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

Pituitary adenomas (PAs) are well known as a common intracranial benign tumor, and a portion of PAs are refractory to current therapeutic methods. ErbB receptors family signaling pathway regulates the expression of PAs activation associated gene. Inhibition of epidermal growth factor receptor (EGFR) can inhibit proliferation of PAs. Leucine-rich repeats and immunoglobulin-like domains protein 1 ( LRIG1), a negative mediated gene of ErbB receptors family, plays a role in many tumors. However, there are seldom researches about the functional role of LRIG1 in PAs. The aim of this study is to explore the potential effect of LRIG1 and its regulating mechanism in PAs. First, we investigated the role of LRIG1 in cell migration, invasion of PAs with transfected LRIG1 or control. Then, we explored its impact on cell proliferation and apoptosis of PAs in vivo. To study the regulating mechanism of LRIG1, we examined the expression of molecular factor of PI3K/AKT and Ras/Raf/ERK pathway using Western blotting in vitro and RT-PCR in vitro and in vivo. It was found that LRIG1 over-expression inhibited cell migration, invasion and proliferation, and promoted apoptosis of PAs in vivo and in vitro. Furthermore, LRIG1 suppressed the expression of signaling of PI3K/AKT and Ras/Raf/ERK pathways in PAs. LRIG1, as a negative mediated gene of tumor, can inhibit biological function of PAs via inhibiting PI3K/AKT and Ras/Raf/ERK pathways, and it might be a new target for gene therapy of PAs.
Animals ; Apoptosis ; genetics ; Brain Neoplasms ; genetics ; pathology ; Cell Line, Tumor ; Cell Movement ; genetics ; Cell Proliferation ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; MAP Kinase Signaling System ; genetics ; Membrane Glycoproteins ; biosynthesis ; genetics ; Mice ; Oncogene Protein v-akt ; biosynthesis ; Phosphatidylinositol 3-Kinases ; genetics ; Pituitary Neoplasms ; genetics ; pathology ; Xenograft Model Antitumor Assays ; raf Kinases ; biosynthesis ; genetics

Phosphatidylinositol-3-kinase (PI3K) pathway signaling is an established oncogenic signal transduction pathway implicated in multiple malignancies. Therapeutic targeting of PI3K pathway components has improved outcomes in chronic lymphocytic leukemia, kidney cancer, breast cancer, and neuroendocrine tumors. Gastric cancers harbor some of the highest rates of oncogenic alterations in PI3K but attempts to translate this genomic observation have met with limited clinical success and novel approaches are needed. In the following review we discuss PI3K signaling, previous preclinical and clinical investigations in gastric cancer, and discuss future strategies aimed at overcoming resistance and improving efficacy. Identification and refinement of molecular tumor subtypes, development of predictive biomarkers along, and rational drug combination strategies are key to capitalizing on the therapeutic potential of PI3K pathway directed therapies in gastric cancers.
Biomarkers ; Breast Neoplasms ; Kidney Neoplasms ; Leukemia, Lymphocytic, Chronic, B-Cell ; Molecular Targeted Therapy ; Neuroendocrine Tumors ; Oncogene Protein v-akt ; Signal Transduction ; Stomach Neoplasms* ; TOR Serine-Threonine Kinases

Phosphatidylinositol-3-kinase (PI3K) pathway signaling is an established oncogenic signal transduction pathway implicated in multiple malignancies. Therapeutic targeting of PI3K pathway components has improved outcomes in chronic lymphocytic leukemia, kidney cancer, breast cancer, and neuroendocrine tumors. Gastric cancers harbor some of the highest rates of oncogenic alterations in PI3K but attempts to translate this genomic observation have met with limited clinical success and novel approaches are needed. In the following review we discuss PI3K signaling, previous preclinical and clinical investigations in gastric cancer, and discuss future strategies aimed at overcoming resistance and improving efficacy. Identification and refinement of molecular tumor subtypes, development of predictive biomarkers along, and rational drug combination strategies are key to capitalizing on the therapeutic potential of PI3K pathway directed therapies in gastric cancers.
Biomarkers ; Breast Neoplasms ; Kidney Neoplasms ; Leukemia, Lymphocytic, Chronic, B-Cell ; Molecular Targeted Therapy ; Neuroendocrine Tumors ; Oncogene Protein v-akt ; Signal Transduction ; Stomach Neoplasms* ; TOR Serine-Threonine Kinases

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

PURPOSE: Non-steroidal anti-inflammatory drugs (NSAIDs) and statins are potential chemopreventive or chemotherapeutic agents. The mechanism underlying the deregulation of survivin by NSAIDs and statins in human non-small cell lung cancer cells has not been elucidated. In this study, we investigated the synergistic interaction of sulindac and simvastatin in lung cancer A549 cells. MATERIALS AND METHODS: Cell viability was measured by an MTT assay, while the expression of apoptotic markers, AKT, and survivin in response to sulindac and simvastatin was examined by Western blotting. DNA fragmentation by apoptosis was analyzed by flow cytometry in A549 cells. Reactive oxygen species (ROS) generation was measured by flow cytometry using H2DCFDA and MitoSOX Red, and the effects of pretreatment with N-acetylcysteine were tested. The effects of AKT on survivin expression in sulindac- and simvastatin-treated cells were assessed. Survivin was knocked down or overexpressed to determine its role in apoptosis induced by sulindac and simvastatin. RESULTS: Sulindac and simvastatin synergistically augmented apoptotic activity and intracellular ROS production in A549 cells. Inhibition of AKT by siRNA or LY294002 inhibited survivin, while AKT overexpression markedly increased survivin expression, even in the presence of sulindac and simvastatin. Moreover, survivin siRNA enhanced sulindac- and simvastatininduced apoptosis. In contrast, survivin upregulation protected against sulindac- and simvastatin-induced apoptosis. CONCLUSION: Combined treatment with sulindac and simvastatin augmented their apoptotic potential in lung cancer cells through AKT signaling-dependent downregulation of survivin. These results indicate that sulindac and simvastatin may be clinically promising therapies for the prevention of lung cancer.
Acetylcysteine ; Anti-Inflammatory Agents, Non-Steroidal ; Apoptosis* ; Blotting, Western ; Carcinoma, Non-Small-Cell Lung ; Cell Survival ; DNA Fragmentation ; Down-Regulation* ; Flow Cytometry ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Lung Neoplasms* ; Oncogene Protein v-akt ; Reactive Oxygen Species ; RNA, Small Interfering ; Simvastatin* ; Sulindac* ; Up-Regulation

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