Silencer of death domains controls cell death through tumour necrosis factor-receptor 1 and caspase-10 in acute lymphoblastic leukemia

Matteucinol combined with temozolomide inhibits glioblastoma proliferation, invasion, and progression: an in vitro, in silico, and in vivo study

Glioblastoma is the most prevalent and malignant brain tumor identified in adults. Surgical resection followed by radiotherapy and chemotherapy, mainly with temozolomide (TMZ), is the chosen treatment for this type of tumor. However, the average survival of patients is around 15 months. Novel approaches to glioblastoma treatment are greatly needed. Here, we aimed to investigate the anti-glioblastoma effect of the combination of matteucinol (Mat) (dihydroxyflavanone derived from Miconia chamissois Naudin) with the chemotherapeutic TMZ in vitro using tumor (U-251MG) and normal astrocyte (NHA) cell lines and in vivo using the chick embryo chorioallantoic membrane (CAM) assay. The combination was cytotoxic and selective for tumor cells (28 μg/mL Mat and 9.71 μg/mL TMZ). Additionally, the combination did not alter cell adhesion but caused morphological changes characteristic of apoptosis in vitro. Notably, the combination was also able to reduce tumor growth in the chick embryo model (CAM assay). The docking results showed that Mat was the best ligand to the cell death membrane receptor TNFR1 and to TNFR1/TMZ complex, suggesting that these two molecules may be working together increasing their potential. In conclusion, Mat-TMZ can be a good candidate for pharmacokinetic studies in view of clinical use for the treatment of glioblastoma.

Bcl2-associated athanogene 4 promotes the invasion and metastasis of gastric cancer cells by activating the PI3K/AKT/NF-κB/ZEB1 axis

Bcl2-associated athanogene 4 (BAG4) has been found to be aberrantly expressed in several types of human cancers. However, little is known about its expression, role, and clinical significance in gastric cancer (GC). In this study, we aimed to address these issues and to explore the underlying mechanisms. The expression level of BAG4, measured by immunohistochemistry, was significantly higher in GC tissues than in paired normal tissues. Elevated BAG4 expression was positively correlated with T stage, lymph node metastasis, and tumor size of GC and was associated with unfavorable outcomes of the patients. The overexpression of BAG4 promoted the in vitro invasion and in vivo metastasis of GC cells, and opposite results were observed after silencing of BAG4. Silencing of BAG4 significantly reduced the phosphorylation of PI3K, AKT, and p65, whereas overexpression of BAG4 markedly enhanced the phosphorylation of these molecules. At the same time, manipulating BAG4 expression resulted in the corresponding changes in p65 nuclear translocation and ZEB1 expression. Luciferase reporter and chromatin immunoprecipitation assays verified that p65 binds to the promoter of ZEB1 to upregulate its transcription. Our results demonstrate that BAG4 plays an oncogenic role in the invasion and metastasis of GC cells by activating the PI3K/AKT/NF-κB/ZEB1 axis to induce epithelial-mesenchymal transition.

Defined factors to reactivate cell cycle activity in adult mouse cardiomyocytes

Adult mammalian cardiomyocytes exit the cell cycle during the neonatal period, commensurate with the loss of regenerative capacity in adult mammalian hearts. We established conditions for long-term culture of adult mouse cardiomyocytes that are genetically labeled with fluorescence. This technique permits reliable analyses of proliferation of pre-existing cardiomyocytes without complications from cardiomyocyte marker expression loss due to dedifferentiation or significant contribution from cardiac progenitor cell expansion and differentiation in culture. Using this system, we took a candidate gene approach to screen for fetal-specific proliferative gene programs that can induce proliferation of adult mouse cardiomyocytes. Using pooled gene delivery and subtractive gene elimination, we identified a novel functional interaction between E2f Transcription Factor 2 (E2f2) and Brain Expressed X-Linked (Bex)/Transcription elongation factor A-like (Tceal) superfamily members Bex1 and Tceal8. Specifically, Bex1 and Tceal8 both preserved cell viability during E2f2-induced cell cycle re-entry. Although Tceal8 inhibited E2f2-induced S-phase re-entry, Bex1 facilitated DNA synthesis while inhibiting cell death. In sum, our study provides a valuable method for adult cardiomyocyte proliferation research and suggests that Bex family proteins may function in modulating cell proliferation and death decisions during cardiomyocyte development and maturation.

The PI3K/mTOR dual inhibitor BEZ235 suppresses proliferation and migration and reverses multidrug resistance in acute myeloid leukemia

Aberrant activation of the PI3K/Akt/mTOR pathway contributes to the proliferation of malignant cells, and may confer resistance to chemotherapy in various malignancies, including acute myeloid leukemia (AML). Chemoresistance is the major reason for relapse in AML. RAD001 (everolimus) has been used at d1 and d7 of an induction chemotherapy regimen for AML, which has acceptable toxicity and may improve conventional chemotherapeutic treatment. Dual inhibitors of PI3K and mTOR overcome some of the intrinsic disadvantages of rapamycin and its derivatives. In this study, we evaluated the effects of BEZ235, a PI3K/mTOR dual inhibitor, on the multidrug-resistant AML cell lines HL-60/VCR and K562/ADR in vitro. BEZ235 dose-dependently inhibited the viability of HL-60/VCR and K562/ADR cells with the IC₅₀ values of 66.69 and 71.44 nmol/L, respectively. BEZ235 (25-100 nmol/L) dose-dependently inhibited the migration of the two AML cell lines, and it also significantly sensitized the two AML cell lines to VCR and ADR. After treatment with BEZ235, the miR-1-3p levels were markedly increased in HL-60/VCR cells. Using TargetScan analysis and luciferase assays, we showed that miR-1-3p targeted BAG4, EDN1 and ABCB1, the key regulators of cell apoptosis, migration and multidrug resistance, and significantly decreased their levels in the two AML cell lines. Transfection of HL-60/VCR and K562/ADR cells with miR-1-3p-AMO to inhibit miR-1-3p could reverse the anti-proliferation effects of BEZ235. In conclusion, the PI3K/mTOR dual inhibitor BEZ235 effectively chemosensitizes AML cells via increasing miR-1-3p and subsequently down-regulating BAG4, EDN1 and ABCB1.

Aspirin Action in Endothelial Cells: Different Patterns of Response Between Chemokine CX3CL1/CX3CR1 and TNF-α/TNFR1 Signaling Pathways

Purpose

TNF-α induces fractalkine (CX3CL1) and its receptor CX3CR1 in endothelial cells through NF-қB activation. NF-қB inhibitors may reduce the expression of CX3CL1, and modulation of the CX3CL1/CX3CR1 signaling was proposed as a new target for aspirin. We examined the effects of aspirin on CX3CL1 and TNF-α production, as well as CX3CR1 and TNFR1 expression.

Methods

HUVECs isolated after term pregnancies (N = 28) were cultured in vitro. Lipopolysaccharide (1 μg/ml) was used as CX3CL1 inducer. HUVECs were exposed to six different concentrations of aspirin (between 1.0 and 6.0 mM) during 7 days. The levels of CX3CL1 and TNF-α in the culture media were measured using ELISA. After termination of the cultures, mean expressions of CX3CR1 and TNFR1 were examined in the immunostained paraffin sections using quantitative immunohistochemistry.

Results

Aspirin significantly (p < 0.05) decreased CX3CL1 production, and the mean decrease in CX3CL1 production was inversely proportional to increased (p < 0.05) expression of CX3CR1. The combined mean CX3CL1 concentrations, including all time points, equaled 782.18 ± 74.4 pg/ml in aspirin treated HUVECs compared to a total concentration of 2467.53 ± 127.5 pg/ml combined from the respective time points in the controls.

An inhibition of TNF-α production in HUVECs after pretreatment with aspirin was observed. Unlike in the case of CX3CR1 expression, there were no signs of TNFR1 upregulation.

Conclusions

Autoregulation between CX3CL1 and CX3CR1 may explain overexpression of CX3CR1 as the compensatory effect in aspirin-treated HUVECs. Inhibition of CX3CR1 could prevent thrombotic complications in the early period after discontinuation of aspirin.

RETRACTED: Annexin A7 modulates BAG4 and BAG4-binding proteins in mitochondrial apoptosis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concerns were raised in the public domain and also reported by the authors to the journal regarding the similarity between various sections from Figures 1B, 2A, 3A and 4A. Given also the findings of the investigation conducted by the funder, the journal requested the authors to provide the raw data. However, the authors were not able to provide raw data of sufficient quality and detail for the journal to independently audit the provenance and validity of the data, and therefore the Editor-in-Chief decided to retract the article.