CircRNA protein tyrosine phosphatase receptor type a suppresses proliferation and induces apoptosis of lung adenocarcinoma cells via regulation of microRNA-582-3p.

Circular RNAs (circRNAs) are associated with cancer progression. The present study aimed to examine the function of circRNA protein tyrosine phosphatase receptor type A (circRNA_PTPRA) in lung cancer cells and elucidate the underlying molecular mechanisms. The levels of circRNA_PTPRA and microRNA (miRNA/miR)-582-3p were measured in lung cancer tissue and cells using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell proliferation and apoptosis were evaluated using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. The expression of cyclin D1, caspase-3, and cleaved caspase-3 was assessed via western blotting. The sites of circRNA_PTPRA/miR-582-3p interaction were identified using StarBase, and validated using a dual-luciferase reporter assay. We observed that circRNA_PTPRA levels were remarkably decreased, and miR-582-3p expression was up-regulated in lung cancer tissues and cells. circRNA_PTPRA directly interacts with miR-582-3p and downregulates miR-582-3p expression in lung cancer cells. Moreover, an miR-582-3p inhibitor decreased lung cancer cell proliferation and promoted apoptosis. The overexpression of circRNA_PTPRA decreased cell proliferation and increased apoptotic cell numbers, whereas miR-582-3p overexpression reversed these effects. These findings demonstrate that the up-regulation of circRNA_PTPRA significantly reduces lung cancer cell proliferation and induces apoptosis by regulating miR-582-3p expression.

A label-free photoelectrochemical aptasensor for bisphenol A based on surface plasmon resonance of gold nanoparticle-sensitized ZnO nanopencils.

A simple and novel photoelectrochemical (PEC) aptasensor for selective detection of bisphenol A (BPA) was developed using surface plasmon resonance of Au nanoparticles activated ZnO nanopencils. With the irradiation of simulated light, the increased photocurrent of nano-Au/ZnO than that of pure ZnO nanopencil is induced by the hot electrons from excited Au nanoparticles. The perfect selectivity is attributed to the specific binding of BPA to its aptamer. With the addition of BPA, the conformation of aptamer changed to a G-quadruplex structure, which resulted in the blockages of photogenerated electron-transfer channels. Based on the above mechanisms and the optimized conditions, the assembled PEC aptasensor was linear with the concentration of BPA in the range of 1-1000nmolL(-1) with a detection limit of 0.5nmolL(-1). The presence of the same concentration and similar structure of other organics did not interfere in the detection of BPA and the recovery was between 96.2% and 108.4%. It has been successfully applied to the detection of BPA in drinking water and liquid milk samples. This PEC aptasensor has good performances in novelty, selectivity, sensitivity and low cost, and it provides an alternative approach to the detection of BPA.

A sensitive and label-free photoelectrochemical aptasensor using Co-doped ZnO diluted magnetic semiconductor nanoparticles.

Co-doped ZnO diluted magnetic semiconductor as a novel photoelectric beacon was first constructed for photoelectrochemical (PEC) aptasensor of acetamiprid. The fabricated PEC sensing is based on the specific binding of acetamiprid and its aptamer, which induces the decreasement of enhanced photocurrent produced by the electron donor of quercetin. Co(2+) doping has a beneficial effect in extending the band width of light absorption of ZnO into the visible region and to promote the separation of the photoinduced carriers due to the sp-d exchange interactions existing between the band electrons and the localized d electrons of Co(2+). The fabricated aptasensor was linear with the concentration of acetamiprid in the range of 0.5-800 nmolL(-1) with the detection limit of 0.18 nmolL(-1). The presence of same concentration of other conventional pesticides did not interfere in the detection of acetamiprid and the recovery is between 96.2% and 103.7%. This novel PEC aptasensor has good performances with high sensitivity, good selectivity, low cost and portable features. The strategy of Co-doped ZnO diluted magnetic semiconductor paves a new way to improve the performances of PEC aptasensor.

Electro-optically tunable microwave source based on composite-cavity microchip laser.

A compact and electric tuning microwave source based on a diode-pumped composite Nd:YAG-LiNbO(3) cavity microchip laser is demonstrated. The electro-optical element introduces an electric tuning intra-cavity birefringence which causes a tunable frequency difference between two spilt orthogonal polarization states of a longitude mode. Thus a continuously tunable microwave signal with frequency up to 14.12 GHz can be easily generated by beating the two polarization modes on a high speed photodetector.