Response of Subcutaneous Xenografts of Endometrial Cancer in Nude Mice to Inhibitors of Phosphatidylinositol 3-Kinase/Akt and Mitogen-Activated Protein Kinase (MAPK) Pathways: An Effective Therapeutic Strategy for Endometrial Cancer

Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.

PI3K-like Kinases Restrain Pim Gene Expression in Endothelial Cells

Pim kinases contribute to tumor formation and development of lymphoma,which shows enhanced DNA replication,DNA recombination and repair.Endothelial cells (ECs) express all the three members of Pim kinase gene family.We hypothesized that DNA repair gene would regulate Pim ex-pression in ECs.Human umbilical vein endothelial cells (HUVECs) were isolated and maintained in M199 culture medium.The cellular distribution of Pim-3 in ECs was determined by immunofluorescent staining.The siRNA fragments were synthesized and transfected by using Lipofectamine LTX.The total cellular RNA was extracted from the cells by using Trizol reagent.cDNAs were quantified by semi-quantity PCR.The effects of LY294002 and wortmannin on RNA stability in ECs were also ex-amined.Our data showed that LY294002 and wortmannin,phosphatidylinositol 3-kinase (PI3K) and PI3K-like kinase inhibitors,increased Pim mRNA expression in ECs without altering the mRNA stabil-ity.RNA interference (RNAi) targeting DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia telangiectasia mutated (ATM) increased mRNA expression of Pim-3 and Pim-1,respectively.Silencing of Akt decreased Pim-1 instead of Pm-2 and Pim-3 gene expression in ECs.But etoposide,a nucleoside analogue,which could activate DNA-PKcs and ATM,increased Pim expression in ECs.Our study indicates that the expression of Pim kinases is physiologically related to DNA-PKcs and ATM in ECs.

Mechanism of total glucosides from Chishao(Radix Paeoniae Rubra)on proliferation and apoptosis of hepatocellular carcinoma cells via phosphatase and tensin homolog deleted on chromosome ten/phosphatidylinositol 3-kinase/protein kinase B signaling pathway

OBJECTIVE:To investigate the possible molecular mechanism of total glycosides of Chishao(Radix Paeoniae Rubra)(TG-RPR)on proliferation and apoptosis of hepatocellular carcinoma cells.METHODS:The proliferation of TG-RPR on Hep G2 cells was detected using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.The apoptosis of Hep G2 cells was measured by annexin V-FITC/double staining.The phosphatase and tensin homolog deleted on chromosome ten(PTEN)/phosphatidylinositol 3-kinase(PI3 K)/protein kinase B(Akt)signaling pathway was evaluated by Western Blot and reverse transcription-polymerase chain reaction(RT-PCR).RESULTS:TG-RPR can up-regulation the expression of pro-apoptotic factors such as PTEN and BCL2-Associated X(Bax),down-regulation the expression of anti-apoptotic factors including B-cell lymphoma-2(Bcl-2),PI3 K,and Akt.CONCLUSION:TG-RPR significantly inhibits the proliferation of Hep G2 cells in a dose-dependent manner and promotes apoptosis.These results demonstrated TG-RPR has significant inhibitory effect on Hep G2 cells.These results identify a critical role of TG-RPR in proliferation and apoptosis of Hep G2 cells via modulating PTEN/PI3 K/Akt signaling pathway.TG-RPR may offer a promise as a potential pharmaceutical therapy for hepatocellular carcinoma.

Efficacy of Ganshuang granules(肝爽颗粒)on non-alcoholic fatty liver and underlying mechanism:a network pharmacology and experimental verification

OBJECTIVE:To investigate the potential pharmacological mechanisms of Ganshuang granules(肝爽颗粒,GSG)in treating non-alcoholic fatty liver(NAFLD).METHODS:All the active components and targets of GSG were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform.Protein-Protein interaction network,Kyoto Encyclopedia of Genes and Genomes and Gene Ontology function annotation of common targets were analyzed to predict the mechanisms of action of GSG in the treatment of NAFLD.Then,the mouse models of NAFLD were constructed in a diet-induced manner and treated with GSG.The levels of interleukin 6(IL-6),tumor necrosis factor-alpha(TNF-α)and phosphatidylinositol 3-kinase/protein kinase B(PI3K/AKT)pathway-related proteins in the liver of mice in each group were measured by enzyme linked immunosorbent assay and Western blot,respectively.RESULTS:Network pharmacology revealed a total of 159 potential targets of GSG for the treatment of NAFLD.Functional enrichment analysis indicated that the PI3K/AKT signaling pathway may be involved during GSG treatment of NAFLD.Further experiments showed that the significantly decreased alanine aminotransferase,aspartate aminotransferase,alkaline phosphatase,total cholesterol,triglyceride and low-density lipoprotein cholesterol levels in NAFLD model mice serum after GSG treatment,as well as the expression levels of IL-6 and TNF-αin the liver.Furthermore,drug intervention increased the protein expression levels of phosphorylated-PI3K(P-PI3K)and P-AKT in the liver of the model group mice,and decreased the protein expression level of sterol regulatory element-binding protein 1.CONCLUSION:We found that GSG is effective in treating NAFLD and the potential therapeutic targets may be involved in PI3K/AKT signaling pathway.

Effects of electroacupuncture at Taichong(LR 3) and Baihui(DU 20)on cardiac hypertrophy in rats with spontaneous hypertension

OBJECTIVE: To investigate the effects of electroacupuncture(EA) at Taichong(LR 3) and Baihui(DU 20)on myocardial hypertrophy in spontaneously hypertensive rats(SHRs).METHODS: Thirty-six SHRs were randomly assigned to model, EA, and Losartan groups, with twelve rats per group. Twelve Wistar Kyoto rats were selected as the normal control group. Systolic blood pressure(SBP) and cardiac function were measured in all rats.Expression levels of factors associated with the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR) pathway were evaluated by Western blotting and real-time PCR.Pathological changes of the heart tissue were observed by hematoxylin-eosin staining.RESULTS: After treatment, enhanced SBP was significantly decreased in the EA and Losartan groups compared with the model group(P < 0.01). Echocardiographic and morphological analyses revealed that enhanced end-diastolic interventricular septal thickness and left ventricular posterior wall thickness, as well as ratio of left ventricular weight to body weight were markedly diminished in the EA and Losartan groups(P < 0.01 or P < 0.05), while reduced left ventricular end-diastolic dimension and left ventricular ejection fraction were significantly ameliorated(P < 0.01). Real-time PCR and western blotting analyses showed that the expression levels of PI3K,Akt, and mT OR in SHRs were significantly up-regulated by EA and Losartan(P < 0.01), while the expression levels of PTEN and ANP were down-regulated(P < 0.01).CONCLUSION: EA at Taichong(LR 3) and Baihui(DU20) inhibited the development of cardiac hypertrophy and improved the cardiac function in SHRs, possibly through regulation of the PI3K/Akt/mTOR signalling pathway.