Shaowei Qiu

N-Cadherin and Tie2 positive CD34 + CD38 − CD123 + leukemic stem cell populations can develop acute myeloid leukemia more effectively in NOD/SCID mice

Emerging studies suggest that the population of malignant cells found in human acute myelogenous leukemia (AML) arises from a rare population of leukemic stem cells (LSCs). A lot of investigators have reported the identification of cell surface markers, such as CD123. Here, we report the identification of N-cadherin and Tie2 as LSCs markers. Inoculation of CD34(+)CD38(-)CD123(+)N-cadherin(+) and CD34(+)CD38(-)CD123(+) Tie2(+) population can induce leukemia in NOD/SCID mice. The leukemic blast cells from the primary leukemic mice could also induce leukemia in the secondary transplantation. These findings suggested that N-cadherin and Tie2 were the important markers that can assist in leukemia development.

Clinical and laboratory studies of 17 patients with acute myeloid leukemia harboring t(7;11)(p15;p15) translocation

The cellular and molecular genetic aberrations of hematopoietic and lymphoid tissues are increasingly important in leukemia classification and are prognostically significant. Although some recurrent molecular cytogenetic abnormalities in AML have been extensively studied, others including t(7;11)(p15;p15) have not been well characterized. In this paper, seventeen AML patients with t(7;11)(p15;p15) were retrospectively reviewed for cell morphology, immuno-phenotype, cytogenetics as well as clinical features and prognosis. Among them, thirteen were female; nine were AML-M2. Six patients who were newly diagnosed were alive, one was lost for followed up and ten died. The median survival was 8 months. Taking together, AML with t(7;11)(p15;p15) is a rare and distinct disease. Most patients with this translocation are female at younger age and have special clinical and hematological characteristics such as M2-subtype of AML, easy to relapse and poor prognosis.

Distinct genetic alteration profiles of acute myeloid leukemia between Caucasian and Eastern Asian population

Racial and ethnic disparities in malignancies attract extensive attention. To investigate whether there are racial and ethnic disparities in genetic alteration between Caucasian and Eastern Asian population, data from several prospective AML trials were retrospectively analyzed in this study. We found that there were more patients with core binding factor (CBF) leukemia in Eastern Asian cohorts and there were different CBF leukemia constitutions between them. The ratios of CBF leukemia are 27.7, 22.1, 21.1, and 23.4%, respectively, in our (ChiCTR-TRC-10001202), another Chinese, Korean, and Japanese Eastern Asian cohorts, which are significantly higher than those in ECOG1900, MRC AML15, UK NCRI AML17, HOVON/SAKK AML-42, and German AML2003 (15.5, 12.5, 9.3, 10.2, and 12%, respectively). And CBFbeta-MYH11 occurred more prevalently in HOVON/SAKK AML- 42 and ECOG1900 trials (50.0 and 54.3% of CBF leukemia, respectively) than in Chinese and Japanese trials (20.1 and 20.8%, respectively). The proportion of FLT3-ITD mutation is 11.2% in our cohort, which is lower than that in MRC AML15 and UK NCRI AML17 (24.6 and 17.9%, respectively). Even after excluding the age bias, there are still different incidence rates of mutation between Caucasian and Eastern Asian population. These data suggest that there are racial and ethnic disparities in genetic alteration between Caucasian and Eastern Asian population.

Flow cytometric analysis of cerebrospinal fluid in adult patients with acute lymphoblastic leukemia during follow-up

To explore the value of flow cytometric (FCM) analysis of cerebrospinal fluid (CSF) in the diagnosis of central nervous system involvement in adult patients with acute lymphoblastic leukemia (ALL) during follow‐up.

The number of CD34+CD38+CD117+HLA-DR+CD13+CD33+ cells indicates post-chemotherapy hematopoietic recovery in patients with acute myeloid leukemia

Hematopoietic recovery is considered to be associated with the number of multipotent hematopoietic stem cells in the bone marrow, as observed in functional assays involving stem cell transplantation. However, there is little evidence related to hematopoietic recovery in non-transplantation settings, which is accomplished by endogenous hematopoietic cells. A recent study suggested that progenitors are the main contributors during this steady-state hematopoiesis, which differs from exogenous transplantation. We hypothesized that endogenous progenitor support post-chemotherapy hematopoietic recovery. To investigate the potential impact of these progenitor cell percentage on hematopoietic recovery, we retrospectively analyzed the percentage of CD34+CD38+CD117+HLA-DR+CD13+CD33+ cells (P cells) and hematopoietic recovery in 223 newly diagnosed acute myeloid leukemia patients during two courses of consolidation chemotherapy after complete remission. We found that a lower P cell percentage was significantly associated with prolonged neutropenia recovery time after the first and second courses of consolidation chemotherapy (p = 0.001; p = 0.045, respectively). We also observed similar results with regard to platelet recovery time after the first course of consolidation chemotherapy (p = 0.000). Univariate analysis showed that P cell percentage and consolidation chemotherapy regimens, and not gender, age, induction chemotherapy regimens, infection grade, WHO classification and NCCN risk category, were associated with neutrophil recovery after chemotherapy. Multivariate analysis demonstrated that P cell percentage is an independent factor affecting neutrophil recovery capacity for both the first and second courses (p = 0.008; p = 0.032, respectively). Our results indicate that CD34+CD38+CD117+HLA-DR+CD13+CD33+ cells before each course of chemotherapy is independently associated with chemotherapy-related hematopoietic reconstitution capacity. These findings may help modify future chemotherapy regimens based on progenitor cell percentages.

Regulation of HtrA2 on WT1 gene expression under imatinib stimulation and its effects on the cell biology of K562 cells

The aim of the present study was to investigate the regulation of Wilms Tumor 1 (WT1) by serine protease high-temperature requirement protein A2 (HtrA2), a member of the Htr family, in K562 cells. In addition, the study aimed to observe the effect of this regulation on cell biological functions and its associated mechanisms. Expression of WT1 and HtrA2 mRNA, and proteins following imatinib and the HtrA2 inhibitor 5-[5-(2-nitrophenyl) furfuryl iodine]-1, 3-diphenyl-2-thiobarbituric acid (UCF-101) treatment was detected with reverse transcription-quantitative polymerase chain reaction and western blot analysis. Subsequent to treatment with drugs and UCF-101, the proliferative function of K562 cells was detected using MTT assays, and the rate of apoptosis was detected using Annexin V with propidium iodide flow cytometry in K562 cells. The protein levels in the signaling pathway were analyzed using western blotting following treatment with imatinib and UCF-101. In K562 cells, imatinib treatment activated HtrA2 gene at a transcription level, while the WT1 gene was simultaneously downregulated. Following HtrA2 inhibitor (UCF-101) treatment, the downregulation of WT1 increased gradually. At the protein level, imatinib induced the increase in HtrA2 protein level and concomitantly downregulated WT1 protein level. Subsequent to HtrA2 inhibition by UCF-101, the WT1 protein level decreased temporarily, but eventually increased. Imatinib induced apoptosis in K562 cells, but this effect was attenuated by the HtrA2 inhibitor UCF-101, resulting in the upregulation of the WT1 protein level. However; UCF-101 did not markedly change the proliferation inhibition caused by imatinib. Imatinib activated the p38 mitogen activated protein kinase (p38 MAPK) signaling pathway in K562 cells, and UCF-101 affected the activation of imatinib in the p38 MAPK signaling pathway. Imatinib inhibited the extracellular signal-related kinase (ERK1/2) pathway markedly and persistently, but UCF-101 exhibited no notable effect on the inhibition of the ERK1/2 pathway. HtrA2 and its regulatory effect on WT1 may affect the sensitivity of BCR/ABL(+) cell lines to target therapy drugs through different mechanisms. Regulation of WT1 by HtrA2 occurs in K562 cells, and the regulation may affect the apoptosis of K562 cells under the stress caused by chemotherapeutic treatment. The p38 MAPK signaling pathway, which serves an important role in cell apoptosis, is a downstream pathway of this regulation.

Sertad1 antagonizes iASPP function by hindering its entrance into nuclei to interact with P53 in leukemic cells

BackgroundAs the important suppressor of P53, iASPP is found to be overexpressed in leukemia, and functions as oncogene that inhibited apoptosis of leukemia cells. Sertad1 is identified as one of the proteins that can bind with iASPP in our previous study by two-hybrid screen.MethodsCo-immunoprecipitation and immunofluorescence were perfomed to identified the interaction between iASPP and Sertad1 protein. Westernblot and Real-time quantitative PCR were used to determine the expression and activation of proteins. Cell proliferation assays, cell cycle and cell apoptosis were examined by flow cytometric analysis.ResultsiASPP combined with Sertad1 in leukemic cell lines and the interaction occurred in the cytoplasm near nuclear membrane. iASPP could interact with Sertad1 through its Cyclin-A, PHD-bromo, C terminal domain, except for S domain. Overexpression of iASPP in leukemic cells resulted in the increased cell proliferation and resistance to apoptosis induced by chemotherapy drugs. While overexpression of iASPP and Sertad1 at the same time could slow down the cell proliferation, lead the cells more vulnerable to the chemotherapy drugs, the resistance to chemotherapeutic drug in iASPPhi leukemic cells was accompanied by Puma protein expression. Excess Sertad1 protein could tether iASPP protein in the cytoplasm, further reduced the binding between iASPP and P53 in the nucleus.ConclusionsSertad1 could antagonize iASPP function by hindering its entrance into nuclei to interact with P53 in leukemic cells when iASPP was in the stage of overproduction.