Strategy of Graphdiyne (g-Cn H2n-2 ) Preparation Coupling with the Flower-Like NiAl-LDH Heterojunctions for Efficient Photocatalytic Hydrogen Evolution*.

Graphdiyne (g-Cn H2n-2 ), a novel two-dimension carbon allotrope material composed of a sp- and sp2 -hybrid carbon network, has been widely explored since it was synthesized for the first time by Li's group in 2010. A series distinct and excellent properties bestow graphdiyne excellent performance in many fields. Here, an innovative progress for preparing graphdiyne by using Cu+ contained material as catalyst is reported and the composite CuI-GD is coupled with flower-like NiAl-LDH to produce H2 from photocatalytic water splitting. The results of FTIR and Raman spectroscopy together reveal that graphdiyne nanosheets are synthesized successfully by employing a cross-coupling method. Photocatalytic hydrogen evolution performance shows that the hydrogen production activity of CuI-GD/NiAl-LDH has a 15- and 216-fold enhancement compared with CuI-GD and NiAl-LDH, respectively. A series of characterizations are carried out to expound the underlying reasons in the enhancement of the photocatalytic hydrogen production performance of CuI-GD/NiAl-LDH. Meanwhile, a possible mechanism for the photocatalytic hydrogen evolution process was proposed to understand the interaction among these materials.

Advances in Small-Molecule Dual Inhibitors Targeting EGFR and HER2 Receptors as Anti-Cancer Agents.

As members of the protein tyrosine kinase family, the Epidermal Growth Factor Receptor (EGFR) and Human Epidermal Growth Factor Receptor 2 (HER2) play essential roles in cellular signal transduction pathways. Overexpression or abnormal activation of EGFR and HER2 can lead to the development of various solid tumors. Therefore, they have been confirmed as biological targets for the development of anticancer drugs. Due to the fact that many cancers are highly susceptible to developing resistance to single-target EGFR inhibitors in clinical practice, dual inhibitors that target both EGFR and HER2 have been developed to increase efficacy, reduce drug resistance and interactions, and improve patient compliance. Currently, a variety of EGFR/HER2 dual inhibitors have been developed, with several drugs already approved for marketing or in clinical trials. In this review, we summarize recent advancements in small-molecule EGFR/HER2 dual inhibitors by focusing on structure-activity relationships and share novel insights into developing anticancer agents.

Cinchonine activates endoplasmic reticulum stress-induced apoptosis in human liver cancer cells.

Cinchonine is a natural compound present in Cinchona bark. It exerts multidrug resistance reversal activity and synergistic apoptotic effect with paclitaxel in uterine sarcoma cells. Whether cinchonine is effective against human liver cancer, however, remains elusive. A total of five liver cancer cell lines including Bel-7402, MHCC97H, HepG2, Hep3B and SMCC7721 were used. The anti-proliferative effects of cinchonine on these liver cancer cell lines were assessed by MTT assay. The apoptotic effects of cinchonine on liver cancer cell lines were assessed by flow cytometry with Annexin V/propidium iodide assay. Caspase-3 activation, poly (ADP-Ribose) polymerase (PARP) cleavage as well as the endoplasmic-reticulum (ER) stress response was detected by western blotting. Balb/c-nude mice bearing HepG2 xenograft tumors were used to evaluate the in vivo antitumor effect of cinchonine. It was demonstrated that cinchonine inhibited cell proliferation and promoteed apoptosis in liver cancer cells in a dose-dependent manner. Cinchonine promoted caspase-3 activation and PARP1 cleavage in liver cancer cells. Furthermore, cinchonine activated the ER stress response by upregulating GRP78 and promoting PERK and Eukaryotic Translation Initiation Factor 2 α phosphorylation. The Balb/c-nude mice experiment revealed that cinchonine suppressed HepG2 xenograft tumor growth in mice. The findings indicated that cinchonine promoted ER stress-induced apoptosis in liver cancer cells and suggested that cinchonine may have a potential beneficial effect for liver cancer treatment.

MEK/ERK signaling pathway in apoptosis of SW620 cell line and inhibition effect of resveratrol.

OBJECTIVE: To study the involvement of MAPK MEK/ERK signaling transduction pathway in the apoptosis process of SW620 tumor cell line and the inhibition effect of resveratrol. METHODS: SW620 cell lines were divided into 5 groups, namely, control group, PD98059 group, low-dose resveratrol group, mid-dose resveratrol group and high-dose resveratrol group. The inhibition rate of cell proliferation was detected by MTT method. The expression of apoptotic molecules and MEK/ERK signaling pathway related proteins were assayed by real-time PCR and Western blotting. RESULTS: Compared with control group, the proliferation of cells treated with resveratrol was significantly inhibited. In the case of apoptotic molecules, the expression of Bax, Caspase 3 and Caspase 9 was increased significantly while the expression of anti-apoptotic molecule Bcl2 was decreased significantly in resveratrol groups with a dose-dependent manner. In the case of molecules in MEK/ERK signaling pathway, the expression of Ras, Raf, MEK and ERK1/2 was decreased significantly in resveratrol groups with a dose-dependent manner. CONCLUSIONS: PD98059 and resveratrol can effectively inhibit the proliferation of SW620 through inhibiting the MEK/ERK signaling pathway.

Silencing of high mobility group A1 enhances gemcitabine chemosensitivity of lung adenocarcinoma cells.

BACKGROUND: The high mobility group A1 (HMGA1) proteins are architectural transcription factors found to be overexpressed in lung adenocarcinoma. Lentivirus-mediated RNA interference (RNAi) technology is a powerful tool for silencing endogenous or exogenous genes in human cancer cells. Our preliminary study shows that gemcitabine inhibits growth of the human lung cancer cell line SPCA-1 and induces apoptosis, and this effect might link with down-regulation of HMGA1 expression. This study aimed to investigate the chemosensitivity change of the lung adenocarcinoma cells SPCA-1 after HMGA1 inhibition by lentivirus-mediated RNAi. METHODS: We studied a highly malignant lung adenocarcinoma cell line (SPCA-1 cells). Lentiviral short-hairpin RNA (shHMGA1) expression vectors targeting HMGA1 were used for generation of lentiviral particles. After being transfected into the lung adenocarcinoma cell line SPCA-1, the expression of HMGA1 was determined by retrotranscriptase polymerase chain reaction (RT-PCR) and Western blotting. The effect of gemcitabine on proliferation of positive and negative cells was observed by methyl thiazolyl tetrazolium (MTT) assay and clonogenic survival assay. Apoptosis was observed by flow cytometery. Chemosensitivity to gemcitabine was determined by IC50 analysis. Caspase activity was quantitated by a caspase colorimetric protease assay kit. RESULTS: HMGA1-siRNA silenced its target mRNA specifically and effectively in SPCA-1 cells. The apoptotic rates of the scramble control group were (7.43 ± 0.21)%, (11.00 ± 0.20)%, and (14.93 ± 0.31)%, and the apoptotic rates in the silenced group were (9.53 ± 0.42)%, (16.67 ± 0.45)%, and (25.40 ± 0.79)% under exposure to 0.05, 0.5 and 5.0 µg/ml of gemcitabine (P < 0.05). The IC(50) of the silenced group was (0.309 ± 0.003) µg/ml which was significantly lower than in the scramble control group, (0.653 ± 0.003) µg/ml (P < 0.05). It reduced cancer cell proliferation and increased apoptotic cell death after being treated with gemcitabine compared with the scramble control group. HMGA1 silencing resulted in reduction in the phosphorylation of Akt, and promoted the activation of caspases 3, 8 and 9 upon exposure to gemcitabine. CONCLUSIONS: Lentivirus-mediated RNA interference of HMGA1 enhanced chemosensitivity to gemcitabine in lung adenocarcinoma cells. The mechanism may be associated with the PI-3K/Akt signal pathway. HMGA1 may represent a novel therapeutic target in lung cancer.