Radio-sensitizing effects of microRNA-27a elevation in lung cancer cells by inhibiting ZEB1 expression and activating DNA damage repair pathway.

MicroRNAs (miRNAs or miRs) exert either as tumor-inhibiting or oncogenic roles in tumorigenesis of lung cancer. In the present study, we identified a novel microRNA (miR)-27a as being involved in the radiosensitivity of lung cancer cells. Therefore, we sought to characterize its potential underlying mechanism in lung cancer cell sensitivity to radiotherapy. To this end, A549 and H460 cells irradiated with 8 Gy irradiation (IR) were used as a cell model. RT-qPCR exhibited that the expression of miR-27a increased, whereas ZEB1 was poorly expressed in A549 and H460 cells exposed to IR. As reflected by dual-luciferase reporter gene assay, miR-27a could target and inversely modulate ZEB1 expression. Gain- and loss-of-function experiments exhibited that miR-27 inhibition promoted proliferation of IR-treated A549 and H460 cells and reduced the sensitivity of A549 and H460 cells to radiotherapy, which was rescued by silencing of ZEB1. Further, miR-27a inhibition disrupted the homologous recombination (HR)-mediated DNA repair, evidenced by reduced ATM, pCHK2 and Rad51 levels. Collectively, miR-27a activates HR-mediated DNA repair by inhibiting ZEB1 expression to enhance the radiosensitivity of lung cancer cells, highlighting a therapeutic target for lung cancer radiosensitivity.

[Research progress in pathogenesis of pneumoconiosis].

Pneumoconiosis is an occupational lung disease that is mainly caused by diffuse fibrosis of lung tissue due to long-term inhalation of productive dust during occupational activities and retention in the lungs. Macrophages, epithelial cells and other cells can release a large number of cytokines, such as transforming growth factor-ß, monocyte chemotactic protein-1, etc. These cytokines can participate in pathologies such as local injury, inflammatory response, and pulmonary fibrosis. This article reviews the role of cytokines in the pathogenesis of pneumoconiosis in order to provide a basis for further research.

An anionic defensin from Plutella xylostella with potential activity against Bacillus thuringiensis.

Insect defensins, are cationic peptides that play an important role in immunity against microbial infection. In the present study, an anionic defensin from Plutella xylostella, (designated as PxDef) was first cloned and characterized. Amino acid sequence analysis showed that the mature peptide owned characteristic six-cysteine motifs with predicted isoelectric point of 5.57, indicating an anionic defensin. Quantitative real-time polymerase chain reaction analysis showed that PxDef was significantly induced in epidermis, fat body, midgut and hemocytes after injection of heat-inactivated Bacillus thuringiensis, while such an induction was delayed by the injection of live B. thuringiensis in the 4th instar larvae of P. xylostella. Knocking down the expression of nuclear transcription factor Dorsal in P. xylostella by RNA interference significantly decreased the mRNA level of PxDef, and increased the sensitivity of P. xylostella larvae to the infection by live B. thuringiensis. The purified recombinant mature peptide (PxDef) showed higher activity against Gram-positive bacteria, with the minimum inhibition concentrations of 1.6 and 2.6 µM against B. thuringiensis and Bacillus subtilis, respectively. To our knowledge, this is the first report about an anionic PxDef, which may play an important role in the immune system of P. xylostella against B. thuringiensis.

Molecular cloning and characterization of gloverin from the diamondback moth, Plutella xylostella L. and its interaction with bacterial membrane.

Gloverin restricted to Lepidoptera is known to be a glycine-rich and heat stable antimicrobial protein. The current research reports a 650 bp full-length cDNA encoding gloverin from Plutella xylostella (PxGlo) by reverse transcription polymerase chain reaction and rapid amplification of cDNA ends. PxGlo transcript was detected in both developmental stages and several tissues of 4th instar naïve larvae of P. xylostella with higher levels in the fat bodies. The mRNA levels of PxGlo increased appreciably in fat bodies after injection of Escherichia coli K12. The recombinant PxGlo expressed in S2 cells was purified by Anti-V5 M2 agarose beads which showed high activity against E. coli K12, while low activity against Bacillus thuringiensis, Staphylococcus aureus and E. coli D31. The analysis of transmission electron microscope and scan electron microscope showed PxGlo to cause significant morphological alteration in the E. coli K12 cell surface. Knockdown of PxGlo expression by RNAi increased the larval susceptibility towards the pathogenic bacteria i.e., Serratia marcescens and B. thuringiensis. Our results showed that PxGlo is an inducible antibacterial peptide which exhibits high activity mainly against E. coli K12, and PxGlo performs vital roles against the infection of pathogenic bacteria.

[The gene expression of the protein SLAWD, mediating the toxic effect of destruxin A on Spodoptera litura larvae, in procaryotic cells: purification and characterization].

Spodoptera litura is one of the most destructive phytophagous pest infesting cotton, vegetable, oilseed and ber crops around the world. Dextruxin A (DA), is a one of a kind microbial insecticide, which has potent toxins with bioactivity against S. litura larvae. An abnormal wing disc (AWD) protein was identified as a DA toxic effect protein in S. litura SL-1 cells. To better understand the role of the AWD gene of S. litura (SLAWD) it was purified and characterized. The entire coding region of the SLAWD gene was cloned into a pET-32a(+) expression vector and transformed into competent Escherichia coli BL21 (DE3) cells. SDS-PAGE and western blotting analysis and western blotting showed that the best induction conditions were 1 mmol mL(-1) isopropyl-ß-D-thiogalactopyranoside (IPTG) for 6 h at 37°C; the molecular weight of the fusion protein was 35.0 kDa. The production of polyclonal antibodies and an enzyme-linked immunosorbent assay (ELISA) showed that the titer of antiserum was 1:25,600; western blotting analysis showed that the recombinant SLAWD was recognized by the anti-SLAWD polyclonal antibody. AWD is a key protein involved in wing development in insects. These tools will assist in the further characterization of SLAWD and studies on the mechanism of action of destruxin A.

[Liver gamma imaging and its clinical evaluation--an analysis of 80 cases].

This paper describes the preliminary experiences in the diagnosis of 80 space occupying lesions of the liver by liver gamma imaging. Of these 80 cases, there were 38 primary hepatocellular carcinomas, 12 metastatic cancers, 4 liver abscesses, 5 hepatic polycystic diseases, 4 other types of hepatic tumor, 1 hydatid cyst, 6 space occupying lesions of hepatic and biliary ducts, 2 extrahepatic masses, 7 hepatic hemangiomas and 1 liver cirrhosis. All the cases were proven by surgery, autopsy or pathology. The diagnostic accuracy was 85.9% and that of the liver cancer was 88%. The results suggested that the liver gamma imaging, being of high accuracy, safety, fast imaging and simplicity, be valuable in the diagnosis of the primary hepatocellular carcinoma and other intrahepatic space occupying lesions.