Downregulation of PHLPP induced by endoplasmic reticulum stress promotes eIF2α phosphorylation and chemoresistance in colon cancer.

Aberrant activation of endoplasmic reticulum (ER) stress by extrinsic and intrinsic factors contributes to tumorigenesis and resistance to chemotherapies in various cancer types. Our previous studies have shown that the downregulation of PHLPP, a novel family of Ser/Thr protein phosphatases, promotes tumor initiation, and progression. Here we investigated the functional interaction between the ER stress and PHLPP expression in colon cancer.

Inhibition of protein tyrosine phosphatase receptor type F suppresses Wnt signaling in colorectal cancer.

Wnt signaling dysregulation promotes tumorigenesis in colorectal cancer (CRC). We investigated the role of PTPRF, a receptor-type tyrosine phosphatase, in regulating Wnt signaling in CRC. Knockdown of PTPRF decreased cell proliferation in patient-derived primary colon cancer cells and established CRC cell lines.

Upregulation of CPT1A is essential for the tumor-promoting effect of adipocytes in colon cancer.

Colon tumors grow in an adipose tissue-enriched microenvironment. Locally advanced colon cancers often invade into surrounding adipose tissue with a direct contact with adipocytes. We have previously shown that adipocytes promote tumor growth by modulating cellular metabolism.

The mitochondrial retrograde signaling regulates Wnt signaling to promote tumorigenesis in colon cancer.

Cancer cells are known to upregulate aerobic glycolysis to promote growth, proliferation, and survival. However, the role of mitochondrial respiration in tumorigenesis remains elusive. Here we report that inhibition of mitochondrial function by silencing TFAM, a key transcription factor essential for mitochondrial DNA (mtDNA) replication and the transcription of mtDNA-encoded genes, markedly reduced tumor-initiating potential of colon cancer cells.

Erbin Suppresses KSR1-Mediated RAS/RAF Signaling and Tumorigenesis in Colorectal Cancer.

Erbin belongs to the LAP (leucine-rich repeat and PDZ domain) family of scaffolding proteins that plays important roles in orchestrating cell signaling. Here, we show that Erbin functions as a tumor suppressor in colorectal cancer. Analysis of Erbin expression in colorectal cancer patient specimens revealed that Erbin was downregulated at both mRNA and protein levels in tumor tissues.

Downregulation of SREBP inhibits tumor growth and initiation by altering cellular metabolism in colon cancer.

Sterol regulatory element-binding proteins (SREBPs) belong to a family of transcription factors that regulate the expression of genes required for the synthesis of fatty acids and cholesterol. Three SREBP isoforms, SREBP1a, SREBP1c, and SREBP2, have been identified in mammalian cells. SREBP1a and SREBP1c are derived from a single gene through the use of alternative transcription start sites.

PHLPP regulates hexokinase 2-dependent glucose metabolism in colon cancer cells.

Increased glucose metabolism is considered as one of the most important metabolic alterations adapted by cancer cells in order to generate energy as well as high levels of glycolytic intermediates to support rapid proliferation. PH domain leucine-rich repeat protein phosphatase (PHLPP) belongs to a novel family of Ser/Thr protein phosphatases that function as tumor suppressors in various types of human cancer. Here we determined the role of PHLPP in regulating glucose metabolism in colon cancer cells.

Adipocytes activate mitochondrial fatty acid oxidation and autophagy to promote tumor growth in colon cancer.

Obesity has been associated with increased incidence and mortality of a wide variety of human cancers including colorectal cancer. However, the molecular mechanism by which adipocytes regulate the metabolism of colon cancer cells remains elusive. In this study, we showed that adipocytes isolated from adipose tissues of colon cancer patients have an important role in modulating cellular metabolism to support tumor growth and survival.

Pleckstrin Homology (PH) Domain Leucine-rich Repeat Protein Phosphatase Controls Cell Polarity by Negatively Regulating the Activity of Atypical Protein Kinase C.

The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown.

PHLPP negatively regulates cell motility through inhibition of Akt activity and integrin expression in pancreatic cancer cells.

Pancreatic adenocarcinoma is currently the fourth leading cause for cancer-related mortality. Malignant progression of pancreatic cancer depends not only on rapid proliferation of tumor cells but also on increased cell motility. In this study, we showed that increased PHLPP expression significantly reduced the rate of migration in pancreatic ductal adenocarcinoma (PDAC) cells whereas knockdown of PHLPP had the opposite effect.

Loss of PHLPP protects against colitis by inhibiting intestinal epithelial cell apoptosis.

A common feature of inflammatory bowel disease (IBD) is the loss of intestinal epithelial barrier function due to excessive apoptosis of intestinal epithelial cells (IECs). However, the molecular mechanism underlying increased IEC apoptosis remains unclear. Here, we investigated the role of PHLPP, a novel family of protein phosphatases, in regulating inflammation-induced IEC apoptosis in mouse models of colitis.

Downregulation of PHLPP expression contributes to hypoxia-induced resistance to chemotherapy in colon cancer cells.

Hypoxia is a feature of solid tumors. Most tumors are at least partially hypoxic. This hypoxic environment plays a critical role in promoting resistance to anticancer drugs.

Silencing of PCDH10 in hepatocellular carcinoma via de novo DNA methylation independent of HBV infection or HBX expression.

PCDH10 is a key tumor suppressive gene for nasopharyngeal, esophageal, and other carcinomas with frequent methylation. In this study, we investigated the potential epigenetic modification of the PCDH10 gene by hepatitis B virus × protein (HBx), a pivotal factor in the progression of HBV replication and potential carcinogenesis. PCDH10 expression was found to be down-regulated in 9/13 (69.

Use of duplex mutation primers for real-time PCR quantification of hepatitis C virus RNA in serum.

Background: The duplex mutation primers offer many advantages over other multi-labeled probes for real-time detection of amplification products.

Objectives: To develop and validate a novel real-time PCR for quantification of HCV RNA based on the duplex mutation primers technology.

Materials And Methods: The duplex mutation primers were selected in the highly conservative 5' non-coding region (5'NCR) of the HCV RNA.

Hepatic expression profile of forkhead transcription factor genes in normal Balb/c mice and their dynamic changes after bile duct ligation.

Dysregulation of Forkhead box (Fox) transcription factor family genes was previously shown to lead to congenital disorders, diabetes mellitus, and carcinogenesis, and recent reports suggested that several Fox genes play important roles in the pathogenesis of liver fibrosis. The present study was initiated to determine the expression profiles of the Fox genes in normal Balb/c mouse liver and their dynamic expression changes during fibrogenesis induced by experimental bile duct ligation (BDL). RT-PCR was employed to detect 18 FOX family members including FOXO1, FOXO3, FOXM1, and FOXL1 in normal mouse liver.

Introduction of β-cyclodextrin into poly(aspartic acid) matrix for adsorption and time-release of ibuprofen.

Biodegradable copolymers with molecule inclusion ability was prepared by introduction of β-cyclodextrin into poly(aspartic acid) matrices. The ibuprofen loading and dissolution properties of poly(aspartic acid)-β-cyclodextrin were investigated.

C/EBPα down-regulation is associated with reduced hepatic cellular viability during hypoxia in vitro and in vivo.

C/EBPα transcription factor is a key regulator in liver biology and was preliminarily shown to be down-regulated in hypoxic primary rat hepatocytes. The aim of this study was to explore the possible association between C/EBPα expression level and hepatocyte viability in both the in-vitro cultured hypoxic rat primary hepatocytes and two models of acute liver hypoxia induced by carbon tetrachloride or Fas antibody. C/EBPα mRNA was significantly down-regulated under hypoxic conditions both in vitro and in vivo, which was paralleled by a similar decrease in hepatocyte viability and partially reversed by 3D matrix and dexamethasone.

Biliary intervention aggravates cholestatic liver injury, and induces hepatic inflammation, proliferation and fibrogenesis in BDL mice.

Obstructive cholestasis occurs in various clinical situations, whose pathological process is complex and not well known. The present study was initiated to display the complex and multifaceted pathological process caused by obstructive cholestasis in bile duct-ligated mice. Adult mice were bile-duct-ligated or sham-operated, and serum and liver tissues were collected at the indicated time points.

Macrophage-specific overexpression of antimicrobial peptide PR-39 inhibits intracellular growth of Salmonella enterica serovar Typhimurium in macrophage cells.

Although purified and synthesised PR-39 shows potent antibacterial effects in vitro, its ability to kill intracellular bacteria in macrophages, which are a major cause of refractory intracellular infection, has not yet been demonstrated. Both to enhance its antimicrobial potential and to reduce systemic side effects, it would be desirable to deliver PR-39 into macrophage cells and to limit its activation to the site of infection. To address this issue, PR-39 DNA was inserted into the eukaryotic expression plasmid pIRES2-EGFP and the adenoviral vector Ad-MSP, from which PR-39 can be specifically expressed in macrophage cells from the macrophage-specific promoter.

Enhanced glucose synthesis in three-dimensional hepatocyte collagen matrix.

Three-dimensional (3D) cell culture model offers a unique opportunity to study hepatocytes that require extracellular matrix to keep the cells at the differentiated state. In this report, we cultured isolated mouse hepatocytes in a 3D collagen matrix system and developed a protocol to measure glucose production at 3h, 6h, 18h and 24h after culture. The results demonstrated that hepatocytes cultured under 3D collagen matrix condition consistently produced glucose at 240-290 mg/10(6) cells for up to 24h.

[The clinical significance of real-time fluorescence PCR quantification of hepatocyte growth factor mRNA expression in acute leukemia].

Objective: To detect quantitatively hepatocyte growth factor (HGF) mRNA expressions of bone marrow mononuclear cells (MNCs) in acute leukemia (AL) and investigate its clinical significance.

Methods: Total mRNA of quantitated bone marrow MNCs isolated from 67 de novo AL cases was extracted and then cDNA was synthesized. Expression of HGF mRNA was quantified absolutely using real-time fluorescence quantification PCR (FQ-PCR).

Study of serum argininosuccinate lyase determination for diagnosis of liver diseases.

The objectives of this research were to establish an automatic analysis method for the determination of serum argininosuccinate lyase (ASL) and to investigate the value of serum ASL test in the diagnosis of various liver disorders. According to the chemical reaction catalyzed by ASL, an enzyme-coupled reaction system was designed, and a methodology evaluation of this method was performed. A total of 291 patients with various liver diseases, 247 patients with nonliver disease and 32 healthy controls, were recruited, their serum levels of ASL and traditional hepatopathy markers, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and total bilirubin (TBil), were all determined, and their diagnostic values in liver diseases were analyzed and compared.

[Construction and targeting study of eukaryotic expression vector modulated by a macrophage-specific promoter].

Aim: To construct a macrophage-specific eukaryotic expression vector and to investigate its expressing specificity.

Methods: Macrophage-specific promoter was synthesized using PCR, and substituted the CMV promoter of eukaryotic expression vector pEGFP-N1 to construct a recombinant vector (pSP-GFP), which were cotransfected with pERFP-N1 vector into different cell lines. The green fluorescent protein (GFP) and red fluorescent protein (RFP) was observed by fluorescence microscopy, and the target specificity of macrophage-specific promoter was judged by comparison of expressed level of GFP and RFP in various cell lines.

Development of a novel quantitative real-time assay using duplex scorpion primer for detection of Chlamydia trachomatis.

A novel quantitative real-time PCR method using the duplex scorpion primer for detection of Chlamydia trachomatis DNA was developed and validated. The assay employs a duplex primer; its most important feature is the intramolecular probe-target interaction. The assay had many prominent characteristics.