FOLFOX方案同步放疗对局部晚期结直肠癌患者手术疗效及预后的影响

目的探讨FOLFOX同步放疗对T3-T4期结直肠癌手术疗效及预后的影响。方法回顾性收集本院2008年6月至2012年5月收治的T3-T4期结直肠癌患者125例,分为单纯手术治疗组(对照组,61例)以及FOLFOX方案化疗同步放疗后手术治疗组(治疗组,64例)。观察术前FOLFOX方案化疗同步放疗对结直肠癌患者的肿瘤切除率、手术相关并发症、保肛率、3年复发率及生存率的影响。结果对照组和治疗组分别有28例和45例肿瘤完全切除,差异有统计学意义(P0.01)。对照组和治疗组分别有9例和19例切除肿瘤后行保肛手术(P=0.04);两组患者在总生存率和复发率差异均无统计学意义,但在第1、2年的复发率和生存率差异有统计学意义。结论局部晚期结直肠患者术前行FOLFOX方案同步放疗能够提高肿瘤切除率和保肛率,降低近期复发率。     

三氧化二砷对人肝癌细胞株SMMC-7721中p27~(kip1)及其相关分子Skp2表达的影响

目的 通过检测三氧化二砷(As2O3)对肝癌SMMC-7721细胞周期素依赖性激酶抑制剂(CDKI)p27kip1及S期激酶相关蛋白2(Skp2)的影响,探讨其抗癌作用机制.方法 体外培养人肝癌细胞株SMMC-7721,用2μmol/L As2O3处理72h,流式细胞仪检测细胞周期变化及细胞凋亡率,应用Western blot方法检测p27kip1、Skp2及CDK2基因编码蛋白的表达.结果 与对照组比较,As2O3使SMMC-7721细胞周期阻滞在G2/M期.经As2O3作用的人肝癌细胞p27kip1基因编码蛋白表达增加,而p27kip1相关分子Skp2及CDK2的表达减少.结论 As2O3可干扰细胞周期的进程,抑制SMMC-7721细胞的增殖.其作用机制与上调p27kip1蛋白及下调Skp2、CDK2有关.     

ALKBH5对紫外线诱导的晶状体上皮细胞氧化损伤模型中DNA损伤修复的影响

目的　探究N⁶-甲基腺苷（m⁶A）去甲基化酶ALKBH5对紫外线诱导的晶状体上皮细胞（LEC）氧化损伤模型中DNA损伤修复的影响。方法　运用qRT-PCR和免疫印迹实验检测年龄相关性白内障（ARC）患者和对照组晶状体前囊膜上皮细胞中ALKBH5的mRNA和蛋白的表达。通过紫外线B（UVB）构建晶状体上皮细胞株SRA01/04细胞氧化损伤模型和靶向ALKBH5设计小干扰RNA（siRNA）转染构建敲降模型,运用qRT-PCR和免疫印迹实验检测氧化损伤模型和敲降模型中ALKBH5的mRNA和蛋白表达。运用CCK-8法检测Control组、UVB组、UVB+siNC组和UVB+siALKBH5#3组中SRA01/04细胞活力变化。免疫荧光染色检测UVB+siNC组和UVB+siALKBH5#3组中15A3的荧光强度变化。运用qRT-PCR检测转染对照siNC组和转染siALKBH5#3组中11个DNA氧化损伤修复基因（ODRGs）的mRNA表达变化。结果　在ARC患者的晶状体前囊膜上皮细胞中,ALKBH5的mRNA和蛋白表达水平均显著升高。在UVB以时间梯度诱导SRA01/04的细胞氧化损伤模型中,ALKBH5的mRNA和蛋白表达水平均呈上升后下降趋势,其中UVB照射10 min后ALKBH5 mRNA和蛋白表达升高最为显著。ALKBH5敲降效率结果显示,与转染对照siNC组相比,转染靶向ALKBH5的siRNA后,ALKBH5的mRNA和蛋白表达均显著下降。CCK-8法检测结果显示,与UVB+siNC组相比,UVB+siALKBH5#3组SRA01/04细胞活力明显降低。免疫荧光染色检测结果显示,与UVB+siNC组相比,UVB+siALKBH5#3组SRA01/04细胞内DNA氧化损伤指标15A3染色显著增加。同时,与转染对照siNC组相比,转染ALKBH5#3组SRA01/04细胞的ODRGs中,TREX1、FANCD2、LIG1、MSH2、MSH3、RPA2、SMUG1、XRCC6 mRNA的表达均显著上升,DCLRE1A mRNA的表达显著下降,MGMT和MRE11A mRNA的表达则未见明显差异。结论　m⁶A去甲基化酶ALKBH5在UVB诱导的LEC氧化损伤模型中诱导性表达上升,敲降ALKBH5可促进LEC内大部分ODRGs表达升高,参与调控LEC内损伤DNA的修复,阻止ARC的发生。     

生物素化葡聚糖胺顺行追踪标记大鼠皮质脊髓束

目的:探讨生物素化葡聚糖胺(BDA)对皮质脊髓束(CST)示踪的应用价值。方法:采用成年SD大鼠40只,随机分为单侧锥体束损伤组(n=24)、假损伤组(n=8)和正常组(n=8)。在锥体交叉上方选择性切断左侧锥体建立单侧锥体束横断损伤模型。运用Rivlin斜板试验进行运动功能检测。在双侧感觉运动皮层多点分层立体定位注射BDA,BDA注射14天后取脑和脊髓切片进行ABC免疫组织化学染色显示BDA标记信号,观察皮质脊髓束的走行。结果:Rivlin斜板试验显示单侧锥体束横断损伤组倾斜平面临界角度变化明显小于正常对照组和假损伤组(P<0.05)。正常组和假损伤组大鼠BDA示踪显示BDA标记阳性细胞定位于双侧感觉运动皮层的锥体细胞,锥体细胞发出的BDA阳性纤维束对称分布于双侧皮层、内囊、大脑脚、脑桥基底部、延髓锥体中的皮质脊髓束内,继而经锥体交叉到脊髓后索,在双侧后索最深层、灰质后连合背侧下行至脊髓骶段。锥体束横断损伤大鼠在损伤部位以上可见双侧对称的BDA阳性纤维束,损伤平面以下在右侧延髓锥体和左侧脊髓后索中见有BDA阳性纤维束,损伤侧锥体和右侧脊髓后索中未见有BDA阳性纤维束。结论:BDA顺行示踪技术可以清楚地显示皮...     

TSA体外抑制Ⅱ型胶原诱导的抗原特异性T细胞增殖

目的：检测TSA对Ⅱ型胶原诱导的T细胞增殖的抑制作用。方法：采用CIA小鼠模型，收集引流淋巴结细胞。MTT法观察不同浓度TSA对T细胞的抑制作用，Annexin-v观察细胞凋亡情况。用Caspase3试剂盒检测Caspase3酶活性。结果：TSA呈时间和剂量依赖性抑制T细胞增殖，经20ng／ml TSA处理后，T细胞凋亡率增高，呈现时间依赖性效应关系。20ng/ml TSA作用T细胞后，实验组与对照组相比Caspase3活性明显升高。结论．TSA可能通过上调Caspase 3活性，诱导细胞凋亡，从而抑制T细胞增殖。     

Identification and potential role of PSD-95 in Schwann cells

Postsynaptic density-95 (PSD-95) is one of neuronal nitric oxide synthase (nNOS)-anchoring proteins and plays an important role in specifying the sites of reaction of nitric oxide (NO) in the nervous system. The present study aims to investigate the presence of PSD-95 in rat Schwann cells (SCs) and the association of PSD-95 and nNOS with serum-induced SCs proliferation. The expression of both molecules downregulated significantly after 48 h of serum deprivation, and increased gradually to the peak at 12 h, ultimately returned to the control level at 48 h after serum stimulation. The association of PSD-95 with nNOS was observed in Ki67 and BrdU-positive SCs. The selective nNOS inhibitor arrested the cell cycle progress and decreased the proliferating cell nuclear antigen (PCNA) levels. These findings suggested that PSD-95 and nNOS may collectively participate in the proliferation of SCs, providing further evidence for the role of NO during peripheral nerve regeneration.     

Estrogen receptors are involved in polychlorinated biphenyl-induced apoptosis on mouse spermatocyte GC-2 cell line

Polychlorinated biphenyls (PCBs) are widespread persistent environmental contaminants which have been shown to have reproductive toxicity and to disturb spermatogenesis. But the precise mechanism is not clear. A mouse pachytene spermatocyte-derived cell line, GC-2 cells were used in the present study to investigate the toxic effect of PCBs (Aroclor 1254) and explore the underlying molecular mechanism. Results showed that Aroclor 1254 inhibited cell proliferation, caused the arrest of cells in G0/G1 phase and induced apoptosis which might be partly explained by the decreased expression of Bcl-2 and cell cycle regulator cyclin D1 together with the activation of caspase-3. Besides, the treatment of Aroclor 1254 decreased the protein expression of estrogen receptor (ER)-α while increasing that of ERβ. Then the administration of selective ERα agonist PPT partly reversed Aroclor 1254-induced alteration in Bcl-2, caspase-3 and cyclin D1 protein expression while selective ERβ agonist DPN accelerated it. These results suggest that Aroclor 1254, working through ERα and ERβ, interferes with the expression of proteins involved in the balance between cellular apoptosis and proliferation.     

Iso-suillin from the mushroom Suillus flavus induces cell cycle arrest and apoptosis in K562 cell line

Iso-suillin, an isomer of suillin that belongs to the prenylphenol class of fungal derivatives, was isolated from petroleum ether extracts of Suillus flavus. The IC₅₀ value of iso-suillin in K562 cells was 0.87 μM, which was lower than the positive control cisplatin (19.33 μM). Iso-suillin-treated K562 cells exhibited an increased rate of apoptosis, mitochondrial membrane potential (MMP) depolarization, and G0/G1 arrest. Western blot analysis revealed that these cells displayed significantly upregulated expression of several apoptosis-related proteins, including cytochrome c, caspase 9, FADD (Fas-associating protein with a novel death domain), caspase 8, caspase 3, and Bax. Moreover, the expression of two anti-apoptosis proteins, NF-κB and Bcl-2, was downregulated. Inhibitors of caspase 9 and caspase 8 protected the K562 cells from apoptosis. Taken together, our results suggest that iso-suillin induces K562 apoptosis through the mitochondrial and death receptor pathways and that iso-suillin may represent a candidate anti-leukemia treatment.