Direct activation of STAT5 by ETV6-LYN fusion protein promotes induction of myeloproliferative neoplasm with myelofibrosis

Myeloproliferative neoplasms (MPN), a group of haematopoietic stem cell (HSC) disorders, are often accompanied by myelofibrosis. We previously identified the fusion of the ETV6 gene to the LYN gene (ETV6-LYN) in idiopathic myelofibrosis with ins(12;8)(p13;q11q21). The introduction of ETV6-LYN into HSCs resulted in fatal MPN with massive myelofibrosis in mice, implicating the rearranged LYN kinase in the pathogenesis of MPN with myelofibrosis. However, the signalling molecules directly downstream from and activated by ETV6-LYN remain unknown. In this study, we demonstrated that the direct activation of STAT5 by ETV6-LYN is crucial for the development of MPN. ETV6-LYN was constitutively active as a kinase through autophosphorylation. ETV6-LYN, but not its kinase-dead mutant, supported cytokine-free proliferation of haematopoietic cells. STAT5 was activated in a JAK2-independent manner in ETV6-LYN-expressing cells. ETV6-LYN interacted with STAT5 and directly activated STAT5 both in vitro and in vivo. Of note, ETV6-LYN did not support the formation of colonies by Stat5-deficient HSCs under cytokine-free conditions and the capacity of ETV6-LYN to induce MPN with myelofibrosis was profoundly attenuated in a Stat5-null background. These findings define STAT5 as a direct target of ETV6-LYN and unveil the LYN-STAT5 axis as a novel pathway to augment proliferative signals in MPN and leukaemia.     

Secretory Carcinoma of the Oral Cavity: A Retrospective Case Series with Review of Literature

Secretory carcinoma (SC) is an uncommon salivary gland neoplasm of the oral cavity that microscopically may mimic acinic cell carcinoma (ACC) and mucoepidermoid carcinoma (MEC). This study describes a series of SC in minor glands with a literature review. We performed a retrospective search for oral SC, within the archives of the University of Florida, Oral Pathology and Surgical Pathology Biopsy services from 2010 to 2018. A total of 10 SCs were identified in the oral and maxillofacial region, four of which were in the minor salivary glands. The demographic, clinical, histological, and molecular findings were aggregated for all 4 cases. Patient age varied from 30 to 60 years, with an average of 45 years. Two cases each were in female and male patients. Two cases presented on the labial mucosa, and one each on the hard and soft palate. Immunohistochemical (IHC) staining showed mammaglobin positivity in all cases, GATA3 positivity in two cases, S100 positivity in three cases, and SOX10 positivity in only one case. Fluorescence in situ hybridization demonstrated positivity for ETV6-NTRK3 fusion in 4 cases. Although oral SC is rare, pathologists should be aware of the histologic overlap between the SC and other salivary gland neoplasms such as ACC and MEC. A judicious application of IHC staining would aid in diagnosis. SC should be considered in the differential diagnosis for intraoral salivary gland tumors.     

恩替卡韦治疗慢性重症乙型肝炎的临床疗效观察

目的：观察恩替卡韦（ETV）对慢性重症乙型肝炎临床疗效的影响,并比较慢性重症乙型肝炎早、中、晚期的疗效。方法：将我院2009年1月至2010年6月期间收治的251例慢性重症乙型肝炎早、中、晚期患者按同期随机分为治疗组和对照组。对照组采用综合内科治疗,治疗组在此基础上加用恩替卡韦。定期观察肝功能、凝血酶原时间（PT）、HBV DNA载量及患者的治愈、好转率。结果：治疗组在血清生化学、HBV DNA载量、临床综合疗效方面效果明显优于对照组,能显著提高总有效率,特别是早期给药更显著降低HBV DNA载量、降低病死率,差异均具有统计学意义（P﹤0.05）。结论：恩替卡韦能有效提高重型肝炎治疗有效率,降低病死率,其疗效与抑制病毒复制有关,临床上应早期使用疗效更佳。     

恩替卡韦联合阿德福韦酯治疗拉米夫定耐药慢性乙型肝炎患者的疗效观察

目的观察恩替卡韦联合阿德福韦酯治疗拉米夫定耐药慢性乙型肝炎(CHB)患者的疗效和安全性。方法选取昆山市人民医院2011年5月至2013年5月门诊和住院的拉米夫定耐药患者45例,随机分成两组,治疗组23例应用恩替卡韦联合阿德福韦酯挽救治疗,对照组22例应用拉米夫定联合阿德福韦酯挽救治疗,观察两组治疗前及治疗后4、12、24、48周HBV DNA、ALT、AST、TBil、Alb、HBV血清学标志物含量变化以及治疗48周时非rtM204I位点变异发生率。计量资料组间比较用t检验,计数资料的组间比较用四格表χ2检验。结果治疗组挽救治疗后4、12周ALT、AST下降较对照组相比差异有统计学意义(t值为3.124、5.271、4.476、5.125,P值均0.01),挽救治疗24、48周后较对照组相比差异有统计学意义(t值为2.240、2.307、2.886、2.908,P值均0.05)。治疗4、12、24、48周后,治疗组HBV DNA转阴率分别为73.9%、86.8%、95.7%、100%,较对照组差异有统计学意义(χ2值为11.79、5.75、10.29、5.89,P值均0.05)。HBeAg阳性患者阴转率在治疗组及对照组间差异无统计学意义。治疗组48周后未出现新的非rtM204I位点变异,而对照组非rtM204I位点变异情况为4例,两组相比差异有统计学意义(χ2=4.59,P0.05)。结论恩替卡韦联合阿德福韦酯用于既往拉米夫定耐药的CHB患者的挽救治疗疗效明显,值得临床推广。     

恩替卡韦联合阿德福韦酯治疗耐拉米夫定慢性乙型肝炎患者48周的疗效分析

目的：观察恩替卡韦（ETV）联合阿德福韦酯（ADV）治疗耐拉米夫定（LAM）慢性乙型肝炎的疗效。方法选取 LAM 耐药患者66例,随机分成两组,治疗组36例应用 ETV 联合 ADV 挽救治疗,对照组30例应用 LAM 联合 ADV 挽救治疗,观察两组治疗前及治疗后12周、48周谷丙转氨酶（ALT）、谷草转氨酶（AST）、总胆红素（TBIL）、乙型肝炎病毒 DNA（HBV-DNA）、乙型肝炎 e 抗原（HBeAg）含量变化以及治疗48周时非 rtM204I 位点变异发生率。结果治疗组挽救治疗后12周 ALT 和 AST 分别降至（36．5±13．23）U／L 和（50．2±11．66）U／L,显著低于同期对照组 ALT[（60．3±12．28）U／L,P ＜0．01]及 AST [（69．7±13．56）U／L,P ＜0．01]含量;治疗后48周治疗组 ALT 和 AST 降至（27．9±10．58）U／L 和（26．7±10．95）U／L,低于同期对照组 ALT[（50．4±11．53）U／L,P ＜0．01]及 AST[（44．9±15．33）,P ＜0．05]含量。治疗12周及48周,治疗组 HBV-DNA 转阴率分别为85．5％及91．7％,显著高于同期对照组转阴率（53．3％和73．3％,P 均＜0．05）。治疗组48周后出现1例新的非 rtM204I 位点变异,而对照组非 rtM204I位点变异情况为6例,两组相比差异有统计学意义（χ2＝5．12,P ＝0．024）。结论ETV 联合 ADV 用于既往 LAM 耐药的慢性乙型肝炎患者的挽救治疗疗效明显,值得临床推广。     

Whole-Exome Sequencing of ETV6/RUNX1 in Four Childhood Acute Lymphoblastic Leukaemia Cases

Background: ETV6/RUNX1 gene fusion is the most frequently seen chromosomal abnormality in childhood acute lymphobastic leukamia (ALL). However, additional genetic changes are known to be required for the development of this type of leukaemia. Therefore, we here aimed to assess the somatic mutational profile of four ALL cases carrying the ETV6/RUNX1 fusion gene using whole-exome sequencing. Methods: DNA was isolated from bone marrow samples using a QIAmp DNA Blood Mini kit and subsequently sequenced using the Illumina MiSeq system. Results: We identified 12,960 to17,601 mutations in each sample, with a total of 16,466 somatic mutations in total. Some 15,533 variants were single nucleotide polymorphisms (SNPs), 129 were substitutions, 415 were insertions and 389 were deletions. When taking into account the coding region and protein impact, 1,875 variants were synonymous and 1,956 were non-synonymous SNPs. Among non-synonymous SNPs, 1,862 were missense, 13 nonsense, 35 frameshifts, 11 nonstop, 3 misstart, 15 splices disrupt and 17 in-frame indels. A total of 86 variants were located in leukaemia-related genes of which 32 variants were located in the coding regions of GLI2, SP140, GATA2, SMAD5, KMT2C, CDH17, CDX2, FLT3, PML and MOV10L1. Conclusions: Detection and identification of secondary genetic alterations are important in identifying new therapeutic targets and developing rationally designed treatment regimens with less toxicity in ALL patients.     

MiR-17-92 and miR-221/222 cluster members target KIT and ETV1 in human gastrointestinal stromal tumours

Background:

Gastrointestinal stromal tumours (GIST) are characterised by high expression of KIT and ETV1, which cooperate in GIST oncogenesis. Our aim was to identify microRNAs that are deregulated in GIST, have a role in GIST pathogenesis, and could potentially be used as therapeutic tool.

Methods:

Differentially expressed microRNAs between primary GIST (n=50) and gastrointestinal leiomyosarcomas (GI-LMS, n=10) were determined using microarrays. Selected microRNA mimics were transfected into GIST-882 and GIST-T1 cell lines to study the effects of microRNA overexpression on GIST cells. Luciferase reporter assays were used to establish regulation of target genes by selected microRNAs.

Results:

MiR-17-92 and miR-221/222 cluster members were significantly (P<0.01) lower expressed in GIST vs GI-LMS and normal gastrointestinal control tissues. MiR-17/20a/222 overexpression in GIST cell lines severely inhibited cell proliferation, affected cell cycle progression, induced apoptosis and strongly downregulated protein and – to a lesser extent – mRNA levels of their predicted target genes KIT and ETV1. Luciferase reporter assays confirmed direct regulation of KIT and ETV1 by miR-222 and miR-17/20a, respectively.

Conclusion:

MicroRNAs that may have an essential role in GIST pathogenesis were identified, in particular miR-17/20a/222 that target KIT and ETV1. Delivering these microRNAs therapeutically could hold great potential for GIST management, especially in imatinib-resistant disease.     

Efficacy and tolerance of a combination of tenofovir disoproxil fumarate plus emtricitabine in patients with chronic hepatitis B: A European multicenter study

Background and aims

The combination of tenofovir disoproxil fumarate (TDF) plus emtricitabine (FTC) is used extensively to treat HIV infection and also has potent activity against hepatitis B virus (HBV) infection. The aim of this study was to assess the efficacy and tolerance of TDF + FTC in patients with chronic hepatitis B (CHB).

Methods

Seventy eight consecutive CHB patients from five European centers were included. All started a TDF + FTC combination between October 2005 and March 2010. Virological, biochemical, and clinical data were recorded during follow-up. Tolerance was also monitored. Patients were classified into either treatment simplification (TS), where efficacy of the previous treatment was obtained at TDF + FTC initiation, and treatment intensification (TI), where the previous line of therapy had failed.

Results

TDF + FTC was given as a TI to 54 patients (69%) and as a TS to 24 (31%). Among patients with TI, 83% were males. The median baseline HBV-DNA was 4.4 log₁₀ IU/mL, and median alanine-transaminase (ALT) was 1.10 × ULN. Sixty percent were HBeAg positive, 47% had significant fibrosis (?F3 Metavir equivalent), and 29% had confirmed cirrhosis. Median treatment duration was 76 weeks (interquartile range 60–116). Kaplan–Meier analysis showed that, 48 weeks after TI, the probability of being HBV-DNA becoming undetectable was 76%, and reached 94% at week 96. No viral breakthrough occurred. Patients with TS (87% males, median baseline HBV-DNA 1.1 log₁₀ IU/mL, median ALT 0.79 × ULN, 33% HBeAg positive, 61% with significant fibrosis) were treated for a median duration of 76 weeks. In this subgroup, all patients but one remained HBV-DNA undetectable and no ALT flare-up occurred during follow-up. Creatinine levels did not show kidney-function deterioration in either group of patients.

Conclusions

After a median follow-up of >76 weeks, the TDF + FTC combination showed encouraging antiviral efficacy and a good safety profile in all patients with CHB. TDF + FTC may represent an interesting clinical option to simplify therapy and increase the barrier to resistance, which should be assessed in the long term.