miR-135a contributes to paclitaxel resistance in tumor cells both in vitro and in vivo

Cancer cell resistance to paclitaxel continues to be a major clinical problem. In this study, we utilized microRNA (miRNA) arrays to screen for differentially expressed miRNAs in paclitaxel-resistant cell lines established in vitro. We observed concordant upregulation of miR-135a in paclitaxel-resistant cell lines representing three human malignancies. Subsequently, the role of miRNA-135a was evaluated in an in vivo model of paclitaxel resistance. In this model, mice were inoculated subcutaneously with a non-small cell lung carcinoma cell line and treated with paclitaxel for a prolonged period. In paclitaxel-resistant cell lines, established either in vitro or in vivo, blockage of miR-135a sensitized resistant cell lines to paclitaxel-induced cell death. We further demonstrated a correlation between paclitaxel response and miR-135a expression in paclitaxel-resistant subclones that were established in vivo. The paclitaxel-resistant phenotype of these subclones was maintained upon retransplantation in new mice, as shown by decreased tumor response upon paclitaxel treatment compared with controls. Upregulation of miR-135a was associated with reduced expression of the adenomatous polyposis coli gene (APC). APC knockdown increased paclitaxel resistance in parental cell lines. Our results indicate that paclitaxel resistance is associated with upregulation of miR-135a, both in vitro and in vivo, and is in part determined by miR-135a-mediated downregulation of APC.

Synthesis in ionic liquids: [Bi2Te2Br](AlCl4), a direct gap semiconductor with a cationic framework

The Lewis acidic ionic liquid EMIMBr-AlCl(3) (EMIM = 1-ethyl-3-methylimidazolium) allows a novel synthetic route to the semiconducting layered metal chalcogenides halide [Bi(2)Te(2)Br](AlCl(4)) and its Sb analogue. [Bi(2)Te(2)Br](AlCl(4)) is a direct band gap, strongly anisotropic semiconductor and consists of cationic infinite layers of [Bi(2)Te(2)Br](+) and [AlCl(4)](-) anions inserted between the layers.

Axitinib or bevacizumab (bev) plus FOLFOX or FOLFIRI as second-line therapy in patients (pts) with metastatic colorectal cancer (mCRC)

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Background: Axitinib (AG-013736,AG), an oral selective inhibitor of vascular endothelial growth factor (VEGF) receptors 1, 2, and 3, shows activity in multiple tumor types including those refractory to front-line chemotherapy.

Methods: This multicenter, open-label, randomized phase II trial compared AG and bev in combination with FOLFOX or FOLFIRI in second-line mCRC. Pts previously treated with irinotecan were randomized to mFOLFOX6 plus AG 5 mg BID or bev 5 mg/kg q2wk; pts who received oxaliplatin were randomized to FOLFIRI with AG or bev at the same doses, with stratification by performance status and prior bev therapy. Primary endpoint was progression-free survival (PFS).

Results: 171 pts were randomized from March 2008 to July 2009. There were no significant differences in PFS or median overall survival (mOS) between the AG and bev arms with FOLFOX or FOLFIRI. However, there was a trend towards reduced mOS in the FOLFIRI arms with AG compared to bev, and a trend towards improved mOS with AG+FOLFOX vs bev+FOLFOX. There were more treatment discontinuations (DCs) and a higher incidence of grade ≥3 adverse events (AEs) in the AG arms (diarrhea, asthenia, fatigue; Table).

Conclusions: This study did not meet the primary endpoint, showing similar PFS with AG compared to bev when added to second-line chemotherapy. A potential factor in these results was earlier DCs in the AG versus bev arms, likely secondary to increased AEs. While VEGF inhibitors may have a role in second-line treatment of mCRC, at current dosing regimens AG-based chemotherapy shows no improvement in outcome compared to bev.

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[Table: see text]

Enhanced reduction of excess sludge and nutrient removal in a pilot-scale A2O-MBR-TAD system

In this study, a pilot scale anaerobic-anoxic-oxic (A2O) process with submerged membrane (MBR) in the oxic tank was coupled with thermophilic aerobic digestion (TAD) reactor and was operated for longer than 600 days to treat real domestic wastewater. Regardless of the varying conditions of the system, the A2O-MBR-TAD process removed MLSS, TCOD, BOD, TN, TP, and E. coli about 99%, 96%, 96%, 70%, 83%, and 99%, respectively. The additional TP removal of the system was due to the precipitating agent directly added in the oxic reactor, without which TP removal was about 56%. In the TAD reactor, receiving MLSS from the oxic tank (MBR), about 25% of TSS and VSS were solubilized during 2 days of retention. The effluent of the TAD reactor was recycled into the anoxic tank of A2O-MBR to provide organic carbon for denitrification and cryptic growth. By controlling the flowrate of wasting stream from the MBR, sludge production decreased to almost zero. From these results, it was concluded that the A2O-MBR-TAD process could be a reliable option for excellent effluent quality and near zero-sludge production.

Retinal Toxicity of Commercial Tissue Plasminogen Activator Is Mediated by the Induction of Nitric Oxide in the Mouse Retinal Primary Cells

PURPOSE

Tissue plasminogen activator (tPA) is an efficient thrombolytic agent, but the dose-dependent retinal toxicity of intravitreal injection of commercial tPA (containing L-arginine) has been reported. Here, we sought to investigate the mechanism of tPA-induced cell death in mouse retinal cell cultures and the role of nitric oxide (NO).

METHODS

Primary retinal cell cultures were maintained using glial conditioned medium (GCM) solution. Mouse retinal cell death was observed by using Hoechst-propidium iodide staining. Mouse retinal cell death was also measured by lactate dehydrogenase (LDH) assay. The formation of NO was measured using Griess reagent.

RESULTS

tPA-induced cell death was detected in mouse retinal cell cultures by Hoechst-propidium iodide staining or LDH assay. L-arginine seems to be the major factor in retinal toxicity of commercial tPA (containing L-arginine). The formation of NO was markedly increased in mouse retinal cell cultures treated with tPA (containing L-arginine) or L-arginine. NO inhibitor reduced the cell death induced by commercially available tPA or L-arginine.

CONCLUSIONS

This study suggests that l-arginine from commercial tPA (containing L-arginine) induces the majority of cell death in mouse retinal cell cultures and that its cytotoxicity may depend on the induction of NO.