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This aim of the present study was to identify the relationship between hesperidin and microRNA (miR)‑132, and to study the role of hesperidin and miR‑132 in the pathogenesis of non‑small cell lung cancer (NSCLC). Computational analysis and luciferase assays were performed to identify the target of miR‑132. Subsequently, reverse transcription‑quantitative PCR and western blot assays were used to detect the effect of miR‑132 and hesperidin on the expression of haematological and neurological expressed 1 (HN1) and zinc finger E‑box binding homeobox 2 (ZEB2). Finally, MTT assays and flow cytometry analysis were used to investigate the effect of hesperidin on cell proliferation and apoptosis. ZEB2 was identified as a target gene of miR‑132, and transfection with miR‑132 mimic reduced the luciferase activity of the wild‑type ZEB2 3'‑untranslated region (3'‑UTR) but not that of the mutant ZEB2 3'‑UTR. By contrast, neither transfection with miR‑132 mimic nor hesperidin treatment affected HN1 expression. Furthermore, hesperidin evidently inhibited cell proliferation and promoted apoptosis in a dose‑dependent manner. Furthermore, the tumour volume in rats transplanted with NSCLC cells and treated with hesperidin was notably smaller compared with that in rats transplanted with NSCLC cells alone, while treatment with hesperidin significantly reduced the colony formation efficiency of NSCLC cells by increasing miR‑132 expression and decreasing ZEB2 expression. To the best of our knowledge, the present study demonstrated for the first time that the administration of hesperidin decreased the expression of ZEB2 by upregulating the expression of miR‑132, which in turn promoted apoptosis and inhibited the proliferation of NSCLC cells.

Objective To investigate the effect of metformin on the cell proliferation, cell cycle and apoptosis of rat prolactinoma MMQ cells in vitro and related molecular mechanisms. Methods The MMQ cells were treated with 1.25, 2.5, 5, 10, 20 mmol/L metformin for 48 hours. CCK-8 assay was used to assess the cell proliferation ability; flow cytometry was used to analyze the cell cycle distribution and apoptosis; Western blotting was performed to detect the expressions of AMPKα1/2, p-AMPKα, mTOR, p-mTOR, insulin like growth factor 1 receptor (IGF-1R), ERK1/2, p-ERK1/2, AKT, p-AKT, P21, CDK4, cyclin D1, caspase-3, cleaved caspase-3(c-caspase-3), Bcl-2 and BAX. Results Compared with the control group, metformin inhibited cell proliferation, induced cell cycle arrest in the G0/G1 phase and promoted cell apoptosis in MMQ cells. The expressions of P21 and c-caspase-3 increased, meanwhile, the expressions of CDK4, cyclin D1, caspase-3 and Bcl-2 decreased by metformin. Besides, the expression of p-AMPKα was elevated, but p-mTOR was reduced. Furthermore, the expressions of IGF-1R, p-AKT and p-ERK descended after metformin treatment. Conclusion Metformin could inhibit cell proliferation, induce cell cycle arrest and apoptosis in MMQ cells by activating AMPK/mTOR signaling pathway and inhibiting IGF-1R signaling pathway.

Salicylate-induced ototoxicity leading to sensorineural hearing loss (SNHL) and tinnitus is well documented. However, the exact mechanisms are poorly defined. Caspase-3 is a member of the class of effector caspases and has been activated in nearly every model of apoptosis. To examine its role in salicylate-induced injury, we subjected guinea pigs to treatment with a specific inhibitor zDEVD-FMK via the round window niche (RWN) followed by a systemic injection of salicylate at a dose of 200 mg · kg(-1) · d(-1) i.p. for 10 consecutive days. For those animals administered with salicylate, immunohistochemical studies revealed that caspase-3 was activated in the spiral ganglion neurons (SGNs) and method of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) to identify neuronal apoptosis showed that fragmented nuclei were distributed in Rosenthal's canal. Topical administration of the zDEVD-FMK at a concentration of 500 mM blocked caspase-3 activation and had an effect in reducing the number of TUNEL-positive auditory neurons. In contrast, the inhibitor at a concentration of 125 or 250 mM caused no variation in the expression of activated caspase-3, or in the ratio of TUNEL-positive neurons. These results indicate that caspase-3 is a crucial mediator of apoptosis induced by salicylate in the primary auditory neuron in vivo, and suggest that the specific inhibitor at a relatively high concentration may be therapeutically beneficial in salicylate-induced apoptosis.

In the current study, we explored whether chronic salicylate exposure could induce apoptosis in outer hair cells (OHCs) and spiral ganglion neurons (SGNs) of the cochlea. Guinea pig received sodium salicylate (400 mg/kg/d) or saline vehicle for 10 consecutive days. Programmed cell death (PCD) executioner was evaluated with immunohistochemistry detection of activated caspase-3. Apoptosis was examined with a terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. Repeated salicylate administration activated caspase-3 and caused apoptosis in OHCs and SGNs (p<0.01 vs. saline control for both measures and in both cell types). Cell counting showed a significant loss in OHCs (p<0.01 vs. saline control), but not in inner hair cells (IHCs). Transmission electron microscopy (TEM) revealed chromatin condensation and nucleus margination in salicylate-treated cochlea. Scanning electron microscopy (SEM) demonstrated stereociliary bundles breakdown and fusion at the apical of OHCs, villous matter was discovered to attach on the surface of SGNs. These findings suggest that long-term administration of high-dose salicylate can activate caspase-3 pathway to induce OHC and SGN apoptosis., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Ganoderma lucidum (Leyss. ex Fr.) Karst. (Polyporaceae) triterpenoids (GLTs), the main components and bioactive metabolites of G. lucidum, have antitumour activity. We investigated the effects of GLTs in lung cancer tumour-bearing nude mice and their potential mechanism. Forty BALB/c nude mice were randomly divided into four groups: saline control, GLT (1 g/kg/day), gefitinib (GEF, 15 mg/kg/day), and GLT (1 g/kg/day) + GEF (15 mg/kg/day) for 14 days. Cell viability was conducted using the Cell Counting Kit-8 assay. The tumour volume, inhibition rate, histopathological, microvessel density (MVD), mRNAs, and proteins were determined. GLTs inhibited the cell viability of A549 cells with an IC50 value of 14.38 ± 0.29 mg/L, while the IC50 value of GEF was 10.26 ± 0.47 μmol/L. The tumour inhibition rate in the GLT + GEF group (51.54%) was significantly decreased relative to the saline control... group (p < 0.05). The MVD in the GLT + GEF group (2.9 ± 0.7) was significantly decreased than that in the saline control group (12.8 ± 1.4, p < 0.05). The angiostatin, endostatin, and Bax protein expression in the GLT, GEF, and GLT + GEF groups were significantly increased compared to those in the saline control group, while the VEGFR2 and Bcl-2 protein expression were decreased. Our study provided evidence that GLT and GEF combination therapy may be a promising candidate for the treatment of lung cancer and as an experimental basis for clinical treatment. [ABSTRACT FROM AUTHOR]

Abstract Pituitary corticotroph tumors lead to excess adrenocorticotrophic hormone (ACTH) secretion, resulting in Cushing's disease (CD), which is associated with significant mortality. Standard treatments include neurosurgery, radiotherapy and medical therapy. Both surgery and radiotherapy have undesirable complications and high recurrence rates. At present, there is only one medical option available that targets pituitary adenoma and ACTH secretion, the drug pasireotide. However, hyperglycemia is common during pasireotide treatment. In addition, some patients have discontinued pasireotide treatment because of hyperglycemia-related adverse events or uncontrolled diabetes. New medical treatments directly targeting the corticotroph cells and suppressing ACTH secretion are urgently required. Metformin is a commonly used antidiabetic drug that has been widely used to control the hyperglycemia that occurs in patients with CD, which is secondary to both cortisol excess and pasireotide treatment. Recent studies suggest that metformin has direct anticancer activities against many tumor cell lines. In the present study, we investigated whether metformin exerts an anti-tumor effect by directly targeting pituitary corticotroph tumors and exploring the underlying mechanisms. Using the mouse corticotroph tumor cells, AtT20 cells, we report that metformin inhibited cell proliferation, promoted cell apoptosis and decreased ACTH secretion but did not block the cell cycle in cells. The apoptosis induced by metformin was accompanied by increased caspase-3 activity. Meanwhile, metformin down-regulated the anti-apoptotic protein B cell lymphoma 2 (Bcl-2) but up-regulated the pro-apoptotic protein Bcl2-associated X (BAX), which suggests the involvement of the mitochondrial-mediated apoptosis pathway. Furthermore, metformin promoted AMP-activated protein kinase (AMPK) phosphorylation but inhibited insulin-like growth factor-1 receptor (IGF-1R) expression, protein kinase B (PKB/AKT) phosphorylation and mammalian target of rapamycin (mTOR) phosphorylation. Finally, the IGF-1R inhibitor picropodophyllin (PPP) significantly inhibited the cell proliferation of AtT20 cells. We conclude that metformin inhibits cell proliferation and induces apoptosis in AtT20 cells by activating AMPK/mTOR and inhibiting IGF-1R/AKT/mTOR signaling pathways. Metformin may have direct antitumor activity against pituitary corticotroph tumors. Highlights • Metformin inhibits the viability of mouse pituitary corticotroph adenoma AtT20 cells. • Metformin promotes apoptosis of the AtT20 cells. • Metformin suppresses the levels of intracellular and secreted ACTH in AtT20 cells. • Metformin activated AMPK/mTOR and inhibited IGF-1R/AKT/mTOR pathways in AtT20 cells. [ABSTRACT FROM AUTHOR]

Summary: Members of the ING family of tumor suppressors regulate cell cycle progression, apoptosis, and DNA repair as important cofactors of p53. ING1 and ING3 are stable components of the mSin3A HDAC and Tip60/NuA4 HAT complexes, respectively. We now report the purification of the three remaining human ING proteins. While ING2 is in an HDAC complex similar to ING1, ING4 associates with the HBO1 HAT required for normal progression through S phase and the majority of histone H4 acetylation in vivo. ING5 fractionates with two distinct complexes containing HBO1 or nucleosomal H3-specific MOZ/MORF HATs. These ING5 HAT complexes interact with the MCM helicase and are essential for DNA replication to occur during S phase. Our data also indicate that ING subunits are crucial for acetylation of chromatin substrates. Since INGs, HBO1, and MOZ/MORF contribute to oncogenic transformation, the multisubunit assemblies characterized here underscore the critical role of epigenetic regulation in cancer development. [Copyright &y& Elsevier]