The experimental research of Neutrophil Gelatinase-associated Lipocalin(NGAL) siRNA encapsulated by UAC on NGAL gene silence in colon cancer cells / 中国生化药物杂志

Objective To explore the effect of NGAL knockdown by NGAL siRNA encapsulated with urocanic acid-modified chitosan nanoparticles (UAC).MethodsNGAL siRNA encapsulated by UAC and chitosan (CTS) respectively, which were then used to transfect human colon cancer cell lines HT29.The expression level of NGAL protein were detected by Enzyme Linked Immunosorbent Assay(ELISA).ResultsThe ELISA study revealed that the expression level of NGAL protein in UAC group(average 0.583μg/L) was significantly lower than in CTS group (average 0.772μg/L) and control group(average 1.071μg/L) (P<0.05).ConclusionThe NGAL expression of mRNA and protein in HT29 cells could be down-regulated by siRNA encapsulated by UAC.

Experimental research of neutrophil gelatinase-associated lipocalin siRNA encapsulated by urocanic acid-coupled chitosan on colon cancer cells / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the impact of neutrophil gelatinase-associated lipocalin (NGAL) knockdown by NGAL siRNA encapsulated with urocanic acid-modified chitosan nanoparticles (UAC) on the proliferation, migration and apoptosis of human colon cancer cells.</p><p><b>METHODS</b>NGAL siRNA was encapsulated by UAC and chitosan (CTS) respectively, and then was transfected into human colon cancer cell lines HT29. The NGAL mRNA was detected by real-time quantitative PCR (RT-QPCR). Relationships of NGAL gene silencing with the proliferation, migration and apoptosis of HT29 cell were analyzed.</p><p><b>RESULTS</b>Under the fluorescence microscope, the transfection efficiency of siRNA in UAC group was (37.52±7.17)%, which was significantly higher than (11.32±3.39)% in CTS group (t=6.102, P=0.005). Forty-eight hours after transfection, RT-QPCR examination showed that the level of NGAL mRNA expression was 0.350 in UAC group and 0.529 in CTS group with significant difference (t=-3.743, P=0.02), meanwhile both levels were significantly lower as compared to control group(F=163.538, P<0.001). Proliferation analysis revealed that after silencing NGAL gene, proliferation rate of UAC group and CTS group was slightly lower than control group, and no significant differences were found (F=9.520, P=0.438). However, migration assay demonstrated that the 24-hour migration rate of UAC group and CTS group was significantly lower than that of control group (F=6.756, P=0.029), meanwhile the migration rate of UAC group was slightly lower than that of CTS group [(77.90±7.14)% vs. (87.67±3.98)%, t=-1.704, P=0.164]. Apoptosis detection revealed that the apoptosis rate in UAC group was significantly higher than that in CTS group and the control group 2 days after transfection [(15.800±1.054)% vs. (12.900±0.656)%, (11.933±1.914)%, F=7.004, P=0.027].</p><p><b>CONCLUSIONS</b>The encapsulated ability and transfection efficiency of chitosan modified by urocanic acid elevate significantly. Silencing NGAL gene by UAC carrier can down-regulate the expression of NGAL mRNA in HT29 colon cell line, inhibit their migration and facilitate their apoptosis.</p>

Effect of sodium chloride on growth and lipid accumulation of Chlorella protothecoides CS-41 / 生物工程学报

With basal medium, we studied the growth status, lipid droplet distribution, total lipid content of Chlorella protothecoides CS-41 treated with different concentrations of sodium chloride (0, 150, 300 and 600 mmol/L) by optical microscopy, electron microscopy, confocal laser focusing and Nile red staining. Results show that the addition of NaCl affected the growth of Chlorella protothecoides CS-41. With the increase of NaCl concentration, the growth rate of Chlorella was inhibited. Chlorella cell wall became thicker, and lipid droplets increased. At the early stage, the amount of lipid droplets in the 600 mmol/L NaCl culture was the highest, but at the late-log stage, the amount of lipid droplets increased with the increase of the biomass of culture in 150 and 300 mmol/L NaCl culture. At the stable stage, biomass (dry weight) in 300 mmol/L NaCl culture was 73.55% of that in the control, but the total lipid content was 2.22 times higher than that in the control. A certain concentration of sodium chloride treatment can significantly increase the lipid content of Chlorella protothecoides CS-41.

Isolation, identification and anticancer activity of an endophytic fungi from Juglans mandshurica / 中国中药杂志

The endophytic fungus named FSN006 was isolated from the inner bark of Juglans mandshurica. It grew quickly and formed circular colony on PDA plate. The upper side of the colony was white, while the lower side of the colony and the conditioned medium were light yellow as a result of significant yellow pigment substances were produced and secreted by the fungi. Green elliptic conidia appeared when cultured on CMX plate. Based on the morphology identification and ITS sequence, it was clear that this fungus belonged to the Deuteromycotina, HyPhomycetes, Moniliales, Trichoderma longibrachiatum. The conditioned medium of FSN006 showed a high anti-tumor ability against liver cancer cell-HepG2, and reached its IC50 concentration after being diluted 20 times, while the IC50 concentration of curcumine was(11.49 +/- 0.12) mg x L(-1). In addition, there was preeminent selective inhibiting effect against the normal liver cell strain HL-7702 and its caner counter strain HepG2. The inhibiting effect against strain HL-7702 was only one quarter of that against HepG2 at the concentration of IC50. Therefore, the fermentation of FSN006 may provide a possible way to produce anticancer drug with higher efficiency and lower toxicity.