Design, synthesis and mechanistic studies of novel arylformylhydrazone butylphenyltin complexes as potential anticancer agents.

Many diorganotin complexes with various alkyl groups exhibit excellent in vitro anticancer activity. However, most diorganotin is the same alkyl group, and the asymmetric alkyl R group has been rarely reported. Hence, in this paper, twenty butylphenyl mixed dialkyltin arylformylhydrazone complexes have been synthesized by microwave "one-pot" reaction with arylformylhydrazine, substituted α-keto acid or its sodium salt and butylphenyltin dichloride. The crystal structures of nine complexes were determined, indicating that the complexes C1, C2, C11, C12, and C16 âˆ¼ C19 possessed a central symmetric structure of a dinuclear Sn2O2 tetrahedral ring; while the complex C9 is a trinuclear tin-oxygen cluster with a 6-membered ring encased in a 12-membered macrocyclic structure. The inhibiting activity of complexes was tested against the human cell lines NCI-H460, MCF-7, HepG2, Huh-7 and HL-7702. Complex C2 demonstrated the optimal inhibitory effect on HepG2 cells, with an IC50 value of 0.82 ± 0.03 µM. Cellular biology experiments revealed that complex C2 could induce apoptosis and G2/M phase cell cycle arrest in HepG2 and Huh-7 cells. The complex also caused the collapse of the mitochondrial membrane potential and increased intracellular reactive oxygen species in HepG2 and Huh-7 cells. Western blot analysis further clarified that complex C2 could induce cell apoptosis through the mitochondrial pathway along with the release of reactive oxygen species.

"Turn-on" and pinhole-free ultrathin core-shell Au@SiO2 nanoparticle-based metal-enhanced fluorescent (MEF) chemodosimeter for Hg2.

This study reports a metal-enhanced fluorescence chemodosimeter for highly sensitive detection of Hg2+ ions. Silica-coated Au nanoparticles (Au@SiO2 NPs) with a pinhole-free 4-5 nm shell were synthesized and functionalized with a monolayer of turn-on fluorescent probes. Compared to other organic fluorescent probes suffering from poor biocompatibility and detection limits, this design of a monolayer of turn-on fluorescent probes immobilized on the Au@SiO2 NPs with a pinhole-free 4-5 nm shell avoids fluorescence quenching and allows the fluorescent probe within the field of the inner Au NPs to experience metal-enhanced fluorescence. With this design, the chemodosimeter permits fluorescence emission in the presence of Hg2+ ions, because they trigger the ring-opening reaction of the fluorescent probe immobilized on the Au@SiO2 NPs. Additionally, the fluorescent probe is distanced by the thin SiO2 shell from directly attaching to the metallic Au NPs, which not only avoids fluorescence quenching but allows the fluorescent probe within the long-ranged field of the inner Au NPs to experience metal-enhanced fluorescence. As a result, the detection limit for the chemodosimeter can reach up to 5.0 × 10-11 M, nearly two orders of magnitude higher than that achieved for the free fluorescent probe. We also demonstrate the acquisition of images of Hg2+ in HTC116 cells and zebrafish using a simple fluorescence confocal imaging technique. The fluorescence response results for HTC116 cells and zebrafish show that the probes can permeate into cells and organisms. Considering the availability of the many organic fluorescent probes that have been designed, the current designed metal-enhanced fluorescence chemodosimeter holds great potential for fluorescence detection of diverse species and fluorescence imaging.

LncRNA CASC9 activated by STAT3 promotes the invasion of breast cancer and the formation of lymphatic vessels by enhancing H3K27ac-activated SOX4.

Numerous long noncoding RNAs (lncRNAs) are abnormally expressed in breast cancer (BC), but the underlying mechanisms remain large unknown. Here, we aimed to investigate the functions and mechanisms of lncRNA cancer susceptibility candidate 9 (CASC9) in BC. Western blotting and quantitative real-time PCR (qRT-PCR) were performed to assess gene and protein expression, respectively. The proliferative and metastatic abilities of BC cells were tested by cell counting kit-8 and transwell assays, respectively. The formation of lymphatic vessels was detected by tube formation assay. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were performed to verify molecular interactions. CASC9 was found to be highly expressed in BC tissues and cell lines, and ectopic overexpression was positively associated with tumor volume, TNM stage, and lymph node metastasis. In addition, CASC9 silencing significantly inhibited the proliferation and invasion of BC cells, as well as BC-associated invasion and formation of lymphatic vessels of human dermal lymphatic endothelial cells. Mechanical studies demonstrated that CASC9 could be transcriptionally activated by STAT3 and elevate SOX4 expression by enhancing the acetylation of its promoter region. Our results illustrated that STAT3-activated CASC9 served as a tumor-promoting gene involved in promoting BC invasion and BC-associated formation of lymphatic vessels by upregulating SOX4 through altering H3K27ac level. This finding elucidated a new underlying network of CASC9 in the metastasis of BC.

Ultrasensitive electrochemical assay for microRNA-21 based on CRISPR/Cas13a-assisted catalytic hairpin assembly.

MicroRNAs (miRNAs) are related to many biological processes and regarded as biomarkers of disease. Rapid, sensitive, and specific methods for miRNA assay are very important for early disease diagnostic and therapy. In the present work, an ultrasensitive electrochemical biosensing platform has been developed for miRNA-21 assay by combining CRISPR-Cas13a system and catalytic hairpin assembly (CHA). In the presence of miRNA-21, it would hybridize with the spacer region of Cas13a/crRNA duplex to activate the cleavage activity of CRISPR-Cas13a system, leading to the release of initiator of CHA to generate amplified electrochemical signals. Base on the CRISPR-Cas13a-mediated cascade signal amplification strategy, the developed electrochemical biosensing platform exhibited high sensitivity with a low detection limit of 2.6 fM (S/N = 3), indicating that the platform has great potential for application in early clinical diagnostic.

Ambrosin sesquiterpene lactone exerts selective and potent anticancer effects in drug-resistant human breast cancer cells (MDA-MB-231) through mitochondrial mediated apoptosis, ROS generation and targeting Akt/ß-Catenin signaling pathway.

PURPOSE: Breast cancer accounts for a significant proportion of cancer burden among women world over. Concerning breast cancer treatment, there are only few chemotherapeutic agents available, which also have serious side effects. The present study was thus designed to explore in vitro the antitumor effects of ambrosin sesquiterpene lactone against human drug-resistant breast cancer cells (MDA-MB-231). METHODS: WST-1 assay was used to determine cell viability. The fact that ambrosin induced apoptosis was studied through acridine orange (AO)/ethidium bromide (EB) staining using fluorescence microscopy as well as using flow cytometry in association with annexin-v/propidium iodide (PI) staining. Furthermore, western blot assay was used to study effects of ambrosin on apoptosis-related protein expressions including Bax and Bcl-2, as well as to study the effects on numerous caspases and Akt/ß-Catenin Signaling Pathway. The effects on reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were evaluated by flow cytometry. RESULTS: The results showed that ambrosin with an IC50 value of 25 µM decreased the viability of the MDA-MB-231 cells. The cytotoxicity of ambrosin was also investigated on the MCF-12A normal breast cells which showed that it exerted very low toxic effects on these cells. Ambrosin also caused remarkable changes in the morphology and suppressed the colony forming potential of MDA-MB-231 cells. The AO/EB staining assay showed that ambrosin inhibits the viability of cancer cells via induction of apoptotic cell death which was associated with increase in Bax and reduction in Bcl-2 levels. The apoptotic cells increased from 3.5% in the controls to around 56% at 50 µM concentration in the MDA-MB-231 cells. It was also seen that ambrosin treatment to these cancer cells resulted in substantial suppression in MMP and remarkable rise in ROS in a dose-dependent manner. This molecule also significantly inhibited the Akt/ß-catenin signalling pathway by reducing the expressions of phosphorylated GSK-3ß and Akt. CONCLUSIONS: Taken all together, the results of our study indicate that ambrosin sesquiterpene may be developed as a promising anticancer agent in human breast cancer provided further in-depth studies are performed.

circIQCH sponges miR-145 to promote breast cancer progression by upregulating DNMT3A expression.

As a unique type of RNA, circular RNAs (circRNAs) are important regulators of multiple biological processes in the progression of cancer. However, the potential role of most circRNAs in breast cancer lung metastasis is still unknown. In this study, we characterized and further investigated circIQCH (hsa_circ_0104345) by analyzing the circRNA microarray profiling in our previous study. circIQCH was upregulated in breast cancer tissues, especially in the metastatic sites. CCK-8, transwell, wound-healing and mouse xenograft assays were carried out to investigate the functions of circIQCH. Knockdown of circIQCH inhibited breast cancer cell proliferation and migration to lung. Moreover, luciferase reporter assays and RNA immunoprecipitation assays were performed to elucidate the underlying molecular mechanism of circIQCH. The results showed that circIQCH sponges miR-145 and promotes breast cancer progression by upregulating DNMT3A. In summary, our study demonstrated the pivotal role of circIQCH-miR-145-DNMT3A axis in breast cancer growth and metastasis via the mechanism of competing endogenous RNAs. Thus, circIQCH could be a potential therapeutic target for breast cancer.

Diversity of complexes based on p-nitrobenzoylhydrazide, benzoylformic acid and diorganotin halides or oxides self-assemble: Cytotoxicity, the induction of apoptosis in cancer cells and DNA-binding properties.

Eight organotin(IV) complexes (C1-C8) have been synthesized and characterized by elemental analysis, fourier transform infrared spectroscopy (FT-IR), multinuclear nuclear magnetic resonance (1H, 13C and 119Sn NMR), high resolution mass spectroscopy (HRMS) and single crystal X-ray structural analysis. Crystallographic data show that C1 was a tetranuclear 16-membered macrocycle complex, C2-C4 and C7 were centrosymmetric dimer distannoxane and there was a Sn2O2 four-membered ring in the middle of the molecule, respectively, C5 and C6 are monoorganotin complexes due to the dehydroalkylation effect during the reaction, while C8 forms a one-dimensional chain structure. The cytotoxicity of all complexes were tested by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assays against three human tumor cell lines NCI-H460, MCF-7 and HepG2. The dibutyltin complex C2 has been shown to be more potent antitumor agents than other complexes and carboplatin. Cell apoptosis study of C2 with the high activity on HepG2 and MCF-7 cancer cell lines was investigated by flow cytometry, it was shown that the antitumor activity of C2 was related to apoptosis, but it has different cell cycle arrest characteristics from platinum compounds, and the proliferation was inhibited by blocking cells in S phase. The DNA binding activity of the C2 was studied by UV-visible absorption spectrometry, fluorescence competitive, viscosity measurements and gel electrophoresis, results shown C2 can be well embedded in the double helix of DNA and cleave DNA.

Inhibition of cancer cell growth by Tangeretin flavone in drug-resistant MDA-MB-231 human breast carcinoma cells is facilitated via targeting cell apoptosis, cell cycle phase distribution, cell invasion and activation of numerous Caspases.

PURPOSE: In this study, the anticancer effects of a natural flavonoid-Tangeretin, were examined against the drug-resistant MDA-MB-231 breast cancer (BC) cell line and the normal breast cell line Hs 841.T. METHODS: The MTT assay was employed for cell viability determination. Apoptosis was demonstrated by DAPI and Annexin V/propidium iodide (PI) staining. Flow cytometric analyses were performed to gain insights about cell cycle distribution. Western blot assay was used for protein expression determination. RESULTS: Tangeretin inhibited the growth of the drug-resistant MDA-MB-231 cells concentration-dependently and its IC50 was 9 µM, whereas the IC50 was >100 µM against the normal cells. The anti-proliferative effects were due to induction of apoptotic cell death. The apoptotic cell percentage was increased from 5.7% to around 69% as the concentration of Tangeretin was increased. Tangeretin also caused an increase in the Bax/Bcl-2 ratio and activation of the Caspase 3, 8 and 9. In addition, Tangeretin led to arrest of the cells at G2/M phase which was accompanied by depletion of cyclin B1 and D. Transwell assay showed that Tangeretin also reduced the invasion of the MDA-MB-231 cells. CONCLUSION: The findings of this study suggest that Tangeretin exerts potent anticancer effects on the MDA-MB-231 cells and may therefore prove a beneficial lead molecule in BC research.