A case of myelofibrosis with a t(4;13)(q25;q12): evidence for involvement of a second 13q12 locus in chronic myeloproliferative disorders

Aberrations of 13q are frequently found in myeloproliferative disorders (MPD). In a case of primary proliferative polycythaemia which transformed to myelofibrosis, karyotype analysis at transformation revealed an acquired t(4;13)(q25;q12). FISH and Southern analysis demonstrated that the ZNF198 gene, disrupted in the t(8;13)(p11;q12) myeloproliferative syndrome, was unaffected by the t(4;13). FISH analysis mapped the 13q12 breakpoint to the genomic region flanked by the genetic markers D13S1126 and D13S1121. Physical mapping estimated this region to be <80 kbp. Our results suggest the possibility of a novel gene, distinct from ZNF198, that is located at chromosome 13q12 and involved in the pathogenesis of myelofibrosis.     

A novel type of +2‐base pair frameshift CALR mutation in a patient with myeloproliferative neoplasm

Somatic CALR mutations have been identified in the majority of JAK2 mutation‐negative essential thrombocythaemia (ET) and primary myelofibrosis. Almost all CALR mutations have been reported to typically generate a +1‐base pair (bp) frameshift in the open reading frame. Here, we describe an ET patient with a +2‐bp frameshift CALR mutation. A 41‐year‐old man was admitted because of headache, and diagnosed as JAK2‐negative ET. After 4 years, his disease progressed to post‐ET myelofibrosis, and CALR mutation analysis demonstrated a +2‐bp frameshift CALR mutation caused by two different CALR mutations, c.1139_1151del and c.1211_1215delinsTTGA, on the same allele. The resultant mutant protein sequence shared 19 amino acids with those from type 1 and type 2 CALR mutations, but the downstream C‐terminal sequences were different. To our knowledge, CALR double mutations causing +2‐bp frameshift are extremely rare. Identification of this novel type of CALR mutation has potential implications for better understanding of CALR oncogenesis.     

Detection of a new heterozygous germline ETV6 mutation in a case with hyperdiploid acute lymphoblastic leukemia

ETV6 is a target of recurrent aberrations in sporadic and familial acute lymphoblastic leukemia (ALL). Here, we report on a new pedigree with a germline ETV6 mutation in which the index patient and his father developed high hyperdiploid (HeH) ALL and polycythemia vera at age 13 and 51, respectively. The index patient achieved durable complete remission without transplantation but had persistent moderate thrombocytopenia without bleeding tendency. To determine the prevalence of ETV6 alterations in HeH‐ALL, we screened 81 unrelated subjects with HeH‐ALL by single nucleotide polymorphism array and high‐throughput sequencing for the ETV6 gene. Overall, ETV6 microdeletions and mutations were identified in 9% of cases, all of which were somatic and considered as secondary events. Apart from the index patient, no germline ETV6 aberration was identified. Finally, we reviewed the literature for ETV6 germline aberrations and predispositions to ALL.     

Genome-wide analysis of cytogenetic aberrations in ETV6/RUNX1-positive childhood acute lymphoblastic leukaemia

The chromosomal translocation t(12;21) resulting in the ETV6/RUNX1 fusion gene is the most frequent structural cytogenetic abnormality among patients with childhood acute lymphoblastic leukaemia (ALL). We investigated 62 ETV6/RUNX1-positive childhood ALL patients by single nucleotide polymorphism array to explore acquired copy number alterations (CNAs) at diagnosis. The mean number of CNAs was 2·82 (range 0-14). Concordance with available G-band karyotyping and comparative genomic hybridization was 93%. Based on three major protein-protein complexes disrupted by these CNAs, patients could be categorized into four distinct subgroups, defined by different underlying biological mechanisms relevant to the aetiology of childhood ALL. When recurrent CNAs were evaluated by an oncogenetic tree analysis classifying their sequential order, the most common genetic aberrations (deletions of 6q, 9p, 13q and X, and gains of 10 and 21) seemed independent of each other. Finally, we identified the most common regions with recurrent gains and losses, which comprise microRNA clusters with known oncogenic or tumour-suppressive roles. The present study sheds further light on the genetic diversity of ETV6/RUNX1-positive childhood ALL, which may be important for understanding poor responses among this otherwise highly curable subset of ALL and lead to novel targeted treatment strategies.     

Acquisition of genomic events leading to lymphoblastic transformation in a rare case of myeloproliferative neoplasm with BCR–JAK2 fusion transcript

We report a case of myeloproliferative neoplasm (MPN) with an atypical t(9;22;15)(p24;q11;q21) translocation, leading to a BCR–JAK2 fusion, associated with a trisomy of chromosome 8 in clonal evolution at karyotype. Patient's evolution was marked by an aggressive clinical course with rapid progression to blast phase within the first year after diagnosis. Examination of matched chronic phase and blast crisis samples by SNP‐array karyotyping identified secondary acquired cryptic genetic events at the time of lymphoblastic transformation, including biallelic IKZF1 alteration and EBF1 and CDKN2A/B codeletions. This case is the first report describing acquisition of secondary genetic events leading to acute lymphoblastic progression in a rare MPN with BCR–JAK2 fusion.     

Blastic plasmacytoid dendritic cell neoplasm: the first report of two cases treated by 5‐Azacytidine

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy which was first included as an independent cutaneous lymphoma in the 2008 World Health Organisation (WHO) classification (1). BPDCN usually has an extremely poor prognosis, with quick relapses after chemotherapy (2; 3). Here, we report two cases of patients diagnosed in 2011 with BPDCN and myelodysplasia, and who were treated for the first time with 5‐azacytidine (5‐Aza); a drug approved by the Food and Drug Administration (FDA) and mainly used in the treatment of myelodysplastic syndrome (Kaminskas E, et al. 2005 Clin Cancer Res, 11, 3604–8). The first case was an 81‐year‐old man who presented with unusual CD10+, CD56‐ immunohistochemistry and 45X, ‐Y abnormality using fluorescent in situ hybridization (FISH) analysis. The second case was a 78‐year‐old woman who manifested monosomy 13 and chromosome instability due to D13S319 locus deletion in 13q14 as determined by FISH. Both patients showed excellent responses of their skin lesions after one cycle of chemotherapy, and their hematological disease was stabilized; however, pulmonary sepsis set in, followed by neutropenia after the fourth and the fifth cycle of treatment, that is, eight and 9 months postdiagnosis, respectively, leading to patient death.     

High incidence of the ETV6/RUNX1 fusion gene in paediatric precursor B-cell acute lymphoblastic leukaemias with trisomy 21 as the sole cytogenetic change: a Nordic series of cases diagnosed 1989-2005

Trisomy 21 is common in ETV6/RUNX1-positive acute lymphoblastic leukaemia (ALL); both these aberrations are associated with a favourable outcome. The prognostic impact of +21 as a sole cytogenetic change could be due to a cryptic t(12;21)(p13;q22). The occurrence of ETV6/RUNX1 was determined in 66 childhood ALLs with an acquired +21 and a chromosome number <51. ETV6/RUNX1 was found in 45% of cases and in the majority (10/18; 56%) of ALLs with sole +21. Event-free survival did not differ between the t(12;21)-positive and -negative cases. Thus, the prognostic impact of +21 is not attributable to cryptic ETV6/RUNX1.     

Clinical and genetic studies of ETV6/ABL1-positive chronic myeloid leukaemia in blast crisis treated with imatinib mesylate

Most chronic myeloid leukaemia (CML) patients are genetically characterized by the t(9;22)(q34;q11), generating the BCR/ABL1 fusion gene. However, a few CML patients with rearrangements of 9q34 and 12p13, leading to ETV6/ABL1 chimaeras, have also been reported. Here we describe the clinical and genetic response to imatinib mesylate treatment of an ETV6/ABL1-positive CML patient diagnosed in blast crisis (BC). A chronic phase was achieved after acute myeloid leukaemia induction therapy. Then, treatment with imatinib mesylate (600 mg/d) was initiated and the effect was assessed clinically as well as genetically, including by repeated interphase fluorescence in situ hybridization studies. Until d 71 of imatinib mesylate therapy, stable improvements in the clinical and laboratory features were noted, and the frequency of ABL1-rearranged peripheral blood cells decreased from 56% to 11%. At d 92, an additional t(12;13)(p12;q13), with the 12p breakpoint proximal to ETV6, was found. The patient relapsed into BC 126 d after the start of the imatinib mesylate treatment and succumbed to the disease shortly afterwards. No mutations in the tyrosine kinase domain of ABL1 of the ETV6/ABL1 fusion were identified in the second BC. However, whereas the ETV6/ABL1 expression was seemingly the same at diagnosis and at second BC, the expression of ETV6 was markedly lower at the second BC. This decreased expression of wild-type ETV6 may have been a contributory factor for the relapse.     

信号转导及转录激活蛋白3与白细胞介素-6表达与胃癌病理分期及预后的关系

目的 探讨信号转导及转录激活蛋白3(STAT3)、白细胞介素(IL)-6的表达与胃癌病理分期及预后的关系.方法 应用酶联免疫吸附试验(ELISA)测定55例胃癌患者血清中IL-6的表达;应用免疫组化方法测定55例胃癌组织及癌旁组织中STAT3、磷酸化信号转导及转录激活蛋白3(p-STAT3)和IL-6的表达.结果 胃癌患者术前及术后血清IL-6的表达均明显高于对照组;胃癌组织中STAT3、p-STAT3和IL-6的表达均明显高于正常癌旁组织;p-STAT3在低分化胃癌组织的表达明显高于高-中分化胃癌组;胃癌组织中p-STAT3和IL-6的表达均与淋巴结的转移状态有关;胃癌组织中p-STAT3活化程度与IL-6的表达呈正相关(r=0.251,P=0.01).结论 IL-6/STAT3信号通路的激活可能参与了胃癌的发生、发展、浸润以及转移的全过程,联合检测血清IL-6、活检组织的IL-6及p-STAT3水平对胃癌的辅助诊断、恶性程度及浸润转移潜能的预测具有临床意义.     

丙型肝炎NS5ATP6基因原核表达载体的构建和表达纯化及多克隆抗体的制备

目的构建丙型肝炎病毒NS5A蛋白反式激活蛋白6基因的原核表达载体并进行表达、鉴定。方法从已构建的pGBKT7-NS5ATP6质粒上切取NS5ATP6基因,再克隆入pET32a( )质粒,构建pET32a( )-NS5ATP6表达重组体。结果以pET32a( )-NS5ATP6重组体分别转化DH5α和Rosseta大肠埃希菌后,经IPTG诱导,pET32a( )-NS5ATP6表达出分子量为41KD左右的重组蛋白。免疫动物并经Westernblot检测证实其具有良好的抗原性。结论成功地构建了原核表达载体pET32a( )-NS5ATP6,诱导表达和纯化了NS5ATP6融合蛋白,并制备了该蛋白的多克隆抗体,为下一步该基因功能研究奠定了基础。     

Circular RNA circVAPA promotes chemotherapy drug resistance in gastric cancer progression by regulating miR-125b-5p/STAT3 axis

BACKGROUND Gastric cancer(GC)is a prevalent malignancy,leading to a high incidence of cancer-associated death.Cisplatin(DDP)-based chemotherapy is the principal therapy for clinical GC treatment,but DDP resistance is a severe clinical challenge and the mechanism remains poorly understood.Circular RNAs(circRNAs)have been identified to play crucial roles in modulating the chemoresistance of gastric cancer cells.AIM To explore the effect of circVAPA on chemotherapy resistance during GC progression.METHODS The effect of circVAPA on GC progression and chemotherapy resistance was analyzed by MTT assay,colony formation assay,Transwell assay,wound healing assay,and flow cytometry analysis in GC cells and DDP resistant GC cell lines,and tumorigenicity analysis in nude mice in vivo.The mechanism was investigated by luciferase reporter assay,quantitative real-time PCR,and Western blot analysis.RESULTS CircVAPA expression was up-regulated in clinical GC tissues compared with normal samples.CircVAPA depletion inhibited proliferation,migration,and invasion and increased apoptosis of GC cells.The expression of circVAPA,STAT3,and STAT3 downstream genes was elevated in DDP resistant SGC7901/DDP cell lines.CircVAPA knockdown attenuated the DDP resistance of GC cells.Mechanically,circVAPA was able to sponge miR-125b-5p,and miR-125b-5p could target STAT3 in the GC cells.MiR-125b-5p inhibitor reversed circVAPA depletion-enhanced inhibitory effect of DDP on GC cells,and STAT3 knockdown blocked circVAPA overexpression-induced proliferation of DDPtreated SGC7901/DDP cells.The depletion of STAT3 and miR-125b-5p inhibitor reversed circVAPA depletion-induced GC cell apoptosis.Functionally,circVAPA contributed to the tumor growth of SGC7901/DDP cells in vivo.CONCLUSION CircVAPA promotes chemotherapy resistance and malignant progression in GC by miR-125b-5p/STAT3 signaling.Our findings present novel insights into the mechanism by which circVAPA regulates chemotherapy resistance of GC cells.CircVAPA and miR-125b-5p may be considered as the potential targets for GC therapy.