OBJECTIVE: To investigate effects of berberine (BBR) on cholesterol synthesis in HepG2 cells with free fatty acid (FFA)-induced steatosis and to explore the underlying mechanisms. METHODS: A steatosis cell model was induced in HepG2 cell line fed with FFA (0.5 mmol/L, oleic acid:palmitic acid = 2:1), and then treated with three concentrations of BBR; cell viability was assessed with cell counting kit-8 assays. Lipid accumulation in cells was observed through oil red O staining and total cholesterol (TC) content was detected by TC assay. The effects of BBR on cholesterol synthesis mediators were assessed by Western blotting and quantitative polymerase chain reaction. In addition, both silent information regulator 1 (SIRT1) and forkhead box transcription factor O1 (FoxO1) inhibitors were employed for validation. RESULTS: FFA-induced steatosis was successfully established in HepG2 cells. Lipid accumulation and TC content in BBR groups were significantly lower (P < 0.05, P < 0.01), associated with significantly higher mRNA and protein levels of SIRT1(P < 0.05, P < 0.01), significantly lower sterol regulatory element-binding protein 2 (SREBP2) and 3-hydroxy 3-methylglutaryl-CoA reductase levels (P < 0.05, P < 0.01), as well as higher Acetyl-FoxO1 protein level (P < 0.05, P < 0.01) compared to the FFA only group. Both SIRT1 inhibitor SIRT1-IN-1 and FoxO1 inhibitor AS1842856 blocked the BBR-mediated therapeutic effects. Immunofluorescence showed that the increased SIRT1 expression increased FoxO1 deacetylation, and promoted its nuclear translocation. CONCLUSION BBR can mitigate FFA-induced steatosis in HepG2 cells by activating SIRT1-FoxO1-SREBP2 signal pathway. BBR may emerge as a potential drug candidate for treating nonalcoholic hepatic steatosis.
Berberine/pharmacology* ; Cholesterol ; Forkhead Box Protein O1/genetics* ; Humans ; Non-alcoholic Fatty Liver Disease/drug therapy* ; Sirtuin 1/genetics* ; Sterol Regulatory Element Binding Proteins

OBJECTIVETo explore the expression of miR-135b in endometrial carcinoma and the mechanism by which miR-135b promotes the proliferation of endometrial cancer cells.

METHODSThe expressions of miR-135b and FOXO1 were using RT-PCR detected in 22 fresh endometrial cancer tissues and paired adjacent tissues and also in endometrial cancer cell lines JEC, Ishikawa, HEC-1-B, and RL-952. The RL-952 and Ishikawa cell lines were transfected with miR-135b mimics or inhibitors, and the changes in their proliferative activity were detected with MTT assay; the expressions of FOXO1 mRNA and protein were detected by RT-PCR and Western blotting, respectively.

RESULTSThe expression of miRNA135b was significantly up-regulated and FOXO1 expression was down-regulated in endometrial carcinoma tissues as compared with the adjacent tissues (P<0.05). The mRNA expression of miR-135b was negatively correlated with the expression of FOXO1 in endometrial carcinoma. In RL-952 and Ishikawa cell lines, transfection with miR-135b mimics obviously promoted the cell proliferation (P<0.05). Up-regulation of miR-135b significantly decreased the expressions of FOXO1 protein and mRNA (P<0.05), and down- regulation of miR-135b increased FOXO1 expressions (P<0.05).

CONCLUSIONSMiR-135b plays an important role in the occurrence and development of endometrial carcinoma partially by regulating its target gene FOXO1.

Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Endometrial Neoplasms ; genetics ; metabolism ; Female ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; genetics ; metabolism ; RNA, Messenger ; Transfection ; Up-Regulation

Physalin B (PB), one of the major active steroidal constituents of Solanaceae Physalis plants, has a wide variety of biological activities. We found that PB significantly down-regulated β-amyloid (Aβ) secretion in N2a/APPsw cells. However, the underlying mechanisms are not well understood. In the current study, we investigated the changes in key enzymes involved in β-amyloid precursor protein (APP) metabolism and other APP metabolites by treating N2a/APPsw cells with PB at different concentrations. The results indicated that PB reduced Aβ secretion, which was caused by down-regulation of β-secretase (BACE1) expression, as indicated at both the protein and mRNA levels. Further research revealed that PB regulated BACE1 expression by inducing the activation of forkhead box O1 (FoxO1) and inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). In addition, the effect of PB on BACE1 expression and Aβ secretion was reversed by treatment with FoxO1 siRNA and STAT3 antagonist S3I-201. In conclusion, these data demonstrated that PB can effectively down-regulate the expression of BACE1 to reduce Aβsecretion by activating the expression of FoxO1 and inhibiting the phosphorylation of STAT3.
Alzheimer Disease ; Amyloid Precursor Protein Secretases/metabolism* ; Amyloid beta-Peptides/metabolism* ; Aspartic Acid Endopeptidases/metabolism* ; Down-Regulation ; Forkhead Box Protein O1/genetics* ; Humans ; Phosphorylation ; STAT3 Transcription Factor/metabolism* ; Secosteroids

OBJECTIVETo detect the PAX3/PAX7-FKHR fusion transcripts to identify genetic alteration in embryonal rhabdomyosarcoma (ERMS) and alveolar rhabdomyosarcoma (ARMS) tissues.

METHODSOne-step reverse transcription- polymerase chain reaction (RT-PCR) were used to detect the expression of the PAX3/PAX7-FKHR fusion transcrips in 16 cases of rhabdomyosarcoma (7 cases of ARMS, 9 cases of ERMS) and 16 specimens were compared to the surrounding normal tissue. Comparative genomic hybridization (CGH) was employed to detect the genomic imbalance (DNA loss or amplification) in 16 RMS cases.

RESULTSPAX3-FKHR fusion transcripts were positive in 3/7 and PAX 7-FKHR fusion transcripts were positive in 2/7 of ARMS patients, respectively, and were all negative in ERMS and Control tumors. There were different chromosome variations for each RMS, chromosome amplification was frequently seen in 1p36 (69%), 5q32 (56%), 8q21 (63%), 13q14 (69%), 19q (63%), 20q (56%). Chromosome loss was frequently seen in 3p21-pter (56%), 9p23-pter (50%), 10q (69%), 16/16q24 (56%).

CONCLUSIONOne-step RT-PCR assay for detection specific fusion gene provides a useful tool for confirmation of the diagnosis of RMS in diagnostically difficult cases and in retrospective studies. Chimeric gene transcript resulting from specific chromosomal translocations is a reliable index for the molecular diagnosis of RMS.

Chromosome Aberrations ; Comparative Genomic Hybridization ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Oncogene Proteins, Fusion ; genetics ; PAX3 Transcription Factor ; PAX7 Transcription Factor ; genetics ; Paired Box Transcription Factors ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Rhabdomyosarcoma ; genetics

To explore the role of forkhead box protein O1 (FOXO1) in the progression of glioblastoma multiforme (GBM) and related drug resistance, we deciphered the roles of FOXO1 and miR-506 in proliferation, apoptosis, migration, invasion, autophagy, and temozolomide (TMZ) sensitivity in the U251 cell line using in vitro and in vivo experiments. Cell viability was tested by a cell counting kit-8 (CCK8) kit; migration and invasion were checked by the scratching assay; apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and flow cytometry. The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506. Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment. We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ, which was mediated by autophagy. FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation. MiR-506 could downregulate E26 transformation-specific 1 (ETS1) expression by targeting its 3'-untranslated region (UTR). Interestingly, ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells. Consistently, both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models. Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity. Thus, the above axis might be a promising therapeutic target for GBM.
Animals ; Mice ; Brain Neoplasms/genetics* ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Feedback ; Gene Expression Regulation, Neoplastic ; Glioblastoma/metabolism* ; MicroRNAs/metabolism* ; Temozolomide/therapeutic use* ; Humans ; Forkhead Box Protein O1/metabolism*

This study was aimed to analyze the expression profiles of PI3K/AKT signaling pathway genes from bone marrow samples of AML and ALL patients and normal samples. AML, ALL and normal bone marrow samples were collected from 6 AML, 6 ALL patients and 4 normal persons. The expression of PI3K/AKT signaling pathway genes including PTEN, CCND1, mTOR, RICTOR, FOXO1 were detected by real-time fluorescent quantification RT-PCR while GAPDH gene expression was used as an internal reference. The relative gene expression level was calculated by the method of the 2(-ΔΔCt). The results showed that the gene expression profiles were different between normal and leukemic groups. PTEN, mTOR and RICTOR expression levels were down-regulated, while FOXO1 and CCND1 levels were up-regulated in AML and ALL. PTEN was down-regulated in 10 out of the 12 samples; mTOR was down-regulated in 9 out of the 12 samples; RICTOR was down-regulated in 7 out of the 12 samples; FOXO1 was up-regulated in 9 out of the 12 samples and CCND1 was up-regulated in 7 out of the 12 samples. It is concluded that PI3K/AKT signal pathway is activated in both AML and ALL leukemic cells.
Carrier Proteins ; genetics ; metabolism ; Case-Control Studies ; Cyclin D1 ; genetics ; metabolism ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; metabolism ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia ; genetics ; metabolism ; PTEN Phosphohydrolase ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; genetics ; Rapamycin-Insensitive Companion of mTOR Protein ; Signal Transduction ; TOR Serine-Threonine Kinases ; genetics ; metabolism ; Transcriptome

Aging-related oxidative stress and free radical theory has become accepted increasingly as explaination, at least in part of the aging process. In murine models of aging, a genetic deficiency of the p66(Shc) (66-kilodalton isoform of Shc gene products) gene, which encodes a phosphotyrosine signal adapter protein, extends life span by 30%, and confers resistance to oxidative stress. Upon oxidative stress, p66(Shc) is phosphorylated at Ser36, contributing to inactivation of the forkhead-type transcription factors (FKHR/ FoxO1), which regulates the gene expression of cellular antioxidants. The p66(Shc) has a direct connection with the life span related signaling, which is conserved evolutionarily. Shc is basically not expressed in mature neurons of the adult brain and spinal cord. Instead, two Shc homologues, Sck/ShcB and N-Shc/ ShcC, which have been proved to be effective on oxidative stress and aging, are expressed in neural system. The expression of Shc-related genes is affected in the aging process, which may be relevant to cellular dysfunction, stress response and/or cognitive decline during aging.
Aging ; physiology ; Animals ; Brain ; metabolism ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; metabolism ; Gene Deletion ; Humans ; Mice ; Neurons ; metabolism ; Oxidative Stress ; physiology ; Phosphorylation ; Shc Signaling Adaptor Proteins ; deficiency ; genetics ; metabolism ; physiology ; Signal Transduction ; physiology ; Spinal Cord ; metabolism ; Src Homology 2 Domain-Containing, Transforming Protein 1 ; Src Homology 2 Domain-Containing, Transforming Protein 2 ; Src Homology 2 Domain-Containing, Transforming Protein 3

BACKGROUNDPancreatic β cells are susceptible to fatty acid-induced apoptosis. The 17β-estradiol (E2) protects pancreatic β cells from apoptosis, mediated by the estrogen receptor-α (ERα). The mRNA level and promoter activity of leukemia-related protein (LRP) 16 were significantly increased by E2 in ER-α and LRP16 was a co-activator of ER-α. The aim of the study was to assess the effects of LRP16 on fatty acid-induced apoptosis in MIN6 cells.

METHODSCells with over-expressing LRP16 were obtained by lipidosome transfection. Insulin content and glucose-stimulated insulin secretion (GSIS) were examined by radioimmunoassay. Western blotting was applied to detect protein expression. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and flow cytometry. The forkhead boxO1 (FoxO1) subcellular localization was determined by immunocytochemical analysis.

RESULTSMIN6-LRP16 cells with overexpression of LRP16 were successfully established, and protein expression of LRP16 was 2.29-fold of that of control cells (MIN6-3.1, P < 0.05). Insulin content and GSIS in MIN6-LRP16 were substantially increased compared with those in control cells. When cells were stimulated with glucose, increased phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and serine-threonine kinase (Akt) were observed in MIN6-LRP16. When cells were under palmitate pressure, the TUNEL-positive rate in MIN6-LRP16 was (17.0 ± 0.5)%, while it in MIN6-3.1 was (22.0 ± 0.4)%. In palmitate-treated cells, attenuated Akt phosphorylation was observed, but the attenuation in Akt activity was partially restored in MIN6-LRP16 cells. Meanwhile, nuclear localization of FoxO1 in MIN6-LRP16 was apparently reduced compared with that in control cells.

CONCLUSIONSLRP16 regulated insulin content and GSIS in MIN6 cells by ERK1/2 and Akt activated way. Meanwhile, LRP16 overexpression protected MIN6 cells from fatty acid-induced apoptosis by partially restoring Akt phosphorylation and inhibiting FoxO1 nuclear redistribution. Therefore, LRP16 played important roles not only in insulin content and GSIS but also in the antilipotoxic effect mediated by Akt/FoxO1 signaling.

Animals ; Apoptosis ; drug effects ; Blotting, Western ; Cell Line, Tumor ; Fatty Acids ; pharmacology ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; metabolism ; Mice ; Neoplasm Proteins ; genetics ; metabolism ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; drug effects ; genetics

OBJECTIVETo establish a model of ER stress-induced apoptosis with tunicamycin and to examine whether Bim is dysregulated and its potential role in resistance of melanoma cells to apoptosis under endoplasmic reticulum (ER) stress.

METHODSA model of ER stress-induced apoptosis was established with tunicamycin. Apoptotic cells were quantitated using the annexin V/propidium iodide method by flow cytometry. Hoechst staining was also used to confirm the apoptotic cell death. Western blotting was used to measure the activation of caspase-3 and -9, and the expression of Bim, GRP78, CHOP, and Foxo1 at the protein level. The expression of Bim, CHOP and Foxo1 at the mRNA level was quantitated by qPCR. The siRNA technique was used to inhibit the expression of Bim.

RESULTSTreatment of the melanoma cells with tunicamycin did not induce significant apoptosis and activation of caspase cascade, whereas it caused marked activation of caspase-3 and -9, and apoptosis in HEK293 cells which were used as a control. With exposure to tunicamycin (3 µmol/L) for 12, 24, 36 hours the Bim protein levels were not increased in Mel-RM and MM200 cells. Its mRNA levels were 0.37 ± 0.05, 0.13 ± 0.02 and 0.02 ± 0.01 in Mel-RM cells, while 0.41 ± 0.06, 0.16 ± 0.04 and 0.21 ± 0.03 in MM200 cells, respectively. The expression of Bim mRNA was significantly reduced compared with that in the control groups of the two cell lines (P < 0.01). siRNA knockdown of Bim protected HEK293 cells against activation of caspase-3. The cell apoptosis of Bim siRNA group was (5.69 ± 0.38)%, significantly lower than that of the siRNA control group (40.32 ± 1.64)% and blank control group (35.46 ± 2.01)% (P < 0.01). In the melanoma cells after exposure to tunicamycin (3 µmol/L) for 6, 12, 24, and 36 hours the transcription factor CHOP at mRNA level were significantly increased and the expressions at protein level were also up-regulated. The expressions of another transcription factor Foxo1 at mRNA level significantly decreased and the expressions at protein level were down-regulated, too.

CONCLUSIONSThe lack of Bim up-regulation contributes to the resistance of melanoma cells to ER stress-induced apoptosis and may be a mechanism by which melanoma cells adapt to ER stress conditions. Transcription factors CHOP and Foxo1 may be responsible for the dysregulation of Bim in melanoma cells upon ER stress.

Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; Bcl-2-Like Protein 11 ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Line, Tumor ; Endoplasmic Reticulum Stress ; drug effects ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; metabolism ; HEK293 Cells ; Heat-Shock Proteins ; metabolism ; Humans ; Melanoma ; genetics ; metabolism ; pathology ; Membrane Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transcription Factor CHOP ; genetics ; metabolism ; Tunicamycin ; pharmacology