High-risk B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive disease, often characterized by resistance to chemotherapy. A frequent feature of high-risk B-ALL is loss of function of the ...IKAROS (encoded by the IKZF1 gene) tumor suppressor. Here, we report that IKAROS regulates expression of the BCL2L1 gene (encodes the BCL-XL protein) in human B-ALL. Gain-of-function and loss-of-function experiments demonstrate that IKAROS binds to the BCL2L1 promoter, recruits histone deacetylase HDAC1, and represses BCL2L1 expression via chromatin remodeling. In leukemia, IKAROS' function is impaired by oncogenic casein kinase II (CK2), which is overexpressed in B-ALL. Phosphorylation by CK2 reduces IKAROS binding and recruitment of HDAC1 to the BCL2L1 promoter. This results in a loss of IKAROS-mediated repression of BCL2L1 and increased expression of BCL-XL. Increased expression of BCL-XL and/or CK2, as well as reduced IKAROS expression, are associated with resistance to doxorubicin treatment. Molecular and pharmacological inhibition of CK2 with a specific inhibitor CX-4945, increases binding of IKAROS to the BCL2L1 promoter and enhances IKAROS-mediated repression of BCL2L1 in B-ALL. Treatment with CX-4945 increases sensitivity to doxorubicin in B-ALL, and reverses resistance to doxorubicin in multidrug-resistant B-ALL. Combination treatment with CX-4945 and doxorubicin show synergistic therapeutic effects in vitro and in preclinical models of high-risk B-ALL. Results reveal a novel signaling network that regulates chemoresistance in leukemia. These data lay the groundwork for clinical testing of a rationally designed, targeted therapy that combines the CK2 inhibitor, CX-4945, with doxorubicin for the treatment of hematopoietic malignancies.
•CK2 and IKAROS regulate chemoresistance to doxorubicin via repression of BCL2L1 (BCL-XL).•Combination treatment with CK2 inhibitor and doxorubicin have a synergistic therapeutic effect on high-risk B-ALL in vivo.
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Acute leukemias are a heterogeneous group of aggressive malignant neoplasms associated with severe morbidities due to the nonselectivity of current chemotherapeutic drugs to nonmalignant cells. The ...investigation of novel natural and synthetic structures that might be used for the development of new drugs with greater efficiency and selectivity to leukemic cells is mandatory. In this context, thiosemicarbazones have been well described in the literature by their several biological properties and their reaction is known as versatile, low-cost, and highly chemoselective. With this perspective, this study aimed to investigate the cytotoxic effect and the main death mechanisms of a novel thiosemicarbazone (LAP17) on acute leukemia cell lines K562 and Jurkat. The results show that the strong cytotoxic effect of LAP17 to leukemic cells is due to apoptosis induction, which resulted in caspase-3 activation and DNA fragmentation. Intrinsic apoptosis seems to be related to the inversion of Bax/Bcl-2 expression, ΔΨm loss, and AIF release, whereas extrinsic apoptosis was initiated by FasR. Gene-expression profiling of HL-60 cells treated with LAP17 by the microarray technique revealed a significant enrichment of gene sets related to cell cycle arrest at G2/M. Accordingly, K562 and Jurkat cells treated with LAP17 revealed a clear arrest at G2/M phase. Taking into consideration that LAP17 was not cytotoxic to nonhematological cells (peripheral blood mononuclear cell and erythrocytes), these results suggest that LAP17 is a promising new compound that might be used as a prototype for the development of new antileukemic agents.
Anacardium occidentale leaves are used in folk medicine due its therapeutic properties attributed to phenolic compounds. Therefore, this study was undertaken on its hydroethanolic leaf extract (AoHE) ...to evaluate cytotoxicity and apoptosis induction on acute lymphoblastic leukaemia cells. Results indicated that AoHE interfered in the cell cycle progression, inducing apoptosis by activation of casp3 at lower concentrations, thence, a promising candidate for the development of new cancer drugs.
Approximately 5-10% of breast cancers are hereditary. Among hereditary syndromes, Hereditary Breast and Ovarian Cancer Syndrome (HBOC) and Li-Fraumeni Syndrome (LFS) have received the most attention. ...HBOC is due to mutations in the BRCA1 and BRCA2 genes and is characterized by breast adenocarcinoma and/or epithelial ovarian carcinoma. LFS is associated with germline mutations in TP53; the most frequent cancer types associated with this syndrome are sarcoma, breast cancer, leukemia, brain tumors and adrenocortical carcinomas. Other cancers related to LFS are found at lower frequencies. In Brazil, especially in the southern part of the country, a specific mutation in the TP53 gene, TP53 p.R337H, occurs at a high frequency in childhood adrenocortical tumors. It has been proposed that this mutation increases breast cancer risk in southern Brazilian women.
We carried out a case-control study to determine the prevalence of the TP53 p.R337H mutation in 28 female cancer patients attended at the Cancer Genetic Counseling Service of the General Hospital of the University of São Paulo Medical School of Ribeirão Preto who fulfilled Hereditary Breast and Ovary Cancer Syndrome genetic test criteria compared to healthy woman (controls). TP53 p.R337H mutation status was determined using the High Resolution Melting (HRM) method, followed by DNA sequencing. Fisher's test was used to compare the prevalence of TP53 p.R337H in the patient and control groups.
Two of the breast cancer cases (7.1%) and none of the controls carried the TP53 p.R337H mutation. At the time of the investigation, both cases fulfilled testing criteria for Hereditary Breast and Ovary Cancer Syndrome but not Li-Fraumeni or Li-Fraumeni-like Syndrome, based on genetic testing criteria of NCCN Clinical Practice Guidelines in Oncology (v.1.2010).
We suggest that genetic screening of Brazilian breast cancer patients who fulfill Hereditary Breast and Ovary Cancer Syndrome criteria and have a family history that includes other tumors of the LFS/LFL spectrum be tested for the TP53 p.R337H mutation.
Abstract
Objective: IKZF1 gene-coding protein, Ikaros functions as a leukemia suppressor. Casein Kinase II activity is overexpressed in acute lymphoblastic leukemia (ALL) and CK2-mediated-dysfunction ...of Ikaros is one of the key reason for high-risk ALL and CK2 inhibitor -CX4945 treatment shows high therapeutic efficacy on high-risk ALL. The anti-apoptotic factors are highly expressed in leukemia and the commonly-used 1st-line chemotherapy drugs exerts the anti-tumor effect by suppression of anti-apoptosis signaling. Ikaros binding peaks was identified in the promoter of anti-apoptotic genes by ChIP-seq, suggesting Ikaros regulation on their expression. These observations also suggest the synergistic effect of restoring Ikaros function with common chemotherapy durgs in ALL.
Methods: The ChIP-seq and qChIP assays were performed to determine the enrichment of Ikaros and H3K4me3 in promotor of the genes. Lentiviral Ikaros or IKZF1 shRNA were used for functional analysis. WST-1 cell proliferation assay, Annexin-V staining plus flow cytometry and Patients-derived xenograft mouse (PDX) model were used for observing the anti-tumor effect in vitro and in vivo, respectively.
Results: ChIP-seq and qChIP assays identified Ikaros binding peaks in the promoter of anti-apoptotic genes in cell-lines and patients’ samples. Ikaros overexpression suppresses but IKZF1 knockdown promotes the gene expression. CX-4945 suppresses the expression of the genes by decreasing the H3k27me3 enrichment in an Ikaros and HDAC1-dependent manner in B-ALL cells. The anti-apoptotic gene is significantly up-regulated in ALL patients. CX-4945+chemoterhapy drugs significantly induces the cell proliferation arrest and apoptosis compared to single drugs in vitro and also show the synergistic effect analyzed by CalcuSyn software. CX-4945+chemotherapy drugs significantly reduced the total leukemia cells and % leukemic cells in the three high-risk B-ALL Patient Derived Xenograft (PDX) mice model compared to that of single drugs, which indicated that their synergistic therapeutic efficacy on leukemia development.
Conclusion: Ikaros suppressed anti-apoptotic gene expression through histone modification in ALL. CK2 inhibitor, CX-4945 by restoring Ikaros function have synergistic efficacy with common chemotherapy drugs on high-risk B-ALL.
Citation Format: chunhua song, Zheng Ge, Chandrika Gowda, Yali Ding, Jonathon Payne, Bihua Tan, Nathalia M. Cury, Elanora Dovat, Zhijun Zhao, Xiaoguang Lyu, Mary McGrath, Dhimant Desai, Soumya lyer, Pavan K. DhanyamRaju, Kimberly J. Payne, Sinisa Dovat. Synergistic efficacy of CK2 inhibitor with common chemotherapy drugs by restoring Ikaros function in high-risk ALL abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 286.
3-(Thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboximidamides were efficiently prepared through a cyclocondensation of thiophenylchalcones with aminoguanidine hydrochloride under ultrasonic conditions ...in the presence of KOH and ethanol as a green solvent in short reaction times (15-35 min) and good yields (62-95%). All compounds produced were evaluated against the human Jurkat and RS4;11 acute lymphoblastic leukemia cell lines of T- and B-cell origin, respectively, and the K562 myelogenous leukemia cell line. Six compounds presented half maximal inhibitory concentration (IC50) values around 15 µmol L-1 and five compounds presented IC50 values around 40 µmol L-1 for at least one of the three cell lines analyzed. One compound was not significantly cytotoxic, presenting IC50 value > 100 µmol L-1.
Crotalphine is a structural analogue to a novel analgesic peptide that was first identified in the crude venom from the South American rattlesnake Crotalus durissus terrificus. Although crotalphine's ...analgesic effect is well established, its direct mechanism of action remains unresolved. The aim of the present study was to investigate the effect of crotalphine on ion channels in peripheral pain pathways. We found that picomolar concentrations of crotalphine selectively activate heterologously expressed and native TRPA1 ion channels. TRPA1 activation by crotalphine required intact N-terminal cysteine residues and was followed by strong and long-lasting desensitization of the channel. Homologous desensitization of recombinant TRPA1 and heterologous desensitization in cultured dorsal root ganglia neurons was observed. Likewise, crotalphine acted on peptidergic TRPA1-expressing nerve endings ex vivo as demonstrated by suppression of calcitonin gene-related peptide release from the trachea and in vivo by inhibition of chemically induced and inflammatory hypersensitivity in mice. The crotalphine-mediated desensitizing effect was abolished by the TRPA1 blocker HC030031 and absent in TRPA1-deficient mice. Taken together, these results suggest that crotalphine is the first peptide to mediate antinociception selectively and at subnanomolar concentrations by targeting TRPA1 ion channels.
Oxygen-derived free radical damage is associated with the molecular toxicity of hemoglobin. Especially in thalassemia syndromes, this toxicity has a relationship with "free" alpha globin ...concentrations. This study of beta thalassemia trait blood samples from 39 individuals shows that the evaluation of methemoglobin is a sensitive method of indicating molecular toxicity and the superoxide dismutase concentration revealing the intensity of oxidative stress of this process.
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