Inhibition of miR-128-3p Attenuated Doxorubicin-Triggered Acute Cardiac Injury in Mice by the Regulation of PPAR-γ.

BACKGROUND: The clinical usefulness of doxorubicin (DOX), an anthracycline with antitumor activity, is limited by its cardiotoxicity. Oxidative stress and myocardial apoptosis were closely associated with DOX-induced cardiac dysfunction. It has been reported that microRNA-128-3p (miR-128-3p) was involved into the regulation of redox balance. However, the role of miR-128-3p in DOX-related cardiac injury remains not yet understood. The aim of this study was to investigate the biological effect of miR-128-3p in DOX-induced cardiotoxicity. METHODS: To induce DOX-related acute cardiac injury, mice were subjected to a single injection of DOX. Inhibition of myocardial miR-128-3p was achieved by an adeno-associated virus (AAV9) system carrying a miR-128-3p sponge. RESULTS: The data in our study indicated that miR-128-3p was upregulated in DOX-treated hearts and cardiomyocytes. Inhibition of miR-128-3p attenuated DOX-related cardiac injury and improved cardiac function in mice. Moreover, miR-128-3p inhibition could suppress myocardial inflammatory response, oxidative damage, and cell apoptotic death in DOX-treated mice. Further analysis showed that miR-128-3p could directly target peroxisome proliferator-activated receptor γ (PPAR-γ) and decrease PPAR-γ expression. Moreover, the protective effects provided by miR-128-3p inhibition were abolished by a PPAR-γ antagonist in vivo and in vitro. CONCLUSIONS: miR-128-3p inhibition attenuated DOX-related acute cardiac injury via the regulation of PPAR-γ in mice.

Protective Effects of Oroxylin A against Doxorubicin-Induced Cardiotoxicity via the Activation of Sirt1 in Mice.

Doxorubicin- (DOX-) related cardiac injury impairs the life quality of patients with cancer. This largely limited the clinical use of DOX. It is of great significance to find a novel strategy to reduce DOX-related cardiac injury. Oroxylin A (OA) has been identified to exert beneficial effects against inflammatory diseases and cancers. Here, we investigated whether OA could attenuate DOX-induced acute cardiotoxicity in mice. A single dose of DOX was used to induce acute cardiac injury in mice. To explore the protective effects, OA was administered to mice for ten days beginning from five days before DOX injection. The data in our study indicated that OA inhibited DOX-induced heart weight loss, reduction in cardiac function, and the elevation in myocardial injury markers. DOX injection resulted in increased oxidative damage, inflammation accumulation, and myocardial apoptosis in vivo and in vitro, and these pathological alterations were alleviated by treatment of OA. OA activated the sirtuin 1 (Sirt1) signaling pathway via the cAMP/protein kinase A, and its protective effects were blocked by Sirt1 deficiency. OA treatment did not affect the tumor-killing action of DOX in tumor-bearing mice. In conclusion, OA protected against DOX-related acute cardiac injury via the regulation of Sirt1.

MicroRNA-223-3p Protect Against Radiation-Induced Cardiac Toxicity by Alleviating Myocardial Oxidative Stress and Programmed Cell Death via Targeting the AMPK Pathway.

Objectives: Radiotherapy improves the survival rate of cancer patients, yet it also involves some inevitable complications. Radiation-induced heart disease (RIHD) is one of the most serious complications, especially the radiotherapy of thoracic tumors, which is characterized by cardiac oxidative stress disorder and programmed cell death. At present, there is no effective treatment strategy for RIHD; in addition, it cannot be reversed when it progresses. This study aims to explore the role and potential mechanism of microRNA-223-3p (miR-223-3p) in RIHD. Methods: Mice were injected with miR-223-3p mimic, inhibitor, or their respective controls in the tail vein and received a single dose of 20 Gy whole-heart irradiation (WHI) for 16 weeks after 3 days to construct a RIHD mouse model. To inhibit adenosine monophosphate activated protein kinase (AMPK) or phosphodiesterase 4D (PDE4D), compound C (CompC) and AAV9-shPDE4D were used. Results: WHI treatment significantly inhibited the expression of miR-223-3p in the hearts; furthermore, the levels of miR-223-3p decreased in a radiation time-dependent manner. miR-223-3p mimic significantly relieved, while miR-223-3p inhibitor aggravated apoptosis, oxidative damage, and cardiac dysfunction in RIHD mice. In addition, we found that miR-223-3p mimic improves WHI-induced myocardial injury by activating AMPK and that the inhibition of AMPK by CompC completely blocks these protective effects of miR-223-3p mimic. Further studies found that miR-223-3p lowers the protein levels of PDE4D and inhibiting PDE4D by AAV9-shPDE4D blocks the WHI-induced myocardial injury mediated by miR-223-3p inhibitor. Conclusion: miR-223-3p ameliorates WHI-induced RIHD through anti-oxidant and anti-programmed cell death mechanisms via activating AMPK by PDE4D regulation. miR-223-3p mimic exhibits potential value in the treatment of RIHD.

Immune checkpoint inhibitors in non-small-cell lung cancer: current status and future directions.

Since 2015, immunotherapies, especially immune checkpoint inhibitors (ICIs), have made great breakthroughs in non-small-cell lung cancer (NSCLC). Among them, nivolumab, pembrolizumab and atezolizumab have been granted US Food and Drug Administration approval for NSCLC. It is imperative to combine ICIs with chemotherapy, radiotherapy, antivascular therapy and targeted therapy. But in the bright future, there are two problems. One is how to use biomarkers to select the beneficiaries. The other is how to achieve a balance between drug effectiveness and safety. There are now seven drugs targeting the programmed death-1/programmed death ligand-1 (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) pathways that have been or are expected to enter clinical treatment. This review focuses on these drugs and summarizes clinical trials that have been reported or that ongoing ones have already entered the recruiting state.

N-acetyltransferase 2 phenotype and risk of esophageal cancer: a meta analysis.

N-acetyltransferase 2 (NAT2) gene encodes a phase II enzyme taking part in detoxification of aromatic amines. Published studies have demonstrated that N-Acetyltransferase 2 (NAT2) phenotype is a risk factor of various cancers. Many studies have investigated the association between NAT2 phenotype and susceptibility to esophageal cancer but yielded controversial results. To derive a more precise estimation of this association, a meta-analysis was performed. Electronic databases (Pubmed/Medline, ISI Web of Science and China National Knowledge Infrastructure) in English and Chinese were searched. A total of 5 articles including 476 cases and 1,093 controls were included in this meta-analysis. Odds ratio (OR) with 95% confidence interval (95% CI) was used to evaluate intensity of associations. Pooling studies together, NAT2 slow acetylator phenotype was a significant risk factor of esophageal squamous cell cancer (OR=1.35, 95% CI=1.03-1.77, n=5 studies) but not esophageal adenocarcinoma (OR=0.97, 95% CI=0.47-2.04, n=2 studies). There was a significant association between NAT2 acetylator phenotypes and ESCC in South Asian populations (OR=1.51, 95% CI=1.03-2.20), but not in East Asian populations (OR=1.19, 95% CI=0.80-1.77). Significant association between NAT2 acetylator phenotypes and esophageal cancer was found in population-based control subgroup (OR=1.63, 95% CI=1.07-2.50) but not in hospital-based control subgroup (OR=1.19, 95% CI=0.84-1.69). There is a significant association between NAT2 acetylator phenotype and esophageal cancer in both smokers (OR=1.681, 95% CI=1.179-2.395) and non-smokers (OR=1.614, 95% CI=1.173-2.222). In conclusion, NAT2 slow acetylator phenotype was a significant risk factor of ESCC in Asian populations.

5-Lipoxygenase contributes to the progression of hepatocellular carcinoma.

5-Lipoxygenase (5-LOX) has been implicated in the development and progression of lung, pancreatic and esophageal cancers. However, its role in hepatocellular carcinoma (HCC) remains unclear. This study aimed to explore the role of 5-LOX in the pathogenesis of HCC. The expression of 5-LOX was detected in human HCC, HepG2 cells and diethylnitrosamine (DEN)-induced rat HCC using immunohistochemistry (IHC) staining or reverse transcriptase-polymerase chain reaction. Apoptosis in rat HCC was evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) assay. Cell viability and apoptosis were determined in HepG2 cells by MTT assay and flow cytometry, respectively. IHC staining showed that the 5-LOX protein was highly expressed in human HCC, HepG2 cells and rat HCC, but not in the normal liver tissues. 5-LOX mRNA expression in human and rat HCC was also significantly increased compared to normal liver tissues. Zileuton, a 5-LOX inhibitor, reduced the nodule incidence and the mean number of nodules per nodule-bearing liver in DEN-induced rats. Further study using TUNEL assay showed that zileuton treatment induced apoptosis in the liver as the result of inhibition on 5-LOX levels. This result is consistent with our observation of significantly higher apoptotic indices in rats treated with DEN/zileuton, which were significantly higher compared to those from the control groups. In addition, zileuton reduced cell viability and induced apoptosis in a concentration- and time-dependent manner as detected using HepG2 cells in our in vitro analysis. In conclusion, 5-LOX is expressed in HCC, and the inhibition of 5-LOX blocks the development of HCC via the induction of apoptosis in tumor cells.

Hepatic oval cells activated by hepatocyte apoptosis in diethylnitrosamine-induced rat liver cirrhosis.

OBJECTIVE: To investigate whether hepatic oval cells are activated in diethylnitrosamine (DEN)-induced rat liver cirrhosis, and to explore its mechanism. METHODS: Liver cirrhosis was induced in rats (n=8) by weekly intraperitoneal injections of DEN at a dose of 50mg/kg body weight for 12 weeks followed by a 2-week wash out period. Rats (n=5) that received isovolumic vehicle served as the control group. Liver pathology was examined. Apoptotic hepatocytes were identified and quantified by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) assay. Oval cells were detected using immunohistochemical staining for pyruvate kinase type M2 (M2PK) and cytokeratin 19 (CK19). The work was carried out at Renmin Hospital of Wuhan University, Wuhan, Hubei, China from February to December 2009. RESULTS: Liver cirrhosis developed in rats subjected to DEN administration. The TUNEL and morphology assay showed that a substantial number of hepatocytes underwent apoptosis. The apoptotic index in rats subjected to DEN administration (0.75 0.15) was much higher than normal control rats (0.10 0.05). Both CK19 and M2PK were moderately expressed in the rat liver cirrhosis, and the expression was dispersed or forming small cords in the liver; but the expression was hardly detected in the liver tissue of normal control rats. CONCLUSION: In the DEN-induced rat liver cirrhosis, oval cells are activated and stimulated to proliferation, the mechanism of which may be related to substantial hepatocyte apoptosis in the model.

[Protein kinase B inhibitor enhance sensitivity of gastric cancer cell to etoposide].

OBJECTIVE: To observe the effects of etoposide on protein kinase B (PKB) activity in distinct differentiated gastric cancer cell lines and the change of sensitivity to etoposide after pretreatment by wortmannin, a PKB inhibitor. To explore the relationship between PKB activity in gastric cancer cells and their sensitivity to etoposide chemotherapy. METHODS: Four distinct differentiated gastric cancer cell lines, including MKN-28 (well differentiated), SGC-7901 (moderate differentiated), BGC-823 (poorly differentiated) and HGC-27 (undifferentiated), were studied. The PKB activities of these cell lines were detected by nonradioactive protein-kinase assay at different time points after etoposide treatment for 0,3,6,12,24 h with or without wortmannin pretreatment. Cell viabilities were assayed by MTT and cell apoptosis was analyzed by flow cytometry. RESULTS: Poorer differentiated gastric cancer cell lines had higher PKB activities. Etoposide treatment resulted in increase in PKB activity and apoptosis rate,and decrease in cell survival rate in a time-dependent manner in gastric cancer cell lines. Wortmannin pretreatment abolished PKB activity completely in gastric cancer cells,and decreased survival rate and increased apoptosis rate in SGC-7901, BGC-823, and HGC-27 cell lines. CONCLUSIONS: Etoposide can induce the PKB activity in gastric cancer cell lines. Wortmannin pretreatment enhances sensitivity of median and low differentiated gastric cancer cells to etoposide chemotherapy.