Amy Zhou

Mass cytometry analysis reveals hyperactive NF Kappa B signaling in myelofibrosis and secondary acute myeloid leukemia

Myeloproliferative neoplasms (MPNs) feature a malignant clone containing the JAK2 V617F mutation, or another mutation causing dysregulated JAK2 kinase activity. The multiple disease phenotypes of MPNs, and their tendency to transform phenotypically, suggest pathophysiologic heterogeneities beyond a common phenomenon of JAK2 hyperactivation. JAK2 has the potential to activate multiple other signaling molecules, either directly through downstream effectors, or indirectly through induction of target gene expression. We have interrogated myeloproliferative signaling in myelofibrosis (MF) and secondary acute myeloid leukemia (sAML) patient samples using mass cytometry, which allows the quantitative measurement of multiple signaling molecules simultaneously at the single-cell level, in cell populations representing a nearly complete spectrum of hematopoiesis. MF and sAML malignant cells demonstrated a high prevalence of hyperactivation of the JAK-STAT, MAP kinase, PI3 kinase and NFκB signaling pathways. Constitutive NFκB signaling was evident across MF and sAML patients. A supporting gene set enrichment analysis (GSEA) of MF showed many NFκB target genes to be expressed above normal levels in MF patient CD34+ cells. NFκB inhibition suppressed colony formation from MF CD34+ cells. This study indicates that NFκB signaling contributes to human myeloproliferative disease and is abnormally activated in MF and sAML.

Concomitant JAK2 V617F-positive polycythemia vera and BCR-ABL -positive chronic myelogenous leukemia treated with ruxolitinib and dasatinib

Concomitant JAK2 V617F-positive polycythemia vera and BCR-ABL -positive chronic myelogenous leukemia treated with ruxolitinib and dasatinib

Is the Incidence of Heparin-Induced Thrombocytopenia Affected by the Increased Use of Heparin for VTE Prophylaxis?

BACKGROUND The increased exposure to heparin products for thromboprophylaxis against VTE in hospitalized patients raises concerns for an increase in the incidence of heparin-induced thrombocytopenia(HIT). METHODS We analyzed, among 90,875 patients exposed to heparin products between 2005 and 2009, the number of hematologic consultations for thrombocytopenia, requests for heparin induced antibodies by enzyme-linked immunosorbent assay, and cases given a diagnosis of HIT by the hematology consult service. RESULTS We observed that despite a doubling in the number of patients receiving pharmacoprophylaxis with heparin, there was no significant increase in the number of consultations for thrombocytopenia,the number of requests for HIT tests, the number of positive HIT test results, or the number of HIT diagnoses. The number of cases of HIT was low and represented < 0.1% of patients exposed to heparin. CONCLUSIONS We conclude that concerns about HIT should not be a limiting factor for the systematic implementation of heparin-based VTE prophylaxis.

Cholesterol esterification inhibition and imatinib treatment synergistically inhibit growth of BCR-ABL mutation-independent resistant chronic myelogenous leukemia

Since the advent of tyrosine kinase inhibitors (TKIs) such as imatinib, nilotinib, and dasatinib, chronic myelogenous leukemia (CML) prognosis has improved greatly. However, ~30–40% of patients develop resistance to imatinib therapy. Although most resistance is caused by mutations in the BCR-ABL kinase domain, 50–85% of these patients develop resistance in the absence of new mutations. In these cases, targeting other pathways may be needed to regain clinical response. Using label-free Raman spectromicroscopy, we evaluated a number of leukemia cell lines and discovered an aberrant accumulation of cholesteryl ester (CE) in CML, which was found to be a result of BCR-ABL kinase activity. CE accumulation in CML was found to be a cancer-specific phenomenon as untransformed cells did not accumulate CE. Blocking cholesterol esterification with avasimibe, a potent inhibitor of acyl-CoA cholesterol acyltransferase 1 (ACAT-1), significantly suppressed CML cell proliferation in Ba/F3 cells with the BCR-ABLT315I mutation and in K562 cells rendered imatinib resistant without mutations in the BCR-ABL kinase domain (K562R cells). Furthermore, the combination of avasimibe and imatinib caused a profound synergistic inhibition of cell proliferation in K562R cells, but not in Ba/F3T315I. This synergistic effect was confirmed in a K562R xenograft mouse model. Analysis of primary cells from a BCR-ABL mutation-independent imatinib resistant patient by mass cytometry suggested that the synergy may be due to downregulation of the MAPK pathway by avasimibe, which sensitized the CML cells to imatinib treatment. Collectively, these data demonstrate a novel strategy for overcoming BCR-ABL mutation-independent TKI resistance in CML.

Prognostication in MF: From CBC to cytogenetics to molecular markers

Myelofibrosis (MF) is a clonal stem cell disorder characterized by ineffective erythropoiesis and extramedullary hematopoiesis leading to progressive bone marrow failure, severe anemia, constitutional symptoms, hepatosplenomegaly, and thrombosis. MF can arise following a history of polycythemia vera (PV) or essential thrombocythemia (ET), or can present de novo as primary myelofibrosis (PMF). The disease course is variable with median survival ranging from months to years. Clinical and biological features such as advanced age, leukocytosis, anemia, transfusion dependence, and elevated inflammatory markers can impact prognosis in patients with PMF. Cytogenetic abnormalities and molecular markers such as JAK2 V617F, ASXL1, and CALR mutations have also been identified as prognostic variables. Several different scoring systems have been developed based on these prognostic factors. In this review, we will discuss the clinical, biological, molecular, and cytogenetic prognostic factors that have been identified in PMF, and the current prognostic models that have been developed to guide treatment decisions.

Splanchnic vein thrombosis in myeloproliferative neoplasms: Pathophysiology and molecular mechanisms of disease

Myeloproliferative neoplasms (MPNs) are the most common underlying prothrombotic disorder found in patients with splanchnic vein thrombosis (SVT). Clinical risk factors for MPN-associated SVTs include younger age, female sex, concomitant hypercoagulable disorders, and the JAK2 V617F mutation. These risk factors are distinct from those associated with arterial or deep venous thrombosis (DVT) in MPN patients, suggesting disparate disease mechanisms. The pathophysiology of SVT is thought to derive from local interactions between activated blood cells and the unique splanchnic endothelial environment. Other mutations commonly found in MPNs, including CALR and MPL, are rare in MPN-associated SVT. The purpose of this article is to review the clinical and molecular risk factors for MPN-associated SVT, with particular focus on the possible mechanisms of SVT formation in MPN patients.

Clinical Improvement with JAK2 Inhibition in Chuvash Polycythemia

Rare mutations in the VHL gene may lead to polycythemia in children. Ruxolitinib resulted in clinical improvement in three people with this disorder.

Systemic Therapy for Combined Hepatocellular-Cholangiocarcinoma: A Single-Institution Experience

Background: Combined hepatocellular-cholangiocarcinoma tumors (cHCC-CCA) are a heterogeneous group of rare malignancies that have no established optimal treatment. Patients and Methods: We identified patients with cHCC-CCA treated at a tertiary center and retrospectively examined their histology, interventions, and outcomes. We calculated disease control rate (DCR), disease progression, overall survival, and progression-free survival (PFS) between treatment subgroups. Results: A total of 123 patients were evaluable. Interventions included resection, locoregional therapy, transplant, chemotherapy, and targeted agents. Ultimately, 68 patients received systemic treatment-57 with gemcitabine plus either 5-fluoropyrimidine (5-FU) or a platinum combination. Disease progression was more common in the gemcitabine/5-FU group versus gemcitabine/platinum (P=.028), whereas DCR favored gemcitabine/platinum (78.4% vs 38.5%; P=.0143). Median PFS from time of initial diagnosis favored the gemcitabine/platinum group, but the difference did not reach statistical significance. Targeted agents had minimal to no effect on survival metrics. Conclusions: Gemcitabine/platinum seems to be a superior regimen for patients with cHCC-CCA who require systemic treatment. Further studies are needed to clarify the regimens efficacy and applicability in patient subgroups.

An Analysis of the Inclusion of Medications Considered Potentially Inappropriate in Older Adults in Chemotherapy Templates for Hematologic Malignancies: One Recommendation for All?

BackgroundThere remains a paucity of data regarding the use of potentially inappropriate medications (PIMs) in the supportive management of older adults undergoing chemotherapy. Raising awareness among healthcare providers regarding the frequency of their use and potential toxicities may help to minimize the risks to patients.ObjectiveThe aim of this study was to evaluate the frequency of six specific classes of medications considered PIMs by the American Geriatrics Society Beers Criteria that are commonly included in the National Comprehensive Cancer Network (NCCN) chemotherapy order templates for hematologic malignancies. The six PIMs evaluated are first-generation antihistamines, benzodiazepines, corticosteroids, H2-receptor antagonists, metoclopramide, and antipsychotics.MethodsA total of 311 unique chemotherapy order templates published online by the NCCN for the treatment of hematologic malignancies were reviewed to determine the frequency that these six specific PIMs were recommended for supportive care.ResultsApproximately 45% of the NCCN chemotherapy templates for hematologic malignancies specifically recommended the use of at least one of the six PIMs examined. The remainder of the templates evaluated referred exclusively to the NCCN Guidelines® on Oncology for Antiemesis, which also included the use of at least one of the six PIMs evaluated.ConclusionsThese findings demonstrate that PIMs are frequently used as supportive therapy in the treatment of hematologic malignancies. Increasing healthcare provider awareness of their potential side effects may minimize the risks associated with their use in older adults with hematologic malignancies undergoing chemotherapy.

Prognostication in Philadelphia Chromosome Negative Myeloproliferative Neoplasms: a Review of the Recent Literature

Purpose of ReviewThe prognosis for patients with Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPNs) is highly variable. All Ph-negative MPNs carry an increased risk for thrombotic complications, bleeding, and leukemic transformation. Several clinical, biological, and molecular prognostic factors have been identified in recent years, which provide important information in guiding management of patients with Ph-negative MPNs. In this review, we critically evaluate the recent published literature and discuss important new developments in clinical and molecular factors that impact survival, disease transformation, and thrombosis in patients with polycythemia vera, essential thrombocythemia, and primary myelofibrosis.Recent FindingsRecent studies have identified several clinical factors and non-driver mutations to have prognostic impact on Ph-negative MPNs independent of conventional risk stratification and prognostic models. In polycythemia vera (PV), leukocytosis, abnormal karyotype, phlebotomy requirement on hydroxyurea, increased bone marrow fibrosis, and mutations in ASXL1, SRSF2, and IDH2 were identified as additional adverse prognostic factors. In essential thrombocythemia (ET), JAK2 V617F mutation, splenomegaly, and mutations in SH2B3, SF3B1, U2AF1, TP53, IDH2, and EZH2 were found to be additional negative prognostic factors. Bone marrow fibrosis and mutations in ASXL1, SRSF2, EZH2, and IDH1/2 have been found to be additional prognostic factors in primary myelofibrosis (PMF). CALR mutations appear to be a favorable prognostic factor in PMF, which has not been clearly demonstrated in ET.SummaryThe prognosis for patients with PV, ET, and PMF is dependent upon the presence or absence of several clinical, biological, and molecular risk factors. The significance of additional risk factors identified in these recent studies will need further validation in prospective studies to determine how they may be best utilized in the management of these disorders.