Antitumor effects of Cypaliuruside F from Cyclocarya paliurus on HepG2 cells.

An undescribed dammarane triterpenoid saponin Cypaliuruside F was isolated from the leaves of Cyclocarya paliurus in our preliminary study. The MTT assay, flow cytometry, cell scratch, and DAPI staining were used to detect the antitumor effects of Cypaliuruside F on HepG2 cells. Subsequently, network pharmacology and molecular docking analysis were used to analyse the key targets of Cypaliuruside F against HCC. In addition, a Western blot was performed to determine the effects of Cypaliuruside F on the expression of key proteins in HepG2 cells. The experimental results indicated that the damarane triterpenoid saponin Cypaliuruside F from Cyclocarya paliurus inhibits the proliferation of HepG2 cells by inducing apoptosis and cell cycle arrest. These changes may promote the apoptosis of HepG2 cells by inhibiting the expression of mTOR, STAT3, and Bcl-2 while activating Bax.

l-Carnitine conjugated chitosan-stearic acid polymeric micelles for improving the oral bioavailability of paclitaxel.

A delivery system based on l-carnitine (LC) conjugated chitosan (CS)-stearic acid polymeric micelles has been developed for improving the oral bioavailability of paclitaxel (PTX) through targeting intestinal organic cation/carnitine transporter 2 (OCTN2). Stearic acid grafted chitosan (CS-SA), as micelle skeleton material, was synthesized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. The PTX-loaded micelles were prepared by solvent evaporation-hydration method, and the ligand LC was conjugated onto the micelle surface by anchoring its derivative stearoyl group to the lipophilic core of micelle. The modified polymeric micelles showed regular spherical shapes with small particle size of 157.1 ± 5.2 nm and high drug loading capacity of 15.96 ± 0.20 wt%, and the micelle stability in water was supported by low critical micelle concentration of 14.31 ± 0.21 µg/ml. The drug-loaded micelles presented a slow and incomplete in vitro release, and the pharmacokinetic studies indicated the micelle carriers increased the relative bioavailability of PTX to 165.8% against the commercial formulation. The enhancement effect on intestinal absorption was also confirmed by the intracellular uptake of Caco-2 cells. The proposed micelle carrier system manifested a prospective tool for oral drug delivery.

Proteomics analysis of G protein-coupled receptor kinase 4-inhibited cellular growth of HEK293 cells.

G protein-coupled receptor kinases (GRKs) are involved in a wide range of cellular physiology and pathological activities by specifically phosphorylating activated G protein-coupled receptors (GPCRs) to terminate GPCR signaling, or through regulating non-GPCR substrates. We recently reported that overexpression of GRK4 halts cell proliferation and induces cellular senescent phenotype in HEK293 cells. In this study, a quantitative proteomic assay was performed to analyze the protein profiles between HEK293 cells expressing and not expressing GRK4. Results revealed 39 upregulated and 59 downregulated differently expressed proteins (DEPs) in a total of 4124 identified proteins. Gene ontology (GO) annotation and functional enrichment revealed that the DEPs were related to metabolic processes regulated by the binding of these RNA/proteins under the biological processes. The Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis showed pathways of cell development, division, proliferation, apoptosis, aging, autophagy, cell death and cell cycle progression are involved in. Immunoblotting validation of expression of six key target proteins, CALM1, STAT3, CDK1, CDK6, TOP2A, and GRK4, which speculatively maintain abnormal activity in the above pathways, was consistent with the results of proteomics analysis. Lastly, a biological phenotype assay confirmed that GRK4 promoted HEK293 cell growth blockage and G1/0 arrest. Taken together, this study identified some novel molecules that involve in GRK4 signaling and provided valuable information for further studying the mechanisms underlying GRK4-induced proliferative inhibition. SIGNIFICANCE: A quantitative proteomic assay was performed in HEK293 cells expressing and not expressing GRK4 39 upregulated and 59 downregulated differently expressed proteins (DEPs)were identified. DEPs involved in pathways of cell development, division, proliferation, apoptosis, aging, autophagy, cell death and cell cycle progression. Biological phenotype assay confirmed that GRK4 prompted HEK293 cell growth blockage and G1/0 arrest.

G protein-coupled receptor kinase 4-induced cellular senescence and its senescence-associated gene expression profiling.

Senescent cells have lost their capacity for proliferation and manifest as irreversibly in cell cycle arrest. Many membrane receptors, including G protein-coupled receptors (GPCRs), initiate a variety of intracellular signaling cascades modulating cell division and potentially play roles in triggering cellular senescence response. GPCR kinases (GRKs) belong to a family of serine/threonine kinases. Although their role in homologous desensitization of activated GPCRs is well established, the involvement of the kinases in cell proliferation is still largely unknown. In this study, we isolated GRK4-GFP expressing HEK293 cells by fluorescence-activated cell sorting (FACS) and found that the ectopic expression of GRK4 halted cell proliferation. Cells expressing GRK4 (GRK4(+)) demonstrated cell cycle G1/G0 phase arrest, accompanied with significant increase of senescence-associated-ß-galactosidase (SA-ß-Gal) activity. Expression profiling analysis of 78 senescence-related genes by qRT-PCR showed a total of 17 genes significantly changed in GRK4(+) cells (≥ 2 fold, p < 0.05). Among these, 9 genes - AKT1, p16INK4, p27KIP1, p19INK4, IGFBP3, MAPK14, PLAU, THBS1, TP73 - were up-regulated, while 8 genes, Cyclin A2, Cyclin D1, CDK2, CDK6, ETS1, NBN, RB1, SIRT1, were down-regulated. The increase in cyclin-dependent kinase inhibitors (p16, p27) and p38 MAPK proteins (MAPK14) was validated by immunoblotting. Neither p53 nor p21Waf1/Cip1 protein was detectable, suggesting no p53 activation in the HEK293 cells. These results unveil a novel function of GRK4 on triggering a p53-independent cellular senescence, which involves an intricate signaling network.

Curcumol triggers apoptosis of p53 mutant triple-negative human breast cancer MDA-MB 231 cells via activation of p73 and PUMA.

Triple-negative breast cancer (TNBC; estrogen receptor-negative, progesterone receptor-negative and Her-2-negative) is often accompanied by a higher frequency of p53 gene mutations. Therefore, TNBC is challenging to treat due to a lack of biological targets and a poor sensitivity to conventional therapies. Curcumol is a monomer composition isolated from the ethanol extracts of Curcuma wenyujin, a Chinese medicinal herb traditionally used as a cancer remedy. Previous studies have revealed that curcumol is able to block proliferation in various human tumor cell lines. However, the underlying mechanisms have yet to be elucidated. The present study aimed to investigate the anticancer effects of curcumol in the human p53 mutant TNBC MDA-MB-231 cell line and its underlying mechanisms. Cell viability and growth were determined by MTT and a mice xenograft model assay, respectively. Cell cycle distribution was examined by flow cytometry. Apoptosis was evaluated by apoptotic morphology analysis with DAPI staining and flow cytometric analysis following Annexin V/propidium iodide staining. The protein expression in cells was evaluated by immunoblotting. Treatment of MDA-MB-231 cells with curcumol resulted in a significant inhibition of cell proliferation in vitro [half maximal inhibitory concentration (IC50)=240.7±85.0 µg/ml for 48 h and IC50=100.2±13.5 µg/ml for 72 h]. Curcumol treatment also resulted in the suppression of xenograft growth in vivo (100 or 200 µg/kg for 21 days), as well as G1 phase arrest and an apoptotic response, which were accompanied by the upregulation of p73 expression and the activation of the expression of p53 upregulated modulator of apoptosis (PUMA) and Bcl-2 antagonistic killer (Bak). No cleavage of poly (ADP-ribose) polymerase was detected. To the best of our knowledge, the present data demonstrate for the first time that curcumol inhibits the growth of MDA-MB-231 cells and triggers p53-independent apoptosis, which may be mediated by the p73-PUMA/Bak signaling pathway. Curcumol may, therefore, be a potential compound for use in the development of novel TNBC therapeutics.

[Signifinace of cyclin D1 expression in CNE2 cells processed by EGCG].

OBJECTIVE: To study the expression of Cyclin D1 in nasopharyngeal carcinoma cells processed by epigallocatechin gallate(EGCG) and it's significance, and revealed the anti-tumor mechanism of EGCG against nasopharyngeal carcinoma. METHOD: CNE-2 cells were treated by EGCG at different concentrations, the morphological changes of CNE-2 cells were observed by inverted microscope; the inhibition ratio of cell proliferation was detected by MTT colorimetric method, flow cytometry was used to analyze the changes of cell cycle. The expression of Cyclin D1 mRNA was detected by RT-PCR. RESULT: After treated by EGCG, the CNE2 cells decreased in amount and density, some of which became roll and small; Floating and dead cells can be seen in the inverted microscopy; cell proliferation was significantly inhibited in a time and dose dependent (P < 0.05). CNE-2 cells were arrested at G1/G0 phase. The expression of Cyclin D1 mRNA was down-regulated by EGCG with concentration and action time dependent (P < 0.05). CONCLUSION: EGCG resisted nasopharyngeal carcinoma by inhibiting the cell proliferation, The down regulation of Cyclin D1 mRNA expression in a time and dose dependent may be the possible mechanisms.

[Mechanism study on anti-proliferative effects of curcumol in human hepatocarcinoma HepG2 cells].

OBJECTIVE: To investigate the anti-proliferative effects of curcumol, an herbal extract from curcuma, in human hepatocarcinoma HepG2 cells, and its possible molecular mechanism. METHOD: The effects of curcumol on human hepatocarcinoma cells were assessed in vitro. Proliferation of HepG2 cells treated with various concentration (2.5-10 mg x L(-1)) of curcumol was determined using the MTT assay and the distribution of cell cycle of HepG2 cells was analyzed using the FCM technique. Expression of 14 cell cycle regulation-related genes were assessed by TaqMan real-time polymerase chain reaction (RT-PCR) method and Western blot. RESULT: Curcumol significantly inhibited the proliferation of HepG2 cells and induced G1 phase arrest in a dose- and time-dependent manner. The mRNA levels of pRB1, cyclin D1, CDK2, CDK8 and p27KIP1 were elevated, while cyclin A1 decreased, in both of the low (25 mg x L(-1)) and the high dose (100 mg x L(-1)) treatment of curcumol. There were no significant changes in the expression of either cyclin E1 or CDK4. The expression of p53 and its target genes p21WAF1 and Wip1 protein were increased. CONCLUSION: Curcumol can inhibit the proliferation of HepG2 cells in vitro and induce G1 arrest of cell cycle through mechanisms activating p53 and pRB pathways that involve genes of cyclin A1, CDK2, CDK8, p21WAF1 and p27KIP1.

[Effects of vitamin C on A549 cell proliferation, apoptosis and expressions of Caspase, Survivin].

BACKGROUND AND OBJECTIVE: It was proven that Vitamin C could inhibit the growth of many types of tumors as an antioxidant. The aim of this study is to explore role of Vitamin C in proliferation and apoptosis of lung carcinoma cell line A549 and the underlying mechanism. METHODS: A549 cells were cultured in vitro and incubated with Vitamin C. The cell viability was measured by growth curve and clonogentic assay. Flow cytometry was used to analyze cell cycle and detect apoptosis. The levels of expression of Caspase-3 mRNA and Survivin mRNA were detected by RT-PCR. RESULTS: Vitamin C of 400 microg/mL, 4 mg/mL significantly inhibited the growth of A549 cell lines (P = 0.024, P = 0.015, respectively). Flow cytometry showed that the cells major stagnation stayed in the G0/G1 and S phase and the apoptotic rate increased with time prolonged. Vitamin C signifiantly up-regulated the expression of Caspase-3 mRNA, but had no effect on Survivin mRNA. CONCLUSION: Vitamin C can inhibit the proliferation of A549, block A549 cells in G0/G1 and S phase, and induce apoptosis of A549 cells. Apotosis occurred by up-regulated the expression of Caspase-3.

[Study on heavy metals in growing area soils and young fruit of Citrus grandis 'Tomentosa'].

OBJECTIVE: To determine the status of heavy metals contamination in growing area soils and young fruits of Citrus grandis. METHOD: Application of Nemerow's index for heavy metals assessment of soil and young fruit of Citrus grandis, as well as according to national environmental quality standard for soils and green trade standards of importing & exporting medicinal plants & preparations. RESULT: The heavy metals content of most of the growing area soils of Citrus grandis rates as first, and of the rest ones rates as second. The heavy metals content in young fruits of Citrus grandis is within the limitation of quantity of criteria. CONCLUSION: The environmental quality of growing area soils of Citrus grandis in Huazhou City is totally in good.