Clinical characteristics of 11 patients with chronic lymphocytic leukemia with t (14;19) (q32;q13) / 中华血液学杂志

Objective: To analyze the clinicopathological characteristics of 11 cases of chronic lymphocytic leukemia (CLL) with t (14;19) (q32;q13) . Methods: The case data of 11 patients with CLL with t (14;19) (q32;q13) in the chromosome karyotype analysis results of the Blood Diseases Hospital, Chinese Academy of Medical Sciences from January 1, 2018, to July 30, 2022, were retrospectively analyzed. Results: In all 11 patients, t (14;19) (q32;q13) involved IGH::BCL3 gene rearrangement, and most of them were accompanied by +12 or complex karyotype. An immunophenotypic score of 4-5 was found in 7 patients and 3 in 4 cases. We demonstrated that CLLs with t (14;19) (q32;q13) had a mutational pattern with recurrent mutations in NOTCH1 (3/7), FBXW7 (3/7), and KMT2D (2/7). The very-high-risk, high-risk, intermediate-risk, and low-risk groups consisted of 1, 1, 6, and 3 cases, respectively. Two patients died, 8 survived, and 2 were lost in follow-up. Four patients had disease progression or relapse during treatment. The median time to the first therapy was 1 month. Conclusion: t (14;19) (q32;q13), involving IGH::BCL3 gene rearrangement, is a rare recurrent cytogenetic abnormality in CLL, which is associated with a poor prognosis.

Molecular features of 109 patients with chronic myelomonocytic leukemia in a single center / 中华血液学杂志

Objective: To explore the molecular features of chronic myelomonocytic leukemia (CMML) . Methods: According to 2022 World Health Organization (WHO 2022) classification, 113 CMML patients and 840 myelodysplastic syndrome (MDS) patients from March 2016 to October 2021 were reclassified, and the clinical and molecular features of CMML patients were analyzed. Results: Among 113 CMML patients, 23 (20.4%) were re-diagnosed as acute myeloid leukemia (AML), including 18 AML with NPM1 mutation, 3 AML with KMT2A rearrangement, and 2 AML with MECOM rearrangement. The remaining 90 patients met the WHO 2022 CMML criteria. In addition, 19 of 840 (2.3%) MDS patients met the WHO 2022 CMML criteria. At least one gene mutation was detected in 99% of CMML patients, and the median number of mutations was 4. The genes with mutation frequency ≥ 10% were: ASXL1 (48%), NRAS (34%), RUNX1 (33%), TET2 (28%), U2AF1 (23%), SRSF2 (21.1%), SETBP1 (20%), KRAS (17%), CBL (15.6%) and DNMT3A (11%). Paired analysis showed that SRSF2 was frequently co-mutated with ASXL1 (OR=4.129, 95% CI 1.481-11.510, Q=0.007) and TET2 (OR=5.276, 95% CI 1.979-14.065, Q=0.001). SRSF2 and TET2 frequently occurred in elderly (≥60 years) patients with myeloproliferative CMML (MP-CMML). U2AF1 mutations were often mutually exclusive with TET2 (OR=0.174, 95% CI 0.038-0.791, Q=0.024), and were common in younger (<60 years) patients with myelodysplastic CMML (MD-CMML). Compared with patients with absolute monocyte count (AMoC) ≥1×10(9)/L and <1×10(9)/L, the former had a higher median age of onset (60 years old vs 47 years old, P<0.001), white blood cell count (15.9×10(9)/L vs 4.4×10(9)/L, P<0.001), proportion of monocytes (21.5% vs 15%, P=0.001), and hemoglobin level (86 g/L vs 74 g/L, P=0.014). TET2 mutations (P=0.021) and SRSF2 mutations (P=0.011) were more common in patients with AMoC≥1×10(9)/L, whereas U2AF1 mutations (P<0.001) were more common in patients with AMoC<1×10(9)/L. There was no significant difference in the frequency of other gene mutations between the two groups. Conclusion: According to WHO 2022 classification, nearly 20% of CMML patients had AMoC<1×10(9)/L at the time of diagnosis, and MD-CMML and MP-CMML had different molecular features.

Genomics of next generation sequencing in pediatric B-acute lymphoblastic leukemia and its impact on minimal residual disease / 中华儿科杂志

Objective: To describe the gene mutation profile of newly diagnosed pediatric B-acute lymphoblastic leukemia (B-ALL) and analyze its effect on minimal residual disease (MRD). Methods: A total of 506 newly diagnosed B-ALL children treated in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences from September 2018 to July 2021 were enrolled in this retrospective cohort study. The enrolled children were divided into MRD ≥1.00% group and <1.00% group according to MRD results on the 19th day since chemotherapy, and MRD ≥0.01% group and <0.01% group according to MRD results on the 46th day. Clinical characteristics and gene mutations of two groups were compared. Comparisons between groups were performed with chi-square test or Fisher's exact test. Independent risk factors of MRD results on the 19th day and the 46th day were analyzed by Logistic regression model. Results: Among all 506 patients, there were 318 males and 188 females. On the 19th day, there were 114 patients in the MRD ≥1.00% group and 392 patients in the MRD <1.00% group. On the 46th day, there were 76 patients in the MRD ≥0.01% group and 430 patients in the MRD <0.01% group. A total of 187 gene mutations were detected in 487 (96.2%) of 506 children. The most common gene mutations were signal transduction-related KRAS gene mutations in 111 cases (22.8%) and NRAS gene mutations in 99 cases (20.3%). Multivariate analysis showed that PTPN11 (OR=1.92, 95%CI 1.00-3.63), KMT2A (OR=3.51, 95%CI 1.07-11.50) gene mutations and TEL-AML1 (OR=0.48, 95%CI 0.27-0.87), BCR-ABL1 (OR=0.27, 95%CI 0.08-0.92) fusion genes and age >10 years (OR=1.91, 95%CI 1.12-3.24) were independent influencing factors for MRD ≥1.00% on the 19th day. BCORL1 (OR=2.96, 95%CI 1.18-7.44), JAK2 (OR=2.99, 95%CI 1.07-8.42) and JAK3 (OR=4.83, 95%CI 1.50-15.60) gene mutations and TEL-AML1 (OR=0.43, 95%CI 0.21-0.87) fusion gene were independent influencing factors for MRD ≥0.01% on the 46th day. Conclusions: Children with B-ALL are prone to genetic mutations, with abnormalities in the RAS signaling pathway being the most common. Signal transduction related PTPN11, JAK2 and JAK3 gene mutations, epigenetic related KMT2A gene mutation and transcription factor related BCORL1 gene mutation are independent risk factors for MRD.

Clinical and laboratory features compared between JAK2 exon12 and JAK2 V617F mutated polycythemia vera / 中华血液学杂志

Objective: To compare clinical and laboratory features between JAK2 exon12 and JAK2 V617F mutated polycythemia vera (PV) . Method: We collected data from 570 consecutive newly-diagnosed subjects with PV and JAK2 mutation, and compared clinical and laboratory features between patients with JAK2 exon12 and JAK2 V617F mutation. Results: 543 (95.3%) subjects harboured JAK2 V617F mutation (JAK2 V617F cohort) , 24 (4.2%) harboured JAK2 exon12 mutations (JAK2 exon12 cohort) , and 3 (0.5%) harboured JAK2 exon12 and JAK2 V617F mutations. The mutations in JAK2 exon12 including deletion (n=10, 37.0%) , deletion accompanied insertion (n=10, 37.0%) , and missense mutations (n=7, 25.9%) . Comparing with JAK2 V617F cohort, subjects in JAK2 exon12 cohort were younger [median age 50 (20-73) years versus 59 (25-91) years, P=0.040], had higher RBC counts [8.19 (5.88-10.94) ×10(12)/L versus 7.14 (4.11-10.64) ×10(12)/L, P<0.001] and hematocrit [64.1% (53.7-79.0%) versus 59.6% (47.2%-77.1%) , P=0.001], but lower WBC counts [8.29 (3.2-18.99) ×10(9)/L versus 12.91 (3.24-38.3) ×10(9)/L, P<0.001], platelet counts [313 (83-1433) ×10(9)/L versus 470 (61-2169) ×10(9)/L, P<0.001] and epoetin [0.70 (0.06-3.27) versus 1.14 (0.01-10.16) IU/L, P=0.002] levels. We reviewed bone marrow histology at diagnosis in 20 subjects with each type of mutation matched for age and sex. Subjects with JAK2 exon12 mutations had fewer loose megakaryocyte cluster (40% versus 80%, P=0.022) compared with subjects with JAK2 V617F. The median follow-ups were 30 months (range 4-83) and 37 months (range 1-84) for cohorts with JAK2 V617F and JAK2 exon12, respectively. There was no difference in overall survival (P=0.422) and thrombosis-free survival (P=0.900) . Conclusions: Compared with patients with JAK2 V617F mutation, patients with JAK2 exon12 mutation were younger, and had more obvious erythrocytosis and less loose cluster of megakaryocytes.

Clinical manifestations and gene analysis of 18 cases of hereditary protein S deficiency / 中华血液学杂志

Objective: To analyze the clinical manifestations and molecular pathogenesis of 18 patients with inherited protein S (PS) deficiency. Methods: Eighteen patients with inherited PS deficiency who were admitted to the Institute of Hematology & Blood Diseases Hospital from June 2016 to February 2019 were analyzed: activity of protein C (PC) and antithrombin (AT) , PS activity were measured for phenotype diagnosis; high throughput sequencing (HTS) was used for screening of coagulation disease-related genes; Sanger sequencing was used to confirm candidate variants; Swiss-model was used for three-dimensional structure analysis. Results: The PS:C of 18 patients ranged from 12.5 to 48.2 U/dL. Among them, 16 cases developed deep vein thrombosis, including 2 cases each with mesenteric vein thrombosis and cerebral infarction, and 1 case each with pulmonary embolism and deep vein thrombosis during pregnancy. A total of 16 PROS1 gene mutations were detected, and 5 nonsense mutations (c.134_162del/p.Leu45*, c.847G>T/p.Glu283*, c.995_996delAT/p.Tyr332*, c.1359G> A/p.Trp453*, c.1474C>T/p.Gln492*) , 2 frameshift mutations (c.1460delG/p.Gla487Valfs*9 and c.1747_1750delAATC/p.Asn583Wfs*9) and 1 large fragment deletion (exon9 deletion) were reported for the first time. In addition, the PS:C of the deep vein thrombosis during pregnancy case was 55.2 U/dL carrying PROC gene c.565C>T/p.Arg189Trp mutation. Conclusion: The newly discovered gene mutations enriched the PROS1 gene mutation spectrum which associated with inherited PS deficiency.

Detection of heterogeneity and evolution of subclones in t(8;21) AML by QM-FISH / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the heterogeneous subclones in acute myeloid leukemia (AML) with t(8;21) by quantitative multicolor- fluorescence in situ hybridization (QM-FISH), and to figure out whether there is putative ancestral relationship among different subclones.</p><p><b>METHODS</b>Bacterial artificial chromosomes (BAC) clones that contain the targeted genes including AML1, ETO, WT1, p27 and c-kit were searched in the data base UCSC Genome Bioinformatics. Multicolor FISH probes were prepared by linking fluorescein labeled dUTP or dCTP to targeted genes by nick translation. Bone marrow mononuclear cells from t (8;21) AML patients are dropped on to the wet surface of glass slides after hypotonic treatment and fixation. After hybridization, the fluorescence signals were captured by Zeiss fluorescence microscope. The copy number of AML1, ETO, WT1, p27, c- kit and the AML1-ETO fusion gene in AML1-ETO positive cells was counted. The cells with same signals were defined as a subclone. Various subclones were recorded and their proportions were calculated, and their evolutionary relationship was deduced. The subclones in matched primary and relapsed samples were compared, the evolution of dominant clones were figured out and the genomic abnormality that is associated with relapse and drug resistance were speculated.</p><p><b>RESULTS</b>In this study, 36 primary AML with t(8;21) cases and 1 relapsed case paired with the primary case were detected. In these 36 primary cases, 4 cases (11.1%) acquired additional AML1-ETO fusion signal, 3(8.3%) had additional AML1 signal, 4(11.1%) had additional ETO signal, 20(55.6%) had additional WT1 signal, 15(41.7%) had additional p27 signal and 14(38.9%) had additional c-kit signal. In addition, 10(27.8%) displayed AML1 signal deletion, and such an aberration represents statistic significance in male patients. It seems that male patients usually accompany AML1 signal deletion. Of 36 cases, 28(77.8 %) harbored at least 2 subclones (ranged from 2 to 10). According to the genetic signature of subclones, we can assemble a putative ancestral tree, and the genetic architecture is linear or branching. In particular, the clonal architecture of the relapsed sample exhibited significant clonal evolution compared to its paired sample at diagnosis, including proportion changes in dominant clone, subclone disappearance and appearance of new dominant clones.</p><p><b>CONCLUSION</b>Genomic abnormality is very diverse in t(8;21) AML. Subclones have linear or complex branching evolutionary histories, and clonal architecture is dynamic.</p>

Effects of transcription factor GATA-2 on transcriptive regulation of iASPP gene / 中国实验血液学杂志

iASPP can prompt the cell proliferation and inhibit the apoptosis of many cells. There are putative binding sites of transcription factor GATA-2 upstream of iASPP transcription start site. GATA-2 plays an important role in the proliferation and differentiation of hematopoietic stem cells (HSC) and progenitors. This study was aimed to explore the role of GATA-2 protein in iASPP gene transcription. Firstly, the expression of iASPP and GATA-2 protein in some leukemia cell lines was detected by Western blot. Second, The expressive vector of pCMV5-GATA2 and the luciferase reporter vectors containing possible binding sites of GATA-2 were constructed and co-transfected into HEK293 and CV-1 cells. Then the luciferase activity was assayed by luminometer. Also, ChIP assays were performed to further confirm the specific binding of GATA-2 to iASPP promoter. The results showed that GATA-2 was overexpressed in most cell lines with high level of iASPP. GATA-2 exhibited a significant effect on luciferase activity of reporter gene iASPP and in a dose-dependant manner. The relative luciferase activity was up-regulated to about two-fold of the empty vector control when the transfection dose of pCMV5-GATA2 plasmid was increased to 100 ng. While the effect was more significant in CV-1 cells and showed a 6.7-fold increase. The ChIP assay demonstrated the in vivo specific binding of GATA-2 to iASPP. The binding sites of GATA2 were located between nt -361 ∼ -334 in upstream of iASPP gene transcription start site. It is concluded that transcription factor GATA-2 can bind with the cis-regulatory region of the iASPP promoter and up-regulate iASPP expression.

Effect of metformin on acute promyelocytic leukemia cell line NB4 and its mechanism / 中国实验血液学杂志

The purpose of this study was to investigate the effect and molecular mechanism of metformin (Met) on biological characteristics of acute promyelocytic leukemia (APL) cell line NB4. NB4 cells were treated with various concentrations of Met for different time, MTT method was used to detect cell proliferation, the alteration of cell apoptosis was analyzed by flow cytometry, and the change of cell adhesion ability was examined by cell adhesion assay. NB4 cells were pretreated with U0126, a specific inhibitor for extracellular signal-regulated kinase (ERK) phosphorylation, ERK phosphorylation was assessed by Western blot analysis, apoptosis and cell adhesion ability were evaluated by flow cytometry and cell adhesion test respectively. The results showed that Met could inhibit the cell proliferation, induce the cell apoptosis and increase the ability of cell adhesion. The pretreatment of NB4 cells with 5 µmol/L U0126 could effectively inhibit the phosphorylation of ERK, and reduce cell apoptosis and adhesion induced by 5 mmol/L Met. It is concluded that Met can inhibit the proliferation and promote the apoptosis and adhesion of NB4 cells. MEK/ERK signaling pathway may be one of the molecular mechanisms of metformin on NB4 cells.

Study on expression of PTEN gene and its pseudogene PTENP1 in acute leukemia and correlation between them / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of PTEN (phosphatase and tension homology deletion on chromosome 10, PTEN) and its pseudogene PTENP1 in acute leukemia (AL) and correlation between them, and to explore the role of PTENP1 on the PTEN expression in AL cells.</p><p><b>METHODS</b>PTEN and PTENP1 mRNA expression were evaluated in bone marrow (BM) samples from 138 newly diagnosed AL patients and 15 healthy controls by quantitative real-time RT-PCR (qRT-PCR). pCDH1-PTENP1 3'UTR-GFP lentivirus vectors were constructed. 293T cells were transfected by calcium phosphate precipitation to produce retrovirus. HL-60 cell line was infected with the retroviral vectors expressing pCDH1-GFP and pCDH1-PTENP1 3'UTR-GFP respectively. The flow cell sorter was used to sort the HL-60 with GFP positively expressed. The mRNA expression of PTEN and PTENP1 was detected by qRT-PCR, the expression of PTEN protein by western blot, and the impact of PTENP13'UTR on the proliferation of HL-60 cells by MTT assay.</p><p><b>RESULTS</b>AML patients showed significantly lower PTEN and PTENP1 mRNA expression in BM compared to healthy controls. Correlation analysis showed that the expression of PTEN and PTENP1 mRNA were positively correlated (P < 0.05). The 108 cases of PTENP1(+) AML were classified according to the prognostic classification of 2011 NCCN Clinical Practice Guidelines in AML, there was no difference among different subgroups. HL-60 cell line was infected with the retroviral vectors expressing pCDH1-GFP (control group) and pCDH1-PTENP1 3'UTR-GFP respectively. Compared with the control group, PTENP1 mRNA level of HL-60 infected with the retroviral vectors expressing pCDH1-PTENP1 3'UTR-GFP increased significantly, and PTEN mRNA level also increased. While the PTEN protein level and the cell growth rate of the PTENP1 3'UTR group didn't change significantly.</p><p><b>CONCLUSION</b>PTEN and PTENP1 mRNA expression level of BM cells from AL patients is significantly lower. There is a positive correlation between expression of PTEN and PTENP1 mRNA. PTENP1 may regulate the expression of PTEN in mRNA level.</p>