[Bioinformatics analysis of drug-resistant ceRNA in epithelial ovarian cancer].

Objective: To explore the possible biological function of long-chain non-coding RNA (lncRNA) on epithelial ovarian cancer (EOC) drug resistance and the value of new diagnostic markers through bioinformatics analysis, clinical testing and verification methods. Methods: (1) Mining the lncRNA related to EOC and constructing the competing endogenous RNA (ceRNA) regulatory network: comprehensively apply text mining, data prediction and network construction and other bioinformatics methods to establish a potential ceRNA regulatory network related to EOC drug resistance, namely lncRNA-microRNA (miRNA)-mRNA regulatory network. (2) Clinical verification: a total of 95 cancer tissue specimens were collected from EOC patients who underwent cytoreductive surgery at the Affiliated Tumor Hospital of Guangxi Medical University from June 2008 to October 2016, of which 54 were platinum-resistant patients (resistance group), 41 platinum-based drug-sensitive patients (sensitive group). Real-time fluorescent quantitative PCR was used to detect the expression of lncRNA in EOC tissues of the two groups, the effect of lncRNA expression on the prognosis of EOC patients, and the diagnostic efficacy of lncRNA expression on resistance to EOC were also analyzed. Results: (1) Text mining preliminarily screened out 25 differentially expressed lncRNA related to the occurrence and development of EOC, and further subcellular localization analysis found that 8 lncRNA exist in the cytoplasm. Through further data mining, collinear literature analysis and construction of ceRNA, the regulatory network predicts that the two lncRNA molecules, GAS5 and HOTAIR, could serve as key ceRNA molecules. (2) Through real-time fluoressent quantitative PCR verification, it was found that both GAS5 and HOTAIR were highly expressed in drug-resistant EOC tissues, which affects the progression-free survival (PFS) and overall survival (OS) time of patients with drug-resistant EOC independent risk factors (P<0.05). The receiver operating characteristic (ROC) area under the curve (AUC) of GAS5 alone was 0.678, the AUC of HOTAIR alone was 0.863, and the AUC of GAS5 combined with HOTAIR was 0.871, and there were statistically significant differences (all P<0.05). Conclusions: The high expression of GAS5 and HOTAIR is closely related to the drug resistance of EOC, which could be used as a potential predictor of response to chemotherapy. At the same time, the combined detection of GAS5 and HOTAIR has a certain diagnostic efficiency for patients with platinum-resistant EOC. This method of using the ceRNA regulatory network to predict key molecules will provide new ideas for the diagnosis and treatment of EOC.

Effective cryopreservation of neural stem or progenitor cells without serum or proteins by vitrification.

Development of effective cryopreservation protocols will be essential to realizing the potential for clinical application of neural stem and progenitor cells. Current cryopreservation protocols have been largely employed in research, which does not require as stringent consideration of viability and sterility. Therefore, these protocols involve the use of serum and protein additives, which can potentially introduce contaminants, and slow cooling with DMSO/glycerol-based cryopreservation solutions, which impairs cell survival. We investigated whether serum- and protein-free vitrification is effective for functional cryopreservation of neurosphere cultures of neural stem or progenitor cells. To protect the samples from introduction of other contaminants during handling and cryostorage, an original "straw-in-straw" method (250 microl sterile straw placed in 500 microl straw) for direct immersion into liquid nitrogen and storing the samples was also introduced. The protocol employed brief step-wise exposure to vitrification solution composed of ethylene glycol (EG) and sucrose (40% v/v EG, 0.6 M sucrose) and removal of vitrification solution at room temperature. Evaluation of the effects of vitrification revealed that there were no differences between control and vitrified neural stem or progenitor cells in expression of the neural stem or progenitor cell markers, proliferation, or multipotent differentiation. This sterile method for the xeno-free cryopreservation of murine neurospheres without animal or human proteins may have the potential to serve as a starting point for the development of cryopreservation protocols for human neural stem and progenitor cells for clinical use.

Effective Cryopreservation of Neural Stem or Progenitor Cells without Serum or Proteins by Vitrification.

Development of effective cryopreservation protocols will be essential to realizing the potential for clinical application of neural stem and progenitor cells. Current cryopreservation protocols have been largely employed in research, which does not require as stringent consideration of viability and sterility. Therefore, these protocols involve the use of serum and protein additives, which can potentially introduce contaminants, and slow cooling with DMSO/glycerol-based cryopreservation solutions, which impairs cell survival. We investigated whether serum- and protein-free vitrification is effective for functional cryopreservation of neurosphere cultures of neural stem or progenitor cells. To protect the samples from introduction of other contaminants during handling and cryostorage, an original "straw-in-straw" method (250 µl sterile straw placed in 500 µl straw) for direct immersion into liquid nitrogen and storing the samples was also introduced. The protocol employed brief step-wise exposure to vitrification solution composed of ethylene glycol (EG) and sucrose (40% v/v EG, 0.6 M sucrose) and removal of vitrification solution at room temperature. Evaluation of the effects of vitrification revealed that there were no differences between control and vitrified neural stem or progenitor cells in expression of the neural stem or progenitor cell markers, proliferation, or multipotent differentiation. This sterile method for the xeno-free cryopreservation of murine neurospheres without animal or human proteins may have the potential to serve as a starting point for the development of cryopreservation protocols for human neural stem and progenitor cells for clinical use.

Astragalus membranaceus and Polygonum multiflorum protect rat heart mitochondria against lipid peroxidation.

We isolated rat heart mitochondria and induced lipid peroxidation with ADP and FeSO4. Oxygen consumption and MDA formation were measured for quantitating the amount of lipid peroxidation. Using these methods, we screened the water extracts of 14 Chinese medicinal herbs for their effect on lipid peroxidation. It was found that Astragalus membranaceus inhibited 42.1 +/- 3.4% of oxygen consumption and 39.8 +/- 3.2% of MDA production at concentration of 2 mg dried herb/ml mitochondrial suspension. At the same concentration, Polygonum multiflorum inhibited 52.1 +/- 7.3% of oxygen consumption and 50.9 +/- 5.3% of MDA production. Other herbs did not inhibit lipid peroxidation to 50% of control at concentration up to 6 mg dried herb/ml mitochondrial suspension. Purification and identification of the active component(s) in Astragalus membranaceus and Polygonum multiflorum as well as their clinical application await further studies.

Some properties of the millimolar Ca2+-dependent proteinase from bovine cardiac muscle.

Three to six mg of the millimolar Ca2+-requiring proteinase (m-calpain) were obtained from 1 kg bovine cardiac muscle (fresh wt) and some enzymatic properties of this proteinase were determined. Activity of bovine cardiac m-calpain decreases as ionic strength increases from 75 to 1000 mM. Maximal activation of m-calpain by Ca2+, La3+, Ba2+, and Mn2+ occurs at 2 to 3 mM concentrations of each of these divalent cations, but La3+ activation is only 20 to 25% and Ba2+ and Mn2+ activation only 6 to 10% as great as Ca2+ activation. Maximum Sr2+ activation occurs at 20 mM Sr2+ and is 90 to 95% of maximum Ca2+ activation. Mg2+, Zn2+, Cr2+, and Cd2+ do not activate m-calpain when added alone; Mg2+ does not affect, but Zn2+ inhibits, Ca2+-stimulated activity. The nonionic detergents, Triton X-100 and Brij 35, activate m-calpain 1.6- to 2.0-fold but do not change its Ca2+ requirement. Sodium dodecyl sulfate and urea inhibit m-calpain completely at 0.045% and 2.0 M, respectively. Because they bind Ca2+ needed for activation, ATP, ADP, and ITP inhibit m-calpain. The trypsin inhibitors, phenylmethylsulfonyl fluoride, ovomucoid trypsin inhibitor, ovoinhibitor, aprotinin, alpha 1-antiproteinase inhibitor, soybean trypsin inhibitor, and lima bean trypsin inhibitor do not affect m-calpain activity; m-calpain does not release measureable quantities of acid-soluble peptides from a rabbit skeletal sarcoplasmic protein fraction but does degrade rabbit skeletal myofibrils and casein.