胶质母细胞瘤(glioblastoma,GBM)是最常见的恶性脑肿瘤,恶性程度高、侵袭力强、易复发和预后差是其显著的特点[1].胶质瘤干细胞(glioma Stem Cells,GSCs)是神经胶质瘤细胞中所包含的一种具有自我更新能力的亚群,其特性包括高致瘤性、自我更新的能力和对放化疗的抵抗,被认为是GBM复发的关键因素之一,也被称之为胶质瘤起始细胞(glioma initiating cells,GICs).

目的 探究Prominin1在不同发育时期小鼠视网膜色素上皮(retinal pigment epithelium,RPE)的表达.方法 孕鼠和出生后的Prom1cre/ERT2+/Gt(ROSA)26SorCAG-ZsGree1+转基因小鼠,腹腔注射他莫昔芬,将视网膜组织冰冻切片后,采用激光共聚焦显微镜检测Prominin1在转基因小鼠RPE中的表达;利用荧光定量PCR和免疫荧光技术检测Prominin1在野生型小鼠不同发育时期RPE中的表达.结果 对13.5 d(E13.5)、15.5 d(E15.5)和出生后1d(P1)小鼠的研究结果显示:Prominin1可能在胎鼠的部分RPE表达,出生后小鼠不表达.定量PCR显示:Prominin1 在胎鼠RPE(E10.5、E13.5、E15.5和E17.5)表达明显高于出生后(P1和P14)(P＜0.01);在胚胎时期,Prominin1在E13.5和E15.5的RPE表达明显高于其他时期(P＜0.05或P＜0.01).免疫荧光染色结果显示,Prominin1在E10.5、E13.5、E15.5和E17.5的RPE表达,而在P1不表达.结论 Prominin1在胎鼠视网膜色素上皮中表达,在E13.5和E15.5的胎鼠中尤为明显.

CD133(Prominin-1)是五次跨膜糖蛋白Prominin家族的成员之一,最初作为特异性标志物用于筛选人造血干细胞和祖细胞,随后用于分离鉴定各种肿瘤干细胞的特定细胞亚群.研究表明,CD133是肿瘤治疗预后的标志物,能与血管内皮生长因子等物质相互作用,参与细胞通路的信号转导,在维持视网膜形态和功能中发挥着重要作用.根据是否与CD133的糖基化表位结合,可将CD133的相关抗体分为糖基化抗体、非糖基化抗体以及其他未指明是否与糖基化表位结合的抗体.围绕CD133近年的研究成果对Prominin家族、CD133的功能、相关抗体和相关研究方法进行综述.

目的 探讨miRNA-29a-3p在喉癌细胞增殖中的作用和分子机制.方法 选择4种人喉癌细胞系(TU212、M4E、M2E、HEP-2)以及正常鼻咽上皮细胞系NP69,将转染mimic-NC质粒和miRNA-29a-3p mimic质粒的细胞分别设为mimic-NC组和miRNA-29a-3p mimic组,并根据是否转染mimic-NC质粒、oe-NC质粒、miRNA-29a-3p mimic质粒、oe-prominin 1(PROM1)质粒分别设立mimic-NC+oe-NC组、miRNA-29a-3p mimic+oe-NC组、miRNA-29a-3p mimic+oe-PROM1组.使用实时定量聚合酶链反应(PCR)检测各细胞系中miRNA-29a-3p表达,利用荧光素酶报告实验验证miRNA-29a-3p与PROM1的靶向关系,采用克隆形成实验及噻唑蓝(MTT)实验检测喉癌细胞的增殖能力,利用Western blot法检测喉癌细胞中PROM1的表达情况.结果 TU212细胞、M4E细胞、M2E细胞和HEP-2细胞的miRNA-29a-3p相对表达量均明显低于正常NP69细胞,差异均有统计学意义(P﹤0.01).选择相对表达量最低的TU212细胞作为受试细胞进行后续实验.miRNA-29a-3p mimic组TU212细胞PROM1蛋白相对表达量明显低于mimic-NC组,差异有统计学意义(P﹤0.01).转染miRNA-29a-3p后,野生型PROM1的荧光素酶活性明显低于mimic-NC组,差异有统计学意义(P﹤0.01);而转染miRNA-29a-3p后,突变型PROM1的荧光素酶活性与mimic-NC组比较,差异无统计学意义(P﹥0.05).miRNA-29a-3p mimic+oe-NC组细胞克隆形成率及各时间点吸光度(OD)值均低于mimic-NC+oe-NC组和miRNA-29a-3p mimic+oe-PROM1组,差异均有统计学意义(P﹤0.05);mimic-NC+oe-NC组与miRNA-29a-3p mimic+oe-PROM1组细胞克隆形成率及各时间点OD值比较,差异均无统计学意义(P﹥0.05).结论 miRNA-29a-3p可明显抑制喉癌细胞的增殖,其可能的机制是通过靶向调控PROM1发挥作用.

Objective Platinum-based chemotherapy is the first-line treatment for non–small cell lung cancer, but the chemoresistance of tumor cells continues to be a considerable challenge in the management of NSCLCs, leading to recurrence of most patients. CD133 (prominin-1) is a five-transmembrane glycoprotein, and recent evidence suggests that CD133+ cells are the cause of drug resistance and tumor recurrence. In this study, the correlation between cisplatin and CD133+ cells was investigated systematically.Methods Four lung cancer cell lines, including A549, H460, 801D and H1299, were treated with different concentrations of cisplatin. Cell viability was determined by MTT assay. Sphere-forming assay was performed to detect the capability of sphere-forming. CD133+ cells was detected by BD FACScaliber flow cytometer. Results The results showed that cisplatin could increase the number of CD133+ cells in both time- and dose-dependent manner. The enrichment would weaken but the proportion of CD133+ cells was still higher than the basic level as incubation time extended after cisplatin was withdrawn. Compared with adherent culture, the proportion of CD133+ cells was higher when the cells were maintained suspension culture. The proportion of CD133+ cells significantly increased when cisplatin was provided in suspension culture. Conclusion These results revealed that cisplatin induces the enrichment of CD133+ cells and CD133 is a new therapeutic target. Our data partially explained drug resistance to second-line chemotherapy in cisplatin-treated patients with NSCLCs.

Cholesterol is biosynthesized by all animal cells. Beyond its metabolic role in steroidogenesis, it is enriched in the plasma membrane where it has key structural and regulatory functions. Cholesterol is thus presumably important for post-injury axon regrowth, and this notion is supported by studies showing that impairment of local cholesterol reutilization impeded regeneration. However, several studies have also shown that statins, inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, are enhancers of axon regeneration, presumably acting through an attenuation of the mevalonate isoprenoid pathway and consequent reduction in protein prenylation. Several recent reports have now shown that cholesterol depletion, as well as inhibition of cholesterol synthesis per se, enhances axon regeneration. Here, I discussed these findings and propose some possible underlying mechanisms. The latter would include possible disruptions to axon growth inhibitor signaling by lipid raft-localized receptors, as well as other yet unclear neuronal survival signaling process enhanced by cholesterol lowering or depletion.