ALBERT

Description: Key Points FBXO11 loss in mice enhances GC B-cell formation and leads to increased BCL6 expression. FBXO11 inactivation, mimicking genetic alterations identified in human lymphomas, represents an alternative mechanism of BCL6 deregulation.

Description: Introduction To preliminary study the repair effect of umbilical cordmesenchymal stem cells (UC-MSCs) homing on local and systemic inflammatory microenvironment and immune inflammatory thrombophilia states of the CIA rata by observing the distribution of the UC-MSCs in the CIA rate and the influence of the UC-MSCs on the expression of the inflammatory cytokines IL-10, TNF-α IL-6, IFN-γ and the thrombosis indicators TF, VWF, DD, FIB's. Methods The clean grade, female, 5-week-old SD rats were randomly divided into a control (C) group, model (M) group, UC-MSCs treatment (SU) group, adding AMD3100 to labled UC-MSCs therapy (ASU) group. Except for control group, the other rats were induced as CIA rats model. Treatment group were injected UC-MSCs suspension by tail vein. The rats were sacrificed in the first, the third and the fifth week after transplantation. HE staining was used to observe the pathological changes of joint tissues. The distribution of UC-MSCs in the joint tissue was detected by FISH. ELISA assay was used to observe the expression of inflammation and thrombosis indicators in peripheral blood. The expression of inflammatory factors in the joint tissue were detected by western blot. Results: 1. One week after injection, the expression of SDF-1 in the injuried joint of the group SU was significantly increased compared with the control group, at the same time, the large number of UC-MSCs occured in injured sites. While, adding AMD3100 to labled UC-MSCs were not expressed in the joint tissue. The expression of SDF-1 in the labled UC-MSCs treating group decreased over time, and the number of UC-MSCs reduced in the inflammatory joints. 2. After given UC-MSCs treatment, the levels of pro-inflammatory cytokines IL-6, TNF-α, IFN-γ in the knee and serum were conspicuously reduced compared with the group M since the first week. While the level of anti-inflammatory cytokine IL-10 was increased (p

Description: We recently found that about one-third of adult AML (60% of all AML with normal karyotype) display aberrant cytoplasmic expression of nucleophosmin (NPM) which is due to mutations occurring at the exon-12 of NPM gene (Falini B, et al., Cytoplasmic nucleophosmin in acute myelogenous leukemia with a normal karyotype..N Engl J Med2005; 352: 254–266). Hereby, we clarify the molecular mechanism underlying cytoplasmic NPM accumulation that yet remained to be elucidated. AML-associated mutated NPM alleles encode abnormal NPM proteins (25 mutants so far identified) which have acquired at the C-terminus a nuclear export signal-(NES) motif and lost at least one of tryptophan residues 288 and 290 which determine nucleolar localization. Both alterations are crucial for mutant NPM export from nucleus to cytoplasm. In fact, the cytoplasmic NPM accumulation is blocked by leptomycin-B and ratjadones which are specific inhibitors of exportin-1/CRM1, and by re-insertion of tryptophan residues 288 and 290, which respectively relocate NPM mutants in the nucleoplasm and nucleoli. Thus, for cytoplasmic accumulation of NPM to occur, the NES motif and tryptophan mutations must act in concert. Possibly, when NPM mutans enter the nucleus by virtue of their nuclear localization signals (NLS), their capability to bind nucleoli must be hindered at least partially to become a CRM-1 target. Specific antibodies anti-NPM mutant proteins showed that the mutants localized exclusively in the cytoplasm and recruited in that site the wild-type NPM protein which is physiologically located in the nucleoli. These findings suggest that the NPM mutants may interfere with the functions of wild-type NPM and possibly contribute to leukemogenesis. Immunostaining of 393 AML cases using anti-NPM monoclonal antibodies predicted the presence of NPM exon-12 mutations in all 191 NPM-cytoplasmic positive cases. This finding is consistent with the fact that, despite genomic heterogeneity, all NPM mutants contain a NES motif which, in the presence of altered tryptophans, promotes their rapid export from the nucleus to the cytoplasm. The immunohistochemical test is diagnostically relevant since it can be used as simple first-step procedure in molecular-genetic characterization of AML and as a surrogate for mutational analysis in selected cases. These findings are also clinically relevant since cytoplasmic NPM/NPM mutations are predictors of good response to induction therapy and favourable prognosis in AML with a normal karyotype.

Description: IGFBP7 (insulin-like growth factor binding protein 7) is a newly-identified protein which can bind with insulin-like growth factors(IGFs), with 45%~65% homology to other IGF binding proteins. Several studies reported that IGFBP7 may be involved in the development of meningioma, breast cancer and prostate cancer, while its correlation with human leukemia had not been reported yet. We have observed an induced expression of IGFBP7 in human leukemia K562 cells which were transfected with and overexpressed RbAp46 gene. Besides, the expression level of WT1, RbAp46 and IGFBP7 was coordinately regulated during the induced differentiation of NB4 acute promyelocytic leukemia cells (data not shown), suggesting a role of IGFBP7 gene in human leukemia.. To investigate the expression level of IGFBP7(previous known as Insulin-like growth factor binding protein related protein 1)in bone marrow (BM) of leukemia patients and its correlation with other leukemia biomarkers, Real-time quantitative reverse transcription polymerase chain reaction (QRT-PCR) method was established for detecting IGFBP7 expression levels in BM of 127 patients with acute leukemia (AL), 24 with chronic myelogenous leukemia in chronic phase (CML-CP), 9 with CML in blast crisis (CML-BC) and 27 with non-leukemias. The M-Estimators of RbAp46N in 63 patients with newly diagnosed AMLs were higher than those of 27 with ALLs and 27 non-leukemic controls and 10 with AMLs in complete remission(CR)(193.80 v.s 88.84, 81.30 and 67.82, respectively). Although IGFBP7N was 101.13 in CML-BC and 168.77 in CML-CP, difference between them was not statistically significant. Difference in IGFBP7N values among CML-BC, AML, ALL and control groups was also not significant. The M-Estimators of IGFBP7N were lowest in M4 and highest in M5 among initial acute leukemia subtypes, and there was statistical differences between M4 and M5, and between M4 and M2. IGFBP7N expression level was not correlated to the expression of fusion genes BCR/ABL and AML1/ETO, but it was positively correlated with the expression level of PML/RARαfusion gene, the WT1 and RbAp46 gene. The correlation coefficiency was 0.71, 0.31 and 0.52, respectively. Our results suggested that IGFBP7 might act in WT1 mediating pathway to participate in acute myelocytic leukemias.

Description: WT1, a tumor suppressor gene originally found to be responsible for the development of childhood kidney tumor, is now thought to be also involved in the pathogenesis of human leukemia. Since WT1 is reported to be expressed at much higher level in bone marrow cells from MDS and all subtypes of leukemia comparing to the normal blood cells, it is proposed to be a “panleukemic marker” for the diagnosis of leukemia. The expression level of WT1 may also have significance in predicting prognosis and monitoring relapse. However, this notion on the usage of WT1 is somehow still remaining controversial because WT1 is also expressed to a certain level in a small population of CD34+cells. To measure more accurately the expression level of WT1 in bone marrow cells of acute leukemia patients (ALs). Real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) method was established for detecting WT1 and GAPDH expression levels in BM of 108 ALs and 23 non-leukemias patients by LightCycler. Besides, BM cells of 15 AL patients, including a total of 111 BM specimen taken during the follow-up after allo-BMT were also subject to RQ-RT-PCR. Normalized WT1 expression level (WT1N) was determined as a ratio between WT1 and GAPDH times 104. The expression levels of WT1N in 70 newly diagnosed ALs and 11 relapsed ALs were statistically higher than those of 23 ALs with complete remission(CR) and 23 non-leukemic controls (108.50±137.08 and 135.00±107.87 vs 3.88±3.09 and 2.23±3.19). Statistical differences were found neither between the CR group and control group, nor between the newly diagnosed group and relapsed group. Of the 70 newly diagnosed ALs, WT1N expression level of acute granulocytic leukemias was significantly higher than that of acute monocytic leukemias, but there were no statistic differences among the M1, M2, M3 and ALL subtypes. Furthermore, the WT1N levels were not correlated to WBC counts in peripheral blood, the blast ratio in the BM and the expression of MDR-1 at presentation, but do correlated to the leukemia cell chromosome karyotypes. The dynamic changes of WT1N levels in 2 patients during treatment suggested that WT1 expression levels could be used to monitor the disease outcome and predict relapse. In gereral, the dynamic curves of WT1 level following allo-BMT were consistemt with the tendnecy of changes in expression levels of corresponding fusion genefor MRD monitoring. A re-increment of WT1 expression level during follow-up could be detected 40 to 180 days earlier to hematological relapse. These studies have provided strong evidence suggesting that WT1 expression levels in cells of AL patients were markedly higher than an undetectable or a marginal level expressed in non-leukemias patients. WT1 can indeed be a marker for evaluating therapy efficacy in leukemias. WT1 expression levels in leukemia patients following allo-BMT measured by real time RT-PCR can be a useful tool for monitoring MRD and warning the clinical relapse during follow-up.