HBx induces the proliferation of hepatocellular carcinoma cells via AP1 over-expressed as a result of ER stress.

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and chronic hepatitis B virus (HBV) infection is the most common risk factor for HCC. The HBV proteins can induce oncogenic or synergy effects with a hyperproliferative response on transformation into HCC. CREBH (cAMP-responsive, element-binding protein H), activated by stress in the endoplasmic reticulum (ER), is an ER-resident transmembrane bZIP (basic leucine zipper) transcription factor that is specifically expressed in the liver.

Bile acid increases expression of the histamine-producing enzyme, histidine decarboxylase, in gastric cells.

Aim: To investigate the effect of bile acid on the expression of histidine decarboxylase (HDC), which is a major enzyme involved in histamine production, and gene expression of gastric transcription factors upon cooperative activation.

Methods: HDC expression was examined by immunohistochemistry, reverse transcriptase polymerase chain reaction, and promoter assay in human gastric precancerous tissues, normal stomach tissue, and gastric cancer cell lines. The relationship between gastric precancerous state and HDC expression induced by bile acid was determined.

Tumor suppressor protein VHL inhibits Hedgehog-Gli activation through suppression of Gli1 nuclear localization.

The transcription factor Gli1 acts in the last known step of the Hedgehog signaling, and deregulation of Gli1 is implicated in human cancers. VHL protein is widely expressed in both fetal and adult tissues and acts as a tumor suppressor. Here, we demonstrate the molecular mechanism through which VHL inhibits the Hedgehog-Gli pathway.

Hypoxia induces expression of COX-2 through the homeodomain transcription factor CDX1 and orphan nuclear receptor SHP in human endometrial cells.

Endometriosis, the presence of ectopic endometrial tissue outside the uterine cavity, is a common disease affecting women during their reproductive years. The aim of this study was to identify the molecular mechanism of transcriptional regulation of inflammatory cyclooxygenase-2 (COX-2) gene during endometriosis by hypoxia. Hypoxia induced COX-2 expression in endometrial cells together with the induction of the orphan nuclear receptor SHP and intestinal-specific transcription factor Caudal-related transcription factor 1 (CDX1).

Oxygenated derivatives of cholesterol promote hepatitis B virus gene expression through nuclear receptor LXRα activation.

Hepatitis B virus (HBV) gene expression and replication are regulated by the activation of a number of liver-enriched transcription factors dependent on intracellular and extracellular stimuli. However, the association between the metabolic events and HBV gene expression remains unclear. In this study, we assessed the effects of cholesterol metabolism on HBV viral replication and gene expression.

SHP (small heterodimer partner) suppresses the transcriptional activity and nuclear localization of Hedgehog signalling protein Gli1.

Gli (glioma-associated oncogene homologue) proteins act as terminal effectors of the Hedgehog signalling pathway, which is implicated in the development of many human malignancies. Gli activation is important for cell proliferation and anti-apoptosis in various cancers. Several studies have suggested that nuclear receptors have anti-cancer effects by inhibiting the activation of various oncoproteins.

The orphan nuclear receptor SHP inhibits apoptosis during the monocytic differentiation by inducing p21WAF1.

Small heterodimer partner (SHP) is an atypical member of nuclear receptor superfamily that lacks a DNA-binding domain. In previous study, we showed that SHP, c-jun, p65 of NF-gammaB subunits, and p21WAF1 expression was increased during monocytic differentiaton with the exposure of human leukemia cells to a differentiation agent, PMA. In this study, c-Jun and p65 were shown to mediate the transcriptional activation of the SHP promoter.

Hepatitis B virus X protein induces lipogenic transcription factor SREBP1 and fatty acid synthase through the activation of nuclear receptor LXRalpha.

HBV (hepatitis B virus) is a primary cause of chronic liver disease, which frequently results in hepatitis, cirrhosis and ultimately HCC (hepatocellular carcinoma). Recently, we showed that HBx (HBV protein X) expression induces lipid accumulation in hepatic cells mediated by the induction of SREBP1 (sterol-regulatory-element-binding protein 1), a key regulator of lipogenic genes in the liver. However, the molecular mechanisms by which HBx increases SREBP1 expression and transactivation remain to be clearly elucidated.

Chemokine stromal cell-derived factor-1 induction by C/EBPβ activation is associated with all-trans-retinoic acid-induced leukemic cell differentiation.

Stromal cell-derived factor-1 (SDF-1/CXCL12) is one of the essential chemokines, which mediates hematopoietic differentiations. However, the mechanism by which SDF-1 expression is regulated in granulocyte differentiation is poorly understood. Here, we suggest a novel mechanism by which all-trans-retinoic acid (ATRA) induces the expression of SDF-1 during the differentiation of promyelomonocytic leukemic U937 cells.

Chemokine stromal cell-derived factor-1 induction by C/EBPbeta activation is associated with all-trans-retinoic acid-induced leukemic cell differentiation.

Stromal cell-derived factor-1 (SDF-1/CXCL12) is one of the essential chemokines, which mediates hematopoietic differentiations. However, the mechanism by which SDF-1 expression is regulated in granulocyte differentiation is poorly understood. Here, we suggest a novel mechanism by which all-trans-retinoic acid (ATRA) induces the expression of SDF-1 during the differentiation of promyelomonocytic leukemic U937 cells.

Hepatitis B virus X protein induces hepatic steatosis via transcriptional activation of SREBP1 and PPARgamma.

Background & Aims: Hepatic steatosis occurs frequently in patients with chronic hepatitis B virus (HBV) or chronic hepatitis C virus (HCV) infection. Recently, several studies suggested that steatosis plays an important role as a cofactor in other liver diseases such as hepatic fibrosis, hepatitis, and liver cancer. In contrast to HCV, however, the molecular mechanism by which HBV mediates hepatic steatosis has not been clearly studied.

Transcriptional repression of the gluconeogenic gene PEPCK by the orphan nuclear receptor SHP through inhibitory interaction with C/EBPalpha.

SHP (short heterodimer partner) is an orphan nuclear receptor that plays an important role in regulating glucose and lipid metabolism. A variety of transcription factors are known to regulate transcription of the PEPCK (phosphoenolpyruvate carboxykinase) gene, which encodes a rate-determining enzyme in hepatic gluconeogenesis. Previous reports identified glucocorticoid receptor and Foxo1 as novel downstream targets regulating SHP inhibition [Borgius, Steffensen, Gustafsson and Treuter (2002) J.