14 research outputs found
Cucurbitacin: Ancient Compound Shedding New Light on Cancer Treatment
Cucurbitacins and their derivatives are triterpenoids found in medicinal plants known for their diverse pharmacological and biological activities, including anticancer effects, throughout human history. Although initial attention to cucurbitacin as a potential anticancer drug withered for decades, recent discoveries showing that cucurbitacin is a strong STAT3 (Signal Transducers and Activators of Transcription-3) inhibitor have reclaimed the attention of the drug industry one more time. There is increasing evidence showing that some cucurbitacins not only inhibit the JAK-STAT pathway, but also affect other signaling pathways, such as the MAPK pathway, which are also known to be important for cancer cell proliferation and survival. Moreover, some reports have shown the synergistic effect of cucurbitacins with known chemotherapeutic agents, such as doxorubicin and gemcitabine. In this review, we will summarize the recent discoveries regarding molecular mechanisms of action of cucurbitacins in human cancer cells and discuss the possibilities of cucurbitacin as a future anticancer drug in clinical settings
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C/EBPε mediates nicotinamide-enhanced clearance of Staphylococcus aureus in mice
The myeloid-specific transcription factor, CCAAT/enhancer-binding protein epsilon (C/EBPε) is a critical mediator of myelopoiesis. Mutation of this gene is responsible for neutrophil-specific granule deficiency in humans, a condition that confers susceptibility to Staphylococcus aureus infection. We found that C/EBPε-deficient mice are severely affected by infection with S. aureus, and C/EBPε deficiency in neutrophils contributes to the infectious phenotype. Conversely, exposure to the epigenetic modulator nicotinamide (vitamin B3) increased expression of C/EBPε in WT myeloid cells. Further, nicotinamide increased the activity of C/EBPε and select downstream antimicrobial targets, particularly in neutrophils. In a systemic murine infection model as well as in murine and human peripheral blood, nicotinamide enhanced killing of S. aureus by up to 1,000 fold but had no effect when administered to either C/EBPε-deficient mice or mice depleted of neutrophils. Nicotinamide was efficacious in both prophylactic and therapeutic settings. Our findings suggest that C/EBPε is an important target to boost killing of bacteria by the innate immune system.Keywords: Transcription factor, Neutrophil, Lactoferrin gene expression, Pharmacokinetics, Binding protein epsilon, Murine model, Cell line, Granule deficiency, Impaired function, AcetylationKeywords: Transcription factor, Neutrophil, Lactoferrin gene expression, Pharmacokinetics, Binding protein epsilon, Murine model, Cell line, Granule deficiency, Impaired function, Acetylatio
Autologous Stem Cell Transplantation in Multiple Myeloma in the Era of Novel Drug Induction: A Retrospective Single-Center Analysis.
Within this retrospective single-center study, we analyzed the survival of 320 multiple myeloma (MM) patients receiving melphalan high-dose chemotherapy (HDCT) and either single (n = 286) or tandem (n = 34) autologous stem cell transplantation (ASCT) from 1996 to 2012. Additionally, the impact of novel induction regimens was assessed. Median follow-up was 67 months, median overall survival (OS) 62 months, median progression-free survival (PFS) 33 months (95% CI 27-39), and treatment-related death (TRD) 3%. Multivariate analysis revealed age ≥60 years (p = 0.03) and stage 3 according to the International Staging System (p = 0.006) as adverse risk factors regarding PFS. Median OS was significantly better in newly diagnosed MM patients receiving induction therapy with novel agents, e.g., bortezomib, thalidomide, or lenalidomide, compared with a traditional regimen (69 vs. 58 months; p = 0.01). More patients achieved at least a very good partial remission in the period from 2005 to 2012 than from 1996 to 2004 (65 vs. 30%; p < 0.001), with a longer median OS in the later period (71 vs. 52 months, p = 0.027). In conclusion, our analysis confirms HDCT-ASCT as an effective therapeutic strategy in an unselected large myeloma patient cohort with a low TRD rate and improved prognosis due to novel induction strategies
C/EBPε mediates nicotinamide-enhanced clearance of Staphylococcus aureus in mice
10.1172/JCI62070Journal of Clinical Investigation12293316-3329JCIN
Allogeneic Transplantation Versus Chemotherapy as Postremission Therapy for Acute Myeloid Leukemia: A Prospective Matched Pairs Analysis
Purpose The majority of patients with acute myeloid leukemia (AML) who achieve complete remission (CR) relapse with conventional postremission chemotherapy. Allogeneic stem-cell transplantation (alloSCT) might improve survival at the expense of increased toxicity. It remains unknown for which patients alloSCT is preferable. Patients and Methods We compared the outcome of 185 matched pairs of a large multicenter clinical trial (AMLCG99). Patients younger than 60 years who underwent alloSCT in first remission (CR1) were matched to patients who received conventional postremission therapy. The main matching criteria were AML type, cytogenetic risk group, patient age, and time in first CR. Results In the overall pairwise compared AML population, the projected 7-year overall survival (OS) rate was 58% for the alloSCT and 46% for the conventional postremission treatment group (P = .037; log-rank test). Relapse-free survival (RFS) was 52% in the alloSCT group compared with 33% in the control group (P < .001). OS was significantly better for alloSCT in patient subgroups with nonfavorable chromosomal aberrations, patients older than 45 years, and patients with secondary AML or high-risk myelodysplastic syndrome. For the entire patient cohort, postremission therapy was an independent factor for OS (hazard ratio, 0.66; 95% CI, 0.49 to 0.89 for alloSCT v conventional chemotherapy), among age, cytogenetics, and bone marrow blasts after the first induction cycle. Conclusion AlloSCT is the most potent postremission therapy for AML and is particularly active for patients 45 to 59 years of age and/or those with high-risk cytogenetics
BACH2 mediates negative selection and p53-dependent tumor suppression at the pre-B cell receptor checkpoint
The B cell-specific transcription factor BACH2 is required for affinity maturation of B cells. Here we show that Bach2-mediated activation of p53 is required for stringent elimination of pre-B cells that failed to productively rearrange immunoglobulin VH-DJH gene segments. After productive VH-DJH gene rearrangement, pre-B cell receptor signaling ends BACH2-mediated negative selection through B cell lymphoma 6 (BCL6)-mediated repression of p53. In patients with pre-B acute lymphoblastic leukemia, the BACH2-mediated checkpoint control is compromised by deletions, rare somatic mutations and loss of its upstream activator, PAX5. Low levels of BACH2 expression in these patients represent a strong independent predictor of poor clinical outcome. In this study, we demonstrate that Bach2(+/+) pre-B cells resist leukemic transformation by Myc through Bach2-dependent upregulation of p53 and do not initiate fatal leukemia in transplant-recipient mice. Chromatin immunoprecipitation sequencing and gene expression analyses carried out by us revealed that BACH2 competes with BCL6 for promoter binding and reverses BCL6-mediated repression of p53 and other cell cycle checkpoint-control genes. These findings identify BACH2 as a crucial mediator of negative selection at the pre-B cell receptor checkpoint and a safeguard against leukemogenesis