[Efficacy and safety of chimeric antigen receptor T-cell therapy followed by allogeneic hematopoietic stem cell transplantation in 21 patients with Ph-like acute lymphoblastic leukemia]

Objective: To evaluate the efficacy and safety of chimeric antigen receptor T-cell (CAR-T) therapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with Ph-like acute lymphoblastic leukemia (Ph-ALL) . Methods: Patients with Ph-ALL who underwent CAR-T therapy followed by allo-HSCT from March 2018 to August 2023 at the First Affiliated Hospital of Soochow University were included, and their clinical data were retrospectively analyzed. Results: Of the 21 patients, 14 were male and 7 were female. The median age at the time of CAR-T therapy was 22 (6-50) years. Seven patients had ABL1-like rearrangements, and 14 had JAK-STAT rearrangements. Prior to CAR-T therapy, 12 patients experienced hematologic relapse; 7 were multiparameter flow cytometry minimal residual disease (MFC-MRD) -positive and 2 were MFC-MRD-negative. CAR-T cells were derived from patients' autologous lymphocytes. Nine patients were treated with CD19 CAR-T cells, and 12 were treated with CD19/CD22 CAR-T cells. After assessment on day 28 after CAR-T therapy, 95.2% of the patients achieved complete remission, with an MRD-negative remission rate of 75%. Nineteen patients developed grade 0-2 cytokine release syndrome (CRS) and 2 patients suffered grade 3 CRS, all cases of which resolved after treatment. All patients underwent allo-HSCT after CAR-T therapy. The median time from CAR-T therapy to allo-HSCT was 63 (38-114) days. Five patients experienced relapse after CAR-T therapy, including four with hematologic relapse and one with molecular relapse. The 3-year overall survival (OS) rates in the ABL1 and JAK-STAT groups were (83.3±15.2) % and (66.6±17.2) %, respectively (P=0.68) . The 3-year relapse-free survival (RFS) rates were (50.0±20.4) % and (55.6±15.4) % in the ABL1 and JAK-STAT groups, respectively. There was no significant difference in 3-year OS or RFS between the two groups. Conclusions: CAR-T therapy followed by allo-HSCT leads to rapid remission in most patients with Ph-ALL and prolongs leukemia-free survival.

Rapid molecular response to dasatinib in Ph-like acute lymphoblastic leukemia patients with ABL1 rearrangements: case series and literature review

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk subtype with a poor prognosis under conventional chemotherapy. Ph-like ALL has a similar gene expression profile to Philadelphia chromosome-positive (Ph+) ALL, but is highly heterogeneous in terms of genomic alterations. Approximately 10-20% of patients with Ph-like ALL harbor ABL class (e.g. ABL1, ABL2, PDGFRB, and CSF1R) rearrangements. Additional genes that form fusion genes with ABL class genes are still being researched. These aberrations result from rearrangements including chromosome translocations or deletions and may be targets of tyrosine kinase inhibitors (TKIs). However, due to the heterogeneity and rarity of each fusion gene in clinical practice, there is limited data on the efficacy of tyrosine kinase inhibitors. Here, we report three cases of Ph-like B-ALL with ABL1 rearrangements treated with the dasatinib backbone for the CNTRL::ABL1, LSM14A::ABL1, and FOXP1::ABL1 fusion genes. All three patients achieved rapid and profound remission with no significant adverse events. Our findings suggest that dasatinib is a potent TKI for the treatment of ABL1-rearranged Ph-like ALL and can be used as a first-line treatment option for such patients.

[Influencing factors of futile recanalization after endovascular therapy in acute ischemic stroke patients with large vessel occlusions]

Objective: To analyze the influencing factors of futile recanalization after endovascular therapy (EVT) in acute ischemic stroke patients with large vessel occlusions (AIS-LVO). Methods: AIS-LVO patients who underwent EVT with successful recanalization between January 2019 and December 2021 in Neurovascular Center of Changhai Hospital of Naval Medical University were retrospectively selected. Modified Rankin scale (mRS) score 3 months after EVT was used as the prognostic evaluation index, and patients with mRS scores≤2 were classified as the meaningful recanalization group and mRS scores 3-6 as the futile recanalization group. The risk factors, National Institutes of Health stroke scale (NIHSS) score, Glasgow coma scale (GCS) score, Alberta Stroke Program Early CT (ASPECT) score, core infarct volume, etc. in both groups were analyzed, and the influencing factors of futile recanalization after EVT were analyzed by multivariate logistic regression. Continuous variables that do not conform to the normal distribution are represented by [M(Q1,Q3)]. Results: A total of 368 patients meeting the inclusion criteria were collected, including 228 males and 140 females, and aged 68 (61, 77) years. There are 196 patients and 172 patients in the meaningful recanalization and futile recanalization groups, respectively, with the rate of futile recanalization 3 months after EVT of 46.74% (172/368). Comparing the general information and risk factors between the two groups found that the age of patients in the futile recanalization group [71 (65, 79) years] was higher than that in the meaningful recanalization group [65 (59, 72) years]. The baseline NIHSS score [18 (14, 22)] and the rate of not achieving modified Thrombolysis in Cerebral Ischemia grade 3 (mTICI 3) reperfusion (36.1%) were higher in the futile recanalization group than those in the meaningful recanalization group [12 (7, 17) and 19.9%]. The baseline GCS score [11 (9, 13)] was lower in the futile recanalization group than that in the meaningful recanalization group [14 (11, 15)]. The core infarct volume in the futile recanalization group [28 (7, 65) ml] was larger than that in the meaningful recanalization group [6 (0, 17) ml]. The ASPECT score [7 (5, 9)] was lower in the futile recanalization group than that in the meaningful recanalization group [9 (7, 10)]. In addition, the proportion of hypertension, atrial fibrillation, general anesthesia, and symptomatic intracranial hemorrhage was higher in the futile recanalization group (all P<0.05). The time from symptom onset to puncture and from symptom onset to reperfusion was longer in the futile recanalization group (both P<0.05). There were statistically significant differences in trial of Org 10172 in acute stroke treatment (TOAST) classification and the site of occluded blood vessels between the two groups (both P<0.05). Multivariate logistic regression indicated that age ≥80 years(OR=1.935,95%CI: 1.168-3.205), baseline NIHSS score (OR=1.999,95%CI: 1.202-3.325), GCS score (OR=2.299,95%CI: 1.386-3.814), previous stroke history (OR=1.977,95%CI: 1.085-3.604), general anesthesia (OR=1.981,95%CI: 1.143-3.435), not achieving grade 3 recanalization (OR=2.846, 95%CI: 1.575-5.143), ASPECT score<6 (OR=2.616, 95%CI: 1.168-5.857), and core infarct volume>70 ml (OR=2.712, 95%CI: 1.130-6.505) were risk factors for futile recanalization. Conclusion: Age≥80 years, previous stroke history, baseline NIHSS score≥20, GCS score≤8, general anesthesia, ASPECT score<6, core infarct volume>70 ml, and failure to achieve Grade 3 recanalization are independent influencing factors for futile recanalization after endovascular therapy in AIS-LVO patients.

Mutation spectrum of FLT3 and significance of non-canonical FLT3 mutations in haematological malignancy

Fms-like tyrosine kinase 3 (FLT3) is frequently mutated in haematological malignancies. Although canonical FLT3 mutations including internal tandem duplications (ITDs) and tyrosine kinase domains (TKDs) have been extensively studied, little is known about the clinical significance of non-canonical FLT3 mutations. Here, we first profiled the spectrum of FLT3 mutations in 869 consecutively newly diagnosed acute myeloid leukaemia (AML), myelodysplastic syndrome and acute lymphoblastic leukaemia patients. Our results showed four types of non-canonical FLT3 mutations depending on the affected protein structure: namely non-canonical point mutations (NCPMs) (19.2%), deletion (0.7%), frameshift (0.8%) and ITD outside the juxtamembrane domain (JMD) and TKD1 regions (0.5%). Furthermore, we found that the survival of patients with high-frequency (>1%) FLT3-NCPM in AML was comparable to those with canonical TKD. In vitro studies using seven representative FLT3-deletion or frameshift mutant constructs showed that the deletion mutants of TKD1 and the FLT3-ITD mutant of TKD2 had significantly higher kinase activity than wild-type FLT3, whereas the deletion mutants of JMD had phosphorylation levels comparable with wild-type FLT3. All tested deletion mutations and ITD were sensitive to AC220 and sorafenib. Collectively, these data enrich our understanding of FLT3 non-canonical mutations in haematological malignancies. Our results may also facilitate prognostic stratification and targeted therapy of AML with FLT3 non-canonical mutations.

Identification of variants in 94 Chinese patients with hereditary spherocytosis by next-generation sequencing

Hereditary spherocytosis (HS) is the most common type of hereditary erythrocyte membrane disease and has varied phenotypic features and genetic patterns. We herein performed a retrospective study of 94 patients with HS and aimed to investigate the genetic variations and genotype-phenotype correlations using targeted next-generation sequencing. In 79/94 (84%) patients, 83 HS variants including 67 novel variants were identified. Pathogenic variants of SPTB, ANK1, SLC4A1, SPTA1, and EPB42 were found in 32/79(41%), 22/79(28%), 15/79 (19%), 8/79 (9%), and 3/79 (4%) of the patients respectively, revealing that SPTB is the most frequently mutated HS gene in Eastern China. Most SPTB and ANK1 gene variations were nonsense and frameshift variations. Missense variants were the main variant type of SLC4A1, SPTA1, and EPB42 genes. Interestingly, one SPTA1 variant (p. Arg1757Cys) showed an autosomal dominant inheritance pattern and one EPB42 variant (p. Gln377His) was apparent as a hotspot variation. Furthermore, genotype-phenotype analysis was performed among the five mutated gene groups. Besides the finding that patients with the SLC4A1 variant had the highest mean corpuscular hemoglobin levels, no clear correlations between genotype and phenotype were observed.

Integrative genomic and transcriptomic profiling reveals distinct molecular subsets in adult mixed phenotype acute leukemia

Mixed phenotype acute leukemia (MPAL) is a subtype of leukemia in which lymphoid and myeloid markers are co-expressed. Knowledge regarding the genetic features of MPAL is lacking due to its rarity and heterogeneity. Here, we applied an integrated genomic and transcriptomic approach to explore the molecular characteristics of 176 adult patients with MPAL, including 86 patients with T-lymphoid/myeloid MPAL (T/My MPAL-NOS), 42 with Ph+ MPAL, 36 with B-lymphoid/myeloid MPAL (B/My MPAL-NOS), 4 with t(v;11q23), and 8 with MPAL, NOS, rare types. Genetically, T/My MPAL-NOS was similar to B/T MPAL-NOS but differed from Ph+ MPAL and B/My MPAL-NOS. T/My MPAL-NOS exhibited higher CEBPA, DNMT3A, and NOTCH1 mutations. Ph+ MPAL demonstrated higher RUNX1 mutations. B/T MPAL-NOS showed higher NOTCH1 mutations. By integrating next-generation sequencing and RNA sequencing data of 89 MPAL patients, we defined eight molecular subgroups (G1-G8) with distinct mutational and gene expression characteristics. G1 was associated with CEBPA mutations, G2 and G3 with NOTCH1 mutations, G4 with BCL11B rearrangement and FLT3 mutations, G5 and G8 with BCR::ABL1 fusion, G6 with KMT2A rearrangement/KMT2A rearrangement-like features, and G7 with ZNF384 rearrangement/ZNF384 rearrangement-like characteristics. Subsequently, we analyzed single-cell RNA sequencing data from five patients. Groups G1, G2, G3, and G4 exhibited overexpression of hematopoietic stem cell disease-like and common myeloid progenitor disease-like signatures, G5 and G6 had high expression of granulocyte-monocyte progenitor disease-like and monocyte disease-like signatures, and G7 and G8 had common lymphoid progenitor disease-like signatures. Collectively, our findings indicate that integrative genomic and transcriptomic profiling may facilitate more precise diagnosis and develop better treatment options for MPAL.

Molecular genetic and clinical characterization of acute myeloid leukemia with trisomy 8 as the sole chromosome abnormality

INTRODUCTION

The aim of the study was to determine molecular genetic and clinical characterization of acute myeloid leukemia (AML) with trisomy 8 as the sole chromosome abnormality, a recurrent but rare chromosomal abnormality in AML.

METHODS

Interphase fluorescence in situ hybridization, reverse transcriptase-quantitative polymerase chain reaction for gene rearrangement and next-generation sequencing (NGS) were performed on sole trisomy 8 AML patients.

RESULTS

A total of 35 AML patients with trisomy 8 as the sole chromosome abnormality were screened. The most frequently mutated genes were DNMT3A(37.1%), RUNX1(28.6%), FLT3-ITD(28.6%), IDH2(22.9%), NPM1(17.1%), and ASXL1 (14.3%). The sole +8 AML patients exhibited more mutations in RUNX1 (28.6% vs. 4.8%, P = 0.001) and ASXL1 (14.3% vs. 4.8%, P = 0.039) by comparing with normal karyotype AML (NK AML) patients(n = 63). The sole +8 AML patients(n = 35) with RUNX1 or IDH2 mutations showed significantly lower WBC counts, while FLT3-ITD showed higher white blood cell (WBC) counts as compared to the corresponding wild-type groups. Total of 45.7% patients achieved complete remission (CR) after the first induction therapy. The CR rate of patients with FLT3-ITD or IDH1 mutation was significantly lower than that in the corresponding wild-type cases (P = 0.047, 0.005, respectively). The median overall survival (OS) and disease-free survival (PFS) were 18.0 (95% CI: 10.8-25.2) and 10 (95% CI: 6.7-13.3) months, respectively. FLT3-ITD mutations and allogeneic hematopoietic stem cell transplantation (allo-HSCT) were independent prognostic markers for OS in multivariable analysis.

CONCLUSION

The results suggest a possible association between trisomy 8 and additional mutations that may influence clinical feature and prognosis.

Comprehensive mutation profile in acute myeloid leukemia patients with RUNX1-RUNX1T1 or CBFB-MYH11 fusions

Objective:

This study was undertaken with the aim of better understanding the genomic landscape of core-binding factor (CBF) acute myeloid leukemia (AML).

Materials and Methods:

We retrospectively analyzed 112 genes that were detected using next-generation sequencing in 134 patients with de novo CBF-AML. FLT3-ITD, NPM1, and CEBPA mutations were detected by DNA-PCR and Sanger sequencing.

Results:

In the whole cohort, the most commonly mutated genes were c-KIT (33.6%) and NRAS (33.6%), followed by FLT3 (18.7%), KRAS (13.4%), RELN (8.2%), and NOTCH1 (8.2%). The frequencies of mutated genes associated with epigenetic modification, such as IDH1, IDH2, DNMT3A, and TET2, were low, being present in 1.5%, 0.7%, 2.2%, and 7.5% of the total number of patients, respectively. Inv(16)/t(16;16) AML patients exhibited more mutations of NRAS and KRAS (p=0.001 and 0.0001, respectively) than t(8;21) AML patients. Functionally mutated genes involved in signaling pathways were observed more frequently in the inv(16)/t(16;16) AML group (p=0.016), while the mutations involved in cohesin were found more frequently in the t(8;21) AML group (p=0.011). Significantly higher white blood cell counts were found in inv(16)/t(16;16) AML patients with c-KIT (c-KIT^mut) or NRAS (NRAS^mut) mutations compared to the corresponding t(8;21) AML/c-KIT^mut and t(8;21) AML/NRAS^mut groups (p=0.001 and 0.009, respectively).

Conclusion:

The mutation profiles of t(8;21) AML patients showed evident differences from those of patients with inv(16)/t(16;16) AML. We have provided a comprehensive overview of the mutational landscape of CBF-AML.

Elucidation of the Complete Biosynthetic Pathway of Phomoxanthone A and Identification of a Para-Para Selective Phenol Coupling Dimerase

Fungal cytochrome P450 enzymes have been shown to catalyze regio- and stereoselective oxidative intermolecular phenol coupling. However, an enzyme capable of catalyzing undirected para-para (C4-4') coupling has not been reported. Here, we revealed the biosynthetic gene cluster (BGC) of phomoxanthone A from the marine fungus Diaporthe sp. SYSU-MS4722. We heterologously expressed 14 biosynthetic genes in Aspergillus oryzae NSAR1 and found that PhoCDEFGHK is involved in the early stage of phomoxanthone A biosynthesis to give chrysophanol and that chrysophanol is then processed by PhoBJKLMNP to yield penexanthone B. A feeding experiment suggested that PhoO, a cytochrome P450 enzyme, catalyzed the regioselective oxidative para-para coupling of penexanthone B to give phomoxanthone A. The mechanism of PhoO represents a novel enzymatic 4,4'-linkage dimerization method for tetrahydroxanthone formations, which would facilitate biosynthetic engineering of structurally diverse 4,4'-linked dimeric tetrahydroxanthones.

Successful application of PD-1 knockdown CLL-1 CAR-T therapy in two AML patients with post-transplant relapse and failure of anti-CD38 CAR-T cell treatment

Patients with relapsed/refractory acute myeloid leukemia (R/R AML) often show resistance to chemotherapy and have dismal outcomes. Therefore, it is urgent to develop new treatment strategies to address this problem. With tremendous achievement of chimeric antigen receptor T cells (CAR-T) therapy against B-cell malignancies, many efforts have been devoted to developing CAR-T therapy for R/R AML but with limited success, in part owing to a lack of specific targets. C-type lectin-like molecule-1 (CLL-1) is highly expressed on AML blasts with no expression on normal hematopoietic stem cells, which makes it an ideal target of immunotherapy for AML. Here, we report 2 R/R AML patients who relapsed after allogeneic stem cell transplantation and failed multiline salvage therapies including anti-CD38 CAR-T therapy, but were successfully treated with PD-1 silenced anti-CLL-1 CAR-T therapy. Both patients achieved molecular complete remission with incomplete hematologic recovery at 28 days of evaluation after CLL-1 CAR-T cell infusion. Cytokine release syndrome in cases 1 and 2 were grade 1 and 2, respectively. At the last follow-up, cases 1 and 2 had maintained continuous remission for 8 and 3 months, respectively. Our results demonstrated that CLL-1 CAR-T cells might be an effective and safe salvage therapy for AML patients with posttransplant relapse.

Identification of STRBP as a Novel JAK2 Fusion Partner Gene in a Young Adult With Philadelphia Chromosome-Like B-Lymphoblastic Leukemia

Philadelphia chromosome-like B-lymphoblastic leukemia (Ph-like ALL) describes a group of genetically heterogeneous, Ph-negative entities with high relapse rates and poor prognoses. A Janus-kinase-2 (JAK2) rearrangement has been reported in approximately 7% of Ph-like ALL patients whose therapeutic responses to JAK inhibitors have been studied in clinical trials. Here, we report a novel STRBP-JAK2 fusion gene in a 21-year-old woman with Ph-like ALL. Although a normal karyotype was observed, a hitherto unreported JAK2 rearrangement was detected cytogenetically. STRBP-JAK2 fusion was identified by RNA sequencing and validated by Sanger sequencing. The Ph-like ALL proved refractory to traditional induction chemotherapy combined with ruxolitinib. The patient consented to infusion of autologous chimeric antigen receptor (CAR) T cells against both CD19 and CD22, which induced morphologic remission. Haplo-identical stem cell transplantation was then performed; however, she suffered relapse at just one month after transplantation. The patient subsequently received donor lymphocyte infusion after which she achieved and maintained a minimal residual disease negative remission. However, she succumbed to grade IV graft-versus-host disease 7 months post-transplant. In conclusion, this report describes a novel STRBP-JAK2 gene fusion in a Ph-like ALL patient with a very aggressive disease course, which proved resistant to chemotherapy combined with ruxolitinib but sensitive to immunotherapy. Our study suggests that CAR T-cell therapy may be a viable option for this type of leukemia.

Comparison of Aspiration versus Stent Retriever Thrombectomy as the Preferred Strategy for Patients with Acute Terminal Internal Carotid Artery Occlusion: A Propensity Score Matching Analysis

BACKGROUND AND PURPOSE

There is no consensus on endovascular treatment for terminal ICA. The purpose of this study was to evaluate the comparative safety and efficacy of preferred aspiration thrombectomy and stent retriever thrombectomy for revascularization in patients with isolated terminal ICA occlusion.

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with terminal ICA occlusion treated with aspiration thrombectomy or stent retriever thrombectomy in our center, from September 2013 to November 2018. To minimize the case bias, propensity score matching was performed. The primary outcomes were successful reperfusion defined by expanded TICI grades 2b-3 at the end of all endovascular procedures and puncture-to-reperfusion time.

RESULTS

A total of 109 consecutive patients with terminal ICA occlusion were divided into the aspiration thrombectomy group (40 patients) and the stent retriever thrombectomy group (69 patients), and 30 patients were included in each group after propensity score matching. The proportion of complete reperfusion was significantly higher in the aspiration thrombectomy group (OR 4.75 [95% CI, 1.10-1.38]; P = .002). The median puncture-to-reperfusion time in the aspiration thrombectomy group was shorter than that in the stent retriever thrombectomy group (38  versus 69 minutes; P = .001). Fewer intracerebral hemorrhage events were recorded in the aspiration thrombectomy group (OR 0.29 [95% CI, 0.09-0.90]; P = .028). No significant differences were observed for good outcomes (OR 1.92 [95% CI, 0.86-4.25]) and mortality (OR 0.84 [95% CI, 0.29-2.44]) at 90 days.

CONCLUSIONS

For the treatment of terminal ICA occlusion, aspiration thrombectomy was technically superior to stent retriever thrombectomy in the absence of a balloon guide catheter in achieving successful reperfusion with shorter puncture-to-reperfusion time and procedure-related adverse events.

The endogenous retrovirus-derived long noncoding RNA TROJAN promotes triple-negative breast cancer progression via ZMYND8 degradation

Human endogenous retroviruses (HERVs) play pivotal roles in the development of breast cancer. However, the detailed mechanisms of noncoding HERVs remain elusive. Here, our genome-wide transcriptome analysis of HERVs revealed that a primate long noncoding RNA, which we dubbed TROJAN, was highly expressed in human triple-negative breast cancer (TNBC). TROJAN promoted TNBC proliferation and invasion and indicated poor patient outcomes. We further confirmed that TROJAN could bind to ZMYND8, a metastasis-repressing factor, and increase its degradation through the ubiquitin-proteasome pathway by repelling ZNF592. TROJAN also epigenetically up-regulated metastasis-related genes in multiple cell lines. Correlations between TROJAN and ZMYND8 were subsequently confirmed in clinical samples. Furthermore, our study verified that antisense oligonucleotide therapy targeting TROJAN substantially suppressed TNBC progression in vivo. In conclusion, the long noncoding RNA TROJAN promotes TNBC progression and serves as a potential therapeutic target.

[ARMS-PCR combined with capillary electrophoresis can be a sensitive and quantitative method for detection of MYD88-L265P mutation in lymphoma]

OBJECTIVE

To investigate the feasibility of sensitive and quantitative detection of MYD88 gene L265P mutation in lymphoma patients by using ARMS-PCR combined with capillary electrophoresis.

METHODS

ARMS-PCR amplified MYD88 gene was analyzed by capillary electrophoresis in ABI 3730 sequencer; Exon 5 of the same gene was sequenced bi-directionally as reported.

RESULTS

The sensitivity of detection L265P mutations by the ARMS-PCR combined with capillary electrophoresis and direct sequencing was 0.2% and 5%, respectively, according to the detection of the gradient-diluted plasmid standards. The detection rate of 184 patients was 13.59% and 8.28%, respectively (p<0.001). Moreover, the former method can successfully detect the mutation ratio(R²=0.979), and the repeatabilities (CV=2.86%, 1.94%, 5.49%) are acceptable.

CONCLUSION

ARMS-PCR combined with capillary electrophoresis can quantitatively detect the MYD88 gene L265P mutation, and the detection sensitivity is significantly higher than sanger sequencing. As a supplement to the latter, it can effectively lead to the earlier diagnose and monitoring of minimal residual disease.

[Clinical features and curative effect analysis of patients with myeloid neoplasms and RUNX1 mutations]

目的

研究伴RUNX1突变髓系肿瘤的临床特征和异基因造血干细胞移植（allo-HSCT）的疗效。

方法

回顾性分析2014年7月至2018年4月在苏州大学附属第一医院行二代测序检出RUNX1基因突变的42例髓系肿瘤患者的临床资料。

结果

全部42例伴RUNX1突变髓系肿瘤患者中，男27例，女15例，中位年龄43.5（16~68）岁，急性髓系白血病（AML）30例，骨髓增生异常综合征（MDS）12例。共突变基因中频率最高的是FLT3（26.2%，11/42），携带FLT3共突变基因的均为AML患者（P=0.014）。而MDS患者中最常见的共突变为ASXL1（25%，3/12）。allo-HSCT组（31例）1年总生存（OS）、无病生存（DFS）率分别为（70.6±9.0）%、（61.0±9.4）%，化疗组（11例）1年OS、DFS率分别为（34.4±16.7）%、（22.4±15.3）%，两组OS、DFS率差异有统计学意义（χ²=4.843，P=0.036；χ²=4.320，P=0.047）。单因素分析提示移植年龄>45岁为影响患者OS及DFS的预后不良因素[HR=4.819（95%CI 1.145~20.283），P=0.032；HR=5.945（95%CI 1.715~20.604），P=0.005]，染色体核型复杂异常为影响OS的预后不良因素[HR=5.572（95%CI 1.104~28.113），P=0.038]。

结论

allo-HSCT可以改善伴RUNX1突变髓系肿瘤患者预后，移植年龄>45岁、染色体核型复杂异常是影响allo-HSCT疗效的不良预后因素。

The Role of FLT3-ITD Mutation on de Novo MDS in Chinese Population

BACKGROUND

FLT3 mutations have been well-studied in acute myeloid leukemia (AML), and the detection of the FLT3 gene has become a clinical routine. However, it has not been fully analyzed in other hematologic malignancies, such as myelodysplastic syndromes (MDS).

MATERIALS AND METHODS

Between 2010 and 2016, 304 adult patients with de novo MDS had the FLT3 sequence tested on their bone marrow sample. With 279 patients who had follow-up information, we also analyzed the impact of clinical and laboratory characteristics as well as FLT3 mutation status and treatment on prognosis.

RESULTS

We found that the transformation rate was 3 (42.9%) of 7 patients in the FLT3-ITD-positive group, compared with 31 (10.4%) of 297 among FLT3-ITD-negative patients (P = .033). The median progression-free survival of the FLT3-ITD mutated and wild-type groups were 43 days and 363.5 days, respectively (P < .0001). The median overall survival (OS) of the 2 groups were 218 days and 410.5 days, respectively (P < .0001). We also found that 5 factors had independent prognostic impact on OS: white blood cell counts, bone marrow blast percentage, cytogenetics, transplantation status, and FLT3-ITD mutation. Furthermore, compared with the transformation group, the non-progression group was younger (P = .034), with a lower platelet count (P = .022), a lower bone marrow blast percentage (P = .001), a lower FLT3-ITD incidence (P = .007), and a longer OS (P < .0001).

CONCLUSIONS

When observed at the MDS stage, patients harboring FLT3-ITD mutations had higher AML transformation rate, quicker disease progression, and shorter survival than wild-type patients. Nevertheless, once the disease progressed to leukemia, the impact of FLT3-ITD mutations on prognosis was slight. In addition, the prognosis of secondary AML was very poor whether there was an FLT3-ITD mutation or not.

[Evaluation of the right ventricular function in patients with pneumoconiosis by echocardiography]

Objective: To investigate right ventricular function in patients with pneumoconiosis, and to provide a basis for quantitative diagnosis and treatment of pneumoconiosis in clinical practice. Methods: A total of 43 patients with pneumoconiosis who were hospitalized consecutively in Shijiazhuang Prevention and Treatment Center for Occupational Diseases from May 2015 to May 2016 were enrolled, and according to the stage of pneumoconiosis, they were divided into stage I group with 16 patients, stage II group with 14 patients, and stage III group with 13 patients. A total of 16 healthy subjects were enrolled as control group. Echocardiography was performed and the relevant parameters were recorded, i.e., right ventricular transverse diameter (RVTD), tricuspid annular plane systolic excursion (TAPSE), and right ventricular myocardial performance index(Tei index). Results: There were significant differences in Tei index and TAPSE between all groups (P <0.05) except between the stage I group and the control group in terms of Tei index (P>0.05) and between the stage I group and the stage II group in terms of TAPSE (P>0.05). Right ventricular Tei index was negatively correlated with TAPSE (r=-0.547,P<0.05). Conclusion: A combination of right ventricular Tei index and TAPSE can be used for early quantitative evaluation of right ventricular function in patients with pneumoconiosis.

[Detection of ASXL1 Mutation and CALR Mutation Coexistance in Patients with Ph Negative Myeloproliferative Neoplasm and Its Clinical Gignificance]

OBJECTIVE

To explore the coexistence of ASXL1 and CALR gene mutations in patients with essential thrombocytheima (ET) and with primary myelofibrosis(PMF), and to compare the differences of clinical characteristics between ET and PMF patients carrying ASXL1 and CALR mutations, and ET and PMF patients carrying solitary gene mutation, and ET and PMF patients without any mutations.

METHODS

The mutations of ASXL1 gene at exon 12, CALR gene at exon 9 and MPL gene at exon 10 in 263 essential ET patients and 29 PMF patients were detected by PCR amplification followed by direct sequencing of genomic DNA. The JAK2V617F mutations were used by allele specific PCR detection.

RESULTS

72.6%(212/292)of patients harbored at least one mutation. The incidences of ASXL1 and CALR mutations were 5.8% and 30.5%, respectively. The frequencies of JAK2V617F and MPL mutations were 39.0% and 2.4%, respectively. 5.1%(15/292) of patients had double mutations, including ASXL1 and CALR(n=11), ASXL1 and JAK2V617F(n=2), MPL and CALR(n=1) and ASXL1 and MPL(n=1). The frequency of concurrent ASXL1 and CALR mutations was found to be high. Significant difference was found on hemoglobin levels and platelet counts between CALR and ASXL1 mutations and single mutation (P<0.05),however, the difference on leukocyte counts and median age was not found. Compared with negative patients, the presence of ASXL1 and CALR mutations was found to be significantly correlative with lower hemoglobin level (P=0.045), lower leukocyte count (P=0.002) and with higher platelet counts(P=0.001), but the difference of median age was not found.

CONCLUSION

The frequency of concurrent ASXL1 and CALR mutations is higher in ET patients. The coexistence of ASXL1 and CALR gene mutations significantly associated with lower hemoglobin level and higher platelet count.

PHF5A Epigenetically Inhibits Apoptosis to Promote Breast Cancer Progression

Alternative splicing (AS) and its regulation play critical roles in cancer, yet the dysregulation of AS and its molecular bases in breast cancer development have not yet been elucidated. Using an in vivo CRISPR screen targeting RNA-binding proteins, we identified PHD finger protein 5A (PHF5A) as a key splicing factor involved in tumor progression. PHF5A expression was frequently upregulated in breast cancer and correlated with poor survival, and knockdown of PHF5A significantly suppressed cell proliferation, migration, and tumor formation. PHF5A was required for SF3b spliceosome stability and linked the complex to histones, and the PHF5A-SF3b complex modulated AS changes in apoptotic signaling. In addition, expression of a short truncated FAS-activated serine/threonine kinase (FASTK) protein was increased after PHF5A ablation and facilitated Fas-mediated apoptosis. This PHF5A-modulated FASTK-AS axis was widely present in breast cancer specimens, particularly those of the triple-negative subtype. Taken together, our findings reveal that PHF5A serves as an epigenetic suppressor of apoptosis and thus provides a mechanistic basis for breast cancer progression and may be a valuable therapeutic target.Significance: This study provides an epigenetic mechanistic basis for the aggressive biology of breast cancer and identifies a translatable therapeutic target. Cancer Res; 78(12); 3190-206. ©2018 AACR.

The impact of FLT3 mutations on treatment response and survival in Chinese de novo AML patients

OBJECTIVE

Two distinct forms of FMS-like tyrosine kinase 3 (FLT3) mutations, internal tandem duplication (ITD) in the juxtamembrane domain and point mutation within the activation loop of the tyrosine kinase domain (TKD), have been identified in considerable number of patients with AML. This study was aimed to analyze the impacts of these mutations on clinical outcomes, and assess the efficacy of different therapeutic regimens (allo-HSCT, sorafenib, or conventional chemotherapy) for AML patients with FLT3 mutations after the standard induction therapy.

MATERIALS AND METHODS

We analyzed DNA samples from 158 consecutive de novo AML patients (18-60 years, excluding APL) with FLT3 mutations between July 2010 and October 2015.

RESULTS

We found that AML patients with FLT3-TKD mutations have more favorable clinical outcomes than those with FLT3-ITD mutations. We also found that allo-HSCT therapy subgroup achieved longer OS and RFS than non-allo-HSCT therapy subgroup for FLT3-ITD positive patients (p < 0.001, p = 0.071). However, compared with the clinical outcomes in non-primary refractory patients, sorafenib did not show an obvious beneficial effect for the primary refractory patients. Further study on a large scale is still recommended.

CONCLUSIONS

FLT3-TKD-mutated AML patients have more favorable clinical outcomes than those with FLT3-ITD mutations. Allo-HSCT therapy subgroup achieved longer OS and RFS than non-allo-HSCT therapy subgroup for FLT3-ITD positive patients. Compared with the clinical outcomes in non-primary refractory patients, sorafenib did not show an obvious beneficial effect for the primary refractory patients.

[Critical roles of matrix metalloproteinases secreted by leukemic cells in the pathogenesis of central nervous system leukemia]

目的

观察白血病细胞分泌的基质金属蛋白酶（MMP）-2和MMP-9对脑微血管内皮细胞（BMVEC）紧密连接蛋白ZO-1、claudin-5、occludin表达及对血脑屏障（BBB）通透性的影响，探讨MMP-2和MMP-9在中枢神经系统白血病（CNSL）发病机制中的作用。

方法

①实时定量PCR检测SHI-1、HL-60、U937细胞MMP-2、MMP-9基因的转录水平；明胶酶谱法检测细胞培养上清中MMP-2和MMP-9蛋白表达；体外穿膜实验观察各白血病细胞株的侵袭能力。②将原代人BMVEC接种于铺有Matrigel胶和纤维黏连蛋白包被的Transwell小室系统中，建立体外BBB模型。将蛋白酶抑制剂GM6001处理或未处理的SHI-1、HL-60、U937细胞或MMP-2/MMP-9基因沉默的SHI-1细胞接种于BBB模型的Transwell小室上层与BMVEC共培养，倒置相差显微镜观察BMVEC的形态变化，激光共聚焦显微镜观察紧密连接蛋白ZO-1、claudin-5和occludin的表达，计算白血病细胞的穿膜率。

结果

①SHI-1细胞表达较高转录水平的MMP-2和MMP-9及酶活性，且侵袭能力强于HL-60、U937细胞（P< 0.01）。②与HL-60、SHI-1和U937细胞共培养后，融合致密的BMVEC之间出现间隙、细胞呈单个生长，紧密连接蛋白ZO-1、claudin-5和occludin的表达明显下调，各白血病细胞均不同程度地穿过体外BBB进入Transwell小室下层。其中SHI-1细胞对BMVEC的形态改变及3种紧密连接蛋白的下调最为明显，穿膜率最高。GM6001明显抑制白血病细胞分泌MMP-2和MMP-9，使BMVEC的形态有所恢复，同时上调ZO-1、claudin-5和occludin的表达，降低了BBB的通透性。③用siRNA分别沉默MMP-2和MMP-9基因后，SHI-1细胞分泌MMP-2和MMP-9被抑制，SHI-1细胞穿膜率较沉默前分别下降43.64％和57.30%（P<0.01），ZO-1、claudin-5和occludin表达上调。

结论

白血病细胞株分泌的MMP-2和MMP-9能通过降解BMVEC紧密连接蛋白ZO-1、claudin-5和occludin而破坏BBB。

[The clinical features of patients with lymphoplasmacytic diseases harboring MyD88 L265P mutation]

Objective: To explore the clinical features of lymphoplasmacytic diseases with MyD88 L265P mutation. Methods: To analyze the distribution of MYD88 L265P mutation in patients with lymphoplasmacytic diseases by using of ARMS PCR-CE. Results: There were 25(30.9%) MyD88 L265P mutated patients in 81 patients. The mutation was frequently observed in 14 patients with WM (77.8%, 14/18), 2 patients with lymphoplasmacytic lymphoma (66.7%, 2/3), 1 acute lymphocytic leukemia patient (50.0%, 1/2), 3 multiple myeloma patients (30.0%, 3/10), 1 patient with monoclonal gammopathy of undetermined significance (25%, 1/4), 3 patients with chronic lymphocytic leukemia (13.0%, 3/23) and 1 lymphoma patient (4.8%, 1/21). 20 (80%, 20/25) patients were identified with IgM subtype. Compared with wild-type group of 56 cases, mutated patients were older (median age: 67 years vs 55 years, P< 0.001), with lower WBC count (median count: 5.23 × 109/L vs 10.80 × 109/L, P=0.001), lower HGB level (median count: 85 g/L vs 119 g/L, P<0.001). Conclusion: MyD88 L265P mutation was mainly observed in patients with IgM subtype lymphoplasmacytic diseases, and Waldenstrom' s macroglobulinemia was the most common disease. Compared with the wild-type group, patients with MyD88 L265P mutation were older and had lower WBC count, lower level of HGB. However, further studies were needed to test the prognostic value of MyD88 L265P mutation.

[Improved clinical outcome of acute myeloid leukemia with FLT3-ITD mutation treated with sorafenib]

OBJECTIVE

To analyze the efficacy of sorafenib on the treatment of patients diagnosed as acute myeloid leukemia(AML) with FLT3-ITD mutation.

METHODS

From January 2012 to February 2015, 42 cases of AML with FLT3-ITD mutation according to MICM (morphology, immunology, cytogenetics and molecular) diagnosis system in our hospital were retrospectively analyzed. Thirty-two cases were refractory to chemotherapy or relapsed, who were treated with sorafenib or combined with chemotherapy. Ten patients relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT), who were retreated with sorafenib or combined with donor lymphocyte infusion (DLI) or chemotherapy. In the first group, 13 of 32 patients accepted allo-HSCT.

RESULTS

The overall response rate of all 42 patients was 73.8%, including 4 (9.5%) complete molecular remission (CMR), 9 (21.4%) complete remission (CR), 8 (19%) complete remission with incomplete hematologic recovery (CRi), 10 (23.8%) partial remission (PR), and 11 (26.2%) none remission (NR). The response rate of sorafenib alone for 17 patients was 70.6%, and that of sorafenib plus chemotherapy was 66.7% (P=0.555). Thirteen patients who received allo-HSCT included 6 CMR/CR/CRi, 4 PR, and 3 NR before transplant. The 2-year overall survival (OS) rate and progress free survival (PFS) rate in all patients were 36.9% and 28.7%, and the corresponding median time were 18 months and 9 months respectively. The 2-year OS rate in 23 patients who received sorafenib combined with allo-HSCT was superior to that in 19 patients not receiving allo-HSCT (45.5% vs 23.9%, P=0.041), so was PFS rate (44.0% vs 9.7%, P=0.014). Twelve cases died of disease progression, four of infection, and one of chronic graft versus host disease after transplant.

CONCLUSIONS

Sorafenib combined with chemotherapy improves response rate of AML patients with FLT3-ITD mutation. Those who are treated with sorafenib plus allo-HSCT obtain better long-term survival.

Metabolic engineering of Escherichia coli to produce zeaxanthin

Zeaxanthin is a high-value carotenoid that is used in nutraceuticals, cosmetics, food, and animal feed industries. Zeaxanthin is chemically synthesized or purified from microorganisms as a natural product; however, increasing demand requires development of alternative sources such as heterologous biosynthesis by recombinant bacteria. For this purpose, we molecularly engineered Escherichia coli to optimize the synthesis of zeaxanthin from lycopene using fusion protein-mediated substrate channeling as well as by the introduction of tunable intergenic regions. The tunable intergenic regions approach was more efficient compared with protein fusion for coordinating expression of lycopene β-cyclase gene crtY and β-carotene 3-hydroxylase gene crtZ. The influence of the substrate channeling effect suggests that the reaction catalyzed by CrtZ is the rate-limiting step in zeaxanthin biosynthesis. Then Pantoea ananatis, Pantoea agglomerans and Haematococcus pluvialis crtZ were compared. Because P. ananatis crtZ is superior to that of P. agglomerans or H. pluvialis for zeaxanthin production, we used it to generate a recombinant strain of E. coli BETA-1 containing pZSPBA-2(P37-crtZPAN) that produced higher amounts of zeaxanthin (11.95 ± 0.21 mg/g dry cell weight) than other engineered E. coli strains described in the literature.

Comparison of intravitreal bevacizumab with macular photocoagulation for treatment of diabetic macular edema: a systemic review and Meta-analysis

AIM

To further evaluate the efficacy and safety of intravitreal bevacizumab (IVB) versus macular photocoagulation (MPC) in treatment of diabetic macular edema (DME) by Meta-analysis.

METHODS

Pertinent publications were identified through systemic searches of PubMed, Medline, EMBASE, and the Cochrane Controlled Trials Register up to 30 November, 2013. Changes in central macular thickness (CMT) in µm and best-corrected visual acuity (BCVA) in logMAR equivalents were extracted at 1, 3, 6, 12 and 24mo after initial treatment, and a Meta-analysis was carried out to compare results between groups receiving IVB and MPC.

RESULTS

Five randomized controlled trial (RCTs) and one high-quality comparative study were identified and included. Our Meta-analysis revealed that both IVB and MPC resulted in the improvements of CMT and BCVA in eyes with DME at 1mo after initial treatment, with IVB being significantly superior to MPC (P=0.01 and 0.02, respectively). The improvements of both measure outcomes at 3, 6, 12 and 24mo after treatment did not vary significantly between the IVB groups and MPC groups (CMT at 3mo, P=0.85; at 6mo, P=0.29; at 12mo, P=0.56; at 24mo, P=0.71; BCVA at 3mo, P=0.31; at 6mo, P= 0.30; at 12mo, P=0.23; at 24mo, P=0.52). However, the number of observed adverse events was low in all studies.

CONCLUSION

Current evidence shows IVB treatment trends to be more effective in improvements of macular edema and vision in eyes with DME at an earlier follow up (1mo) compared with MPC. At other time, both interventions have comparable efficacy without statistical significances.

[Frequently ABL kinase domain G:C→A:T mutation and uracil DNA glycosylase abnormal expression in TKI-resistant acute lymphoblastic leukemia of Chinese population]

Most Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) patients often show rapid recurrence and development of ABL kinase domain (KD) mutation after tyrosine kinase inhibitor (TKI) treatment. To further investigate the mechanism of Ph(+) ALL fast relapse after TKI treatment, ABL KD mutation in 35 Chinese Ph(+) ALL with TKI resistance was detected by direct sequencing. The results showed that 77.1% (27/35) Ph(+) ALL patients with TKI resistance had ABL KD mutation and 55.6% (15/27) Ph(+) ALL patients with ABL KD mutation had T315I. Interestingly, 77.8% (21/27) Ph(+)ALL showed ABL mutation G: C→A:T, including T315I, E255K and E459K. Furthermore, all the Ph(+) ALL patients with two or more ABL KD mutations collaborated with complex chromosome abnormality and all the TKI-resistant Ph(+) ALL patients, whose karyotype progressed from simple t (9;22) into complex, developed ABL KD mutation. Moreover, the expression level of uracil-DNA glycosylase UNG2, which inhibits G:C→A:T transition in genomic DNA, decreased in Ph(+) ALL with TKI-resistance compared to that in newly diagnosis Ph(+) ALL. It is concluded that there is a high frequent ABL KD G:C→A:T mutation and a high genomic instability in Chinese TKI-resistant Ph(+) ALL. In addition, the decreased UNG2 expression in TKI-resistant Ph(+) ALL probably contributes to their high rate of ABL KD G:C→A:T mutation.

Chromosomal evolution of Escherichia coli for the efficient production of lycopene

Background

Plasmid-based overexpression of genes has been the principal strategy for metabolic engineering. However, for biotechnological applications, plasmid-based expression systems are not suitable because of genetic instability, and the requirement for constant selective pressure to ensure plasmid maintenance.

Results

To overcome these drawbacks, we constructed an Escherichia coli lycopene production strain that does not carry a plasmid or an antibiotic marker. This was achieved using triclosan-induced chromosomal evolution, a high gene copy expression system. The engineered strain demonstrated high genetic stability in the absence of the selective agent during fermentation. The replacement of native appY promoter with a T5 promoter, and the deletion of the iclR gene in E. coli CBW 12241 further improved lycopene production. The resulting strain, E. coli CBW 12241(ΔiclR, P_T5-appY), produced lycopene at 33.43 mg per gram of dry cell weight.

Conclusions

A lycopene hyper-producer E. coli strain that does not carry a plasmid or antibiotic marker was constructed using triclosan-induced chromosomal evolution. The methods detailed in this study can be used to engineer E. coli to produce other metabolites.

[Construction of AML1-ETO eukaryotic expression vector and its effects on proliferation and differentiation of U937 cells]

OBJECTIVE

To construct a pcDNA3.1-AML1-ETO expression vector and investigate its effects on proliferation and differentiation of U937 leukemic cells.

METHODS

AML1-ETO gene was amplified by PCR from pCMV5-AML1-ETO and inserted into eukaryotic expression plasmid pcDNA3.1/V5-His-TOPO. The recombinant plasmid was transfected into U937 cells by Lipofectamin 2000. Individual clones selected with G418 were isolated. The integration and the expression levels of AML1-ETO in transfectants were determined by PCR, RT-PCR and Western blot analysis respectively. Trypan blue refusal staining method was used to detect the proliferation of U937 cells. Light microscope was applied to observe the morphologic changes of the cell. The expression of myeloid cell differentiation antigen was detected using flow cytometry.

RESULTS

The recombinant pcDNA3.1-AML1-ETO was confirmed by enzyme digestion and sequencing. The highly expressing AML1-ETO subclone was established. AML1-ETO was expressed in U937 cells transfected with pcDNA3.1-AML1-ETO. The growth of the monoclonal cells was inhibited evidently (P < 0.05). The expression of CD11b in transfected group \[(4.17 ± 0.31)%\] was lower than that in empty plasmid transfected group and non-transfected group \[(11.40 ± 0.17)% and (11.03 ± 0.15)%\] respectively (P < 0.001). Transfected cells displayed morphology of less differentiation. The expression level of CDl1b was unchanged in transfected cells treated with TPA (P > 0.05).

CONCLUSION

The eukaryotic expression vector for AML1-ETO gene was successfully constructed and expressed in U937. AML1-ETO inhibits the proliferation and differentiation of transfected cells. It provides the basis for further study of mechanisms of AML1-ETO in leukemogenesis.

GKLF transfection inhibits the growth of xenograft tumors derived from human gastric carcinoma cell line SGC-7901 in nude mice

AIM: To investigate the effects of transfection of the gut-enriched Krüppel-like factor (GKLF) gene on the growth of xenograft tumors derived from human gastric carcinoma cell line SGC-7901 in nude mice and to explore the potential role of the GKLF gene in gastric carcinogenesis.

METHODS: A recombinant plasmid carrying the GKLF gene (pcDNA3.1-GKLF) was transfected into SGC-7901 cells by lipofectin-mediated method. Cells stably expressing the GKLF gene were selected using G418. SGC-7901 cells untransfected and those transfected with empty pcDNA3.1 plasmid were used as controls. A xenograft tumor model was then established. Tumor growth was monitored. Tumor histopathological changes were determined by hematoxylin and eosin (HE) staining. The expression of GKLF and Ki-67 proteins in xenograft tissue was detected by immunohistochemistry.

RESULTS: Compared with the SGC7901-pcDNA3.1 and SGC-7901 groups, the period of latency was significantly lengthened in the SGC7901-pcDNA3.1-GKLF group (14.67 d ± 3.08 d vs 8.33 d ± 1.03 d, 8.67 d ± 1.03 d, both P < 0.05). The weight of xenograft tumors in the SGC7901-pcDNA3.1-GKLF group was significantly lower than that in the SGC7901-pcDNA3.1 and SGC-7901 groups (4.46 g ± 0.92 g vs 8.05 g ± 1.66 g, 7.82 g ± 1.14 g, both P < 0.05). The degree of tumor differentiation in the SGC7901-pcDNA3.1-GKLF group was better than that in the other two groups. Furthermore, the positive proportion of GKLF protein expression in xenograft tissue was increased while that of Ki-67 protein expression was decreased in the SGC7901-pcDNA3.1-GKLF group when compared with the other two groups (4/6 vs 2/6, 2/6; 1/6 vs 4/6, 4/6).

CONCLUSION: Transfection of the GKLF gene inhibits the growth of subcutaneous xenograft tumors derived from SGC-7901 cell line in nude mice by down-regulating the expression of Ki-67. The GKLF gene is a potential target for gene therapy of gastric carcinoma.

[Apoptosis of chronic myeloid leukemia stem/progenitor cells induced by anti-CD44 monoclonal antibody IM7 in vitro]

The aim of this study was to investigate the apoptosis-inducing effect of anti-CD44 monoclonal antibody IM7 on chronic myeloid leukemia (CML) stem/progenitor cells in vitro and to explore its possible mechanism. Leukemic stem/progenitor cells (LSPCs) expressing CD34(+), CD38(-) and CD123(+) were isolated from bone marrow (BM) cells of 20 patients with newly-diagnosed chronic myeloid leukemia by using EasySep(TM) magnetic beads. The percentage of apoptotic CML-LSPCs was assayed by Annexin-V/PI staining; the expression changes of c-myc and NF-kappaB mRNA were detected by real-time quantitative PCR (RQ-PCR) and RT-PCR; the NF-kappaB activity was detected by NF-kappaB Activation Nuclear Translocation Assay Kit; the BCL-2 protein expression was determined in the Western blot method. The results showed that the IM7 effectively induced apoptosis of CML-LSPCs; the mean percentage of early apoptotic cells significantly increased, as compared with the untreated control CML-LSPCs cells 12.58 +/- 2.84% vs 5.42 +/- 1.84% (p < 0.05). The c-myc, NF-kappaB mRNA expressions were down-regulated as compared with the control group (0.65 +/- 0.10 vs 1.00, 0.42 +/- 0.21 vs 1.00, respectively) (p < 0.01) by RQ-PCR and (0.49 +/- 0.09 vs 0.60 +/- 0.12, 0.47 +/- 0.11 vs 0.67 +/- 0.08, respectively)(p < 0.01) by RT-PCR. The BCL-2 protein level in CML-LSPCs treated with IM7 also decreased as compared with the control group (p < 0.01). In addition, the depression of NF-kappaB activity was observed through fluorescence microscope. It is concluded that the anti-CD44 monoclonal antibody IM7 effectively induces apoptosis of CML-LSPCs through down-regulating c-myc and bcl-2 mRNA expression, and decreasing NF-kappaB activity in CML-LSPCs.

Accelerated cellular senescence in myelodysplastic syndrome

OBJECTIVE

To investigate the contribution of cellular senescence to the progression and prognosis of myelodysplastic syndrome (MDS).

MATERIALS AND METHODS

We have analyzed the expression of p16INK4a in bone marrow mononuclear cells or CD34(+) cells from 53 patients with MDS, 12 acute myeloid leukemia (AML), and 11 healthy controls. Additionally, We have assessed quantitatively senescence-associated beta-galactosidase (SA-beta-gal) staining on bone marrow mononuclear cells from MDS and AML patients, HL60 and SHI-1 leukemia cell lines, and healthy control cells.

RESULTS

An upregulated expression of senescence-associated molecular marker p16INK4a was found in MDS compared with healthy controls, while a lower expression of p16INK4a was observed in AML compared with healthy controls. International Prognostic Scoring System score was negatively correlated with the percentage of p16INK4a-positive cells. The SA-beta-gal activity measured by mean percentage of positive cells was significantly higher in MDS cases when compared with controls. Meanwhile, percentage of SA-beta-gal-positive cells was also remarkably higher in dysplastic cells of MDS when compared to nondysplastic cells from MDS.

CONCLUSIONS

These results of our present study suggested an accelerated cellular senescence occurred in MDS, and the cellular senescence may be involved in the progression and prognosis of MDS.

[Quantitative analysis for JAK2 mutation in 98 patients with essential thrombocythemia and its clinical significance]

The objective of this study was to identify the frequency and types of JAK2V617F mutation in chinese patients with essential thrombocythemia (ET), to quantitatively detect the level of mutation transcripts and to investigate its clinical significance. The frequency and types of JAK2V617F mutation were detected by amplification-refractory mutation sequencing polymerase chain reaction (ARMS-PCR), the transcript level of JAK2V617F mutation was determined by using capillary electrophoresis. The results indicated that the JAK2V617F mutation was detected in 59 out of 98 patient with ET, 18 of whom were homozygous mutation. The mean age of patients with homozygous and heterozygous mutation was higher than that of patients with wild type mutation (p < 0.05). The quantitative assay using capillary electrophoresis showed that the transcript level of JAK2V617F mutation in patients with homozygous mutation was (89.9 +/- 6.7)%, which was higher than that in patients with heterozygous mutation (57.1 +/- 6.7)% (p < 0.05); the transcript level of JAK2V617F mutation in patients with age < 60 years was (62.3 +/- 16.5)%, which was lower than that in patients with age > 60 years (72.4% +/- 15.8)% (p < 0.05). The rate of thrombotic complications in patients with JAK2V617F-positive was higher than that in patients with JAK2V617F-negative in which the rate of thrombotic complication in patients with homozygous mutation was higher than that in patients with heterozygous mutation (p < 0.05). Compared with patients without thrombotic events, there were higher level of transcripts of JAK2V617F mutation in patients with thrombotic events. It is concluded that the JAK2V617F positive and negative patients with ET display the different clinical features, therefore, the analysis of mutation types and detection of transcript levels not only helps to identify the disease status and progression, but also guides the treatment of ET patients.

[The quantitative assay and clinical significance of JAK2V617F mutation in 131 patients with chronic myeloproliferative disorders]

OBJECTIVE

To investigate the frequency and mutational status of JAK2V617F mutation in Chinese patients with chronic myeloproliferative disorders (CMPD) and to study the relative quantification of mutated JAK2 mRNA and the clinical significance.

METHODS

JAK2V617F mutation and the mutational status were screened with amplification-refractory mutation system polymerase chain reaction (ARMS-PCR), the relative quantification of mutated JAK2 mRNA was studied by using capillary electrophoresis.

RESULTS

A higher prevalence of JAK2V617F in either the heterozygote or homozygote status in essential thrombocythemia (ET) was observed in elderly patients with ET (P < 0.05). The presence of JAK2V617F was found to be significantly correlated with the age at diagnosis (P < 0.05); patients with age > or = 60 years showed significantly higher JAK2 mutated RNA levels than those with age < 60 years (P < 0.05); the presence of JAK2V617F in polycythemia vera (PV) and ET was found to be significantly associated with higher hemoglobin level and higher leukocyte count (P < 0.05). In addition, higher leukocyte count was observed in homozygous ET patients than in heterozygous ET patients (P < 0.05). The frequency of JAK2V617F mutation and the prevalence of homozygote in PV patients were higher than those in ET patients (P < 0.05). The differences of JAK2V617F mRNA levels among PV, ET and chronic idiopathic myelofibrosis (IMF) were not significant.

CONCLUSIONS

ARMS-PCR technique can be used to detect the frequency and mutational status of JAK2V617F mutation owing to its sensitivity and along with capillary electrophoresis, quantitative assay for mutated JAK2 mRNA, diagnosis of CMPD and judgement of prognosis become possible.

[Detection of clonal immunoglobulin and T-cell receptor gene rearrangements in newly diagnosed adult patients with acute lymphoblastic leukemia by using multiplex PCR protocols]

OBJECTIVE

To provide the evidence of RQ-PCR-based assessment of minimal residual disease (MRD), the clonal immunoglobulin and T-cell receptor (Ig/TCR) gene rearrangements were identified in newly diagnosed adult patients with acute lymphoblastic leukemia (ALL) by multiplex PCR protocols.

METHODS

Forty newly diagnosed adult patients with B-lineage (B-) and T cell (T-) ALL were involved in this study. All DNA samples were obtained from the bone marrow (BM) mononuclear cells (MNC). IgH, IgK, TCRB, TCRG and TCRD gene rearrangements were detected by BIOMED-2 multiplex PCR protocols, which included 96 different primers and 14 multiplex PCR tubes.

RESULTS

The clonal immunoglobulin (Ig) rearrangements were found in 96% of B-ALL, 86% being IgH and 14% IgK. While in T-ALL, clonal TCR rearrangements were found in all of the patients, 83% being TCRB, 78% TCRG and 39% TCRD. More than two clonal markers were found in 91% of B-ALL and 89% of T-ALL patients.

CONCLUSIONS

The detection rate of clonal rearrangements using the BIOMED-2 14 multiplex PCR tubes is high, which can detect virtually all clonal B and T-cell proliferations. It can be used for diagnostic clonality studies as well as for the identification of PCR targets suitable for the detection of minimal residual disease.

A common pharmacophore for Taxol and the epothilones based on the biological activity of a taxane molecule lacking a C-13 side chain

Extensive structure-activity studies done with Taxol have identified the side chain at C-13 as one of the requirements for biological activity. Baccatin III, an analogue of Taxol lacking the C-13 side chain, has none of the biological characteristics of Taxol. Since 2-m-azido Taxol, a Taxol derivative with a m-azido substituent in the C-2 benzoyl ring, has greater activity than Taxol, we questioned whether 2-m-azido baccatin III might be active. 2-m-Azido baccatin III inhibited the proliferation of human cancer cells at nanomolar concentrations, blocked cells at mitosis, and reorganized the interphase microtubules into distinct bundles, a typical morphological change induced by Taxol. In contrast to 2-m-azido baccatin III, 2-p-azido baccatin III was similar to baccatin III, having no Taxol-like activity, further indicating the specificity and significance of the 2-meta position substituent. Molecular modeling studies done with the C-2 benzoyl ring of Taxol indicated that it fits into a pocket formed by His227 and Asp224 on beta-tubulin and that the 2-m-azido, in contrast to the 2-p-azido substituent, is capable of enhancing the interaction between the benzoyl group and the side chain of Asp224. The observation that the C-13 side chain is not an absolute requirement for biological activity in a taxane molecule has enabled the development of a new common pharmacophore model between Taxol and the epothilones.

Primary hemangiopericytoma of the tibia: MR and angiographic correlation

The Magnetic Resonance Imaging (MRI) appearances of primary osseous hemangiopericytoma (HPC) have been rarely described. We report on a 46-year-old Chinese man with primary osseous HPC of the right tibia. The characteristic vascular distribution of this tumor, presenting with a "spoke-wheel" appearance on MR images and with angiographic correlation, is described. Although not pathognomonic, this MR appearance may be an important finding in suggesting the diagnosis of osseous HPC.

Structure-activity profiles of eleutherobin analogs and their cross-resistance in Taxol-resistant cell lines

PURPOSE

Eleutherobin, a natural product, is an antimitotic agent that promotes the polymerization of stable microtubules. Although its mechanism of action is similar to that of Taxol, its structure is distinct. A structure-activity profile of synthetic eleutherobin derivatives that have modifications at C3, C8 and C15 was undertaken to define the structural requirements for microtubule stabilization and cross-resistance in Taxol-resistant cell lines.

METHODS

The biological activity of five eleutherobin analogs was assessed using three techniques: (1) cytotoxicity and drug-resistance in three paired Taxol-sensitive and -resistant cell lines; (2) polymerization of microtubule protein in vitro in the absence of GTP and (3) induction of microtubule bundle formation in NIH3T3 cells.

RESULTS

Eleutherobin had an IC50 value comparable to that of Taxol, whereas neoeleutherobin, which has a carbohydrate domain that is enantiomeric with that of the parent compound, was less cytotoxic and had 69% of the maximum microtubule polymerization ability of eleutherobin. Both of these compounds exhibited cross-resistance in MDRI-expressing cell lines. Removal or replacement of the C15 sugar moiety resulted in reduced microtubule polymerization and cytotoxicity compared to eleutherobin and loss of cross-resistance in the cell lines SKVLB and J7-T3-1.6, both of which express high levels of P-glycoprotein. By contrast, removal of the urocanic acid group at C8 resulted in virtually complete abrogation of biological activity. The compound lost its ability to polymerize microtubules, and its cytotoxicity was reduced by a minimum of 2000-fold in lung carcinoma A549 cells.

CONCLUSIONS

Removal or modification of the sugar moiety alters the cytotoxic potency of eleutherobin and its pattern of cross-resistance in Taxol-resistant cells, although such compounds retain a small percentage of the microtubule-stabilizing activity of eleutherobin. The N(1)-methylurocanic acid moiety of eleutherobin, or perhaps some other substituent at the C8 position, is essential for Taxol-like activity. These findings will be important for the future design and the synthesis of new and more potent eleutherobin derivatives.

The microtubule-destabilizing activity of metablastin (p19) is controlled by phosphorylation

Metablastin (also called p19, stathmin, prosolin, p18, Lap18, and oncoprotein 18) is a highly conserved, cytosolic 149-amino acid polypeptide that is expressed in immature vertebrate cells and undergoes extracellular factor- and cell cycle-regulated serine phosphorylation. The protein was shown recently to destabilize microtubules in vitro (Belmont, L., and Mitchison, T. J. (1996) Cell 84, 623-631). Here we demonstrate that microinjection of recombinant metablastin induces a loss of microtubules in COS-7 cells. This effect is enhanced by serine-to-alanine mutations at several phosphorylation sites and virtually abolished by aspartate substitution at a single site, Ser-63. We also show that stoichiometric amounts of metablastin prevent assembly and promote disassembly of microtubules in vitro. Interestingly, the phosphorylation site mutations of metablastin that have dramatic differential effects in intact cells do not alter the ability of metablastin to block tubulin assembly in vitro. The data suggest that phosphorylation of metablastin controls its microtubule-destabilizing activity in vivo but that this regulation may require additional cellular factors. This control mechanism is poised to play a critical role in the dynamic reorganization of the cellular microtubule network that occurs during morphogenesis and mitosis.

Analysis of MDR1 expression in normal and malignant endometrium by reverse transcription-polymerase chain reaction and immunohistochemistry

The purpose of this study was to quantitate the expression of human MDR1 mRNA levels in normal endometrium and in endometrial carcinoma and to determine the association of MDR1 levels with prognostic indicators. Endometrial samples from 43 postmenopausal patients with endometrial carcinoma and 38 patients (controls) with benign disease undergoing hysterectomy were snap-frozen. MDR1 levels were determined by quantitative reverse transcription-PCR (RT-PCR) and compared to sensitive and resistant cell lines. Immunohistochemistry was done with MM4.17, an anti-MDR1 antibody, on paraffin sections, and the results were compared to those obtained from RT-PCR. Data was analyzed using the Kruskal-Wallis and Bonferroni tests, setting the P value at 0.05. In both postmenopausal endometrial tissue and tumors, MDR1 expression was localized to the epithelial cell layer. Comparison of immunohistochemistry and RT-PCR results demonstrated a correlation of 80%. In control patients, MDR1 expression was significantly higher in postmenopausal endometrium (n = 15) than in the proliferative premenopausal endometrium (n = 15; P = 0.0024). MDR1 expression in all tumors was lower than that measured in the postmenopausal controls. Between each tumor group, there was no significant difference in the MDR1 levels observed. MDR1 expression was significantly lower in patients with high nuclear grade (n = 18) tumors when compared to patients with low nuclear grade (n = 14; P = 0.04) tumors. Comparison of MDR1 levels with multiple prognostic indicators for endometrial cancer was only significant for nuclear grade. The data indicate that MDR1 expression is not a major component of the drug resistance observed in primary endometrial tumors.

A homologue of the mammalian multidrug resistance gene (mdr) is functionally expressed in the intestine of Xenopus laevis

P-glycoprotein is an integral membrane protein that functions in multidrug resistance (MDR) cells as a drug efflux pump to maintain intracellular concentrations of antitumor drugs below cytotoxic levels. A homologue of the mammalian mdr gene has been isolated and characterized from Xenopus laevis (Xe-mdr). The cDNA was isolated from a tadpole cDNA library using the full length mouse mdrlb cDNA as a probe. The Xe-mdr encodes a protein that is 66% identical to the mouse mdrlb and 68% identical to the human mdrl. The predicted structure of the Xe-mdr gene product identifies twelve membrane spanning domains and two ATP binding sites both of which are the hallmark of the ABC (ATP binding cassette) transporters. Xe-mdr mRNA is expressed as a single message of 4.5 kb and is found predominantly in the intestine. Xe-mdr message is increased 3- to 4-fold in the ileum compared to the rest of the small intestine. In situ hybridization of sequential sections from the small intestine localized the expression of the Xe-mdr to the cells lining the lumenal epithelium. Brush border membrane vesicles prepared from the small intestine of Xenopus laevis effluxed vinblastine in an ATP-dependent manner. Efflux was decreased by verapamil, a known inhibitor of P-glycoprotein function. These studies indicate that the structure of Xe-mdr has been conserved and suggest that the protein has a role in maintaining the function of the normal intestine in Xenopus.

[Protective effects of cyproheptadine on myocardial reperfusion injury in isolated rat hearts]

The protective effects of cyproheptadine (Cyp), an antiserotonin-antihistaminic agent with calcium channel blocker activity, on myocardial reperfusion injury in isolated Langendorff heart of rats were studied. After a low perfusion [0.17 ml.min-1, standard Krebs-Henseleit (K-H) buffer without glucose, gassed with 95% O2 + 5% CO2] of 60 min followed by a normal K-H buffer perfusion of 20 min, an extensive and severe myocardial injury appeared: a release of lactate dehydrogenase (LDH) and creatine kinase (CK), a decrease of superoxide dismutase (SOD) and glutathion peroxidase (GSH-Px) activities, and an increase of malondialdehyde (MDA) content. Serious inhibition of cardiac functions and appearance of arrhythmia, even asystole, were also elicited in the injured hearts. Cyp (2.5 and 5 mumol.L-1) effectively antagonized the damage. The results suggested that the protective effects of Cyp on the ischemia-reperfusion injury may be related to its actions of blocking the calcium channel, scavenging the oxygen free radicals, protecting the antioxygen free radical enzymes, and inhibiting the lipid peroxidation in the myocardium.