatment of CML patients would not be resolved until the role of other aberrancies is ignored.Given the involvement of cyclin-dependent kinases(CDKs)in the pathogenesis of CML,the present study aimed to investigate the effects of a multi-CDK inhibitor AT7519 on BCR/ABL-harboring CML-derived K562 cells.Our results showed that AT7519 effectively reduced the survival of K562 and induced its anti-proliferative effect through the induction of G2/M arrest due to elevated p21 and p27.The resulting data also revealed that either direct or indirect suppression of c-Myc using specific c-Myc inhibitor 10058-F4 and selective PI3K inhibitor CAL-101 resulted in a superior cytotoxicity,suggesting that the activation of PI3K pathway could attenuate antileukemic effects of the inhibitor,at least partly,through a c-Mycdependent mechanism.To the best of our knowledge,to date,no study has addressed the effect of autophagy on CML cell response to AT7519,and,herein,we proposed for the first time that the suppression of autophagy boosted AT7519 cytotoxicity against K562.Overall,we suggested that selective CDK inhibitor AT7519 exerted antileukemic effect against CML cells and propose a novel therapeutic application for the inhibitor either as a single agent or in combination with c-Myc and/or PI3K inhibitors.展开更多
We developed two complement-fixing MoAbsHIMand HIM(murine)that were specifically reac-tive with chronic myelogenous leukemia (CML) cells.They were capable of fixing human or rabbit com-plement and suitable for CML cel...We developed two complement-fixing MoAbsHIMand HIM(murine)that were specifically reac-tive with chronic myelogenous leukemia (CML) cells.They were capable of fixing human or rabbit com-plement and suitable for CML cells purging of re-mission marrow from CML patients.HIMreactedwith majority leukemic cells form 7 out of 10 CMLpatients by complement-mediated cytotoxicity(C’MC)assay(positive cells 80%—90%),HIMreacted withmajority CML cells from 4 out of 5 CML by C’MCassay(positive cells 80%—90%).Treatment withHIMor HIMand human C’was capable of lysing97% of K562,U937,HL-60 and CML cells in a 20fold excess of unrelated cells by indirect FITC+EBstain.Using limited dilution culture,incubation withHIMand C’produced 1.5 logs inhibition of growthin K562 cells,and 1.9 logs in U937 cells,and withHIMand C’produced 2.9 logs inhibition in HL-60cells and 3.0 logs in U937 cells.Both MoAbs cocktailwas shown 1.8 logs in K562 cells and 3.2 logs in U937cells.They were no suppression on the growth o展开更多
PNH is a rare acquired clonal hematopoietic stem cell disorder characterized by abnormal sensitivity of red blood cells to lysis by complement. It is caused by genetic mutation resulting in deficiency of glycosyl phos...PNH is a rare acquired clonal hematopoietic stem cell disorder characterized by abnormal sensitivity of red blood cells to lysis by complement. It is caused by genetic mutation resulting in deficiency of glycosyl phosphatidylinositol anchor (GPA) for cell membrane proteins including complement regulating proteins CD55 and CD59. PNH tends to be associated with Aplastic Anemia (anemia due to failure of the bone marrow to produce red and white blood cells as well as platelets), Myelodysplastic Syndrome (a group of cancers in which immature blood cells in the bone marrow do not mature or become healthy blood cells) or rarely Acute Myeloid Leukemia (AML) (also known as acute nonlymphocytic leukemia, representing a group of clonal hematopoietic stem cell disorders in which both a block in differentiation and unchecked proliferation result in the accumulation of myeloblasts at the expense of normal hematopoietic precursors). Here we report a case and assume possible evolution of PNH into CML (a myeloproliferative malignant clonal disease characterized by presence of fusion BCR/ABL fusion oncogene).展开更多
The so-calledPhiladelphia(Ph) chromosome is present in more than 90% of chronic myeloid leukemia (CML) cases. It results in juxtaposition of the 5' part of the BCR gene on chromosome 22 and the 3' part of the ...The so-calledPhiladelphia(Ph) chromosome is present in more than 90% of chronic myeloid leukemia (CML) cases. It results in juxtaposition of the 5' part of the BCR gene on chromosome 22 and the 3' part of the ABL1 gene on chromosome 9. An additional acquired monosomy 7 or deletion of 7q is associated with poor prognosis in a variety of myeloid disorders. Here we report a novel Ph chromosome positive CML case with a ring chromosome 7 [r(7)]. Immunophenotyping was compatible with CML, although 4.5% of total leucocytes appeared like acute myelogeneous leukemia (AML) subtype M2. The r(7) was characterized in detail by array-proven multicolor banding (aMCB), the latter being of enormous significance to characterize breakpoint regions in detail. Underlying mechanisms and prognostic are discussed, as ring chromosomes are rare cytogenetic abnormalities in hematopoietic malignancies.展开更多
在多种肿瘤中,生长阻滞特异性转录因子5(growth-arrest specific transcript 5,GAS5)高表达与患者的良好生存期相关。GAS5存在多种剪接变异体,本研究探讨GAS5部分剪接变异体在髓系白血病细胞系中的表达模式。并基于对凋亡诱导敏感的慢...在多种肿瘤中,生长阻滞特异性转录因子5(growth-arrest specific transcript 5,GAS5)高表达与患者的良好生存期相关。GAS5存在多种剪接变异体,本研究探讨GAS5部分剪接变异体在髓系白血病细胞系中的表达模式。并基于对凋亡诱导敏感的慢性髓系白血病(chronic myeloid leukemia,CML)细胞系K562,研究GAS5部分剪接变异体对K562细胞自身增殖、凋亡以及对靶向药物伊马替尼(imatinib,IM)的敏感性的影响。反转录PCR结果显示,GAS5剪接模式在髓系白血病细胞系HL-60、K562、NB4和KASUMI-1之间未见明显差异。相较于指数增长期,GAS5_AE表达水平在细胞密度引起的生长停滞期有一定程度的累积。通过核转染,将GAS5剪接变异体(pcDNA3-GAS5_1B、-GAS5_2B、-GAS5_3A、-GAS5_4A、-GAS5_O1或-GAS5_AE)转入K562细胞的单克隆株中。通过台盼蓝染色、吖啶橙染色后进行细胞计数,克隆形成实验检测细胞集落形成能力。结果与对照组相比,瞬时转染GAS5剪接变异体并无抑制细胞的基础增殖或增强细胞对药物的敏感性。建立GAS5_O1的稳定转染株,延长培养时程并计算倍增时间,发现GAS5_O1的表达水平和倍增时间成正比(R^(2)=0.5692)。在稳转株O1-C8中观察到GAS5_O1可促进IM引起的细胞生长抑制(56.94%±2.84%vs.36.07%±2.32%,P<0.05)和凋亡(29.33%±1.30%vs.52.00%±2.52%,P<0.05)。上述结果表明,GAS5_O1的上调可能增加CML细胞的倍增时间,并使CML细胞对IM处理敏感。展开更多
基金the grant number:15425 from Shahid Beheshti University of Medical Sciences(Tehran,Iran)(http://en.sbmu.ac.ir/)achieved byD.B.Conflicts of Interest:The authors declare that they have no conflicts of interest to report regarding the present study.
文摘Pathogenesis of chronic myeloid leukemia(CML)has mostly been studied with regard to the oncogenic role of BCR/ABL fusion,however,recent disclosures have declared that the challenges with the treatment of CML patients would not be resolved until the role of other aberrancies is ignored.Given the involvement of cyclin-dependent kinases(CDKs)in the pathogenesis of CML,the present study aimed to investigate the effects of a multi-CDK inhibitor AT7519 on BCR/ABL-harboring CML-derived K562 cells.Our results showed that AT7519 effectively reduced the survival of K562 and induced its anti-proliferative effect through the induction of G2/M arrest due to elevated p21 and p27.The resulting data also revealed that either direct or indirect suppression of c-Myc using specific c-Myc inhibitor 10058-F4 and selective PI3K inhibitor CAL-101 resulted in a superior cytotoxicity,suggesting that the activation of PI3K pathway could attenuate antileukemic effects of the inhibitor,at least partly,through a c-Mycdependent mechanism.To the best of our knowledge,to date,no study has addressed the effect of autophagy on CML cell response to AT7519,and,herein,we proposed for the first time that the suppression of autophagy boosted AT7519 cytotoxicity against K562.Overall,we suggested that selective CDK inhibitor AT7519 exerted antileukemic effect against CML cells and propose a novel therapeutic application for the inhibitor either as a single agent or in combination with c-Myc and/or PI3K inhibitors.
文摘We developed two complement-fixing MoAbsHIMand HIM(murine)that were specifically reac-tive with chronic myelogenous leukemia (CML) cells.They were capable of fixing human or rabbit com-plement and suitable for CML cells purging of re-mission marrow from CML patients.HIMreactedwith majority leukemic cells form 7 out of 10 CMLpatients by complement-mediated cytotoxicity(C’MC)assay(positive cells 80%—90%),HIMreacted withmajority CML cells from 4 out of 5 CML by C’MCassay(positive cells 80%—90%).Treatment withHIMor HIMand human C’was capable of lysing97% of K562,U937,HL-60 and CML cells in a 20fold excess of unrelated cells by indirect FITC+EBstain.Using limited dilution culture,incubation withHIMand C’produced 1.5 logs inhibition of growthin K562 cells,and 1.9 logs in U937 cells,and withHIMand C’produced 2.9 logs inhibition in HL-60cells and 3.0 logs in U937 cells.Both MoAbs cocktailwas shown 1.8 logs in K562 cells and 3.2 logs in U937cells.They were no suppression on the growth o
文摘PNH is a rare acquired clonal hematopoietic stem cell disorder characterized by abnormal sensitivity of red blood cells to lysis by complement. It is caused by genetic mutation resulting in deficiency of glycosyl phosphatidylinositol anchor (GPA) for cell membrane proteins including complement regulating proteins CD55 and CD59. PNH tends to be associated with Aplastic Anemia (anemia due to failure of the bone marrow to produce red and white blood cells as well as platelets), Myelodysplastic Syndrome (a group of cancers in which immature blood cells in the bone marrow do not mature or become healthy blood cells) or rarely Acute Myeloid Leukemia (AML) (also known as acute nonlymphocytic leukemia, representing a group of clonal hematopoietic stem cell disorders in which both a block in differentiation and unchecked proliferation result in the accumulation of myeloblasts at the expense of normal hematopoietic precursors). Here we report a case and assume possible evolution of PNH into CML (a myeloproliferative malignant clonal disease characterized by presence of fusion BCR/ABL fusion oncogene).
文摘The so-calledPhiladelphia(Ph) chromosome is present in more than 90% of chronic myeloid leukemia (CML) cases. It results in juxtaposition of the 5' part of the BCR gene on chromosome 22 and the 3' part of the ABL1 gene on chromosome 9. An additional acquired monosomy 7 or deletion of 7q is associated with poor prognosis in a variety of myeloid disorders. Here we report a novel Ph chromosome positive CML case with a ring chromosome 7 [r(7)]. Immunophenotyping was compatible with CML, although 4.5% of total leucocytes appeared like acute myelogeneous leukemia (AML) subtype M2. The r(7) was characterized in detail by array-proven multicolor banding (aMCB), the latter being of enormous significance to characterize breakpoint regions in detail. Underlying mechanisms and prognostic are discussed, as ring chromosomes are rare cytogenetic abnormalities in hematopoietic malignancies.
