naphthoquinones and Precursor-T-Cell-Lymphoblastic-Leukemia-Lymphoma

T-acute lymphoblastic leukemia (T-ALL) is an aggressive hematological cancer that arises from the malignant transformation of T-cell progenitors. Despite the significant progress in current treatment, challenges remain the lifelong morbidity after current chemotherapy regimens and postrelapse survival. In addition, patients with T-ALL have inferior outcomes compared with those with B-cell precursor; consequently, novel therapeutic approaches are still necessary to improve the outcome in this cohort. YM155 is an imidazolium derivative originally discovered as a suppressant of survivin expression. It has been reported that YM155 has potent antiproliferative activity on a variety of human cancer cell lines; however, its effects in T-ALL cells have been underexplored. The aim of the present study was to examine the effects of YM155 on p53-deficient T-ALL cell lines, JURKAT and CCRF-CEM. Resazurin dye was used to evaluate cell viability. Colony formation was observed in MethoCult methylcellulose medium. Apoptotic cells were detected by flow cytometry (annexin V labeling and TUNEL assay). Cell cycle analysis was carried out by DNA quantification in flow cytometry. DNA damage was assessed using a comet assay and the survivin expression profile was evaluated by real-time PCR and immunoblotting. YM155 treatment decreased cell viability and clonogenicity capacity of T-ALL cells, increased the apoptosis index and DNA damage, and altered the cell cycle dynamic, independent of survivin inhibition. Taken together, the data reinforce that YM155 may be useful as a therapeutic possibility to combat leukemia.

Topics: Adolescent; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Growth Processes; Child, Preschool; DNA Damage; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Jurkat Cells; Male; Naphthoquinones; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Survivin; Tumor Suppressor Protein p53

Of the hematological disorders typified by poor prognoses and survival rates, T-cell acute lymphoblastic leukemia (T-ALL) is one of the most commonly diagnosed. Despite the development of new therapeutic agents, the treatment options for this cancer remain limited. In this manuscript, we investigated the anti-proliferative effects of plumbagin, mediated by the activation of mitogen-activated protein kinase (MAPK) pathways, and inhibition of NF-κB signaling; the human T-ALL MOLT-4 cell line was used as our experimental system. Plumbagin is a natural, plant derived compound, which exerts an anti-proliferative activity against many types of human cancer. Our experiments confirm that plumbagin induces a caspase-dependent apoptosis of MOLT-4 cells, with no significant cytotoxicity seen for normal peripheral blood mononuclear cells (PBMCs). Plumbagin also inhibited LPS-induced phosphorylation of p65, and the transcription of NF-κB target genes. Our results now show that plumbagin is a potent inhibitor of the NF-κB signaling pathway, and suppressor of T-ALL cell proliferation.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Caspases; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cytokines; DNA Primers; Flow Cytometry; Humans; Immunosuppressive Agents; Leukocytes, Mononuclear; Lipopolysaccharides; Naphthoquinones; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Signal Transduction; Transcription, Genetic

LQB 118 is a pterocarpanquinone compound synthesized by our group. It has already been shown that it acts against different leukemia cell lines. However, little is known about the pathway through which this compound induces the death of these cells. In this work, we analyzed the cell death process induced by LQB 118 in K562, a chronic myeloid leukemia cell line, and in Jurkat, a lymphoblastic acute leukemia cell line. For this, we carried out a cell viability assay by MTT, an apoptosis/necrosis assay through the annexin/propidium iodide label, cell cycle by flow cytometry, assessed changes in the mitochondrial membrane potential using DiOC6(3), cytoplasmic calcium analysis by Fluo-3-AM, and a caspase-9 and caspase-12 activity assay. We found that LQB 118 induced apoptosis in both cell lines, measuring caspase-12 and caspase-9 activation, phosphatidylserine externalization, and DNA fragmentation. The compound induced an increase in cytoplasmic calcium on both cell lines. However, the compound could only induce mitochondrial membrane depolarization on K562 cells. Our data show that LQB 118 may have potential therapeutic value for leukemia, being able to overcome multiple resistance mechanisms.

Topics: Antineoplastic Agents; Apoptosis; Calcium; Caspase 12; Caspase 9; Cell Cycle; Cell Survival; Cytoplasm; DNA Fragmentation; Endoplasmic Reticulum Stress; Flow Cytometry; Humans; Jurkat Cells; K562 Cells; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Membrane Potential, Mitochondrial; Naphthoquinones; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Pterocarpans