Identification of a novel HOOK3-FGFR1 fusion gene involved in activation of the NF-kappaB pathway.

BACKGROUND: Rearrangements involving the fibroblast growth factor receptor 1 (FGFR1) gene result in 8p11 myeloproliferative syndrome (EMS), which is a rare and aggressive hematological malignancy that is often initially diagnosed as myelodysplastic syndrome (MDS). Clinical outcomes are typically poor due to relative resistance to tyrosine kinase inhibitors (TKIs) and rapid transformation to acute leukemia. Deciphering the transcriptomic signature of FGFR1 fusions may open new treatment strategies for FGFR1 rearrangement patients. METHODS: DNA sequencing (DNA-seq) was performed for 20 MDS patients and whole exome sequencing (WES) was performed for one HOOK3-FGFR1 fusion positive patient. RNA sequencing (RNA-seq) was performed for 20 MDS patients and 8 healthy donors. Fusion genes were detected using the STAR-Fusion tool. Fluorescence in situ hybridization (FISH), quantitative real-time PCR (qRT-PCR), and Sanger sequencing were used to confirm the HOOK3-FGFR1 fusion gene. The phosphorylation antibody array was performed to validate the activation of nuclear factor-kappaB (NF-kappaB) signaling. RESULTS: We identified frequently recurrent mutations of ASXL1 and U2AF1 in the MDS cohort, which is consistent with previous reports. We also identified a novel in-frame HOOK3-FGFR1 fusion gene in one MDS case with abnormal monoclonal B-cell lymphocytosis and ring chromosome 8. FISH analysis detected the FGFR1 break-apart signal in myeloid blasts only. qRT-PCR and Sanger sequencing confirmed the HOOK3-FGFR1 fusion transcript with breakpoints located at the 11th exon of HOOK3 and 10th exon of FGFR1, and Western blot detected the chimeric HOOK3-FGFR1 fusion protein that is presumed to retain the entire tyrosine kinase domain of FGFR1. The transcriptional feature of HOOK3-FGFR1 fusion was characterized by the significant enrichment of the NF-kappaB pathway by comparing the expression profiling of FGFR1 fusion positive MDS with 8 healthy donors and FGFR1 fusion negative MDS patients. Further validation by phosphorylation antibody array also showed NF-kappaB activation, as evidenced by increased phosphorylation of p65 (Ser 536) and of IKBalpha (Ser 32). CONCLUSIONS: The HOOK3-FGFR1 fusion gene may contribute to the pathogenesis of MDS and activate the NF-kappaB pathway. These findings highlight a potential novel approach for combination therapy for FGFR1 rearrangement patients.

A rare case of atypical chronic myeloid leukemia associated with t(8;22)(p11.2;q11.2)/ BCR-FGFR1 rearrangement: A case report and literature review.

Myeloid/lymphoid neoplasm with t(8;22)(p11.2;q11.2)/BCR-FGFR1 is an extremely rare diagnosis, with few reported cases to date. In contrast to other FGFR1-partner rearrangements that are associated with chronic eosinophilic leukemia, acute myeloid leukemia, and/or lymphoblastic lymphoma, patients with BCR-FGFR1 have a myeloproliferative disorder that closely resembles chronic myeloid leukemia (CML). The current report describes a rare case of a 61 year old man with an atypical CML phenotype associated with t(8;22)(p11.2;q11.2)/BCR-FGFR1. A literature review is presented to enhance the awareness of this rare diagnostic entity.

Myeloid/lymphoid neoplasm with CEP110-FGFR1 fusion: An analysis of 16 cases show common features and poor prognosis.

Objectives: The 8p11 myeloproliferative syndrome (EMS) is an extremely rare, generally aggressive haematologic malignancies. This study provided the clinical outcomes and therapeutic strategies for EMS patients confirmed with CEP110-FGFR1 fusion. Methods: We report here a case of translocation (8;9) (p12;q33)/CEP110-FGFR1 who received allo-HSCT and achieved molecular remission. We searched the PubMed database for relevant medical literatures published between 1992 and 2018. We generalized the laboratory results, clinical features, therapeutic outcomes for EMS with confirmed CEP110-FGFR1 fusion. Results: We identified 16 EMS cases with CEP110-FGFR1 fusions including our patient. The observed common syndrome features were characterized as follows: a male predominance, fatigue (35.7%), tonsil hypertrophy (41.7%), lymphadenopathy (53.8%), hepatosplenomegaly (54.5%). leukocytosis (greater than 20.0 × 109/L, 71.4%), coexisting of eosinophilia and monocytosis (93.3%), and frequent progression to acute leukaemia. High incidence of tonsil hypertrophy and monocytosis may be a feature of EMS with CEP110/FGFR1 fusions. The CR rate for EMS was 23.1%. One patient treated with highly selective FGFR kinase inhibitor, INCB054828, achieved complete molecular remission rapidly. Allo-HSCT was performed in 8 patients. The median survival time for those patients was 9.0 (95%CI 5.599-12.601) months, with a range between 5 and 27 months. Allogeneic HSCT could improve survival in selected patients. Conclusion: FGFR1 and RUNX1 may be potential therapeutic targets for clinical trials. More accumulation of cases is also needed to determine whether allo-HSCT could be an optimal approach.

Precursor T-Lymphoblastic Lymphoma Associated with t(8;9)(p11.2;q33): A Case Report and Review of the Literature.

The 8p11 myeloproliferative syndrome (EMS) is an aggressive neoplasm associated with chromosomal translocations involving the fibroblast growth factor receptor 1 (FGFR1) tyrosine kinase gene on chromosome 8p11-12. A new case of a 9-year-old boy with leukocytosis, eosinophilia, and general lymphadenopathy is reported in this study. Bone marrow examination showed eosinophilic hyperplasia, with blast cells amounting to 6-7%. Karyotyping revealed cytogenetic abnormalities, including t(8;9)(p11.2;q3?3). Fluorescence in situ hybridization for the FGFR1 gene rearrangement yielded positive results. Lymph node biopsy confirmed the diagnosis of precursor T-lymphoblastic lymphoma. The patient responded to chemotherapy, and unmatched related bone marrow transplantation was performed. A successful outcome was obtained with complete cytogenetic remission maintained for 14 months to date. In the future, FGFR1 inhibitors might be specific and effective therapeutic targets for EMS. Similar cases from the literature are reviewed.

[Inhibitory Eefects of the novel tyrosine kinase inhibitor BGJ398 against human leukemic cell line KG-1 cells].

Objective: To explore the effects and possible mechanisms of the novel pan-FGFR inhibitor BGJ398 on KG-1 cells in vitro. Methods: Effects of BGJ398 on cells proliferation were detected by CCK-8, the apoptosis was assessed by Annexin V-FITC. Reverse transcriptionquantitative polymerase chain reaction (q-PCR) analysis was used to detect the expression of apoptosis-related genes B cell lymphoma-2 (Bcl-2) and caspase-3. Western blotting analysis was performed to explore the proteins expression levels of Bcl-2, caspase-3 and the expression of p-AKT, p-S6K, p-ERK and FGFR1. Results: BGJ398 effectively inhibited cell proliferation by dose-dependent manners. BGJ398(1.4 µmol/L) induced apoptosis of KG-1 cells by 36.4%, compared with 4.5% in the control group(P<0.001). Treatment with BGJ398 at 1.4 µmol/L led to significant increases in the expression levels of caspase-3, and decreases in the expression of Bcl-2 (P<0.005). In accordance with these results, Western blot analysis further confirmed the increased expression of Bcl-2 protein along with elevated caspase-3 activity. In addition, BGJ398 markedly down-regulated FGFR1OP2-FGFR1 fusion protein, p-AKT and p-S6K expression, but not p-ERK expression. Conclusion: Novel pan-FGFR inhibitor BGJ398 substantially suppressed KG-1 cell growth and induced apoptosis by inhibiting the expression of FGFR1, p-AKT, p-S6K and regulating apoptosis-related proteins.

Clinical outcomes of myeloid/lymphoid neoplasms with fibroblast growth factor receptor-1 (FGFR1) rearrangement.

OBJECTIVE: Myeloid/lymphoid neoplasms with fibroblast growth factor receptor-1 (FGFR1) rearrangement are hematopoietic stem cell disorders with a poor prognosis, but no established standard therapy. METHODS: We experienced a patient with T-lymphoblastic lymphoma (LBL) associated with FGFR1 rearrangement who underwent cord blood transplantation, but died of pulmonary complication. We collected the clinical data of patients with FGFR1 rearrangement from the medical literature and analyzed 45 patients, including our patient. RESULTS: The primary diagnoses were myeloproliferative neoplasm (MPN) or myelodysplastic syndromes (MDS) in 14 and acute leukemia or LBL in 31. In MPN and MDS patients, the cumulative incidence of transformation to blast phase (BP) at 12 months was 46.2%. The 1-year overall survival (OS) from diagnosis in all cases was 43.1%. With regard to the impact of treatment response on survival, the achievement of complete response with a landmark at 2 months after diagnosis of BP was associated with a superior OS (40.0% vs. 26.0% P = 0.011 for 1-year OS from BP). Allogeneic hematopoietic stem cell transplantation (HSCT) was performed in 13 patients, and the 1-year OS from allogeneic HSCT was 61.5%. The hazard ratio for mortality was 0.34 (95% CI, 0.08-1.51, P = 0.15) for allogeneic HSCT treated as a time-dependent covariate, which suggests that allogeneic HSCT may confer a clinical benefit. CONCLUSION: The further accumulation of clinical data is needed to determine the optimal therapeutic approach for these neoplasms.

Inhibitory Eefects of the novel tyrosine kinase inhibitor BGJ398 against human leukemic cell line KG-1 cells / 中华血液学杂志

Objective@#To explore the effects and possible mechanisms of the novel pan-FGFR inhibitor BGJ398 on KG-1 cells in vitro.@*Methods@#Effects of BGJ398 on cells proliferation were detected by CCK-8, the apoptosis was assessed by Annexin V-FITC. Reverse transcriptionquantitative polymerase chain reaction (q-PCR) analysis was used to detect the expression of apoptosis-related genes B cell lymphoma-2 (Bcl-2) and caspase-3. Western blotting analysis was performed to explore the proteins expression levels of Bcl-2, caspase-3 and the expression of p-AKT, p-S6K, p-ERK and FGFR1.@*Results@#BGJ398 effectively inhibited cell proliferation by dose-dependent manners. BGJ398(1.4 µmol/L) induced apoptosis of KG-1 cells by 36.4%, compared with 4.5% in the control group(P<0.001). Treatment with BGJ398 at 1.4 µmol/L led to significant increases in the expression levels of caspase-3, and decreases in the expression of Bcl-2 (P<0.005). In accordance with these results, Western blot analysis further confirmed the increased expression of Bcl-2 protein along with elevated caspase-3 activity. In addition, BGJ398 markedly down-regulated FGFR1OP2-FGFR1 fusion protein, p-AKT and p-S6K expression, but not p-ERK expression.@*Conclusion@#Novel pan-FGFR inhibitor BGJ398 substantially suppressed KG-1 cell growth and induced apoptosis by inhibiting the expression of FGFR1, p-AKT, p-S6K and regulating apoptosis-related proteins.

Inhibitory Eefects of the novel tyrosine kinase inhibitor BGJ398 against human leukemic cell line KG-1 cells / 中华血液学杂志

Objective: To explore the effects and possible mechanisms of the novel pan-FGFR inhibitor BGJ398 on KG-1 cells in vitro. Methods: Effects of BGJ398 on cells proliferation were detected by CCK-8, the apoptosis was assessed by Annexin V-FITC. Reverse transcriptionquantitative polymerase chain reaction (q-PCR) analysis was used to detect the expression of apoptosis-related genes B cell lymphoma-2 (Bcl-2) and caspase-3. Western blotting analysis was performed to explore the proteins expression levels of Bcl-2, caspase-3 and the expression of p-AKT, p-S6K, p-ERK and FGFR1. Results: BGJ398 effectively inhibited cell proliferation by dose-dependent manners. BGJ398(1.4 µmol/L) induced apoptosis of KG-1 cells by 36.4%, compared with 4.5% in the control group(P<0.001). Treatment with BGJ398 at 1.4 µmol/L led to significant increases in the expression levels of caspase-3, and decreases in the expression of Bcl-2 (P<0.005). In accordance with these results, Western blot analysis further confirmed the increased expression of Bcl-2 protein along with elevated caspase-3 activity. In addition, BGJ398 markedly down-regulated FGFR1OP2-FGFR1 fusion protein, p-AKT and p-S6K expression, but not p-ERK expression. Conclusion: Novel pan-FGFR inhibitor BGJ398 substantially suppressed KG-1 cell growth and induced apoptosis by inhibiting the expression of FGFR1, p-AKT, p-S6K and regulating apoptosis-related proteins.

Primary cells in BCR/FGFR1-positive 8p11 myeloproliferative syndrome are sensitive to dovitinib, ponatinib, and dasatinib.

OBJECTIVES: Translocations involving the fibroblast growth factor receptor 1 (FGFR1) gene are associated with the 8p11 myeloproliferative syndrome (EMS), a rare neoplasm that following a usually short chronic phase progresses into acute myeloid or lymphoid leukemia. The treatment commonly involves chemotherapy and, if possible, allogeneic stem cell transplantation which is the only therapeutic option for long-term survival. Given the aggressive course of EMS, we here evaluated tyrosine kinase inhibitors as treatment options to delay disease progression. METHODS: We described a new case of EMS and used chromosome analyses, PCR, and sequencing to investigate the underlying genetic aberrations. The sensitivity to several tyrosine kinase inhibitors was tested in vitro on the EMS cell line KG1 and on primary cells from the newly diagnosed EMS patient. RESULTS: A translocation involving chromosomes 8 and 22 was detected, and a BCR/FGFR1 fusion gene was confirmed and characterized by sequencing. KG1 cells and primary EMS cells displayed distinct sensitivity to dovitinib, ponatinib, and dasatinib as compared to normal bone marrow control cells. CONCLUSIONS: These results suggest that treatment with tyrosine kinase inhibitors may be beneficial for patients with EMS during the search for a suitable stem cell donor and for those not eligible for transplantation.

Diagnostic application of next-generation sequencing in ZMYM2-FGFR1 8p11 myeloproliferative syndrome: A case report.

The 8p11 myeloproliferative syndrome (EMS), also known as 8p11 myeloproliferative neoplasm (8p11 MPN), is a collection of rare hematologic malignancies that are associated with fusion genes involving the tyrosine kinase receptor gene FGFR1 in chromosome 8p11. The entity is an aggressive disease with a high rate of transformation to acute myeloid leukemia (AML) and pathologically characterized by its associated eosinophilia. In this study, we reported a distinctive EMS case featuring an in-frame ZMYM2-FGFR1 fusion gene identified by next-generation sequencing technology (NGS). This patient exhibited not only typical EMS signs including elevated white blood cells in peripheral blood and hypercellular bone marrow with marked leukocytosis, but also exceptional characteristics including erythrocytosis in blood and bone marrow basophilia. Moreover, we detected 2 novel genomic mutations in 2 known leukemogenic genes, IKZF1 and ASXL1. Whether these 2 mutations play a part in EMS pathogenesis or contribute to its specific presentations clinically remain to be determined. In summary, we present a unique EMS case involving a ZMYM2-FGFR1 fusion with distinctive hematologic characteristics.

Fine-needle aspiration cytology of T-lymphoblastic lymphoma associated FGFR1 rearrangement myeloproliferative neoplasm.

FNA of T-lymphoblastic lymphoma associated FGFR1 rearranged MPN.

STRIPAK complexes: structure, biological function, and involvement in human diseases.

The mammalian striatin family consists of three proteins, striatin, S/G2 nuclear autoantigen, and zinedin. Striatin family members have no intrinsic catalytic activity, but rather function as scaffolding proteins. Remarkably, they organize multiple diverse, large signaling complexes that participate in a variety of cellular processes. Moreover, they appear to be regulatory/targeting subunits for the major eukaryotic serine/threonine protein phosphatase 2A. In addition, striatin family members associate with germinal center kinase III kinases as well as other novel components, earning these assemblies the name striatin-interacting phosphatase and kinase (STRIPAK) complexes. Recently, there has been a great increase in functional and mechanistic studies aimed at identifying and understanding the roles of STRIPAK and STRIPAK-like complexes in cellular processes of multiple organisms. These studies have identified novel STRIPAK and STRIPAK-like complexes and have explored their roles in specific signaling pathways. Together, the results of these studies have sparked increased interest in striatin family complexes because they have revealed roles in signaling, cell cycle control, apoptosis, vesicular trafficking, Golgi assembly, cell polarity, cell migration, neural and vascular development, and cardiac function. Moreover, STRIPAK complexes have been connected to clinical conditions, including cardiac disease, diabetes, autism, and cerebral cavernous malformation. In this review, we discuss the expression, localization, and protein domain structure of striatin family members. Then we consider the diverse complexes these proteins and their homologs form in various organisms, emphasizing what is known regarding function and regulation. Finally, we explore possible roles of striatin family complexes in disease, especially cerebral cavernous malformation.

Research progress of the 8p11 myeloproliferative syndrome / 白血病·淋巴瘤

The 8p11 myeloproliferative syndrome is a rare hematologic malignancy that involves the fibroblast growth factor receptor 1 (FGFR1) gene at chromosome 8p11.The clonal change of the FGFR1 rearrangement is present in BM cells,and in the T-lymphoma cells in the LN.The hematological stem cells transplantation is the only method that can cure this rare hematologic neoplasma.

The 8p11 myeloproliferative syndrome: review of literature and an illustrative case report.

The 8p11 myeloproliferative syndrome (EMS), also called stem cell leukemia/lymphoma (SCLL), is a relatively rare condition characterized in its typical form by the occurrence, either simultaneously or sequentially, of a bcr/abl-negative myeloproliferative disorder and a lymphoma, usually a precursor T lymphoblastic lymphoma. The disease most often terminates in acute myeloid leukemia which is resistant to conventional chemotherapy. The defining cytogenetic abnormality, a translocation at the 8p11 locus, always involves the fibroblast growth factor 1 (FGFR1) gene. To date, eight partner genes have been identified in association with FGFR1 rearrangements. The most frequent FGFR1 translocation partner is the zinc finger gene ZNF198 located at 13q11. The t(8;13)(p11;q11) disrupts intron 8 of the FGFR1 gene and fuses proline-rich and zinc finger domains of the ZNF198 gene with the cytoplasmic tyrosine kinase domain of FGFR1. Oligomerization of the fusion protein occurs, with subsequent activation of downstream signal transduction pathways, culminating in neoplastic cell transformation. This review describes the historical development of the EMS/SCLL and outlines its cytogenetic abnormalities and molecular mechanisms with an illustrative case.