Identification of the common regulators for hepatocellular carcinoma induced by hepatitis B virus X antigen in a mouse model

Abstract

Hepatitis B virus X antigen plays an important role in the development of human hepatocellular carcinoma (HCC). The key regulators controlling the temporal downstream gene expression for HCC progression remains unknown. In this study, we took advantage of systems biology approach and analyzed the microarray data of the HBx transgenic mouse as a screening process to identify the differentially expressed genes and applied the software Pathway Studio to identify potential pathways and regulators involved in HCC. Using subnetwork enrichment analysis, we identified five common regulator genes: EDN1, BMP7, BMP4, SPIB and SRC. Upregulation of the common regulators was validated in the other independent HBx transgenic mouse lines. Furthermore, we verified the correlation of their RNA expression levels by using the human HCC samples, and their protein levels by using the human liver disease tissue arrays. EDN1, bone morphogenetic protein (BMP) 4 and BMP7 were upregulated in cirrhosis, BMP4, BMP7 and SRC were further upregulated in hepatocellular or cholangiocellular carcinoma samples. The trend of increasing expression of the common regulators correlates well with the progression of human liver cancer. Overexpression of the common regulators increases the cell viability, promotes migration and invasiveness and enhances the colony formation ability in Hep3B cells. Our approach allows us to identify the critical genes in hepatocarcinogenesis in an HBx-induced mouse model. The validation of the gene expressions in the liver cancer of human patients and their cellular function assays suggests that the identified common regulators may serve as useful molecular targets for the early-stage diagnosis or therapy for HCC.

Suppression of Hepatocyte Proliferation by Hepatocyte Nuclear Factor 4α in Adult Mice

“…In contrast to the beneficial effects observed in the rodent liver fibrosis model, BMP7 expression is elevated in patients with chronic liver diseases, raising the question of species-specific effects of BMP7 (56,57). A recent study using a hepatitis B model of HCC in mice as well as human HCC samples confirmed up-regulation of BMP7 in cirrhotic and cancerous liver tissues (36). The same study also demonstrated increased cell viability, migration, and invasiveness in the hepatoma cell line Hep3B.…”

“…Interestingly, expression of the Bmp antagonist Gremlin2 (Grem2/Prdc) was significantly reduced in tamoxifen-treated Hnf4a F/F;AlbERT2cre mice. A recent study found elevated BMP7 levels in a hepatitis B mouse model of HCC and further identified elevated BMP7 in human cirrhotic liver and HCC samples (36). To assess whether the induction of Bmp7 in Hnf4a F/F;AlbERT2cre ϩ tamoxifen mice was associated with steatosis and liver damage or cellular proliferation, Bmp7 levels were measured in the Vhl F/F;AlbERT2cre mouse, which displays hepatic steatosis, inflammation, and fibrosis but not cellular proliferation (22).…”

Up‐regulation of golgi α‐mannosidase IA and down‐regulation of golgi α‐mannosidase IC activates unfolded protein response during hepatocarcinogenesis

“…The study protocol was approved by the Institutional Review Board of the National Health Research Institutes (Human Ethics Committee code EC0971102). RNA from these samples was reverse transcribed into complementary DNA (cDNA) for quantitative polymerase chain reaction (qPCR) analysis as described 21. The mRNA expression levels of MAN1A1 , MAN1A2 , MAN1B1 , and MAN1C1 were quantified using qPCR.…”

“…RNA extraction and reverse‐transcription qPCR were performed as described 21. The specific primers used for PCR amplification are shown in Supporting Table S5.…”

Spi-B–Mediated Silencing of Claudin-2 Promotes Early Dissemination of Lung Cancer Cells from Primary Tumors

“…In addition, gene expression profiling analysis has detected Spi-B in some malignant solid tumors including gastric cancer (13) and colorectal cancer (14). IHC staining also detected Spi-B in hepatocellular carcinoma (15,16), suggesting that Spi-B may be aberrantly expressed in some solid tumors. However, the functional consequence of Spi-B expression in carcinomas is completely unknown.…”