Objective To investigate the drug resistance of side population cells in human gallbladder cancer cell line GBC-SD and explore its mechanism. Methods Drug sensitivity assays of 5chemotherapeutic agents were performed on side population cells (SP) and non-SP cells of GBC-SD.GBC-SD was cultured and then treated with the chemotherapeutic agent gemcitabine. The frequency of SP by FACS was measured. RT-PCR and Western blotting were used to detect the expression of AB-CG2 in both the SP and the corresponding non-SP subsets. Results After 1 d treatment with 4 chemotherapeutic agents (gemcitabine, cisplatin, 5-fluorouracil and mitoxantrone) in IC50 concentration to GBC-SD cell line, the reproductive ability of SP was higher than that of non-SP (P<0.05). However, statistical significance was not achieved when compared with epirubicin (P>0.05). The percentage of SP in GBC-SD treated with chemotherapeutic agent gemcitabine after 3 weeks was sharply elevated by FACS (8.02% ±0.13% vs 0.62% ±0.08%, P<0.05), and the expression of ABCG2mRNA and protein were increased in SP as compared with non-SP. Conclusion SP from human gallbladder cancer cell line GBC-SD, like stem cell, showed a heighten resistance to drugs. Increased expression of ABCG2 was largely responsible for the multi-drug resistance.

Objective To investigate the effect of ketamine on the mitochondrial function of rat neurons subjected to anoxia. Methods Primarily cultured rat hippocampal neurons were seeded in culture dishes (35 mm in diameter) at the density of 5×105-1×106 cells∕ml, and divided into 3 groups (n=11 each) using a random number table: control group, anoxia group and ketamine group. The neurons were exposed to 90% N2 plus 10% CO2 50 ml∕min for 5 min in anoxia group. In ketamine group, ketamine was added to the culture medium with the final concentration of 20 μmol∕L at 1 h before anoxia, and then the neurons were exposed to 90% N2 plus 10% CO2 50 ml∕min for 5 min. After the end of treatment in each group, the dead neurons were detected using trypan blue staining, the ATP content was determined by ATP bioluminescence assay, and mitochondrial membrane potential was measured by rhodamine 123 staining. Results Compared with control group, the mortality rate of hippocampal neurons was significantly in?creased, and the ATP content and mitochondrial membrane potential were significantly decreased in anoxia group and ketamine group ( P<0.05) . Compared with anoxia group, the mortality rate of hippocampal neu?rons was significantly decreased, and the ATP content and mitochondrial membrane potential were signifi?cantly increased in ketamine group (P<0.05). Conclusion The mechanism by which ketamine amelio?rates anoxia?induced damage to rat neurons is related to improved mitochondrial function.

Objectives To isolate cancer stem cells (CSCs) in pancreatic cancer cell lines PANC1 and ASPC-1 with serum-free medium( SFM ), and to detect the expression of miR-590-3p in CSCs. Methods PANC1 and ASPC-1 cells was cultured in serum-free medium. The monoclonal formation, differentiation and cell cycle, half inhibitory concentration ( IC50 ), and the expression of the surface markers CD24 + , CD44 + were detected. qRT-PCR was used to detect the expression of miR-590-3p. Results After SFM culture, (0.94 ±0.53 ) ％ of ASPC-1 and (0.57 + 0. 12 ) ％ PANC1 survived, and they formed spheres, and could continuously passage in vitro. Cell spheres differentiation recurred when serum was supplemented in SFM. The G0/G1 stage proportion, CD24+ , CD44 + , CD24+ CD44+ cells proportion, IC50 in ASPC-1 cell were (75.3 ± 5.4)％,0.96％ ～ 2.01％, 27.52％ ～ 34.47％, 0.35％ ～ 0.44％ and (224.37 ± 5.71 ) μg/ml, which were significantly higher than that those in parent cell [ (43.7 ± 3.8 ) ％, 0. 38％ ～ 0.42％, 17.65％ ～ 18.25％,0.05％ ～0.08％, (11.43 ±2.10)μg/ml, P＜0.05]. The G0/G1 stage proportion, CD24+ ,CD44+ ,CD24 +CD44 + cells proportion, IC50 in PANC 1 cell were ( 80. 1 ± 4.7) ％, 5.31％ ～ 9.84％, 72.05％ ～ 93.06％,4.91％ ～5.21％, (296.58±4.27) μg/ml, which were significantly higher than that those in parent cell [ (46.1 ±5.3)％, 4.09％ ～4.97％, 47.71％ ～55.66％, 1.48％ ～2.63％, (26.17 ±3.81)μg/ml, P＜0.05]. The expression of miR-590-3p in ASPC-1, PANC1 spheres was 4.67 and 4.52 times higher than the expression in parent cell lines. Conclusions Pancreatic cancer cell spheres can be isolated from ASPC-1, PANC1 by culture with SFM. miR-590-3p is up-regulated and may play an important role in regulating biological characteristics of pancreatic cancer stem cells.

目的：探讨miRNA-490-3p调控Smad2/TGF-β对结直肠癌奥沙利铂化疗敏感性的影响。方法：选取100例结直肠癌（colorectal cancer，CRC）根治性手术后奥沙利铂（oxaliplatin，OXA）同种联合化疗患者作为研究对象，根据化疗情况分为耐药组（n=40）和非耐药组（n=60），用qPCR检测两组外周血miRNA-490-3p水平；选取人CRC细胞株SW480和CRC奥沙利铂（OXA）耐药型细胞株OXA-SW480进行研究，先用qPCR检测两种细胞株中miRNA-490-3p表达水平；后将miRNA-490-3p过表达载体转染OXA-SW480（过表达组），并设立空载体组（空载体转染OXA-SW480）和空白对照组（OXA-SW480未经任何处理）。用CCK-8检测各组细胞增殖能力，同时用不同浓度OXA处理各组细胞，计算其半数抑制浓度（IC50）；用Annexin-V-FITC/PI染色流式细胞术检测各组细胞凋亡率；用WB检测各组Smad2和TGF-β蛋白表达水平。结果：在CRC患者中，耐药组外周血miR-490-3p水平显著低于非耐药组，在CRC细胞株中，OXA-SW480耐药株细胞miR-490-3p水平显著低于正常株SW480细胞（P<0.05）。与空载体组和空白对照组相比，过表达组miR-490-3p水平显著降低（均P<0.05），增殖抑制率显著升高（均P<0.05），细胞凋亡率显著升高（均P<0.01），Smad2蛋白水平显著降低（均P<0.05），TGF-β蛋白水平显著升高（均P<0.05）。经OXA处理后，过表达组的IC50显著低于空载体组和空白对照组（均P<0.05）。经Pearson相关法分析，miR-490-3p与Smad2的表达呈负相关（r=–0.943，P<0.01），miR-490-3p与TGF-β的表达呈正相关（r=0.961，P<0.01）。结论：过表达miRNA-490-3p可增加CRC SW480细胞的OXA敏感性，此作用Smad2/TGF-β信号通路有关。