Impact of epidermal growth factor receptor protein and gene alteration on Taiwanese hepatocellular carcinomas.

BACKGROUND AND AIM: Epidermal growth factor receptor (EGFR) overexpression is associated with disease progression and poor survival in a variety of solid tumors. The role of EGFR in hepatocellular carcinoma (HCC) remains controversial. METHODS: One hundred thirty-eight HCCs were analyzed for total EGFR (t-EGFR) and phospho-EGFR (p-EGFR) expression and gene amplification using immunohistochemistry and fluorescence in situ hybridization. The role of EGFR was analyzed in relation to the clinicopathological features. RESULTS: Weak to strong p-EGFR immunostaining was noted in 42 of the 138 HCCs. p-EGFR expression correlated with alcoholism (P = 0.03) and chronic hepatitis B infection (P = 0.041). There was no correlation between t-EGFR expression and any of the clinicopathological features. Amplification of the EGFR gene was not identified in the 138 HCCs, but 39.1% of the HCCs showed balanced polysomy of both the EGFR gene and centromere 7. Moreover, 65 tumors showed > 2.2 copies per tumor cell. EGFR copy number gain (CNG) was significantly correlated with gender (P = 0.0491), tumor grade (P = 0.006), and vascular invasion (P = 0.005). HCCs with EGFR CNG also had a poor recurrence-free survival (RFS), as compared with HCCs without EGFR CNG (P = 0.031). When exploring the impact of gender, a significant association of EGFR CNG was found with tumor grade (P = 0.044) and cirrhosis (P = 0.015) exclusively in the male group only; however, the OS and RFS analysis show no significant difference between male and female groups. CONCLUSIONS: EGFR CNG was related to crucial clinicopathological features and early recurrence, indicating that EGFR CNG might be a poor prognosis factor for Taiwanese HCC.

In vitro and in vivo anticancer activity of a synthetic glycolipid as Toll-like receptor 4 (TLR4) activator.

Activation of Toll-like receptor 4 (TLR4) triggers the innate immune response and leads to the induction of adaptive immunity. TLR4 agonists are known to function as immunostimulants and exhibit promising therapeutic potential for cancer immunotherapy. We have previously developed a synthetic serine-based glycolipid (designated as CCL-34) that can activate TLR4-dependent signaling pathways. In this study, the anticancer immunity of CCL-34 was further demonstrated. CCL-34-activated macrophages induced cancer cell death via the apoptotic pathway, and this cytotoxicity was significantly inhibited by NG-monomethyl-L-arginine (an inducible NOS inhibitor). Notably, conditioned medium collected from CCL-34-treated splenocytes also induced cytotoxicity toward cancer cells. Furthermore, CCL-34 treatment suppressed tumor growth and increased the survival rate in TLR4-functional C3H/HeN mice but not in TLR4-defective C3H/HeJ mice. Increased apoptosis, the induction of cytokines (IFN-γ and IL-12) and chemokines (CXCL9 and CXCL10), and the elevation of leukocyte markers (CD11b, CD11c, CD4, and CD8) were detected at tumor sites in C3H/HeN mice but not in C3H/HeJ mice. Structure-and-activity relationship analysis of CCL-34 and its structural analogs revealed that a sugar moiety is essential for its activity. However, the substitution of the galactose in CCL-34 with glucose or fucose did not reduce its activity. Altogether, this study reveals the anticancer activity of a new synthetic TLR4 agonist and broadens the molecular basis of TLR4-activating glycolipids.

Combination of microarray profiling and protein-protein interaction databases delineates the minimal discriminators as a metastasis network for esophageal squamous cell carcinoma.

Microarray profiling of 15 adjacent normal/tumor-matched esophageal squamous cell carcinoma (ESCC) specimens identified 40 up-regulated and 95 down-regulated genes. Verification of the microarray measurement by quantitative real-time reverse transcription PCR in the same set of samples as well as an additional 15 normal/tumor-matched samples revealed >95% consistency. These signatures can also be used to classify a recently reported ESCC microarray dataset. Moreover, these molecular signatures were used as templates to elucidate their corresponding protein-protein interaction (PPI) networks using the PPI databases, POINT and POINeT. As a result, 18 genes, of which six were not disclosed in the initial expression profile analysis, were found to be able to serve as the minimal discriminators for distinguishing ESCC tumors from normal specimens. Of these discriminators, ten (BGN, COL1A1, COL1A2, MMP9, CD44, FN1, TGFBI, PXN, SPARC and VWF) were associated with tumor metastasis and formed a highly interactive network with the first four molecules as 'hubs'. Our study not only reveals how novel insights can be obtained from gene expression profiling, but also highlights a group of highly interacting genes associated with metastasis in ESCC.

Gene expression profiles of the aurora family kinases.

The evolutionarily conserved Aurora family kinases, a family of mitotic serine/threonine kinases, has three members in humans (Aurora-A, -B and -C). Overexpression of Aurora family members, particularly Aurora-A, has been reported in many human cancers and cell lines. In this study, we present evidence based on comparative gene expression analysis via quantitative RT-PCR to delineate the relative contributions of these kinases in 60 cell lines and statistical analysis in five different human cancer microarray datasets. The analysis demonstrated the selective upregulation of these Aurora members in various cancers. In general, Aurora-A exhibited the highest expression levels, with substantially decreased quantities of the Aurora-C transcript detected relative to Aurora-A and -B. Moreover, to characterize the roles of each Aurora member, which share many similarities, we investigated the expression profiles of the family in normal tissues and a panel of different phases of the HeLa cell cycle. Finally, both Aurora-A and -B were overexpressed in a majority of esophageal tumor tissues in comparison to the normal variants. Taken together, the results show that each Aurora member exhibits distinct expression patterns, implying that they are engaged in different biological processes to accomplish more elaborate cell physiological functions in higher organisms.

Long noncoding RNA CPS1-IT1 suppresses the metastasis of hepatocellular carcinoma by regulating HIF-1α activity and inhibiting epithelial-mesenchymal transition.

Recently, increasing numbers of long noncoding RNAs (lncRNAs), with both oncogenic and tumor-suppressive potential, have been found to be aberrantly expressed in various human cancers. However, the function of lncRNAs in hepatocellular carcinoma (HCC) progression remains largely unknown. In this study, we performed a comprehensive microarray analysis of lncRNA expression using human HCC specimens. After validation in 119 human HCC tissues, we identified a novel tumor suppressor lncRNA, CPS1 intronic transcript 1 (CPS1-IT1). To elucidate the clinical significance of CPS1-IT1 in HCC, correlations between CPS1-IT1 levels, clinical parameters, and survival outcomes were analyzed. In vitro and in vivo functional assays were also performed to dissect the potential underlying mechanisms. Expression of CPS1-IT1 was significantly decreased in 73% of HCC tissues, and patients with low CPS1-IT1 expression had poor survival outcomes. Furthermore, in vitro functional assays indicated that CPS1-IT1 significantly reduced cell proliferation, migration and invasion capacities through reduced Hsp90 binding to and activation of HIF-1α, thereby suppressing the epithelial-mesenchymal transition (EMT). An in vivo animal model also demonstrated the tumor suppressor role of CPS1- IT1 via decreased tumor growth and metastasis. In conclusion, lncRNA CPS1-IT1 acts as a tumor suppressor in HCC by reducing HIF-1α activation and suppressing EMT. The findings of this study establish a function for CPS1-IT1 in HCC progression and suggest its potential as a new prognostic biomarker and target for HCC therapy.

Long non-coding RNA AOC4P suppresses hepatocellular carcinoma metastasis by enhancing vimentin degradation and inhibiting epithelial-mesenchymal transition.

Increasing evidence indicates that long non-coding RNAs (lncRNAs) regulate diverse cellular processes, including cell growth, differentiation, apoptosis, and cancer progression. However, the function of lncRNAs in the progression of hepatocellular carcinoma (HCC) remains largely unknown. We performed a comprehensive microarray analysis of lncRNA expression in human HCC samples. After validation in 108 HCC specimens, we identified a differentially expressed novel tumor suppressive lncRNA termed amine oxidase, copper containing 4, pseudogene (AOC4P). The level of AOC4P expression was significantly downregulated in 68% of HCC samples and negatively correlated with advanced clinical stage, capsule invasion and vessel invasion. Low AOC4P expression correlated with poor prognostic outcomes, serving as an independent prognostic factor for HCC. In vitro functional assays indicated that AOC4P overexpression significantly reduced cell proliferation, migration and invasion by inhibiting the epithelial-mesenchymal transition (EMT). RNA immunoprecipitation assays demonstrated that AOC4P binds to vimentin and promotes its degradation. Animal model experiments confirmed the ability of AOC4P to suppress tumor growth and metastasis. Taken together, our findings suggest that AOC4P lncRNA acts as an HCC tumor suppressor by enhancing vimentin degradation and suppressing the EMT. By clarifying the mechanisms underlying HCC progression, these findings promote the development of novel therapeutic strategies for HCC.

The suppression of thoc1 in cancer cell apoptosis mediated by activated macrophages is nitric oxide-dependent.

Activation of Toll-like receptor 4 (TLR4) triggers both innate and adaptive immunity. We previously identified a synthetic glycolipid, CCL-34, which can induce anticancer immunity in a TLR4-dependent manner. In the present study, we demonstrated the involvement of THO complex 1 (thoc1) in the CCL-34-induced anticancer mechanism. The expression of thoc1 was suppressed in bladder cancer cells (MBT-2) co-cultured with CCL-34-activated macrophages, whereas treatment with an iNOS inhibitor could restore the expression of thoc1. Direct treatment of MBT-2 cells with an NO donor also repressed thoc1 expression. Importantly, the thoc1-overexpressing MBT-2 cells (MBT/thoc1) exhibited greater resistance than the MBT-2 cells to cytotoxicity induced by the NO donor or the CCL-34-activated macrophages. In addition, treatments with CCL-34-activated macrophages or the NO donor resulted in the suppression of thoc1 promoter activity in MBT-2 cells, and mutations in the antioxidant response element (ARE) of the thoc1 promoter abolished the repression induced by these treatments. Furthermore, NO treatment increased the expression and nuclear localization of nuclear factor E2-related factor 2 (Nrf2) in MBT-2 cells. Overexpression of Nrf2 suppressed thoc1 promoter activity in an ARE-dependent manner, and knock-down of nrf2 reversed the suppression. Notably, Bcl-2 expression was suppressed in MBT-2 cells, but not in MBT-2/thoc1 cells, treated with CCL-34-activated macrophages or the NO donor. In summary, our results demonstrate that NO-mediated thoc1 downregulation, via Nrf2, is a key step in the cancer cell apoptosis induced by CCL-34-treated macrophages and that downregulated thoc1 could lead to Bcl-2 downregulation and subsequent cancer cell apoptosis.

Effect of Epstein-Barr virus infection on global gene expression in nasopharyngeal carcinoma.

It was proposed that Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC); however, the molecular mechanisms involved in the effect of EBV on NPC host genes have not yet been well defined. For this study, two sets of microarray experiments, NPC (EBV-free) vs normal epithelial cells and EBV(+) vs EBV(-) NPC arrays, were analyzed and the datasets were cross-compared to identify any correlation between gene clusters involved in EBV targeting and the NPC host gene expression profiles. Statistical analysis revealed that EBV seems to have a preference for targeting more genes from the differentially expressed group in NPC cells than those from the ubiquitously expressed group. Furthermore, this trend is also reflected in log ratios where the EBV target genes of the differentially expressed group origin showed greater log ratios than genes with an origin from the ubiquitously expressed NPC group. Taken together, the genome-wide comparative scanning of EBV and NPC transcriptomes has successfully demonstrated that EBV infection has an intensifying effect on the signals involved in NPC gene expression both in breadth (the majority of the genes) and in depth (greater log ratios).