OBJECTIVE: To explore the association between expression of ADAM17 and cetuximad resistance in human colorectal cancer SW480 cells. METHODS: The expression of ADAM17 was detected using Western blotting in different human colorectal cancer cell lines, and the cells highly expressing ADAM17 were selected as the target cells. SW480 cells were transfected with ADAM17-siRNA 1 and ADAM17-siRNA 2 and the changes in the expression of ADAM17 protein were detected using Western blotting. SW480 cells were exposed to cetuximad for 24 h and the cell apoptosis was analyzed using flow cytometry. Transwell assay was used to examine the migration ability of SW480 cells with different expression levels of ADAM17; Western blotting was used to analyze the changes in the expressions of AKT signaling pathway-related proteins in the treated cells. RESULTS: The baseline expressions of ADAM17 were significantly higher in SW480 cells than in the other human colorectal cancer cell lines tested ( < 0.05). Both ADAM17-siRNA 1 and 2 effectively reduced the expression of ADAM17 protein in SW480 cells. Knockdown of ADAM17 with siRNA 1 significantly increased the sensitivity of SW480 cells to tocetuximad ( < 0.05), obviously inhibited the cell proliferation, migration and invasion, and significantly reduced the expressions of p-EGFR and p-AKT in the cells ( < 0.001). CONCLUSIONS ADAM17 knockdown obviously inhibits EGFR-AKT signaling pathway and increases the sensitivity of SW480 cells to tocetuximad.
ADAM17 Protein ; genetics ; metabolism ; Antineoplastic Agents, Immunological ; pharmacology ; Apoptosis ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cetuximab ; pharmacology ; Colorectal Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; Drug Resistance, Neoplasm ; genetics ; ErbB Receptors ; metabolism ; Gene Knockdown Techniques ; Humans ; Neoplasm Invasiveness ; Oncogene Protein v-akt ; metabolism ; RNA, Small Interfering ; Signal Transduction ; Transfection ; methods

This study investigated the effects of SIRT1 gene knock-out on osteoarthritis in mice, and the possible roles of SREBP2 protein and the PI3K/AKT signaling pathway in the effects. Mice were randomly divided into a normal group and a SIRT1 gene knock-out group (6 mice in each group). In these groups, one side of the knee anterior cruciate ligament was traversed, and the ipsilateral medial meniscus was cut to establish an osteoarthritis model of knee joint. The countralateral synovial bursa was cut out, serving as controls. The knee joint specimens were then divided into four groups: SIRT1control group (group A, n=6); SIRT1osteoarthritis group (group B, n=6); SIRT1control group (group C, n=6); SIRT1osteoarthritis group (group D, n=6). HE staining, Masson staining, Safranin O-Fast Green staining and Van Gieson staining were used to observe the morphological changes in the articular cartilage of the knee. Immunohistochemical staining was employed to detect the expression of SIRT1, SREBP2, VEGF, AKT, HMGCR and type II collagen proteins. SA-β-gal staining was utilized to evaluate chondrocyte aging. The results showed clear knee joint cartilage destruction and degeneration in the SIRT1osteoarthritis group. The tidal line was twisted and displaced anteriorly. Type II collagen was destroyed and distributed unevenly. Compared with the SIRT1osteoarthritis group and SIRT1control group, SIRT1 protein expression was not obviously changed in the SIRT1osteoarthritis group (P>0.05), while the expression levels of the SREBP2, VEGF and HMGCR proteins were significantly increased (P<0.05) and the levels of AKT and type II collagen proteins were significantly decreased (P<0.05). SIRT1 gene knock-out may aggravate cartilage degeneration in osteoarthritis by activating the SREBP2 protein-mediated PI3K/AKT signalling pathway, suggesting that SIRT1 gene may play a protective role against osteoarthritis.
Animals ; Cartilage ; pathology ; Chondrocytes ; metabolism ; Collagen Type II ; metabolism ; Disease Models, Animal ; Humans ; Knee Joint ; metabolism ; pathology ; Mice ; Mice, Knockout ; Oncogene Protein v-akt ; genetics ; Osteoarthritis ; genetics ; pathology ; Phosphatidylinositol 3-Kinases ; genetics ; Signal Transduction ; genetics ; Sirtuin 1 ; genetics ; Sterol Regulatory Element Binding Protein 2 ; biosynthesis ; genetics ; Vascular Endothelial Growth Factor A ; biosynthesis

OBJECTIVETo investigate the inhibition effect of curcumin on the proliferation of the human esophageal carcinoma cell line Ec109 and its impact on PEN/PI3K/Akt signaling pathway.

METHODSEsophageal carcinoma Ec109 cells were cultured in vitro conventionally and were treated with curcumin at different concentrations. The cell proliferation level was examined by MIT colorimetry, the ultrastructure of curcumin-treated Ec109 cells were detected with transmission electron microscope (TEM) and cell apoptosis was observed by FCM with AnnexinV-FITC/PI double staining. The protein levels of PTEN, Akt, GSK3P and Caspase 3 of curcumin-treated Ec109 cells were detected by Western blot.

RESULTSMTT test showed that curcumin could inhibit the proliferation of Ec109 cells in a time and concentration-dependent manner. TEM examination indicated that curcumin could induce Ec109 cell apoptosis. FCM detection showed that Ec109 cell apoptotic rate increased significantly with the increase of drug concentration. On the other hand, curcumin could promote the expression of PTEN, GSK3beta and Caspase 3 yet reduce the expression of Akt.

CONCLUSIONCurcumin could obviously up-regulate the expression of PTEN, GSK3beta and Caspase 3, surpress PI3K/Akt signaling pathway and hence inhibit the proliferation of Ec109 cells.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Curcumin ; pharmacology ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Oncogene Protein v-akt ; metabolism ; PTEN Phosphohydrolase ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Signal Transduction ; drug effects

OBJECTIVETo extract two kinds of phenols 4-hydroxy-3, 5-dimethoxy-4-(2-oxopropyl) cyclohexa-2, 5-dien-l-one and 6-methoxy-5,7-dihydroxy coumarin (named as I and H compounds respectively) from Ajania salicifolia and to investigate their antioxidation and cytotoxicity to tumors and explore their pro-apoptosis mechanism.

METHODSThe antioxidant activities of two compounds were assessed by ABTS and DPPH radical-scavenging assays. Two compounds were evaluated for their cytotoxicity against human chronic myelogenous leukemia (K562) cells using the MIT assay. The expression of NF-kappaB P65 mRNA in K562 apoptotic cells was measured by reverse transcription-polymerase chain reaction (RT-PCR), real-time quantitative PCR. In addition, protein expression levels of the NF-ICB P65, p-Akt, Fas, P-catenina and E-cadherin were also measured by Western blot.

RESULTS(1) We found that compound I displayed significant inoxidizability, while compound II had no obvious antioxidizability. (2) In cytotoxicity experiments, compound I didn't display cytotoxicity while compound H displayed obvious cytotoxicity. (3) Compared with the blank group, the expression of NF-kappaB P65 mRNA in K562 cell after treatment with compound II was obviously up-regulated. (4) Compared with the blank group, the expression levels of NF-kappaB P65, Fas, beta-catenina and E-cadherin were significantly increased in compound II treated groups and it appeared obvious dose-effect relationship between the expression of protein and drug concentration.

CONCLUSIONTwo phenols have obvious antioxidizability and cytotoxicity respectively. On the one hand, the tumor-suppressing mechanism of compound II maybe act by up-regulation the expression of NF-kappaB P65 and Fas protein; thereby, affecting the classical Fas apoptosis signaling pathways. On the other hand, it can also up-regulate the expression of protein beta-catenin and E-cadherin, which participate in the adhesion between cells, and accordingly, playing an important role in preventing the proliferation and metastasis of cancer cells.

Apoptosis ; Asteraceae ; chemistry ; Cadherins ; metabolism ; Humans ; K562 Cells ; Oncogene Protein v-akt ; metabolism ; Phenols ; chemistry ; Signal Transduction ; Transcription Factor RelA ; metabolism ; Up-Regulation ; beta Catenin ; metabolism ; fas Receptor ; metabolism

OBJECTIVETo explore the effects of acupuncture and medication on PI3K/Akt/mTOR signaling pathway in rats with premature ovarian failure.

METHODSTen of fifty SPF-grade female SD rats were randomly selected into a normal group, and the remaining 40 rats were treated with intraperitoneal injection of cyclophospha mide (30 mg/kg) for consecutive 5 days to establish rat model of premature ovarian failure. Thirty five successful rat models were randomly divided into a model group (9 cases), a medication group (9 cases), an acupuncture group A (9 cases) and an acupuncture group B (8 cases). The rats in the model group and normal group did not receive any treatment. The rats in the medication group were treated with intragastric administration of diethylstil bestrol, once a day. The rats in the acupuncture group A and acupuncture group B were respectively treated with acupuncture at different acupoints, twice a day. All the treatment was given for 4 weeks. After the treatment, enzyme-linked immunosorbent assay (ELISA) was applied to test the levels of estradiol (E2), progesterone (P), follicle stimulating hormone (FSH) and luteotropic hormone (LH). The ovarian tissue sample was processed with hematoxylin eosin (HE) staining as well as RNA and protein extraction to test the mRNA expression of estrogen receptor alpha (ERalpha), estrogen receptor beta (ERP), phosphatidylinositol 3-kinase/serine/threonine kinase (PI3K), protein kinase B (Akt) and mammalian target of rapamycin (mTOR).

RESULTSHigh-dose short-term in- tervention of cyclophosphamide could establish rat model of premature ovarian failure with a successful rate of 87.5%. Compared with the normal group, the vaginal smear in the model group was featured with signs of estro gen deficiency, early-follicle reduction, structural damage to the follicle, and reducing number of mature follicles; the level of E2 was significantly reduced (P<0.05), levels of P, FSH and ILH were increased (all P<0.05), and mRNA expression of estrogen-related ERP3, PI3K, Akt and mTOR were all reduced (all P<0.05). Compared with the model group, the number of mature follicle was increased in the medication group and acupuncture groups, the levels of E2 was obviously increased (all P<0.05). level of FSH was reduced (all P<0.05), and mRNA expression of PI3K, Akt and mTOR all showed an increasing trend (all P<0.05). The differences of each index result between acupuncture groups and medication group were not significant (all P>0.05).

CONCLUSIONAcupuncture has certain advantage for the treatment of premature ovarian failure, which achieves similar therapeu tic effect as estrogen; the possible mechanism may be related to up-regulation of gene and protein expression in PI3K/Akt/mTOR signaling pathway.

Acupuncture Points ; Acupuncture Therapy ; Animals ; Estradiol ; blood ; Female ; Follicle Stimulating Hormone ; blood ; Humans ; Oncogene Protein v-akt ; genetics ; metabolism ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Primary Ovarian Insufficiency ; blood ; enzymology ; genetics ; therapy ; Progesterone ; blood ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; TOR Serine-Threonine Kinases ; genetics ; metabolism

OBJECTIVETo explore the effect of Buzhong Yiqi decoction on PI3K/AKT signaling pathway in spleen, stomach and lung of nude mice with lung adenocarcinoma transplantation tumor.

METHODTotally 60 nude mice were randomly divided into the blank control group, the tumor-bearing control group, the cisplatin group, the low-dose Buzhong Yiqi decoction group, the middle-dose Buzhong Yiqi decoction group and the high-dose Buzhong Yiqi decoction group. After the corresponding interventions, efforts were made to measure the transplanted tumor volume and calculate the tumor inhibiting rate. The immunohistochemical method and real time PCR were used to detect the expression of PI3K and AKT level in nude mice spleen, stomach and lung.

RESULTBuzhong Yiqi decoction of different concentrations combined with cisplatin could inhibit the growth of the transplanted tumor, with the strongest inhibitory effect in the middle-dose Buzhong Yiqi decoction group and the high-dose Buzhong Yiqi decoction group. All of the expressions of PI3K and AKT protein and gene in the spleen, stomach and lung increased, with the most significant increase in the tumor-bearing group. Along with the increase of the concentration of cisplatin and Buzhong Yiqi decoction, the expressions of PI3K and AKT gradually reduced. Compared with the tumor-bearing control group, there were statistical differences in spleen and stomach tissues (P < 0.05). Compared with the cisplatin group, the middle-dose Buzhong Yiqi decoction group and the high-dose Buzhong Yiqi decoction group showed statistical differences (P < 0.05), but without statistical difference compared with the blank control group.

CONCLUSIONAmong nude mice with lung adenocarcinoma transplantation tumor, the PI3K and AKT protein and gene expressions in spleen, stomach and lung tissues increased, which might indicated the effect of cisplatin and Buzhong Yiqi decoction in reducing PI3K and AKT expressions and the relations between the reduction degree and the concentrations of Buzhong Yiqi decoction. Cisplatin combined with Buzhong Yiqi decoction could decrease the PI3K and AKT protein and gene expression in spleen, stomach and lung, and make the pathway closer to normal, so as to protect the functions of spleen, stomach and lung, there may be target spots of Buzhong Yiqi decoction in PI3K/AKT signal pathway.

Adenocarcinoma ; drug therapy ; enzymology ; genetics ; Animals ; Cell Line, Tumor ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Lung ; drug effects ; enzymology ; Lung Neoplasms ; drug therapy ; enzymology ; genetics ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Oncogene Protein v-akt ; genetics ; metabolism ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Signal Transduction ; drug effects ; Spleen ; drug effects ; enzymology

Hematopoiesis ; Humans ; Leukemia ; metabolism ; Oncogene Protein v-akt ; metabolism ; Signal Transduction

OBJECTIVETo explore the mechanism of protective effect of Sphingosine-1-phosphate(S1P) in cultured neonatal rat cardiomyocytes dining simulated hypoxia/reoxygenation.

METHODSOn the basis of culturing neonatal rat cardiomyocytes, the model of hypoxia-reoxygennation was built by using method of Liquid Paraffin covering, the impact of S1P on apoptosis and p-Akt and mitochondrial membrane potential were studied by using method of Propidine Iodide staining and Western blot and Bhodanmine123 staining.

RESULTSSiP could reduce apoptosis rate (P < 0.01) and stabilize the mitochondrial membrane potential (P < 0.05) and improved the level of p-Akt1 (P < 0.01) in hypoxia/reoxygenation cardiomyocytes significantly. But wonnannin could block these effects of S1P partially.

CONCLUSIONSiP can obviously restrain apoptosis in curtured rat neonatal cardiomyocytes during simulated hypoxia/reoxygenation. Stabilization of mitochondrial membrane potential by P13K-AM signaling pathway is likely to play a role in protective action of S1P.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Cell Hypoxia ; Cells, Cultured ; Female ; Lysophospholipids ; pharmacology ; Male ; Membrane Potential, Mitochondrial ; drug effects ; Myocardial Reperfusion Injury ; prevention & control ; Myocytes, Cardiac ; cytology ; Oncogene Protein v-akt ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Primary Cell Culture ; Protective Agents ; pharmacology ; Rats ; Signal Transduction ; Sphingosine ; analogs & derivatives ; pharmacology

OBJECTIVETo observe the effect of the signal pathway of phosphoinositol-3-kinase (PI3K)/Akt-antypical protein kinase C(iotazeta) (aPKC(iotazeta))-Nuclear factor-E2 related factor (Nrf2) on gamma-glutamylcysteine synthetase (gamma-GCS) of the bronchial epithelial cells of rats after exposure to cigarette smoke extracts (CSE).

METHODSgamma-GCS, Nrf2, p-Akt and p-aPKC(iotazeta) proteins were semi-quantified by Western blot. gamma-GCS protein expression was assessed by immunocytochemistry. gamma-GCS mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR). Nrf2 protein was observed by immunofluorescence. The rate of the cells expressed p-Akt were analyzed by flow cytometry. GSH content and gamma-GCS activity were measured.

RESULTSGSH content, Nrf2 protein of nucleus, p-aPKC(iotazeta) protein, p-Akt protein and positive cells, gamma-GCS protein and mRNA and activity were significantly increased after exposure to CSE for 3 hours. aPK(iotazeta) inhibitor RO813220 significantly reduced the expression of p-aPKC(iotazeta) protein, gamma-GCS protein and mRNA and activity, but enhanced Nrf2 protein of cytoplasm expression, had no effect on p-Akt. p-Akt inhibitor LY294002 and RO813220 + LY294002 decreased p-aPKC(iotazeta) protein, p-Akt protein and positive cells, gamma-GCS protein and mRNA and activity expression, increased Nrf2 protein of cytoplasm expression. The correlation analysises demonstrated that there were a positive correlation between Nrf2 and gamma-GCS, p-Akt, p-aPKC(iotazeta), between p-Akt and Nrf2, p-aPKC(iotazeta), gamma-GCS, between p-aPKC(iotazeta) and Nrf2, p-Akt, gamma-GCS.

CONCLUSIONCSE might upregulate gamma-GCS expression through PI3K/Akt-aPKC(iotazeta)-Nrf2 signaling pathway in the bronchial epithelial cells of rats.

Animals ; Bronchi ; cytology ; enzymology ; Environmental Exposure ; adverse effects ; Epithelial Cells ; enzymology ; GA-Binding Protein Transcription Factor ; metabolism ; Glutamate-Cysteine Ligase ; genetics ; metabolism ; Isoenzymes ; metabolism ; Male ; Oncogene Protein v-akt ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Protein Kinase C ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Tobacco Smoke Pollution ; adverse effects

Deregulation of endothelial nitric oxide synthase (eNOS) plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at Ser(1179) which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models.
Animals ; Cell Line ; Chickens ; Disease Models, Animal ; Endothelium, Vascular/drug effects/*metabolism/pathology ; Enzyme Activation/drug effects ; Female ; Genistein/*pharmacology ; Humans ; Hypertension, Pulmonary/drug therapy/*metabolism/pathology ; Nitric Oxide Synthase Type III/genetics/*metabolism ; Oncogene Protein v-akt/*metabolism ; Phosphorylation ; Signal Transduction/drug effects