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Background: Graphene and its derivative graphene oxide (GO) have been implicated in a wide range of anticancer effects., Purpose: The objective of this study was to systematically evaluate the toxicity and underlying mechanisms of GO on two osteosarcoma (OSA) cancer cell lines, MG-63 and K 7 M 2 cells., Methods: MG-63 and K 7 M 2 cells were treated by GO (0-50 µg/mL) for various time periods. Cell viability was tested by MTT and Live/Dead assays. A ROS Detection Kit based on DHE oxidative reaction was used for ROS detection. An Annexin V-FITC Apoptosis Kit was used for apoptosis detection. Dansylcadaverine (MDC) dyeing was applied for seeking unspecific autophagosomes. Western blot and Immunofluorescence analysis were used for related protein expression and location., Results: K 7 M 2 cells were more sensitive to GO compared with MG-63 cells. The mechanism was attributed to the different extent of the generation of reactive oxygen species (ROS). In K 7 M 2 cells, ROS was easily stimulated and the apoptosis pathway was subsequently activated, accompanied by elevated expression of proapoptosis proteins (such as caspase-3) and decreased expression levels of antiapoptosis proteins (such as Bcl-2). A ROS inhibitor ( N -acetylcysteine) could alleviate the cytotoxic effects of GO in K 7 M 2 cells. However, the production of ROS in MG-63 cells was probably inhibited by the activation of an antioxidative factor, nuclear factor-E2-related factor-2, which translocated from the cytoplasm to the nucleus after GO treatment, while a nuclear factor-E2-related factor-2 inhibitor (ML385) significantly increased ROS production in MG-63 cells when combined with GO treatment. In addition, autophagy was simultaneously stimulated by characteristic autophagosome formation, autophagy flux, and increased the expression level of autophagy-related proteins (such as LC3I to LC3II conversion, ATG5, and ATG7)., Conclusion: This paper proposes various underlying mechanisms of the anticancer effect of GO. The novel synthetic use of GO with an oxidizing agent is the key step for further potential applications in clinical OSA cancer therapy., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Polydatin (PD), a component isolated from Polygonum cuspidatum, has a number of biological functions. However, the antitumor activity of PD has been poorly investigated. In this study, the effect of PD on cell proliferation was evaluated by thiazolyl blue tetrazolium bromide assay. Cell cycle distribution and apoptosis were investigated by flow cytometry. The phosphorylation levels of panel of phosphor-kinases were detected by human phospho-kinase arrays. The expression of several proteins associated with cell cycle and apoptosis were analyzed by Western blot analysis. Results showed that PD effectively inhibited the growth of MDA-MB-231 and MCF-7 breast cancer cell lines. Cell cycle analysis demonstrated that PD induced S-phase cell cycle arrest. Human phosphor-kinase arrays showed that the phosphorylation level of cAMP response element-bingding proteins(Creb) was down-regulated, and the results were further confirmed by Western blot analysis. Western blot analysis showed that the expression of protein of cyclin D1 decreased in a time- and dose- dependent manner. Results suggest that PD is a potential therapeutic natural compound.

THO complex 1 (Thoc1) is a human nuclear matrix protein that binds to the retinoblastoma tumor suppressor retinoblastoma protein (pRb). While some studies suggest that Thoc1 has characteristics of a tumor suppressor protein, whether Thoc1 can inhibit lung cancer cell growth is not clear. In the present study, we observed that Thoc1 is lowly expressed in the lung cancer cell lines SPC-A1 and NCI-H1975. Then, we investigated the potential effects of Thoc1 on lung cancer cell proliferation, cell cycle and apoptosis after stable transfection of these lines with a Thoc1 expression vector. We found that overexpression of Thoc1 can inhibit cell proliferation, induce G2/M cell cycle arrest and promote apoptosis. Further investigation indicated that overexpression of Thoc1 is involved in the inhibition of cell cycle-related proteins cyclin A1 and B1 and of pro-apoptotic factors Bax and caspase-3. In vivo experiments showed that tumors overexpressing Thoc1 display a slower growth rate than the control xenografts and show reduced expression of the protein Ki-67, which localized on the nuclear membrane. Taken together, our data show that in lung cancer cells, Thoc1 inhibits cell growth through induction of cell cycle arrest and apoptosis. These results indicate that Thoc1 may be used as a novel therapeutic target for human lung cancer treatment.

Objective: To investigate the effects of genistein on cell proliferation and apoptosis in HCT-116 human colon cancer cells and its possible mechanism., Methods: After treatment with genistein, cell proliferation was determined by MTT assay. Cell cycle, cell apoptosis, intracellular reactive oxygen species ( ROS) and mitochondrial membrane potential were determined by flow cytometry. Furthermore, ultrastructural change was observed using transmission electron microscopy (TEM)., Results: Genistein inhibited cell proliferation in a dose- and time-dependent manner. Genistein treatment in 0 - 100 micromol/L resulted in G2/M cell cycle arrest. The ratio of Sub-G1 increased from (1.63 +/- 0.44)% to (8.33 -1.51)% (P < 0.01). The ratio of early apoptosis increased from (1.93 +/- 0.32)% to (7.25 +/- 0.86)% (P < 0.01). Genistein caused characteristic apoptotic changes in TEM observation. Genistein treatment in 100 micromol/L increased intracellular ROS level to a peak at 2 h [2 h, (15.53 +/- 1.55)% vs. 0 h, (8.57 +/- 0.35)%, P < 0.01] and decreased mitochondrial membrane potential to a bottom at 1 h [1 h, (0.82 +/- 0.02)% vs. 0 h, (6.70 +/- 0.21)%, P < 0.01)., Conclusion: Our findings indicated that genistein inhibits cell proliferation, induces G2/M cell cycle arrest and apoptosis in colon cancer cell line HCT-116, with the increase of intracellular ROS level and decrease of mitochondrial membrane potential.

Fructus Aurantii (FA) is a traditional herbal medicine that has been widely used for thousands of years in China and possesses a variety of pharmacological effects. However, the active ingredients in FA and the potential mechanisms of its therapeutic effects have not been fully explored. Here, we applied a network pharmacology approach to explore the potential mechanisms of FA. We identified 5 active compounds from FA and a total of 209 potential targets to construct a protein-protein interaction (PPI) network. Prostaglandin G/H synthase 2 (PTGS2), heat shock protein 90 (HSP90), cell division protein kinase 6 (CDK6), caspase 3 (CASP3), apoptosis regulator Bcl-2 (Bcl-2), and matrix metalloproteinase-9 (MMP9) were identified as key targets of FA in the treatment of multiple diseases. Gene ontology (GO) enrichment demonstrated that FA was highly related to transcription initiation from RNA polymerase II promoter, DNA-templated transcription, positive regulation of transcription, regulation of apoptosis process, and regulation of cell proliferation. Various signaling pathways involved in the treatment of FA were identified, including pathways in cancer and pathways specifically related to prostate cancer, colorectal cancer, PI3K-Akt, apoptosis, and non-small-cell lung cancer. TP53, AKT1, caspase 3, MAPK3, PTGS2, and BAX/BCL2 were related key targets in the identified enriched pathways and the PPI network. In addition, our molecular docking results showed that the bioactive compounds in FA can tightly bind to most target proteins. This article reveals via network pharmacology research the possible mechanism(s) by which FA exerts its activities in the treatment of various diseases and lays a foundation for further experiments and the development of a rational clinical application of FA. [ABSTRACT FROM AUTHOR]