Wilms’ tumor 1-associated protein (WTAP) is a key N6-methyladenosine (m6A) methyltransferase that is upregulated in t(8;21) acute myeloid leukemia (AML) under hypoxia inducible factor 1α-mediated transcriptional activation, promoting leukemogenesis through transcriptome-wide m6A modifications. However, the specific substrates and intrinsic regulatory mechanisms of WTAP are not well understood. Here, we provide evidence that PHD finger protein 19 (PHF19) overexpression is regulated by WTAP-mediated m6A modification and promotes cell cycle progression by altering chromatin accessibility. At the same time, high expression of PHF19 and WTAP in t(8;21) AML patients indicates a worse prognosis. Furthermore, inhibition of PHF19 expression significantly suppresses the growth of t(8;21) AML cells in both in vitro and in vivo. Mechanistically, WTAP enhances the stability of PHF19 mRNA by binding to m6A sites in the 3’-untranslated region, thereby upregulating PHF19 expression. Conversely, WTAP suppression reduces m6A modification levels on the PHF19 transcript, leading to increased instability. Knockdown of PHF19 precipitates loss of H3K27 trimethylation and enhanced chromatin accessibility, ultimately resulting in upregulated expression of genes involved in the cell cycle and DNA damage checkpoints. Therefore, WTAP/m6A-dependent PHF19 upregulation accelerates leukemia progression by coordinating m6A modification and histone methylation, establishing its status as a novel therapeutic target for t(8;21) AML.

Hypoxia inducible factor 1α (HIF1α) is abnormally overexpressed in t(8;21) acute myeloid leukemia (AML) and functions as an oncogene through transactivating DNA methyltransferase 3 alpha leading to DNA hypermethylation. However, it remains unclear whether HIF1α influences RNA N6-methyladenosine (m6A) methyltransferases. Here, we show that HIF1α promotes the expression of Wilms tumor 1-associated protein (WTAP), a main component of the m6A methyltransferase complex, markedly alters the transcriptome-wide m6A distribution and enhances cell proliferation in t(8;21) AML. In agreement with this, WTAP is overexpressed and predicts poor prognosis in t(8;21) AML patients. Moreover, WTAP knockdown inhibits growth, and induces apoptosis and differentiation of leukemia cells. Mechanistically, HIF1α transactivates WTAP gene expression by directly binding to the hypoxia-response element of its promoter region. Pharmacological or genetic intervention in the HIF1α-WTAP axis results in the reduction of m6A level on lysine demethylase 4B (KDM4B) transcripts and increased its degradation, correlated with lower expression of KDM4B and higher trimethylation levels of histone H3 on lysine 9. KDM4B knockdown inhibits leukemia cell growth in vitro and in mice. Thus, HIF1α-mediated WTAP high expression enhances the malignant behavior of leukemia cells and drives a crosstalk between m6A RNA methylation and histone methylation through monitoring m6A-dependant KDM4B translation.

To explore the efficacy and safety of G-SCF-mobilized donor lymphocyte infusion (DLI) for treatment of relapse of hematologic malignancies after allogeneic peripheral blood stem cell transplantation, we performed a retrospective analysis in a cohort of patients with morphologic (n = 36) or molecular (n = 22) relapse post transplantation. The 3-year post-DLI survival rates for therapeutic and preemptive DLI recipients were 16.7% and 33.3%, respectively. The occurrence of DLI-associated acute graft-versus-host disease predicted longer survival, whereas diagnosis of T cell acute lymphoblastic leukemia/lymphoma or myelodysplastic syndromes or early relapse after transplant (< 6 months) predicted shorter survival after therapeutic DLI. Cumulative incidence of progression to hematologic relapse and non-relapse mortality after preemptive DLI were 46.8% and 29.1%, respectively. Active disease prior to transplant and early molecular relapse after transplant (< 4 months) were the strongest predictors of non-relapse mortality after preemptive DLI. In conclusion, although therapeutic DLI had limited efficacy against T cell acute lymphoblastic leukemia/lymphoma or myelodysplastic syndromes or early post-transplant relapse, patients who developed DLI-associated acute graft-versus-host disease would benefit from this procedure in the setting of G-SCF-mobilized DLI. Furthermore, preemptive DLI could protect half of patients from hematologic relapse after transplantation with acceptable toxicity.

The t(8;21) fusion product, AML1/ETO, and hypoxia-inducible factor 1α (HIF1α) form a feed-forward transcription loop that cooperatively transactivates the DNA methyltransferase 3a gene promoter that leads to DNA hypermethylation and drives leukemia cell growth. Suppression of the RNA N6-methyladenosine (m6A)-reader enzyme YTH N6-methyladenosine RNA binding protein 2 (YTHDF2) specifically compromises cancer stem cells in acute myeloid leukemia (AML) but promotes hematopoietic stem cell expansion without derailing normal hematopoiesis. However, the relevance of expression between AML1/ETO-HIF1α loop and YTHDF2, and its functional relationship with t(8;21) AML have not been documented. Here, we show that YTHDF2 is highly expressed in t(8;21) AML patients and associated with a higher risk of relapse and inferior relapse-free survival. Knockdown of YTHDF2 in leukemia cells causes an impaired cell proliferation rate in vitro and in mice. Mechanistically, HIF1α is able to bind to the hypoxia-response elements of the 5′-untranslated region of the YTHDF2 gene and promotes the transactivity of the YTHDF2 promoter. Knockdown and overexpression of either AML1/ETO or HIF1α resulted in decreased and increased YTHDF2 protein and mRNA expression in t(8;21) AML cells. In particular, knockdown of YTHDF2 resulted in increased global mRNA m6A levels in t(8;21) AML cells, accompanied by increased TNF receptor superfamily member 1b (TNFRSF1b) mRNA and protein expression levels. Last, we demonstrated that the m6A methylation and expression levels of the TNFRSF1b gene were both negatively correlated with HIF1α expression levels. In conclusion, YTHDF2 is a downstream target of the AML1/ETO-HIF1α loop and promotes cell proliferation probably by modulating the global m6A methylation in t(8;21) AML.

医学研究生的科研不端现象日趋严重,高校亟须加强科研诚信教学中的课程思政建设.文章从探讨课程思政的内涵价值入手,解析课程思政在医学研究生科研诚信教学体系的目标、内容、方法、管理、评价、拓展等方面的融入要点,以及在论文写作诚信、诚信理论教育、实验技术实践诚信、拓展教学类课程等科研诚信教学过程的融合方法.

In allogeneic hematopoietic stem cell transplantation recipients, cytomegalovirus (CMV) infection can cause overt CMV-associated disease, which is a main cause of transplantation-associated mortality. CMV infection correlates closely with donor's type. We therefore examined whether risk factors of CMV reactivation and clinical endpoints in patients with hematologic malignancies after allogeneic peripheral blood stem cell transplantation (PBSCT) differed between using matched-sibling donors (MSD-SCT) and haploidentical donors (HID-SCT). In this retrospective cohort study, we enrolled in 200 consecutive patients received an unmanipulated G-CSF-mobilized allogeneic PBSCT. Ninety (45%) patients received MSD-SCT and 110 (55%) received HID-SCT. Quantitative PCR was used for monitoring of CMV reactivation after transplantation. One-year cumulative incidence of CMV DNAemia was 55.0%, ranging from 23.5% in MSD-SCT group to 81.0% in HID-SCT group (p < 0.001). Although univariate analyses showed that non-myeloid malignancies, disease in complete remission status at transplantation, pretreatment with antithymocyte globulin, HLA-haploidentical donors, male donors, previous Epstein-Barr virus DNAemia, and absolute lymphocyte count on day 30 < 0.6 × 109/L were respectively associated with CMV reactivation after transplantation in total cohort of recipients (all p < 0.05), haploidentical donors were found to be the only independent predictor in multivariate analyses (Hazard ratio = 6.4, p < 0.001). Furthermore, univariate analyses revealed that non-myeloid malignancies and previous Epstein-Barr virus DNAemia were respectively associated with CMV reactivation in MSD-SCT recipients, and female was associated with CMV reactivation in HID-SCT recipients (all p < 0.05). In HID-SCT recipients, but not MSD-SCT recipients, previous CMV DNAemia was associated with a lower cumulative incidence of acute graft-versus-host disease (49.2% vs. 72.6%, p < 0.001). CMV DNAemia did not play a role in the relapse rate, but it was strongly associated with an increased risk of non-relapse mortality either in total cohort of recipients (30.5% vs. 13.7%; p = 0.003) or in the HID-SCT subgroup (36.0% vs. 16.7%; p = 0.030). Relapse-free survival and overall survival in total cohort of recipients with CMV DNAemia were both inferior to those without CMV DNAemia (45.3% vs. 57.6% and 54.8% vs. 65.8%, respectively; both p < 0.05). However, in subgroup analysis according to donor's type, neither relapse-free survival nor overall survival was impacted by CMV status (both p > 0.05). This study addressed differences in incidence, risk factors, and associations with clinical outcomes of CMV reactivation after haploidentical versus matched-sibling PBSCT.

针对医学英语 、医学统计和论文写作等医学研究生基础教学的重点环节,采用虚拟图像联想法教学将必须学习和掌握的基础知识转化为多彩的图像,结合个人不同的联想方式,在脑海中揣摩这些虚拟图像辅助学习.该方法既能克服实体教学的客观条件限制,又能调动自我学习的主动性,为医学研究生基础教学开辟新的途径.

Unmanipulated haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) has been an established treatment to cure high-risk leukemia/lymphoma. Relapse is the main cause of treatment failure for patients with relapsed/refractory disease or with very high-risk gene mutations such as TP53 , TET2 , and DNMT3a . In this study, we aimed to establish the tolerance and efficacy of prophylactic donor lymphocyte infusion (DLI) with G-CSF-primed peripheral blood progenitors for prevention of relapse in these very high-risk patients after haplo-PBSCT. The prophylactic DLI was given at a median of 77 days after transplantation in 31 of 45 consecutive patients with very high-risk leukemia/lymphoma. The median dose of CD3 + cells for infusion was 1.8 × 10 7 /kg. The 100-day incidences of acute graft-versus-host disease (GVHD) grades 2–4 and 3–4 after DLI were 55.3% and 10.2%. The 2-year incidences of chronic GVHD and severe chronic GVHD were 52.0% and 18.2%. The 2-year incidences of non-relapse mortality and relapse were 33.1% and 32.5%. The 2-year probabilities of overall survival and relapse-free survival were 40.1% and 31.9%. Poor-risk gene mutations ( p = 0.029), disease in non-remission status prior to transplantation ( p = 0.005), and donors older than 40 years of age ( p = 0.043) were associated with relapse after DLI. In multivariate analysis, disease in non-remission status prior to transplantation was an independent risk factor of relapse (hazard ratio = 4.079; p = 0.035). These data showed the feasibility of the prophylactic DLI in the haplo-PBSCT setting and the anti-leukemic efficacy in very high-risk leukemia/lymphoma.

Donor lymphocyte infusion (DLI) might be used prophylactically to reduce relapse after allogeneic hematopoietic stem cell transplantation for very high-risk leukemia/lymphoma without effective targeted therapy. To compare the safety and efficacy of prophylactic DLI for prevention of relapse after allogeneic peripheral blood stem cell transplantation from haploidentical donors (HID-SCT) and matched-sibling donors (MSD-SCT) in patients with very high-risk acute myeloid leukemia (AML), we performed a retrospective analysis in a cohort of 21 HID-SCT and 13 MSD-SCT recipients, displaying similar baseline characteristics except for donor’s gender distribution. Grade 2–4 acute graft-versus-host disease (GVHD) at 100-day post-DLI was higher in HID-SCT group than that in MSD-SCT group (59.5% vs. 30.8%, p = 0.05). The grade 3–4 acute GVHD (17.5% vs. 7.7%), 1-year chronic GVHD (36.6% vs. 33.2%), and severe chronic GVHD (15.3% vs. 27.3%) were not statistically significant different between groups. One-year non-relapse mortality was higher in HID-SCT group than that in MSD-SCT group with marginal significance (27.9% vs. 0.0%, p = 0.061). One-year relapse rate was not statistically significant different between HID-SCT group and MSD-SCT group (21.6% vs. 36.5%, p = 0.543). For HID-SCT recipients, 1-year relapse rate was lower in patients receiving prophylactic DLI than that in a control cohort of eight patients with same very high-risk features but not receiving prophylactic DLI (62.5% vs. 28.3%, p = 0.037). No statistically significant difference was observed in 1-year overall survival (OS, 55.1% vs. 83.9%, p = 0.325) and relapse-free survival (RFS, 50.1% vs. 74.0%, p = 0.419) rates between HID-SCT group and MSD-SCT group. In multivariate analyses, non-remission status prior to transplant, poor-risk gene mutations, and donor’s age ≥ 48 years predicted a higher risk of relapse after DLI. Non-remission status prior to transplant predicted inferior OS and RFS. Patient’s age ≥ 40 years also predicted an inferior OS. In conclusion, prophylactic DLI was very safe and efficient for reducing relapse in patients with very high-risk AML receiving MSD-SCT. In the recipients of HID-SCT, the application of prophylactic DLI could reduce the risk of relapse, although with a higher incidence of DLI-associated acute GVHD than those of MSD-SCT.

In allogeneic hematopoietic stem cell transplantation recipients, reactivation of Epstein–Barr virus (EBV) can cause post-transplantation lymphoproliferative disorder (PTLD), which may rapidly progress to multiorgan failure and even death. Development of EBV PTLD correlates very closely with use of anti-thymocyte globulin (ATG) and type of transplant. To assess the incidences and clinical features of EBV DNAemia and PTLD in the setting of stem cell transplantation using unmanipulated G-CSF-primed allogeneic peripheral blood stem cells as graft, we performed a retrospective analysis of stem cell transplantation from HLA-matched sibling donors (MSD-SCT, n = 90) or HLA-haploidentical related donors (HID-SCT, n = 110) in patients with hematological malignancies. All of HID-SCT recipients and 27.8% of MSD-SCT recipients received an ATG-containing conditioning regimen. One-year cumulative incidence of EBV DNAemia was 44.1%, ranging from 4.8% in MSD-SCT recipients not using ATG to 20.0% in MSD-SCT recipients using ATG, and 73.7% in HID-SCT recipients. Risk factors for EBV reactivation included use of ATG (p = 0.008), male donor (p = 0.034), and cytomegalovirus DNAemia (p < 0.001). One-year incidence of EBV PTLD was 11.9%, ranging from 1.8% in recipients of MSD-SCT not using ATG to 4.4% in recipients of MSD-SCT using ATG, and 23.5% in recipients of HID-SCT. Risk factors for PTLD after HID-SCT included in fludarabine-containing conditioning regimen (p = 0.010), cytomegalovirus DNAemia (p = 0.036), and patient’s age < 40-yr (p = 0.032). Two-year non-relapse mortality was higher for patients with EBV DNAemia than those without EBV DNAemia (35.8% vs. 15.3%, p = 0.002). One-year relapse-free survival and overall survival among patients with PTLD were 40.2% and 44.9%, respectively, as opposed to 63.4% and 68.4% among patients without PTLD (both p < 0.05). In multivariate analyses, EBV DNAemia predicted a lower risk of relapse (p = 0.025), while PTLD was a marginally significant predictor of relapse (p = 0.092). This study identified patients at risk of EBV reactivation and PTLD after unmanipulated allogeneic peripheral blood stem cell transplantation.

BACKGROUND Splenic marginal zone lymphomas (SMZLs) are generally uncommon, indolent lymphomas that typically affect older adults, but the development of the transformation to high-grade lymphoma may occur in a small proportion of patients and represents a rare event with blastic cell infiltration in the lymph nodes and bone marrow. CASE REPORT Here, we present a young adult patient who was diagnosed with a SMZL and developed a high-grade transformation to diffuse large B cell lymphoma (DLBCL) with central nervous system involvement. The patient was a 31-year-old woman whose hematologic medical history began with severe anemia and thrombocytopenia associated with atypical lymphoid infiltrate in the bone marrow and massive splenomegaly. A splenectomy was performed and revealed the SMZL. She was first treated with the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) and subsequently with the R-FMD regimen (rituximab, fludarabine, mitoxantrone, and dexamethasone) because the peripheral blood leukocytes were remarkably increased postoperatively. Six months after the splenectomy, she complained of headaches. A magnetic resonance imaging scan of her brain revealed intracerebral tumorous lesions from which a biopsy was taken. On morphological and immunohistochemical examination, the tumor fulfilled the criteria for a DLBCL. Treatment with pulse-dose intravenous methylprednisolone followed by high-dose methotrexate was promptly initiated, but the patient's condition continued to deteriorate and she died of the disease 13 months after the splenectomy. CONCLUSIONS Although there is a general tendency for SMZL to display low aggressiveness, central nervous system involvement associated with a histological transformation to high-grade lymphoma, as presented here, can occur in advanced stage of the disease.

BACKGROUND:Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia chromosome generated by the reciprocal translocation t(9: 22)(q34;q11). CML is usually diagnosed in the chronic phase. Blast crisis represents an advanced phase of CML. Extramedullary blast crisis as the initial presentation of CML with bone marrow remaining in chronic phase is an unusual event. Further, extramedullary blast crisis with T lymphoid/myeloid bilineal phenotype as an initial presentation for CML is extremely unusual. CASE REPORT:Here, we report the case of a 49-year-old male with rapidly enlarged submandibular lymph nodes. Biopsy specimen from the nodes revealed a characteristic appearance with morphologically and immunohistochemically distinct myeloblasts and T lymphoblasts co-localized in 2 adjacent regions, accompanied by chronic phase of the disease in bone marrow. The presence of the BCR/ABL1 fusion gene within both cellular populations in this case confirmed the extramedullary disease represented a localized T lymphoid/myeloid bilineal blastic transformation of CML. After 3 courses of combined chemotherapy plus tyrosine kinase inhibitor treatment, the mass was completely regressed with a 3-log decrease in BCR/ABL1 transcript from baseline. Five months after the diagnosis, the patient showed diminished vision, hand tremors, and weakness of lower extremities. Flow cytometric immunophenotyping of cerebrospinal fluid revealed the presence of myeloid blasts. An isolated central nervous system relapse of leukemia was identified. Following high-dose systemic and intrathecal chemotherapy, the patient continued to do well. CONCLUSIONS:The possibility of extramedullary blast crisis as an initial presentation in patients with CML should be considered. Further, an isolated central nervous system blast crisis should be considered if neurological symptoms evolve in patients who have shown a good response to therapy.