Pillared Graphene Sheets with High-Rate Performance as Anode Material for Lithium-Ion Batteries.

Pillared graphene composite (GP) is prepared by in situ polymerization and subsequent carbonization of graphene oxide (GO) and polyaniline (PANI) precursors. The interlayer spacing of GO layer can reach 1.418 nm with 200% increase compared with the original spacing of 0.706 nm by the intercalation of aniline monomer through π-π conjugate and electrostatic interactions. After carbonization, the graphene composite is reinforced by the intercalated PANI-converted carbon pillars and also has a nitrogen-doped level of ca. 4.49 atom%. Electrochemical characterization studies show that the GP composite exhibits a high reversible capacity of 653 mAh g-1 at a current density of 100 mA g-1 and an excellent rate capability (343 mAh g-1 at a current density of 1 A g-1), which are superior to graphene owing to the unique pillared and the nitrogen-doped structure.

The novel long intergenic noncoding RNA UCC promotes colorectal cancer progression by sponging miR-143.

The human genome contains thousands of long intergenic noncoding RNAs (lincRNAs). However, the functional roles of these transcripts and the mechanisms responsible for their deregulation in colorectal cancer (CRC) remain elusive. A novel lincRNA termed upregulated in CRC (UCC) was found to be highly expressed in human CRC tissues and cell lines. UCC levels correlated with lymph node metastasis, Dukes' stage, and patient outcomes. In SW480 and SW620 cells, knockdown of UCC inhibited proliferation, invasion, and cell cycle progression and induced apoptosis in vitro. Xenograft tumors grown from UCC-silenced SW620 cells had smaller mean volumes and formed more slowly than xenograft tumors grown from control cells. Inversely, overexpression of UCC in HCT116 promoted cell growth and invasion in vitro. Bioinformatics analysis, dual-luciferase reporter assays, and RNA immunoprecipitation assays showed that miR-143 can interact with UCC, and we found that UCC expression inversely correlates with miR-143 expression in CRC specimens. Moreover, mechanistic investigations showed that UCC may act as an endogenous sponge by competing for miR-143, thereby regulating the targets of this miRNA. Our results suggest that UCC and miR-143 may be promising molecular targets for CRC therapy.

Silencing of GATA6 suppresses SW1990 pancreatic cancer cell growth in vitro and up-regulates reactive oxygen species.

BACKGROUND/AIMS: Pancreatic cancer has the worst prognosis of any gastrointestinal cancer with a mortality rate approaching its incidence. Previous studies have indicated that GATA6 plays a key role in organ development and function, and that abnormal expression of GATA6 may induce tumorigenesis. Meanwhile, it has been reported that generation of reactive oxygen species contributes to carcinogenesis. In this study, we set out to study the role of GATA6 expression on proliferation and apoptosis of pancreatic cancer cells and the role of reactive oxygen species. METHODS: Four target miRNA sequences against GATA6 mRNA were synthesized and used to transfect SW1990 cells. Then, GATA6 expression in SW1990 cells was examined by western blot and quantative real-time polymerase chain reaction. Cell proliferation was examined by WST-8 and colony formation assay. Cell cycle progression and apoptosis were measured by flow cytometry. We also measured the generation of reactive oxygen species by immunofluorescence and flow cytometry. RESULTS: RNA interference against GATA6 successfully inhibited mRNA and protein expression of GATA6 in the SW1990 pancreatic cancer cell line. Silencing of GATA6 by RNA interference inhibited cell proliferation and increased apoptosis of SW1990, and enhanced the expression of reactive oxygen species. CONCLUSIONS: These results suggest that the RNA interference approach against GATA6 may be an effective therapeutic approach for treatment of pancreatic cancer.

Transforming growth factor-1 promotes the transcriptional activation of plasminogen activator inhibitor type 1 in carcinoma-associated fibroblasts.

Carcinoma-associated fibroblasts (CAFs) play a pivotal role in promoting the growth, invasion and metastasis of tumor cells. However, to date little is known about the oncogenic mechanisms of CAFs. This study aimed to identify the microenvironmental factors involved in tumor development and progression directed by CAFs in liver metastases. Tissue samples collected from 20 patients with colorectal liver metastases were used in this study. Histological and morphological characterization of the samples was performed using hybridization and immunohistological assays. The mRNA expression of α-smooth muscle actin (α-SMA) was measured by northern blotting. The expression of plasminogen activator inhibitor type 1 (PAI-1) was measured by enzyme-linked immunosorbent assay (ELISA). As a result, co-expression of Thy-1 (CD90) and α-SMA was identified in CAFs, while normal liver samples were negative for α-SMA and Thy-1. Compared with epidermal growth factor (EGF) and tumor necrosis factor (TNF) incubation, the expression of α-SMA increased significantly following transforming growth factor-1 (TGF-1) incubation (P<0.05), while platelet-derived growth factor (PDGF) caused a significant suppression of α-SMA expression (P<0.05). PAI-1 expression was significantly lower in unstimulated fibroblasts compared to TGF-1-treated fibroblasts (P<0.01). The levels of PAI-1 transcription were significantly higher in CAFs from the patient samples compared with the healthy controls. Taken together, our findings suggest that CAFs may be important in migration, matrix degradation, invasion and angiogenesis of tumors, and TGF-1 may promote the activation of PAI-1 transcription in CAFs.

[Expression of actA gene of Listeria monocytogenes in Escherichia coli and preparation of ActA monoclonal antibodies].

The actA gene was amplified from Lm-4 strain of Listeria monocytogenes serotype 1/2a by PCR and inserted into T vector. Sequencing showed actA gene was 1833bp long and nucleotide homology was 100% compared with actA gene of Listeria monocytogenes EGD strain in GenBank. The cloned actA gene was then inserted into prokaryotic expression vector pGEX-6P-1 and pET respectively. The predicted fusion protein was detected by SDS-PAGE after IPTG induction of recombinant bacteria. The fusion protein expressed in both vectors showed approximate molecular weight of 120kDa and 97kDa. The expressed fusion protein His-ActA was purified and used as antigen to immunize BALB/c mice, hybridomas were generated with traditional hybridoma techniques. McAbs were screened by ELISA, four hybridoma cell lines secreting antibodies against ActA protein were established and the ELISA titer of these ascitic McAbs were around 1 :5 x 10(4) - 1: 1 x 10(5) . The subtype and specifity of McAbs were identified by kit and Western blot. The McAb 1A5 reacted with the expressed fusion protein GST-ActA and His-ActA in Western blot, consistent with that of mouse anti-Lm-4 polyclonal antibodies. The successful expression of ActA protein in E. coli and preparation of its monoclonal antibodies has provided useful tools for studies on the biological activity of ActA protein and its role in listerial pathogenesis.

[Prokaryotic expression and bioactivity of the Listeria monocytogenes listeriolysin O].

To express the Listeria monocytogenes hly gene in Escherichia coli and study its primary biological characteristics, hly gene without signal peptide sequence was amplified from Listeria monocytogenes serotype 4b by PCR and inserted into T-easy vector. Sequencing showed this hly gene was 1518 bp and nucleotide homology was more than 99.8% compared with three Listeria monocytogenes hly genes in GenBank. The cloned hly gene was then inserted into prokaryotic expression vector pGEX-6P-1 and transformed into E. coli BL21. The predicted fusion protein was detected by SDS-PAGE after IPTG inducion, which had molecular weight approximately 82 kD. Hemolytic experiment demonstrated the expressed fusion protein can lyse human red cell and its hemolytic titer attained 2.26 x 10(4) HU/mg. Conclusively, the Listeria monocytogenes hly gene was successfully cloned and expressed in E. coli. The successful expression of LLO in E. coli BL21 constituted a solid foundation for further researches such as pathogenesis and immune mechanism, MAb and vaccine development.