IFN-γ enhances the antitumor activity of attenuated salmonella-mediated cancer immunotherapy by increasing M1 macrophage and CD4 and CD8 T cell counts and decreasing neutrophil counts.

Bacteria-mediated cancer immunotherapy (BCI) inhibits tumor progression and has a synergistic antitumor effect when combined with chemotherapy. The anti- or pro-tumorigenic effects of interferon-γ (IFN-γ) are controversial; hence, we were interested in the antitumor effects of IFN-γ/BCI combination therapy. Here, we demonstrated that IFN-γ increased the tumor cell killing efficacy of attenuated Salmonella by prolonging the survival of tumor-colonizing bacteria via blockade of tumor-infiltrating neutrophil recruitment. In addition, IFN-γ attenuated Salmonella-stimulated immune responses by stimulating tumor infiltration by M1-like macrophages and CD4+ and CD8+ T cells, thereby facilitating tumor eradication. Taken together, these findings suggest that combination treatment with IFN-γ boosts the therapeutic response of BCI with S. tΔppGpp, suggesting that IFN-γ/BCI is a promising approach to immunotherapy.

Ursolic acid-enriched kudingcha extract enhances the antitumor activity of bacteria-mediated cancer immunotherapy.

BACKGROUND: Bacteria-mediated cancer immunotherapy (BCI) robustly stimulates the immune system and represses angiogenesis, but tumor recurrence and metastasis commonly occur after BCI. The natural product Ilex kudingcha C. J Tseng enriched with ursolic acid has anti-cancer activity and could potentially augment the therapeutic effects of BCI. The objective of the present study was to determine potential additive effects of these modalities. METHODS: We investigated the anti-cancer activity of KDCE (Kudingcha extract) combined with S.t△ppGpp in the mice colon cancer models. RESULTS: In the present study, KDCE combined with S.t△ppGpp BCI improved antitumor therapeutic efficacy compared to S.t△ppGpp or KDCE alone. KDCE did not prolong bacterial tumor-colonizing time, but enhanced the antiangiogenic effect of S.t△ppGpp by downregulatingVEGFR2. We speculated that KDCE-induced VEGFR2 downregulation is associated with FAK/MMP9/STAT3 axis but not AKT or ERK. CONCLUSIONS: Ursolic acid-enriched KDCE enhances the antitumor activity of BCI, which could be mediated by VEGFR2 downregulation and subsequent suppression of angiogenesis. Therefore, combination therapy with S.t△ppGpp and KDCE is a potential cancer therapeutic strategy.

Chlorogenic acid-enriched extract of Ilex kudingcha C.J. Tseng tea inhibits neutrophil recruitment in injured zebrafish by promoting reverse migration via the focal adhesion pathway.

Neutrophil-regulated inflammation plays crucial roles in tissue damage and repair. Dysregulation of the neutrophil response system can contribute to diseases such as cancer. Clearance of excessive neutrophils at the site of inflammation by reverse migration provides a promising strategy to mitigate the negative effects. Chlorogenic acid treatment of injured zebrafish embryos showed low-developmental toxicity. Using a transgenic zebrafish Tg (mpx: egfp) model, chlorogenic acid-enriched kudingcha extract promoted neutrophil reverse migration via phosphorylation of ERK and AKT. Using i-TRAQ analysis, differentially expressed proteins involved in focal adhesion were identified, such as: Cdc42, SRC, MLC, ITGA, and Calpain. In support of this, ERK and AKT proteins are involved in the focal adhesion pathway. Real time qPCR determined that CGA downregulates genes associated with cancer metastasis, such as: HSPA5, YWHAZ, RP17, and ITGAV. Together, these results suggest that CGA-enriched Kudingcha extract may have potential as an anticancer or anti-inflammatory therapeutic agent. PRACTICAL APPLICATIONS: Ilex kudingcha C.J Tseng, commonly referred to as the large-leaved kudingcha, is a tea variety naturally rich in chlorogenic acid. Chlorogenic acid, the ester of caffeic and quinic acids, has antioxidant, antibacterial, anticancer, and anti-inflammatory, activities. Kudingcha has several known biological functions, including: anticancer, anti-inflammatory, antidiabetic, and hypolipidemic effects. Treatment with kudingcha extract reduces the recruitment of neutrophils, potentially by inhibiting focal adhesion, and activation of cancer metastasis-related genes. Importantly, kudingcha extract could be used as an alternative nutritional supplement for anticancer or anti-inflammation via its ability to suppress neutrophil recruitment.

QSAR Classification-Based Virtual Screening Followed by Molecular Docking Identification of Potential COX-2 Inhibitors in a Natural Product Library.

Developments of natural inhibitors to prevent the function of cyclooxygenase-2 (COX-2) protein, responsible for a variety of inflammations and cancers, are a major challenge in the scientific community. In this study, robust QSAR classification models for predicting COX-2 inhibitor were developed, by which the self-organizing feature map neural network and random forest (RF) were adopted to improve the prediction of classification model ability. The F-score-based criterion combined with RF was used for feature selection, and good performance for COX-2 inhibitor prediction in overall accuracy was demonstrated. We used this model as a virtual screening tool for identifying the potential COX-2 inhibitor from a natural product library and found potential hit compounds. This compound further screened by applying molecular docking simulation identified five potential hits such as osthole, kavain, vanillyl acetone, myristicin, and psoralen, having a comparable binding affinity to COX-2 protein. However, in cell experiment, three hit compounds revealed COX-2 inhibitory activity in mRNA and protein level such as osthole, kavain, and psoralen.

Chlorogenic Acid-Enriched Extract of Ilex kudingcha C.J. Tseng Inhibits Angiogenesis in Zebrafish.

Kudingcha is a particularly bitter tasting tea that has been widely used in China to eliminate fever and itching eyes, and to clear blood toxins. Kudingcha is considered of value for its potential anticancer effects that are attributed to the presence of characteristic bioactive ingredients. The chlorogenic acid (CGA) derivatives 3-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, 3,5-0-dicaffeoylquinic acid, and 4,5-0-dicaffeoylquinic acid were separated from Ilex kudingcha C.J. Tseng extract by high-performance liquid chromatography (HPLC)-photodiode array detector (PDA) and HPLC-nuclear magnetic resonance (NMR). In Tg(flk1:EGFP) zebrafish embryos at 52 hours postfertilization (hpf), angiogenesis was significantly inhibited by kudingcha extract (KDCE) at concentrations of 400 and 500 µg/mL and CGA also showed significant inhibition in embryos treated with 80, 100, and 130 µg/mL. Endothelial cell apoptosis showed a dose-dependent increase in response to KDCE and CGA. CGA derivatives from KDCE could have potential as anticancer agents against tumor angiogenesis.

Radiotherapy combined with an engineered Salmonella typhimurium inhibits tumor growth in a mouse model of colon cancer.

The engineered Salmonella typhimurium ΔppGpp (S.t ΔppGpp) has been studied in terms of its ability to carry imaging probes (bacterial luciferase, Lux) for tumor imaging or carry therapeutic molecules (Cytolysin A) to kill cancer cells. To establish a novel cancer therapy, bacterial therapy was combined with radiotherapy using the attenuated strain S.t ΔppGpp/pBAD-ClyA. Radiotherapy (21Gy) contributed to S. typhimurium colonization in a colon tumor (CT26) model of BALB/c mice. The combination of bacterial therapy and radiotherapy treatments reduced tumor growth compared with only bacterial therapy.

Ketanserin, a 5-HT2 antagonist, directly inhibits the ATP-sensitive potassium channel in mouse ventricular myocytes.

The effects of ketanserin, a 5-HT2 antagonist, on the ATP-sensitive K+ (K(ATP)) channels were studied in mouse ventricular myocytes using patch clamp technique. Under the whole-cell voltage clamp conditions, ketanserin (1-100 microM) reversibly inhibited pinacidil-induced K(ATP) current in a concentration-dependent fashion with a Ki value of 9.36 microM and the Hill coefficient was 0.67. This inhibition was developed even with the presence of 5-hydroxytryptamine (100 microM) in the bath. Prazosin, a selective alpha1-antagonist, also failed to mimic the effect of ketanserin. Ketanserin did not affect the channel activity in inside-out configuration under the ATP-free internal solution. Furthermore, ketanserin applied to the external solution did not affect the pinacidil-induced channel activity in the cell-attached patches, but did inhibit it when applied into the pipette. These results suggest that the inhibitory action of ketanserin observed in this study was probably due to a direct action on the K(ATP) channel rather than to an action through the 5-HT2 receptor or alpha1-adrenoceptor blockade, and that the antiarrhythmic activity of ketanserin against cardiac arrhythmias induced in the ischemic/reperfused heart is at least in part attributable to its inhibition of the K(ATP) channel.