M6 A demethylase fat mass and obesity-associated protein regulates cisplatin resistance of gastric cancer by modulating autophagy activation through ULK1.

Drug resistance is an important factor for treatment failure of gastric cancer. N6 -methyladenosine (m6 A) is the predominant mRNA internal modification in eukaryotes. The roles of m6 A modification in drug resistance of gastric cancer remains unclear. In the present study, the m6 A methylated RNA level was significantly decreased while the expression of m6 A demethylase fat mass and obesity-associated protein (FTO) was obviously elevated in cisplatin-resistant (SGC-7901/DDP) gastric cancer cells. Knockdown of FTO reversed cisplatin resistance of SGC-7901/DDP cells both in vitro and in vivo, which was attributed to the inhibition of Unc-51-like kinase 1 (ULK1)-mediated autophagy. Mechanistically, ULK1 expression was regulated in an FTO-m6 A-dependent and YTHDF2-mediated manner. Collectively, our findings indicate that the FTO/ULK1 axis exerts crucial roles in cisplatin resistance of gastric cancer.

Replication and Pathology of Duck Influenza Virus Subtype H9N2 in Chukar.

To investigate the susceptibility of Chukars to duck avian influenza virus H9N2 and explore their role in interspecies transmission of influenza viruses. Chukars were inoculated with duck avian influenza viruses H9N2. The present study demonstrated that inflammatory lesions and virus antigen were present in the trachea, bronchus, and parabronchus, and the viruses could be isolated from throat swabs and lung tissue homogenate supernatants. At 14 d post virus inoculation, anti-H9 influenza virus antibody in the serum was detected. The results indicated that Chukars are susceptible to duck avian influenza virus and serve as an intermediate host, thereby facilitating viral gene evolution and supporting the need for continued surveillance of epidemiology and evolution of the influenza virus in Chukars.

SOV sensitizes gastric cancer cells to radiation by suppressing radiation-induced autophagy in vitro and in vivo.

Vanadium is a transition metal that naturally occurs in the environment and has a variety of biological and physiological impacts on humans. Sodium orthovanadate (SOV), a well-known chemical compound of vanadium, has shown notable anti-cancer activity in various types of human malignancies. However, the effect of SOV on stomach cancer is yet undetermined. Furthermore, only a few studies have investigated the association of SOV and radiosensitivity with stomach cancer. Our study has investigated the ability of SOV to increase the sensitivity of gastric cancer cells to radiation. To detect autophagy triggered by ionizing radiation and the influence of SOV on cell radiosensitivity, the Cell Counting Kit-8 (CCK8) test, EDU staining experiment, colony formation assay, and immunofluorescence were performed. The possible synergistic effects of SOV and irradiation were examined in vivo using a xenograft mouse model of stomach cancer cells. Both in vitro and in vivo studies showed that SOV markedly reduced the growth of stomach cancer cells and improved their radiosensitivity. Our results showed that SOV increased gastric cancer cells' radiosensitivity, thereby blocking the radiation-induced autophagy-related protein, ATG10. Thus, SOV can be considered a potential agent for radiosensitizing gastric cancer.

MicroRNA-204 plays a role as a tumor suppressor in Newcastle disease virus-induced oncolysis in lung cancer A549 cells.

Tumor development and progression are closely associated with various microRNAs (miRNAs/miRs). We have previously shown that Newcastle disease virus (NDV) strain 7793 induces oncolysis in lung cancer. However, how NDV exerts its oncolytic effect on lung cancer remains to be investigated. The present study assessed the role of miR-204 in the NDV-induced oncolysis of lung cancer A549 cells by oncolysis induction in vitro. miR-204 was significantly upregulated in NDV-treated A549 cells. Overexpression or inhibition of miR-204 was significantly associated with NDV-induced oncolysis in A549 cells. Caspase-3 and Bax, major regulators of the apoptosis pathway, were regulated by miR-204, and the association between caspase-3-related apoptosis and miR-204 was identified in NDV-mediated oncolysis. These data demonstrated that miR-204 as a tumor suppressor played a role in NDV-induced oncolysis in lung cancer cells. The present study demonstrates the potential of strategies using miRs to improve oncolytic NDV potency, and highlights miR-204 as a tumor suppressor in NDV-induced oncolysis of lung cancer cells.

The hemagglutinin-neuramidinase protein of Newcastle disease virus upregulates expression of the TRAIL gene in murine natural killer cells through the activation of Syk and NF-κB.

Newcastle disease virus (NDV) is responsible for tumoricidal activity in vitro and in vivo. However, the mechanisms that lead to this activity are unclear. Natural killer cells are able to induce apoptosis of tumor cells through multiple pathways, including the tumor necrosis factor-related apoptosis-inducing ligand-death receptor pathway. We previously showed that exposure of NK and T cells to NDV resulted in enhanced tumoricidal activity that was mediated by upregulated expression of the TRAIL gene, via an interferon gamma -dependent pathway. Other pathways involved in the upregulated expression of TRAIL are yet to be identified. In the current study, we used mice in which the IFN-γ receptor one gene was inactivated functionally. We identified an IFN-γ-independent TRAIL pathway in the NDV-stimulated NK cells. Hemagglutinin-neuramidinase induced expression of the TRAIL gene in IFN-R1-/- NK cells by binding to the NKp46 receptor. This upregulation was inhibited by pretreatment of NDV with a neutralizing monoclonal antibody against HN, or desialylation of NK cells. Phosphorylation of spleen tryosine kinases and IκBα was increased in HN-induced IFN-R1-/- NK cells. Treatment with the HN neutralizing monoclonal antibody, pharmacological disialylation, or a Syk inhibitor decreased Syk and IκBα phosphorylation levels. We concluded that killer activation receptors pathway is involved in the IFN-γ-independent TRAIL expression of NDV-stimulated NK cells, and these are activated by Syk and NF-κB.

TRAIL is involved in the tumoricidal activity of mouse natural killer cells stimulated by Newcastle disease virus in vitro.

Newcastle disease virus (NDV) is a potential antitumor agent, and its antitumor effect has been evaluated in preclinical tests. However, the mechanisms of NDV-based antitumor therapy are still not completely clear. In the present study we found that NDV-stimulation enhanced the killing ability of mouse spleen natural killer (NK) cells towards mouse hepatoma cell lines, and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) plays an important role in this tumoricidal activity. NDV stimulation induced up-regulation of TRAIL both at the mRNA and protein levels in NK cells. Blocking TRAIL by antibody (Ab) almost completely eliminated the killing effect of NK cells on hepatoma cell lines. Furthermore, neutralizing interferon (IFN)-γ by Ab could inhibit TRAIL expression and tumoricidal activity of NDV-stimulated NK cells. These results indicated a substantial role of TRAIL as an effector molecule in NDV-induced NK cells mediated tumoricidal activity. The NDV stimulation triggered TRAIL expression in mouse spleen NK cells could be mediated by IFN-γ induction.