Hyperoside suppresses hypoxia-induced A549 survival and proliferation through ferrous accumulation via AMPK/HO-1 axis.

BACKGROUND: Hypoxia is commonly existed in tumors and lead to cancer cell chemo/radio-resistance. It is well-recognized that tumor hypoxia is a major challenge for the treatment of various solid tumors. Hyperoside (quercetin-3-O-galactoside, Hy) possesses antioxidant effects and has been reported to protect against hypoxia/reoxygenation induced injury in cardiomyocytes. Therefore, Hy may be attractive compound applicable to hypoxia-related diseases. PURPOSE: This study was designed to determine the role of Hy in hypoxia-induced proliferation of non-small cell lung cancer cells and the underlying mechanism. STUDY DESIGN AND METHODS: A549, a human non-small cell lung cancer (NSCLC) cell line, was used in the present study. 1% O2 was used to mimic the in vivo hypoxic condition of NSCLC. The potential mechanisms of Hy on hypoxia-induced A549 survival and proliferation, as well as the involvement of AMPK/HO-1 pathway were studied via CCK-8 assay, EdU staining, flow cytometry, qRT-PCR and western blot. RESULTS: We showed that pretreatment with Hy suppressed hypoxia-induced A549 survival and proliferation in dose-dependent manner. In terms of mechanism, hypoxia-treated A549 showed the lower AMPK phosphorylation and the reduced HO-1 expression, which were reversed by Hy pretreatment. Both AMPK inhibitor (Compound C) and HO-1 activity inhibitor (Zinc protoporphyrin IX) abolished Hy-evoked A549 cell death under hypoxia stimuli. Of note, Ferrous iron contributed to Hy-induced A549 cell death under hypoxia, while Hy had no effect on lipid peroxidation under hypoxia. CONCLUSION: Taken together, our results highlighted the beneficial role of Hy against hypoxia-induced A549 survival and proliferation through ferrous accumulation via AMPK/HO-1 axis.

Combination of PEI-Mn0.5Zn0.5Fe2O4 nanoparticles and pHsp 70-HSV-TK/GCV with magnet-induced heating for treatment of hepatoma.

BACKGROUND: To explore a new combination of thermal treatment and gene therapy for hepatoma, a heat-inducible herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) gene therapy system was developed in which thermal energy generated by Mn0.5Zn0.5Fe2O4 nanoparticles (MZF-NPs) under an alternating magnetic field was used to activate gene expression. METHODS: First, a recombinant eukaryotic plasmid, pHsp 70-HSV-TK, was constructed as a target gene for therapy. This recombinant plasmid was used to transfect SMMC-7721 hepatoma cells and the gene expression was evaluated. Magnet-induced heating was then applied to cells to assess the antihepatoma effects of the polyethylenimine (PEI)-MZF-NPs/pHsp 70-HSV-TK/GCV complex, in vitro and in vivo. RESULTS: The results showed that cells were successfully transfected with pHsp 70-HSV-TK and that expression levels of HSV-TK remained stable. Both in vitro and in vivo results indicated that the combination of gene therapy and heat treatment resulted in better therapeutic effects than heating-alone group. The rates of apoptosis and necrosis in the combined treatment group were 49.0% and 7.21%, respectively. The rate of inhibition of cell proliferation in the combined treatment group was significantly higher (87.5%) than that in the heating-alone group (65.8%; P<0.01). The tumor volume and mass inhibition rates of the combined treatment group were 91.3% and 87.91%, respectively, and were significantly higher than the corresponding rates of the heating-alone group (70.41% and 57.14%; P<0.01). The expression levels of Stat3 and Bcl-xL messenger RNA and p-Stat3 and Bcl-xL protein in the combined treatment group were significantly lower than those in the other groups (P<0.01). The expression levels of Bax messenger RNA and protein in the recombinant plasmid group were significantly higher than those in the other groups (P<0.01). CONCLUSION: It can therefore be concluded that the combined application of heat treatment and gene therapy has a synergistic and complementary effect and that PEI-MZF-NPs can simultaneously act both as a nonviral gene vector and a magnet-induced source of heat, thereby representing a viable approach for the treatment of cancer.

Neohesperidin induces cellular apoptosis in human breast adenocarcinoma MDA-MB-231 cells via activating the Bcl-2/Bax-mediated signaling pathway.

Neohesperidin, a flavonoid compound found in high amounts in Poncirus trifoliata, has free radical scavenging activity. For the first time, our study indicated that neohesperidin also induces cell apoptosis in human breast adenocarcinoma MDA-MB-231 cells, which was possibly mediated by regulating the P53/Bcl-2/Bax pathway. MDA-MB-231 cells were subjected to treatment with neohesperidin. MTT and Trypan blue exclusion assays were applied to assess the cell viability. The morphological changes of cells were observed using an inverted microscope, and cell apoptosis was detected by flow cytometric analysis. Immunoblot analysis was conducted to evaluate the protein expressions of apoptosis-related genes, including P53, Bcl-2 and Bax. Our results indicated that the proliferation of MDA-MB-231 cells was inhibited by the treatment with neohesperidin in a time- and dose-dependent manner. The IC50 values of neohesperidin at 24 and 48 h were 47.4 +/- 2.6 microM and 32.5 +/- 1.8 microM, respectively. The expressions of P53 and Bax in the neohesperidin-treated cells were significantly up-regulated, while that of Bcl-2 was down-regulated. Our study suggested that neohesperidin could induce apoptosis of MDA-MB-231 cells, a process which was associated with the activation of the Bcl-2/Bax-mediated signaling pathway.

Arsenic trioxide-induced growth arrest of human hepatocellular carcinoma cells involving FOXO3a expression and localization.

Human hepatocellular carcinoma (HCC) remains incurable with current therapies, and novel biologically based therapies are urgently needed. Arsenic agents have long been used as anticancer agents in traditional Chinese medicine. In this study, to evaluate the effect of As(2)O(3) on HCC cells, we investigate cell growth inhibition, cell cycle arrest, and the molecular mechanism after As(2)O(3) treatment in human HCC cells in vitro. We detected the proliferation of HCC cells by the Cell Counting Kit and FACS/Calibur Flow Cytometer and analyzed the expression and localization of FOXO3a by Western blotting Analysis and Cell Fractionation. Furthermore, we study the Akt activation after As(2)O(3) treatment and the HCC cells proliferation after combination of As(2)O(3) with PI3K inhibitor Wortmannin. As(2)O(3) significantly inhibited the proliferation of all the three HCC cell lines (SMMC7721, HepG2, Hep3B) tested in this study in a dose-dependent manner. Western blotting revealed that treatment HCC cells HepG2 with As(2)O(3) resulted in the increasing of FOXO3a expression and triggered phosphorylation of FOXO3a at the Thr(32) residue decrease. This FOXO3a accumulation correlated well with the As(2)O(3)-induced reduction of active Akt. Nuclear and cytoplasmic protein extracts isolated from the HCC cell line HepG2 revealed that the amount of nuclear FOXO3a was increased by treatment with As(2)O(3), whereas the amount of cytoplasmic FOXO3a was decreased. Both As(2)O(3) and PI3K/Akt inhibitor Wortmannin induced cell cycle arrest. However, compared with As(2)O(3) alone, PI3K inhibitor Wortmannin combined with As(2)O(3) enhanced the antitumor effect of As(2)O(3) through induction of apoptosis. These findings suggest that As(2)O(3) at a clinically safe concentration may be an effective chemotherapeutic agent, and that As(2)O(3) and PI3K/Akt inhibitor Wortmannin may synergize for HCC cells. Taken together, the present study may suggest a specific molecular mechanism by which HCC cell lines are susceptible to the As(2)O(3) therapy through FOXO3a expression and localization.