1,196 research outputs found

    Targeting autophagy: a novel anticancer strategy with therapeutic implications for imatinib resistance

    Get PDF
    Autophagy is an ancient, intracellular degradative system which plays important roles in regulating protein homeostasis and which is essential for survival when cells are faced with metabolic stress. Increasing evidence suggests that autophagy also functions as a tumor suppressor mechanism that harnesses the growth and/or survival of cells as they transition towards a rapidly dividing malignant state. However, the impact of autophagy on cancer progression and on the efficacy of cancer therapeutics is controversial. In particular, although the induction of autophagy has been reported after treatment with a number of therapeutic agents, including imatinib, this response has variously been suggested to either impair or contribute to the effects of anticancer agents. More recent studies support the notion that autophagy compromises the efficacy of anticancer agents, where agents such as chloroquine (CQ) that impair autophagy augment the anticancer activity of histone deacetylase (HDAC) inhibitors and alkylating agents. Inhibition of autophagy is a particularly attractive strategy for the treatment of imatinib-refractory chronic myelogenous leukemia (CML) since a combination of CQ with the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) compromises the survival of even BCR-ABL-T315I+ imatinib-resistant CML. Additional studies are clearly needed to establish the clinical utility of autophagy inhibitors and to identify patients most likely to benefit from this novel therapeutic approach

    Evolving Therapeutic Strategies for the Classic Philadelphia-Negative Myeloproliferative Neoplasms

    Get PDF
    AbstractDespite the emergence of JAK inhibitors, there is a need for disease-modifying treatments for Philadelphia-negative myeloproliferative neoplasms (MPNs). JAK inhibitors ameliorate symptoms and address splenomegaly, but because of the heterogeneous contributors to the disease process, JAK inhibitor monotherapy incompletely addresses the burden of disease. The ever-growing understanding of MPN pathogenesis has provided the rationale for testing novel and targeted therapeutic agents, as monotherapies or in combination, in preclinical and clinical settings. A number of intriguing options have emerged, and it is hoped that further progress will lead to significant changes in the natural history of MPNs

    Mutations in DNA repair genes are associated with increased neo-antigen load and activated T cell infiltration in lung adenocarcinoma.

    Get PDF
    Mutations in DNA repair genes lead to increased genomic instability and mutation frequency. These mutations represent potential biomarkers for cancer immunotherapy efficacy, as high tumor mutational burden has been associated with increased neo-antigens and tumor infiltrating lymphocytes. While mismatch repair mutations have successfully predicted response to anti-PD-1 therapy in colorectal and other cancers, they have not yet been tested for lung cancer, and few have investigated genes from other DNA repair pathways. We utilized TCGA samples to comprehensively immunophenotype lung tumors and analyze the links between DNA repair mutations, neo-antigen and total mutational burden, and tumor immune infiltration. Overall, 73% of lung tumors contained infiltration by at least one T cell subset, with high mutational burden tumors containing significantly increased infiltration by activated CD4 and CD8 T cells. Further, mutations in mismatch repair genes, homologous recombination genes, or POLE accurately predicted increased tumor mutational burden, neo-antigen load, and T cell infiltration. Finally, neo-antigen load correlated with expression of M1-polarized macrophage genes, PD-1, PD-L1, IFNγ, GZMB, and FASLG, among other immune-related genes. Overall, after defining the immune infiltrate in lung tumors, we demonstrate the potential value of utilizing gene mutations from multiple DNA repair pathways as biomarkers for lung cancer immunotherapy. Oncotarget 2018; 9(8):7949-796

    Mutations in DNA repair genes are associated with increased neoantigen burden and a distinct immunophenotype in lung squamous cell carcinoma.

    Get PDF
    Deficiencies in DNA repair pathways, including mismatch repair (MMR), have been linked to higher tumor mutation burden and improved response to immune checkpoint inhibitors. However, the significance of MMR mutations in lung cancer has not been well characterized, and the relevance of other processes, including homologous recombination (HR) and polymerase epsilon (POLE) activity, remains unclear. Here, we analyzed a dataset of lung squamous cell carcinoma samples from The Cancer Genome Atlas. Variants in DNA repair genes were associated with increased tumor mutation and neoantigen burden, which in turn were linked with greater tumor infiltration by activated T cells. The subset of tumors with DNA repair gene variants but without T cell infiltration exhibited upregulation of TGF-β and Wnt pathway genes, and a combined score incorporating these genes and DNA repair status accurately predicted immune cell infiltration. Finally, high neoantigen burden was positively associated with genes related to cytolytic activity and immune checkpoints. These findings provide evidence that DNA repair pathway defects and immunomodulatory genes together lead to specific immunophenotypes in lung squamous cell carcinoma and could potentially serve as biomarkers for immunotherapy

    ELR510444 Inhibits Tumor Growth and Angiogenesis by Abrogating HIF Activity and Disrupting Microtubules in Renal Cell Carcinoma

    Get PDF
    Background: Hypoxia-inducible factor (HIF) is an attractive therapeutic target for renal cell carcinoma (RCC) as its high expression due to the loss of von Hippel-Lindau (VHL) promotes RCC progression. Considering this, we hypothesized that ELR510444, a novel orally available small molecule inhibitor of HIF activity, would reduce angiogenesis and possess significant activity in RCC. The mechanism of action and therapeutic efficacy of ELR510444 were investigated in in vitro and in vivo models of RCC. Principal Findings: ELR510444 decreased HIF-1a and HIF-2a levels, reduced RCC cell viability and clonogenic survival, and induced apoptosis. VHL-deficient RCC cells were more sensitive to ELR510444-mediated apoptosis and restoration of VHL promoted drug resistance. Higher concentrations of ELR51044 promoted apoptosis independently of VHL status, possibly due to the microtubule destabilizing properties of this agent. ELR510444 significantly reduced tumor burden in the 786-O and A498 RCC xenograft models. These effects were associated with increased necrosis and apoptosis and inhibition of angiogenesis. Conclusions: ELR510444 is a promising new HIF inhibitor that reduced RCC cell viability, induced apoptosis, and diminished tumor burden in RCC xenograft models. ELR510444 also destabilized microtubules suggesting that it possesses vascula
    corecore