Hematologic malignancy

BACKGROUND: Acute myeloid leukemia (AML) is one of the most common types of adult acute leukemia. Standard chemotherapies can induce complete remission in selected patients; however, a majority of patients eventually relapse and succumb to the disease. Thus, the development of novel therapeutics for AML is urgently needed. Human C-type lectin-like molecule-1 (CLL-1) is a type II transmembrane glycoprotein, and its expression is restricted to myeloid cells and the majority of AML blasts...

Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL) is a biologically, clinically, and genetically distinct subtype of precursor-B ALL. The Ph chromosome, results from a reciprocal translocation of the ABL1 kinase gene on chromosome 9 to the breakpoint cluster region (BCR) gene on chromosome 22. Depending on the translocation breakpoint, typically a p210 BCR-ABL1 or a p190 BCR-ABL onc protein are generated; both are constitutively active tyrosine kinases that play a central role to alter signaling pathways of cell proliferation, survival, and self-renewal, leading to leukemogenesis...

DISEASE OVERVIEW: Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B cells. DIAGNOSIS: The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen and B-cell markers...

For several decades, we have known that epigenetic regulation is disrupted in cancer. Recently, an increasing body of data suggests epigenetics might be an intersection of current cancer research trends: next generation sequencing, immunology, metabolomics, and cell aging. The new emphasis on epigenetics is also related to the increasing production of drugs capable of interfering with epigenetic mechanisms and able to trigger clinical responses in even advanced phase patients. In this review, we will use myeloid malignancies as proof of concept examples of how epigenetic mechanisms can trigger or promote oncogenesis...

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Myeloproliferative neoplasms (MPNs) are a group of related clonal hematologic disorders characterized by excess accumulation of one or more myeloid cell lineages and a tendency to transform to acute myeloid leukemia. Deregulated JAK2 signaling has emerged as the central phenotypic driver of BCR -ABL1-negative MPNs and a unifying therapeutic target. In addition, MPNs show unexpected layers of genetic complexity, with multiple abnormalities associated with disease progression, interactions between inherited factors and phenotype driver mutations, and effects related to the order in which mutations are acquired...

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer, and despite cure rates exceeding 90% in children, it remains an important cause of morbidity and mortality in children and adults. The past decade has been marked by extraordinary advances into the genetic basis of leukemogenesis and treatment responsiveness in ALL. Both B-cell and T-cell ALL comprise multiple subtypes harboring distinct constellations of somatic structural DNA rearrangements and sequence mutations that commonly perturb lymphoid development, cytokine receptors, kinase and Ras signaling, tumor suppression, and chromatin modification...

In this review, we examine the genomic landscapes of lymphomas that arise from B, T, and natural killer cells. Lymphomas represent a striking spectrum of clinical behaviors. Although some lymphomas are curable with standard therapy, the majority of the affected patients succumb to their disease. Here, the genetic underpinnings of these heterogeneous entities are reviewed. We consider B-cell lymphomas, including Burkitt lymphoma, diffuse large B-cell lymphoma, Hodgkin lymphoma, and primary mediastinal B-cell lymphoma...

Hairy cell leukemia (HCL) is a chronic mature B-cell neoplasm with unique clinicopathologic features and an initial exquisite sensitivity to chemotherapy with purine analogs; however, the disease relapses, often repeatedly. The enigmatic pathogenesis of HCL was recently clarified by the discovery of its underlying genetic cause, the BRAF-V600E kinase-activating mutation, which is somatically and clonally present in almost all patients through the entire disease spectrum and clinical course. By aberrantly activating the RAF-MEK-ERK signaling pathway, BRAF-V600E shapes key biologic features of HCL, including its specific expression signature, hairy morphology, and antiapoptotic behavior...

In recent years, our understanding of the molecular pathogenesis of myeloid neoplasms, including acute myeloid leukemia (AML), has been greatly advanced by genomics discovery studies that use novel high-throughput sequencing techniques. AML, similar to most other cancers, is characterized by multiple somatically acquired mutations that affect genes of different functional categories, a complex clonal architecture, and disease evolution over time. Patterns of mutations seem to follow specific and temporally ordered trajectories...

Chronic lymphocytic leukemia (CLL) is a common B-cell malignancy with a remarkably heterogeneous course, ranging from indolent disease with no need for immediate therapy to rapidly progressive disease associated with therapeutic resistance. The recent US Food and Drug Administration approvals of novel targeted therapies such as inhibitors of B-cell receptor signaling and B-cell lymphoma 2 have opened up new opportunities in the clinical management of patients with CLL and heralded a new era in the clinical treatment of this disease...

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