Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the fourth-leading cause of cancer-related deaths worldwide. HCC is refractory to many standard cancer treatments and the prognosis is often poor, highlighting a pressing need to identify biomarkers of aggressiveness and potential targets for future treatments. Kinesin family member 2C (KIF2C) is reported to be highly expressed in several human tumors. Nevertheless, the molecular mechanisms underlying the role of KIF2C in tumor development and progression have not been investigated. In this study, we found that KIF2C expression was significantly upregulated in HCC, and that KIF2C up-regulation was associated with a poor prognosis. Utilizing both gain and loss of function assays, we showed that KIF2C promoted HCC cell proliferation, migration, invasion, and metastasis both in vitro and in vivo. Mechanistically, we identified TBC1D7 as a binding partner of KIF2C, and this interaction disrupts the formation of the TSC complex, resulting in the enhancement of mammalian target of rapamycin complex1 (mTORC1) signal transduction. Additionally, we found that KIF2C is a direct target of the Wnt/β-catenin pathway, and acts as a key factor in mediating the crosstalk between Wnt/β-catenin and mTORC1 signaling. Thus, the results of our study establish a link between Wnt/β-catenin and mTORC1 signaling, which highlights the potential of KIF2C as a therapeutic target for the treatment of HCC.
Adult ; Aged ; Animals ; Carcinoma, Hepatocellular/pathology* ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Epithelial-Mesenchymal Transition/genetics* ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Intracellular Signaling Peptides and Proteins/metabolism* ; Kinesins/metabolism* ; Liver Neoplasms/pathology* ; Male ; Mice ; Mice, Inbred BALB C ; Middle Aged ; Neoplasm Staging ; Prognosis ; Protein Binding ; RNA, Small Interfering/metabolism* ; Survival Analysis ; Tumor Burden ; Wnt Signaling Pathway ; Xenograft Model Antitumor Assays ; beta Catenin/metabolism*

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia characterized by progressive accumulation of fibroblastic foci and destruction of the alveolar structure. Due to an incomplete understanding of the mechanism of the occurrence and progression of IPF, currently no effective means have been available for its early screening or treatment. With a poor overall prognosis, the patients with IPF have a median survival of only 2-4 years. In recent years, several studies have confirmed that dozens of molecules are involved in the development of IPF and can be used as potential biomarkers. These biomarkers play important roles in early diagnosis (such as SP-D, MMP-7, and osteopontin), prognostic evaluation (such as telomerase length, KL-6, mtDNA, HSP-70, LOXL2, CXCL13, miRNA, ICAM-1, and CCL18), and guiding treatment of IPF (such as TOLLIP rs3750920 genotype, SAMS score, and SP-D), and also provide potential therapeutic targets (such as TERT, TERR, RTEC, and PARN).
Amino Acid Oxidoreductases ; metabolism ; Biomarkers ; analysis ; Disease Progression ; Humans ; Idiopathic Pulmonary Fibrosis ; diagnosis ; therapy ; Intracellular Signaling Peptides and Proteins ; metabolism ; Prognosis

OBJECTIVETo investigate the expression of doublecortin-like kinase 1(DCLK1)in gastric cancer and its prognostic significance.

METHODSThe expression of DCLK1 was examined by immunohistochemical staining of paraffin-embedded tumor specimens from 122 patients who underwent curative gastrectomy for gastric cancer at Peking Union Medical College Hospital between July 2002 and December 2006. Survival curves were described by the Kaplan-Meier method and compared by the Log-rank test. Univariate and multivariate analysis was performed with the Cox proportional hazard model.

RESULTSThe expression of DCLK1 in tumor cells was significantly upregulated in 51 of 122 patients. High expression of DCLK1 in tumor cells was strongly correlated with pN stage(P=0.029)and lymphovascular invasion(P=0.029). Kaplan-Meier analysis revealed that patients with DCLK1 high expression had a significantly lower 5-year overall survival(OS)rate than that of patients with DCLK1 low expression(39. 0% vs. 65. 8%, P=0.001), as well as a significantly lower 5-year disease-free survival(DFS)rate(37. 0% vs. 64. 5%, P=0.001). Univariate and multivariate analyses showed that DCLK1 expression(both P=0.036)was an independent factor for predicting OS and DFS rate.

CONCLUSIONSHigh expression of DCLK1 in gastric cancer cells is associated with pN stage and lymphovascular invasion. It may be a predictor for poor survival in patients undergoing surgery for gastric cancer.

Disease-Free Survival ; Gastrectomy ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Kaplan-Meier Estimate ; Multivariate Analysis ; Prognosis ; Proportional Hazards Models ; Protein-Serine-Threonine Kinases ; metabolism ; Stomach Neoplasms ; diagnosis ; epidemiology ; metabolism

OBJECTIVETo investigate the effects of gastric bypass surgery(GBP) on hepatic phosphoenolpyruvate carboxykinase(PEPCK) mRNA expression in type 2 diabetic Goto-Kakizaki rats.

METHODSMale GK rats were randomized into three groups: gastric bypass surgery(n=10), sham operation with diet restriction(n=10), and sham operation alone(n=10). Liver specimens of GK rats were collected during the intraoperative period for self-control study and 8 weeks after surgery. Fasting blood glucose, food intake, and body weight were recorded before surgery and 1, 2, 4, 8 weeks after surgery. The expression of PEPCK mRNA was measured by real-time PCR.

RESULTSThe fasting plasma glucose level decreased from(17.6±2.1) mmol/L before surgery to(7.5±0.9) mmol/L 8 weeks after surgery in GBP group. The level of PEPCK mRNA decreased from 1.08±0.38 before surgery to 0.41±0.10 8 weeks after surgery, significantly lower than that in sham operation alone group(1.04±0.12)(P<0.01). The level of PEPCK mRNA in diet restriction group increased from 1.15±0.16 before surgery to 2.54±0.82 8 weeks after surgery(P<0.01). The expression of PEPCK mRNA in diet restriction was significantly higher than that in CBP group(P<0.01).

CONCLUSIONSGBP can significantly improve hyperglycemia in type 2 diabetic GK rat models, which may be associated with the decrease of hepatic PEPCK mRNA level.

Animals ; Blood Glucose ; analysis ; Diabetes Mellitus, Experimental ; enzymology ; surgery ; Diabetes Mellitus, Type 2 ; enzymology ; surgery ; Gastric Bypass ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Liver ; enzymology ; Male ; Phosphoenolpyruvate Carboxykinase (GTP) ; genetics ; metabolism ; RNA, Messenger ; genetics ; Rats

OBJECTIVETo investigate the influence and significance of gastric bypass surgery on hepatic gluconeogenesis in type 2 diabetic Goto Kakizaki(GK) rats.

METHODSForty GK rats were randomly divided into Roux-en-Y gastric bypass group(group A) and sham operation group(group B). Differences in glucose tolerance experiment(OGTT) at preoperative and postoperative 1, 2 and 4 weeks were compared and weight was recorded. Glycated hemoglobin levels were measured preoperatively and 4 weeks postoperatively. The animals were sacrificed 4 weeks after surgery and liver tissues were harvested to detect the relative expression of mRNA and protein of glucose 6 phosphatase(G-6-P) and phosphoenol pyruvate kinase(PEPCK) with RT-PCR and Western blot.

RESULTSFasting blood glucose levels were 6.5, 4.9, and 4.7 mmol/L in group A, and were 10.3, 10.4, and 12.5 mmol/L in group B, and the differences between two groups were statistically significant(P<0.05). The blood glucose level at 2 h after stomach lavage were 8.3, 6.4 and 5.5 mmol/L in group A, and were 21.4, 23.8 and 24.7 mmol/L in group B at postoperative 1, 2, 4 weeks, and the differences between two groups were statistically significant(P<0.05). The glycosylated hemoglobin at postoperative 4 weeks was(6.8±1.0)%, significantly lower than that in group B[(7.9±0.8)%, P<0.05]. Hepatic G-6-P and PEPCK mRNA relative expression at postoperative 4 weeks was reduced by 21.0% and 25.9% respectively as compared to group B, and the protein expression reduced as well. Immunohistochemistry showed that hepatic glycogen sedimentary in group A increased significantly.

CONCLUSIONThe relative mRNA and protein level of key enzymes of hepatic gluconeogenesis are significantly decreased after Roux-en-Y gastric bypass surgery and hepatic gluconeogenesis is reduced, which may be a potential mechanism of the decrease of blood glucose.

Animals ; Blood Glucose ; analysis ; Diabetes Mellitus, Experimental ; metabolism ; surgery ; Diabetes Mellitus, Type 2 ; metabolism ; surgery ; Gastric Bypass ; Gluconeogenesis ; Glucose-6-Phosphatase ; metabolism ; Glycated Hemoglobin A ; metabolism ; Intracellular Signaling Peptides and Proteins ; metabolism ; Liver ; enzymology ; Male ; Phosphoenolpyruvate Carboxykinase (GTP) ; metabolism ; Rats

OBJECTIVETo determine the expressions of endothelial nitric oxide synthase traffic inducer (NOSTRIN) and endothelial nitric oxide synthase (eNOS) in the testis tissue of azoospermia patients, and investigate their correlation with the pathogenesis of azoospermia.

METHODSWe detected the expressions of NOSTRIN and NOSTRIN mRNA by immunohistochemistry and RT-PCR respectively, determined the activity of eNOS by spectrophotometry, and measured the stable metabolic end product NO, NO2- / NO3-, by nitrate reductase assay in the testis tissues of 17 patients with idiopathic azoospermia (the azoospermia group) and 10 normal men (the normal group).

RESULTSNOSTRIN and NOSTRIN mRNA were expressed in the spermatogonia, sertoli cells, stromal cells and vascular endothelial cells, more lowly in the azoospermia than in the normal group (0.312 +/- 0.076 versus 0.793 +/- 0.082, P < 0.01). The activity of eNOS was significantly increased in the idiopathic azoospermia patients ([33.727 +/- 3.58] U/mg) compared with the normal men ([17.69 +/- 3.84] U/mg) (P < 0.01). The level of NO2- / NO3- was significantly higher in the azoospermia than in the normal group ([48.56 +/- 8.49] micromol/L versus [25.37 +/- 9.61] micromol/L, P < 0.01). The expression of NOSTRIN showed a significant negative correlation with the activity of eNOS (r = -0.57, P < 0.01) as well as with the level of NO2- / NO3- (r = -0.61, P < 0.01) in the testis tissue of the idiopathic azoospermia patients.

CONCLUSIONThe expression of NOSTRIN is decreased, while the activity of eNOS and the level of NO2- / NO3- increased in the testis tissue of azoospermia patients, which may be associated with the pathogenesis of azoospermia.

Adult ; Azoospermia ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Male ; Nitrates ; analysis ; Nitric Oxide Synthase Type III ; metabolism ; Nitrites ; analysis ; Spermatogenesis ; Testis ; metabolism

BACKGROUNDLow-density lipoprotein (LDL) receptor is normally regulated via a feedback system that is dependent on intracellular cholesterol levels. We have demonstrated that cytokines disrupt cholesterol-mediated LDL receptor feedback regulation causing intracellular accumulation of unmodified LDL in peripheral cells. Liver is the central organ for lipid homeostasis. The aim of this study was to investigate the regulation of cholesterol exogenous uptake via LDL receptor and its underlying mechanisms in human hepatic cell line (HepG2) cells under physiological and inflammatory conditions.

METHODSIntracellular total cholesterol (TC), free cholesterol (FC) and cholesterol ester (CE) were measured by an enzymic assay. Oil Red O staining was used to visualize lipid droplet accumulation in cells. Total cellular RNA was isolated from cells for detecting LDL receptor, sterol regulatory element binding protein (SREBP)-2 and SREBP cleavage-activating protein (SCAP) mRNA levels using real-time quantitative PCR. LDL receptor and SREBP-2 protein expression were examined by Western blotting. Confocal microscopy was used to investigate the translocation of SCAP-SREBP complex from the endoplasmic reticulum (ER) to the Golgi by dual staining with anti-human SCAP and anti-Golgin antibodies.

RESULTSLDL loading increased intracellular cholesterol level, thereby reduced LDL receptor mRNA and protein expression in HepG2 cells under physiological conditions. However, interleukin 1 beta (IL-1 beta) further increased intracellular cholesterol level in the presence of LDL by increasing both LDL receptor mRNA and protein expression in HepG2. LDL also reduced the SREBP and SCAP mRNA level under physiological conditions. Exposure to IL-1 beta caused over-expression of SREBP-2 and also disrupted normal distribution of SCAP-SREBP complex in HepG2 by enhancing translocation of SCAP-SREBP from the ER to the Golgi despite a high concentration of LDL in the culture medium.

CONCLUSIONSIL-1 beta disrupts cholesterol-mediated LDL receptor feedback regulation by enhancing SCAP-SREBP complex translocation from the ER to the Golgi, thereby increasing SREBP-2 mediated LDL receptor expression even in the presence of high concentration of LDL. This results in LDL cholesterol accumulation in hepatic cells via LDL receptor pathway under inflammatory stress.

Cell Line, Tumor ; Cholesterol ; analysis ; Endoplasmic Reticulum ; metabolism ; Feedback, Physiological ; Humans ; Interleukin-1beta ; pharmacology ; Intracellular Signaling Peptides and Proteins ; analysis ; genetics ; Membrane Proteins ; analysis ; genetics ; Protein Transport ; RNA, Messenger ; analysis ; Receptors, LDL ; analysis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sterol Regulatory Element Binding Protein 2 ; analysis ; genetics

The distinction between benign and malignant thyroid tumors is critical for the management of patients with thyroid nodules. We applied immunohistochemical staining for galectin-3, HBME-1, cytokeratin 19 (CK19), high molecular weight cytokeratin (HMWCK), cyclin D1 and p27(kip1) in 295 thyroid lesions to determine their diagnostic accuracy. The expression of all markers was significantly associated with differentiated thyroid carcinoma (DTC).The sensitivity for the diagnosis of DTC was 94.7% with galectin-3, 91.3% with HBME-1, and 90.3% with CK19. The specificities of these markers were 95.5%, 69.7%, and 83.1%, respectively. Combining these markers, co-expression of galectin-3 and CK19 or galectin-3 and HBME-1 was seen in 93.2% of carcinomas but in none of the benign nodules. Comparing follicular variant of papillary carcinoma (FVPC) with follicular carcinoma (FC), the expression of galectin-3, CK19, and HMWCK was significantly higher in FVPC. When comparing FC with FA, the expression of galectin-3 and HBME-1 was significantly higher in FC. These results suggest that 1) galectin-3 is a useful marker in the distinction between benign and malignant thyroid tumors, 2) the combined use of HBME-1 and CK19 can increase the diagnostic accuracy, and 3) the use of CK19 and HMWCK can aid in the differential diagnosis between PC and FC.
Adenocarcinoma, Follicular/diagnosis/metabolism ; Carcinoma, Papillary, Follicular/diagnosis/metabolism ; Cyclin D1/analysis ; Cyclin-Dependent Kinase Inhibitor p27/analysis ; Diagnosis, Differential ; Galectin 3/analysis ; Humans ; Immunohistochemistry ; Intracellular Signaling Peptides and Proteins/analysis ; Keratin-19/analysis ; Keratins/analysis ; Sensitivity and Specificity ; Thyroid Gland/chemistry/*pathology ; Thyroid Nodule/*diagnosis/metabolism ; Tumor Markers, Biological/*analysis

OBJECTIVETo construct the NLS(ING1)-GFP vector, transfer it into MRC-5 cells and establish a cell model expressing NLS (ING1)-GFP fusion protein.

METHODSFirstly, cDNA fragment of nuclear locating sequence (NLS) of inhibitor of growth-1 gene (ING1) was gained by RT-PCR and inserted into multi-clone site of pEGFP-C1 to construct the NLS (ING1)-GFP expression vector. Then the vector was used to transfect the MRC-5 cells to observe the subcellular signal localization of green fluorescence protein (GFP).

RESULTSWe successfully constructed the expressing vector of NLS (ING1)-GFP fusion protein. After transferring the fusion expressing vector into MRC-5 cells, we observed that green fluorescence signal located in the cell nucleus. However, the green fluorescence signal located in the cytoplasm in MRC-5 cells transfected with pEGFP-C1 control only expressing GFP.

CONCLUSIONIn living cells, physiologically p33 ING1b locates absolutely in nucleus. The p33(ING1b) NLS plays a decisive role in the transporting process of subcellular localization.

Base Sequence ; Cell Line ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Inhibitor of Growth Protein 1 ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Microscopy, Fluorescence ; Molecular Sequence Data ; Nuclear Proteins ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Transfection ; Tumor Suppressor Proteins ; genetics ; metabolism

OBJECTIVETo investigate the apoptosis-inducing effect of endogenous nitric oxide (NO) suppression in gastric cancer cells and its mechanisms.

METHODSApoptosis of gastric cancer cells was detected by flow cytometry. Expression of phosphorylated FKHRL1 (thr-32, ser-253) and FKHRL1 in gastric cancer cells was analyzed using Western blotting. Immunofluorescence assay was performed to localize the intracellular phosphorylated FKHRL1 (thr-32, ser-253) and FKHRL1. Transfection of FKHRL1-HA wild type and mutant FKHRL1-HA T32A constructs was performed by lipofectamine plus reagent. NO generation was determined by Griess reaction.

RESULTSGastric cancer cells were significantly apoptotic after treatment with N(G)-monomethyl-L-arginine (L-NMMA, a nitric oxide synthase inhibitor), compared with the control (P<0.01). The apoptosis of gastric cancer cells induced by L-NMMA was dose-dependent and time-independent. However, the Z-DEVD-fmk, a caspase-3, 6, 7, 8, 10 inhibitor, did not prevent the apoptosis. The immunofluorescence assays showed that FKHRL1 protein was strongly expressed in the nucleu and p-FKHRL1 thr-32 protein was strongly expressed in the cytoplasm of SGC-7901 cells when endogenous nitric oxide generation was blocked by L-NMMA, but no change in FKHRL1 ser-253 phosphorylation. Nevertheless, ROCK protein was strongly expressed in p-FKHRL1 thr-32-positive SGC-7901 cells. The wortmannin, an inhibitor of phosphoinositol-3-OH kinase (PI3K), did not block the phosphorylated FKHRL1 thr-32 protein induced by L-NMMA. However, Y-27632, a specific inhibitor of the protein kinase ROCK, significantly blocked apoptosis induced by phosphorylated FKHRL1 thr-32 (P < 0.01), which was mediated by L-NMMA. A significant decrease in NO generation (P < 0.01) and a significant increase in apoptosis (P < 0.01) were observed when FKHRL1-HA wild-type cells were transfected, which caused increased FKHRL1 thr-32 phosphorylation.

CONCLUSIONSL-NMMA triggers gastric carcinoma cell apoptosis, possibly by promoting FKHRL1 thr-32 phosphorylation and initiating signal of FKHRL1 to ROCK kinase. This apoptotic signaling process is PI3K/Akt as well as caspase-3 independent.

Antineoplastic Agents ; toxicity ; Apoptosis ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Enzyme Inhibitors ; toxicity ; Forkhead Box Protein O3 ; Forkhead Transcription Factors ; analysis ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Nitric Oxide ; antagonists & inhibitors ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; Protein-Serine-Threonine Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; Stomach Neoplasms ; enzymology ; metabolism ; pathology ; Transfection ; omega-N-Methylarginine ; toxicity ; rho-Associated Kinases