miR-204 inhibits proliferation of Hodgkin lymphoma cells by targeting Sirt1/p53 signaling pathway

AIM: To investigate the effect of microRNA-204 (miR-204) on the proliferation of Hodgkin lymphoma cells and the underlying mechanism. METHODS: The expression of miR-204 and Sirt1 mRNA in Hodgkin lymphoma tissues was detected by RT-qPCR. After transfection with miR-204 mimic, Sirt1 siRNA and miR-204 mimic+pcDNA3.1-Sirt1 into the L428 cells, the cell viability and BrdU incorporation were measured by CCK-8 assay and BrdU assay, respectively. The protein levels of Sirt1 and acetylated p53 (ac-p53) were determined by Western blot.The targeting relationship between miR-204 and Sirt1 was verified by double luciferase reporter assay. RESULTS: The low expression of miR-204 and the high mRNA expression of Sirt1 were found in the Hodgkin lymphoma tissues. Compared with control group, the cell viability, BrdU incorporation and the protein levels of Sirt1 and ac-p53 were significantly decreased after L428 cells were transfected with miR-204 mimic or Sirt1 siRNA (P<0.05). Compared with miR-204 mimic alone group, the cell viability, BrdU incorporation and the protein levels of Sirt1 and ac-p53 were increased after L428 cells were co-transfected with miR-204 mimic and pcDNA3.1-Sirt1 (P<0.05). The results of double luciferase reporter assay confiermed that Sirt1 was the target gene of miR-204. CONCLUSION: The inhibitory effect of miR-204 on the proliferation of L428 cells may be achieved by inhibiting the expression of Sirt1 and promoting the up-regulation of ac-p53.     

27-Hydroxycholesterol modulates lung cancer cell proliferation by activation of LXR signaling pathway

AIM:To investigate the effect of cholesterol metabolite 27-hydroxycholesterol (27-OHC) on the proliferation of lung cancer cells. METHODS:Human lung cancer A549 cells were treated with 27-OHC at different concentrations (0, 0.3125, 0.625, 1.25, 2.5, 5 and 10 μmol/L) for 24~48 h. The cell viability, cell cycle, cell prolife-ration, the intracellular cholesterol levels and cholesterol metabolism-related molecule expression were subsequently assessed by CCK-8 assay, flow cytometry, EdU staining, tissue total cholesterol detection kit, real-time PCR and Western blot. RESULTS:27-OHC decreased the viability of the A549 cells in a dose-and time-dependent manner (P<0.01) and inhibited the cell proliferation (P<0.05). The expression of typical liver X receptor (LXR) downstream target proteins including ATP-binding cassette transporter A1 (ABCA1), low-density lipoprotein receptor (LDLR), and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CR) were modulated, which promoted the efflux of intracellular cholesterol, and reduced cholesterol influx and de novo synthesis, resulting in decreased intracellular cholesterol levels and cell viability. Furthermore, the inhibitory effect of 27-OHC on A549 cell viability was significantly attenuated after the LXR pathway was partially blocked by 5 μmol/L GSK2033 treatment (P<0.05). CONCLUSION:27-OHC inhibits A549 cell prolife-ration via activation of LXR signaling pathway.     

蛋白质激发子Hrip1对小麦黄矮病的诱抗作用

小麦黄矮病是由大麦黄矮病毒（barley yellow dwarf virus，BYDV）引起的一种小麦病毒病，其传播介体是小麦蚜虫，在小麦生产中造成巨大的经济损失。近年来，植物诱导抗性作为一种新兴的植物病虫害防治措施引起了广泛的关注。蛋白质激发子Hrip1可以激活多种植物的免疫防御反应诱导植物产生广谱抗性。本研究评价了Hrip1对小麦黄矮病的诱抗效果。用30 μg/mL的Hrip1溶液进行小麦浸种和幼苗喷雾，随后接种BYDV，接种后第14 d，Hrip1对小麦黄矮病控制效果在50%以上，接种后第21 d控制效果仍在30%以上。实时荧光定量PCR检测结果显示，在Hrip1处理的小麦幼苗体内，BYDV外壳蛋白mRNA的数量显著低于对照组；EPG结果显示，在Hrip1处理的小麦幼苗上，麦二叉蚜寻找叶片刺吸位点和韧皮部取食位点的时间增加。以上结果表明：Hrip1能够有效地抑制BYDV在小麦体内的增殖；影响传毒媒介麦二叉蚜的取食行为，抑制其传毒能力。此外，Hrip1处理小麦能有效缓解BYDV引起的叶片黄化和植株矮化的症状。因此，Hrip1可以作为生物诱导剂综合控制小麦黄矮病。     

表观遗传修饰在骨骼肌细胞增殖分化过程中的研究进展

骨骼肌是肌肉的主要构成部分，骨骼肌细胞发生增殖和分化的过程都是肌肉发育的基础，直接影响着家养动物的产肉性能。研究发现表观遗传修饰作用对骨骼肌细胞增殖分化具有重要的调控作用，表明该遗传修饰作用对家养动物肌肉发育具有重大的意义。作者从DNA甲基化对骨骼肌细胞增殖分化影响、组蛋白乙酰化所含因子调控基因选择表达作用、非编码RNA调控和染色体重塑作用所起的影响等方面分别介绍了表观遗传在骨骼肌细胞增殖分化过程中的研究进展，简述了不同修饰方式和不同作用因子对骨骼肌增殖和分化两个过程的影响。同时也回顾了前人在研究骨骼肌增殖分化过程所用到的方法和手段，进而分析了表观调控作用因子在骨骼肌生长过程中所起到的作用。旨在进一步阐述表观遗传修饰在骨骼肌增殖和分化过程中所起到的重要作用，增强对骨骼肌增殖分化调控过程的了解，为和动物生产实际相结合提供参考途径，同时也为骨骼肌生长发育等分子调控提供更多参考素材。     

SNAT2介导蛋氨酸对牛乳腺上皮细胞增殖与自噬的调节作用

钠离子依赖性中性氨基酸转运体2（SNAT2）是一种氨基酸转运蛋白，可转运中性氨基酸，广泛分布于多种细胞中。氨基酸既可作为蛋白质合成的底物，也是调节细胞新陈代谢的关键信号分子，但SNAT2是否介导氨基酸调节BMECs增殖和自噬尚未见报道。本研究利用CASY细胞计数和Western blotting技术检测SNAT2过表达和siRNA干扰后牛乳腺上皮细胞（BMECs）增殖情况以及SNAT2对自噬标志蛋白LC3-Ⅰ/Ⅱ表达量的影响，并利用免疫荧光检测细胞自噬斑点（LC3-Ⅱ）变化。结果显示，SNAT2过表达时，p-PI3K、p-mTOR和Cyclin D1表达量增加，反之，p-PI3K、p-mTOR和Cyclin D1表达量下降。SNAT2抑制时，LC3-Ⅱ表达量增加，免疫荧光检测自噬斑点增多。添加自噬增强剂海藻糖（trehalose，Tre）和蛋氨酸（methionine，Met）后，与单一添加Tre组相比，Met+Tre组p-mTOR表达量增加，LC3-Ⅱ表达量降低，胞浆内绿色自噬斑点减少；添加Tre和Met并抑制SNAT2时，p-mTOR表达量下降，LC3-Ⅱ表达量增多，胞浆内绿色自噬斑点增加。以上结果表明，SNAT2可介导Met通过调控PI3K-mTOR/Cyclin D1信号通路调节BMECs的增殖与自噬。     

F-box domain is involved in regulating the proliferation of MCF-7 cells by FBXO39 protein

AIM: To investigate the effect of F-box domain on the regulation of MCF-7 cell proliferation by FBXO39 protein. METHODS: The effect of F-box domain on the localization of FBXO39 protein in the MCF-7 cells was investigated. MCF-7 cell cDNA library was used as the template resource. The full-length cDNA sequence of FBXO39 was amplified by PCR method and subcloned into eukaryotic expression vector pEGFP-C2. The pEGFP-FBXO39ΔF (F-box domain deletion mutation) plasmid was successfully constructed with the template resource of pEGFP-FBXO39 plasmid. The recombinant plasmids were transfected into the MCF-7 cells, and then the expression of FBXO39 and FBXO39ΔF were determined by Western blot. The cellular localization of FBXO39 and FBXO39ΔF were observed by confocal microscopy. The localization of endogenous FBXO39 in the MCF-7 cells was detected by immunofluorescence staining. In addition, MTT and EdU assays were used to measure the cell proliferation, flow cytometry was used to measure the cell cycle distribution, and immunohistochemical staining was used to observe the expression of FBXO39 in the breast cancer and para-carcinoma tissues. RESULTS: The eukaryotic expression vector pEGFP-FBXO39 and pEGFP-FBXO39ΔF were constructed successfully. F-box domain had no effect on the cell localization of FBXO39. FBXO39 promoted MCF-7 cell proliferation but FBXO39ΔF did not. FBXO39 was highly expressed in the breast cancer tissues. CONCLUSION: F-box domain had no effect on the cellular localization of FBXO39 protein. However, it plays an important role in the biological function of FBXO39. FBXO39 may be related to breast cancer tumorigenesis.     

蝴蝶兰‘大辣椒’组培快繁技术体系的优化

探索优化蝴蝶兰组培快繁技术体系，以蝴蝶兰‘大辣椒’半木质化花梗为试验材料，研究消毒剂、基础培养基、植物生长调节剂配比及浓度对蝴蝶兰不定芽诱导、增殖和生根过程的影响。结果表明:1）先用2% H₂O₂溶液处理15 min，再用10% NaClO溶液处理10 min，消毒效果良好，花梗污染率低，为26.6%；2）不定芽诱导最适培养基为花宝1号+花宝2号+ 6-BA 3 mg/L+NAA 0.05 mg/L，出芽率为78.9%；3）不定芽增殖最适培养基为花宝1号+6-BA 5 mg/L+NAA 0.05 mg/L，增殖系数为3.60；4）幼苗生根最适培养基为1/2MS+NAA 0.2mg/L，生根率为73.7%。本研究旨在优化‘大辣椒’品种的组培快繁技术体系，为进一步建立蝴蝶兰再生体系和工厂化生产提供技术支持。     

响应面试验优化霍山石斛原球茎增殖培养基

为可持续开发霍山石斛资源，采用响应面法优化霍山石斛原球茎增殖培养基。在单因素试验基础上，根据Box Behnken试验设计原理，采用三因素三水平的响应面分析法，以增殖率为响应值进行回归分析。结果表明，萘乙酸（简称NAA）及6 苄氨基嘌呤（简称6 BA）浓度对增殖率影响最为显著，6 BA与马铃薯两者间交互作用显著，适宜的NAA、6 BA及马铃薯浓度分别为0.05 mg·L-1、0.70 mg·L-1和185 g·L-1，此时增殖率为2 989.82%±205.55%，与模型预测值基本符合。响应面法优化霍山石斛原球茎增殖培养基切实可行。     

朱顶红幼嫩花梗胚性愈伤组织诱导和高效植株再生

为建立高效的朱顶红植株再生和种苗繁育技术体系，以幼嫩花梗为外植体开展胚性愈伤组织诱导和植株再生研究。对2,4-D和噻苯隆（TDZ）浓度、外植体发育时期及大小进行了筛选，结果表明：将切片厚度为1 mm的幼嫩花梗外植体置于添加0.5 mg ? L-1 TDZ 和2.0 mg ? L-1 2,4-D的MS固体培养基上培养8周，胚性愈伤组织诱导率最高，达85.3%。将胚性愈伤组织转移至相同的培养基上，每月继代1次，平均每月增殖10.6倍。在不含任何生长调节剂的MS培养基上，胚性愈伤组织的植株再生率达98.0%，平均每块愈伤组织可再生出12.3个小植株。经过36次（3年）继代培养后，胚性愈伤组织的增殖和植株再生效率没有显著变化。幼苗移栽至温室驯化，成活率达97.5%。再生植株移栽到田间，没有发现明显的表型变异。对随机选择的再生植株和母株进行简单序列重复区间（ISSR）扩增分析，证实再生植株没有发生DNA水平变异。     

Expression and function of circular RNA_0000231 in non-small-cell lung cancer

AIM: To investigate the expression and function of circular RNA_0000231 (circ_0000231) in non-small-cell lung cancer (NSCLC). METHODS: RT-qPCR was used to detect the expression of circ_0000231 in the NSCLC tissues and cell lines. circ_0000231 small interfering RNA (si-circ_0000231) or negative control siRNA of circ_0000231 (NC) was transfected into the NSCLC cells. The proliferation and apoptosis of the NSCLC cells were detected by CCK-8 assay, colony formation assay and flow cytometry, respectively. The expression of cyclin D1 (CCND1) and anti-apoptotic protein Bcl-2 were determined by RT-qPCR and Western blot. RESULTS: The expression of circ_0000231 in the NSCLC tissues and cell lines was significantly up-regulated compared with precancerous tissues and lung epithelial cells BEAS-2B (P<0.05). After transfection of NSCLC cells with si-circ_0000231, the cell viability, colony formation numbers were significantly decreased, and the apoptotic rate in si-circ_0000231 group was significantly increased as compared with NC group (P<0.01). In addition, the results of RT-qPCR and Western blot showed that transfection of si-circ_0000231 inhibited the expression of CCND1 and Bcl-2 (P<0.01). CONCLUSION: The expression of circ_0000231 is significantly increased in the NSCLC tissues and cells. Knock-down of circ_0000231 expression significantly inhibits the proliferation of NSCLC cells.