Chemoprotective effect of atorvastatin against benzo(a)pyrene-induced lung cancer via the inhibition of oxidative stress and inflammatory parameters.

BACKGROUND: Lung cancer affects approximately 9% of women and 17% of men worldwide, and has a mortality rate of 17%. Previously published studies have suggested that oxidative stress expansion can lead to lung cancer. The aim of the current study was to analyze the possible inhibitory pathway of atorvastatin against lung cancer cells in an in vivo model. METHODS: The cytotoxic effects of atorvastatin on lung cancer cell lines H460 and A549 were analyzed, as well as cell cycle arrest and cell morphology. Benzo(a)pyrene (BaP) was used for the induction of lung cancer in experimental rats, and atorvastatin (5, 10, and 20 mg/kg body weight) was used for treatment in a dose-dependent manner. Body weight and lung tumors were calculated at regular intervals. Antioxidants, pro-inflammatory cytokines, phase I and II antioxidant enzymes, polyamine enzymes, and apoptosis markers were determined at end of the experimental study. RESULTS: Cell cycle arrest occurred at the G2/M phase after atorvastatin treatment. Atorvastatin increased cytochrome C expression and caspase activity in a dose-dependent manner, and increased the activity of antioxidative enzymes, such as GPx, SOD, GST, reduced glutathione, and catalase, and reduced the level of nitrate and LPO. It also altered the xanthine oxidase (XO), Lactic Acid Dehydrogenase (LDH), quinone reductase (QR), UDP-glucuronosyltransferase (UDP-GT), adenosine deaminase (ADA), Aryl hydrocarbon hydroxylase (AHH), 5'-nucleotidase, cytochrome P450, cytochrome B5 and NADPH cytochrome C reductase levels. Atorvastatin was found to modulate polyamine enzyme levels, such as histamine, spermine, spermidine, and putrescine, and significantly (P<0.001) reduced the pro-inflammatory cytokine levels, such as tumor necrosis factor-α. Interleukin (IL)-6 and interleukin-1ß (IL-1ß) increased caspase-3 and caspase-9 levels in a dose-dependent manner. CONCLUSIONS: Our findings indicate that atorvastatin can inhibit lung cancer through apoptosis.

MSC-derived exosomes protect against oxidative stress-induced skin injury via adaptive regulation of the NRF2 defense system.

Oxidative stress is a major cause of skin injury induced by damaging stimuli such as UV radiation. Currently, owing to their immunomodulatory properties, mesenchymal stem cell-derived exosomes (MSC-Exo), as a nanotherapeutic agent, have attracted considerable attention. Here, we investigated the therapeutic effects of MSC-Exo on oxidative injury in H2O2-stimulated epidermal keratinocytes and UV-irradiated wild type and nuclear factor-erythroid 2-related factor-2 (Nrf2) knocked down cell and animal models. Our findings showed that MSC-Exo treatment reduced reactive oxygen species generation, DNA damage, aberrant calcium signaling, and mitochondrial changes in H2O2-stimulated keratinocytes or UV-irradiated mice skin. Exosome therapy also improved antioxidant capacities shown by increased ferric ion reducing antioxidant power and glutathione peroxidase or superoxide dismutase activities in oxidative stress-induced cell and skin injury. In addition, it alleviated cellular and histological responses to inflammation and oxidation in cell or animal models. Furthermore, the NRF2 signaling pathway was involved in the antioxidation activity of MSC-Exo, while Nrf2 knockdown attenuated the antioxidant capacities of MSC-Exo in vitro and in vivo, suggesting that these effects are partially mediated by the NRF2 signaling pathway. These results indicate that MSC-Exo can repair oxidative stress-induced skin injury via adaptive regulation of the NRF2 defense system. Thus, MSC-Exo may be used as a potential dermatological nanotherapeutic agent for treating oxidative stress-induced skin diseases or disorders.

Ku80 gene knockdown by the CRISPR/Cas9 technique affects the biological functions of human thyroid carcinoma cells.

In the present study, to evaluate the role of Ku80 in thyroid carcinoma (TC), 86 thyroid tissue samples from patients with a spectrum of thyroid disorders were examined for protein levels of Ku80, nuclear factor­κB (NF­κB) and RET/TC by immunohistochemistry. Furthermore, in TC cells, Ku80 mRNA was detected by reverse transcription­quantitative PCR analysis and silenced using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR­associated protein 9 (Cas9) technique to assess its role. An antibody array was used to identify Ku80­related regulatory genes. The protein levels of Ku80 in the TC tissues were significantly higher than those in non­neoplastic adjacent tissue samples (P<0.01). The activation of NF­kB and expression of RET/TC in the TC group were significantly increased (P<0.05) and were correlated with the protein expression of Ku80 (P<0.05). In papillary TC cells, the mRNA levels of Ku80 were high; Ku80 knockdown resulted in reductions in proliferation, invasion and colony formation, increased apoptosis, and reduced levels of proteins involved in MAPK signaling, cell proliferation and apoptosis. The high expression of Ku80 in TC was found to be associated with the expression of RET/TC and activation of NF­κB, and Ku80 knockdown decreased the malignancy of TC cells.

Knockdown of POLE2 expression suppresses lung adenocarcinoma cell malignant phenotypes in vitro.

In the present study, we profiled ß­elemene­regulated gene expression and investigated the effects of the silencing of the DNA polymerase epsilon 2, accessory subunit (POLE2) in lung cancer cells. Differently expressed genes were profiled in A549 cells incubated in the presence or absence of ß­elemene by Affymetrix Human Gene Expression Array. POLE2 shRNA was then constructed to knock down POLE2 expression. Cells were counted and phenotypes were assessed via CCK­8, colony formation and caspase-3/-7 activity assays. PathScan antibody array analysis was used to identify shPOLE2­regulated genes. The cDNA microarray identified a total of 721 differentially expressed genes in the A549 cells. Furthermore, knockdown of POLE2 expression inhibited A549 and NCI­H1299 cell proliferation and apoptosis. The PathScan data indicated that expression levels of p­Akt (phosphorylated­protein kinase B, p­AKT/p­PKB), p­Smad2 (phosphorylated mothers against decapentaplegic homolog 2), p­p38 MAPK (phosphorylated mitogen­activated protein kinases p38), p­SAPK/JNK (phosphorylated c­Jun N­terminal protein kinase/stress activated protein kinase), cleaved caspase­7, IκBα (nuclear factor of κ light polypeptide gene enhancer in B­cell inhibitor, α), p­Chk1 (phosphorylated checkpoint kinase 1), p­IκBα, p­eIF2α (phosphorylated eukayotic translational initiation factor 2α), p­TAK1 (phosphorylated TGF­B­activated kinase 1), survivin and α­tubulin were significantly lower in shPOLE2 cells than these levels in the shCtrl cells. The PathScan data indicated that the expression levels of p­p53 (phosphorylated tumor protein 53) were significantly higher in the shPOLE2 cells than these levels in the shCtrl cells. ß­elemene can restrain human lung cancer A549 and NCI­H1299 cell proliferation and apoptosis by suppressing POLE2 expression.