Metastasis remains one of the major challenges before hepatocellular carcinoma (HCC) is finally conquered. This paper summarized a decade's studies on HCC metastasis at the Liver Cancer Institute of Fudan University. We have established a stepwise metastatic human HCC model system, which included a metastatic HCC model in nude mice (LCI-D20), a HCC cell line with high metastatic potential (MHCC97), a relatively low metastatic potential cell clone (MHCC97L) and several stepwise high metastatic potential cell clones (MHCC97H, HCCLM3, and HCCLM6) from their parent MHCC97 cell. Endeavors have been made for searching human HCC metastasis-related chromosomes/proteins/genes. Monogene-based studies revealed that HCC invasion/metastasis was similar to that of other solid tumors, and the biological characteristics of small HCC were only slightly better than that of large HCC. Using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), genotyping, cDNA microarray, and 2-dimensional gel electrophoresis, we obtained some interesting results. In particular, in collaboration with the National Institute of Health (NIH) in the United States, we generated a molecular signature that can classify metastatic HCC patients, identified osteopontin as a lead gene in the signature, and found that genes favoring metastasis progression were initiated in the primary tumors. We also found that chromosome 8p deletion, particularly in the region of 8p23, was associated with HCC metastasis. Cytokeratin 19 was identified as one of the proteins, which was found in MHCC97H, but not in MHCC97L cells. Experimental interventions using the high metastatic nude mice model have provided clues for the prevention of HCC metastasis. Translation from workbench to bedside demonstrated that serum VEGF, microvessel density, and p53 scoring may be of value for the prediction of postoperative metastatic recurrence. Interferon alpha proved effective for the prevention of recurrence both experimentally and clinically. In conclusion, HCC metastasis that probably initiated in the primary tumor is a multigene-involved, multistep, and changing process. The further elucidation of the mechanism underlying HCC metastasis will provide a more solid basis for the prediction and prevention of the metastatic recurrence of HCC.

The NSD (nuclear receptor SET domain-containing) family of histone lysine methyltransferases is a critical participant in chromatin integrity as evidenced by the number of human diseases associated with the aberrant expression of its family members. Yet, the specific targets of these enzymes are not clear, with marked discrepancies being reported in the literature. We demonstrate that NSD2 can exhibit disparate target preferences based on the nature of the substrate provided. The NSD2 complex purified from human cells and recombinant NSD2 both exhibit specific targeting of histone H3 lysine 36 (H3K36) when provided with nucleosome substrates, but histone H4 lysine 44 is the primary target in the case of octamer substrates, irrespective of the histones being native or recombinant. This disparity is negated when NSD2 is presented with octamer targets in conjunction with short single- or double-stranded DNA. Although the octamers cannot form nucleosomes, the target is nonetheless nucleosome-specific as is the product, dimethylated H3K36. This study clarifies in part the previous discrepancies reported with respect to NSD targets. We propose that DNA acts as an allosteric effector of NSD2 such that H3K36 becomes the preferred target.

Nuclear factor -B (NF-B)-regulated inflammatory genes, such as TNF-␣ (tumor necrosis factor-␣), play key roles in the pathogenesis of inflammatory diseases, including diabetes and the metabolic syndrome. However, the nuclear chromatin mechanisms are unclear. We report here that the chromatin histone H3-lysine 4 methyltransferase, SET7/9, is a novel coactivator of NF-B. Gene silencing of SET7/9 with small interfering RNAs in monocytes significantly inhibited TNF-␣-induced inflammatory genes and histone H3-lysine 4 methylation on these promoters, as well as monocyte adhesion to endothelial or smooth muscle cells. Chromatin immunoprecipitation revealed that SET7/9 small interfering RNA could reduce TNF-␣-induced recruitment of NF-B p65 to inflammatory gene promoters. Inflammatory gene induction by ligands of the receptor for advanced glycation end products was also attenuated in SET7/9 knockdown monocytes. In addition, we also observed increased inflammatory gene expression and SET7/9 recruitment in macrophages from diabetic mice. Microarray profiling revealed that, in TNF-␣-stimulated monocytes, the induction of 25% NF-B downstream genes, including the histone H3-lysine 27 demethylase JMJD3, was attenuated by SET7/9 depletion. These results demonstrate a novel role for SET7/9 in inflammation and diabetes.NF-B is a pleiotropic transcription factor that plays a pivotal role in regulating multiple biological functions, such as inflammation, immunity, cell proliferation, and apoptosis (1, 2). NF-B plays an important role in the regulation of proinflammatory genes, such as TNF-␣ (tumor necrosis factor ␣) and MCP-1 (monocyte-chemoattractant protein-1), that are associated with several inflammatory diseases, including atherosclerosis, insulin resistance, metabolic syndrome, and diabetes and its complications (3-7). These genes also lead to monocyte activation associated with these inflammatory diseases.NF-B consists of homo-or heterodimers of different subunits, such as p50, p52, p65/RelA, RelB, and c-Rel, with p65/ RelA and p50 being the most common and well studied (1,8). In most unstimulated cells, NF-B resides in the cytoplasm in an inactive latent form complexed with its inhibitor subunit, IB␣. Multiple extracellular stimuli, including inflammatory cytokines, such as TNF-␣, and ligands of the receptor for advanced glycation end products (RAGE), 2 can induce NF-B activation by promoting IB␣ phosphorylation and its proteasomal degradation (6, 9). The released p65-p50 dimer then translocates to the nucleus, where it binds to the promoters of NF-B-dependent inflammatory genes, such as TNF-␣, MCP-1, and IL-6 (interleukin-6), to induce their expression (2). p65 protein is a key transcriptionally active component of NF-B whose transactivation potential is enhanced by several coactivators, including CREB-binding protein/p300, p/CAF, and SRC1 (10), which have histone acetyltransferase activity, and CARM1, which has arginine methyltransferase activity (11,12). Recently, we showed that histone H3 lysine acetylation is enriched...

The etiology of a large proportion of gastrointestinal illness is unknown. In this study, random Sanger sequencing and pyrosequencing approaches were used to analyze fecal specimens from a gastroenteritis outbreak of unknown etiology in a child care center. Multiple sequences with limited identity to known astroviruses were identified. Assembly of the sequences and subsequent reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends generated a complete genome of 6,586 nucleotides. Phylogenetic analysis demonstrated that this virus, named astrovirus VA1 (AstV-VA1), is highly divergent from all previously described astroviruses. Based on RT-PCR, specimens from multiple patients in this outbreak were unequivocally positive for Ast-VA1.

Several studies have shown that tRNAs can be enzymatically cleaved to generate distinct classes of tRNA-derived fragments (tRF). Here, we report that tRF/miR-1280, a 17-bp fragment derived from tRNA and pre-miRNA, influences Notch signaling pathways that support the function of cancer stem-like cells (CSC) in colorectal cancer progression. tRF/miR-1280 expression was decreased in human specimens of colorectal cancer. Ectopic expression of tRF/miR-1280 reduced cell proliferation and colony formation, whereas its suppression reversed these effects. Mechanistic investigations implicated the Notch ligand JAG2 as a direct target of tRF/miR-1280 binding through which it reduced tumor formation and metastasis. Notably, tRF/miR-1280-mediated inactivation of Notch signaling suppressed CSC phenotypes, including by direct transcriptional repression of the Gata1/3 and miR-200b genes. These results were consistent with findings of decreased levels of miR-200b and elevated levels of JAG2, Gata1, Gata3, Zeb1, and Suz12 in colorectal cancer tissue specimens. Taken together, our results established that tRF/miR-1280 suppresses colorectal cancer growth and metastasis by repressing Notch signaling pathways that support CSC phenotypes. Furthermore, they provide evidence that functionally active miRNA can be derived from tRNA, offering potential biomarker and therapeutic uses. .