9 Survivin反义寡核苷酸对人肝癌细胞的抑制作用

目的:探讨survivin反义寡核苷酸（ASODN）对人肝癌细胞HepG2的抑制作用。方法:采用免疫组织化学法检测肝细胞癌（HCC）组织中survivin的表达。采用脂质体介导survivin ASODN体外转染人肝癌细胞株HepG2，Western blot检测细胞survivin蛋白的表达，FCM检测细胞的凋亡率，观察细胞在软琼脂中的集落形成能力。建立人肝癌裸鼠皮下移植瘤模型，观察survivin ASODN的体内抑癌作用。 结果:（1）肝癌组织中survivin表达阳性率为75.8％(25/33)，明显高于癌旁组织和正常肝组织(P<0.01);（2）survivin ASODN体外转染可明显下调HepG2细胞survivin蛋白表达，ASODN组HepG2细胞凋亡率明显高于空白对照组和SODN组(P<0.01)，ASODN组HepG2细胞在软琼脂中形成的集落数目明显少于空白对照组和SODN组(P<0.01);（3）ASODN组瘤体生长速度较空白对照组和SODN组明显减慢(P<0.01)，ASODN组瘤体重量较空白对照组和SODN组明显减轻(P<0.05)。结论:Survivin在HCC组织中高表达;survivin ASODN可以诱导HepG2细胞凋亡，在体外实验和动物实验中对HepG2细胞生长都有抑制作用。     

Microtubule-associated protein tau is required for axonal neurite elaboration by neuroblastoma cells.

NB2a/d1 neuroblastoma cells constitutively express multiple isoforms of the microtubule-associated protein tau and incorporate this protein into the axonal neurites elaborated during serum deprivation. To examine whether or not tau played an essential role in axonal outgrowth, cells cultured in serum-free medium were treated at 24 h intervals with antisense- and sense-oriented cDNA oligonucleotides (25 or 36 mers that span or are upstream of tau initiation codon) and were simultaneously serum deprived. Oligonucleotide uptake was confirmed by determination of intracellular levels of radiolabeled oligonucleotides. Treatment for 48 h with tau antisense oligonucleotides reversibly inhibited the expression of tau and the number of neurite-bearing cells compared with treatment with sense oligonucleotides. By contrast, tubulin expression was not affected. When cells were treated with antisense oligonucleotide simultaneously with serum deprivation, the initial outgrowth of neurites was unaffected, but continued neurite elongation was prevented. By contrast, neurite outgrowth at 4 h was inhibited when cells were pretreated with tau antisense 24 h before serum deprivation. Furthermore, intracellular delivery of anti-tau antiserum prevented neurite outgrowth and, in cells that had previously been deprived of serum for 24 h, induced retraction of existing neurites. These findings indicate that both the initiation and the continued outgrowth of neurites are dependent on tau and that pre-existing cytoplasmic pools of tau can mediate initial neuritogenesis.     

Improved Cellular Delivery of Antisense Oligonucleotides Using Transferrin Receptor Antibody-Oligonucleotide Conjugates

This work is dedicated to the memory of the late Dr Ian Walker.     

乙型肝炎病毒转基因小鼠体内肝靶向反义RNA抗病毒疗效研究

目的：探讨半乳糖修饰的反义RNA真核表达质粒在乙型肝炎病毒转基因小鼠体内的抗病毒作用。方法：以半乳糖多聚赖氨酸（Gal-PLL)作肝靶向载体，将乙型肝炎病毒基因C区的反义RNA真核表达重组质粒（pCEP4-aC）制备为Gal-PLL－pCEP4-aC。将24只血清HBV DNA、HBsAg阳性的小鼠，随机等分为Gal-PLL－pCEP4-aC治疗组、Gal-PLL-pCEP4对照组和生理盐水阴性对照组，于实验第1天尾静脉分别注射Gal-PLL－pCEP4-aC、Gal-PLL－pCEP4（100μg/只）和等体积的生理盐水，观察治疗前后血清HBV DNA以及HBsAg变化。结果：Gal-PLL－pCEP4-aC治疗组21天时血清HBV－DNA转阴率62．5％（5／8），且7，14，21天时血清HBsAg明显降低；而Gal-PLL－pCEP4组血清HBV DNA转阴1只（1／8），生理盐水组8只均未转阴，两组用药后血清中HBsAg与用药前比较差异性均不明显（P＞0．05）。结论：肝靶向反义RNA能在乙肝基因小鼠体内抑制HBV的复制和抗原表达。     

耐药乳腺癌MCF-7/Adr细胞c-myc的表达上调及与耐药的关系

目的观察耐药乳腺癌细胞c-myc表达及其反义寡核苷酸对耐药的逆转效应,探讨c-myc在耐药调控中的作用。方法运用流式细胞仪检测乳腺癌耐药细胞MCF-7/Adr和其药敏亲本系MCF-7的c-myc表达水平。MTT法测定阿霉素作用于上述细胞的药物半数抑制浓度(IC50)。结果MCF-7/Adr耐药细胞c-myc的表达率为70.48%,其亲本药敏细胞系MCF-7c-myc表达率仅46.02%,前者显著高于后者(P<0.05)。阿霉素单独作用于MCF-7/Adr,IC50值为(22.00±1.92)μmol/L,但与4μmol/Lc-myc反义寡核苷酸共孵育后,阿霉素的IC50值则显著下降为(9.60±1.04)μmol/L。结论与其亲本药敏细胞相比较,MCF-7/Adr的c-myc表达显著上调,抑制c-myc的过表达可部分逆转MCF-7/Adr的阿霉素抵抗,提示c-myc参与肿瘤耐药的发生。     

bcl-2反义寡核苷酸对膀胱癌BIU87细胞株的影响

目的:探讨bcl-2反义寡核苷酸对培养的膀胱癌BIU87细胞株的影响.方法:采用bcl-2基因第1外显子的反义寡核苷酸,以硫代磷酸修饰(PS-ASON),序列为5′-TCTCCCAGCGTGCGCCAT-3′,与膀胱癌细胞株BIU87共同孵育作为实验组.加入正义的bcl-2寡核苷酸,序列为5′-TACCGCGTGCGACCCTCT-3′(PS-SON)作为对照组,用流式细胞仪检测细胞凋亡和坏死率,电镜观察细胞形态变化.结果:与对照组相比,实验组的细胞坏死率明显上调,电镜下细胞形态呈坏死改变.结论:bcl-2的反义寡核苷酸引起膀胱癌细胞大量坏死,可能成为膀胱癌的治疗方法之一.     

c-myc反义寡核苷酸对肿瘤细胞表面抗原和对CD3AK杀伤敏感性的调节作用

目的：观察c-myc反义寡核苷酸上调人高转移性肺巨细胞腺癌PG细胞表面抗原分子的表达水平，提高免疫效应细胞杀伤敏感性的作用和机制。方法：PT－PCR方法检测c-myc mRNA表达水平的变化。MTT法检测细胞增殖活性和CD3AK杀伤活性的变化。流式细胞术检测细胞表面抗原表达的变化以及c-myc蛋白表达水平的变化。结果：c-myc反义寡核苷酸（1μmol/L）明显地抑制PG细胞c-myc mRNA和蛋白表达水平，显著提高细胞表面HLA－ABC、ICAM－1分子的表达，其表达率分别从68．44％、38．40％增高到83．16％和42．09％（P＜0．01）。CD3AK对反义寡核苷酸处理的PG细胞的不同效靶比杀伤活性，分别从40．0％、65．0％、74．0％增高到52．0％、74．0％、91．0％（P＜0．01）。结论：c-myc反义寡核苷酸通过抑制PG细胞c-myc mRNA和蛋白表达，上调PG细胞表面HLA－ABC、ICAM－1分子的表达水平，提高其对免疫效应细胞的杀伤敏感性。     

α2，6-唾液酸转移酶（ST6GalⅠ）的表达对结肠癌细胞唾液酸化的影响

目的 研究结肠癌细胞LS174T转染正义和反义的α2，6唾液酸转移酶(ST6GalⅠ)cDNA对结肠癌细胞表面唾液酸化及肿瘤细胞粘附功能的影响．方法 结肠癌细胞株LS174T转染正义ST6GalⅠcDNA或反义ST6GalⅠcDNA的部分序列的表达载体pcDNA3.1，以RT—PCR检测转染子ST6GalⅠmRNA的表达．流式细胞仪检测细胞表面α2，6唾液酸含量．结果 转染正义ST6GalⅠcDNA的克隆显示ST6GalⅠmRNA的表达增强以及接骨木凝集素(SNA)与细胞表面成分的结合增加；而转染反义ST6GalⅠcDNA的部分序列的细胞克隆的ST6GalⅠmRNA的表达减少．SNA与细咆表面成分的结合力降低．结论 ST6GalⅠ的表达直接影响细胞表面α2．6-连接的唾液酸水平并调节肿瘤细胞的粘附功能利用反义核酸技术抑制ST6GalⅠ的表达并降低肿瘤细咆表面α2，6-唾液酸水平可能成为减少癌细胞转移的一种手段．     

Antisense oligonucleotides and short interfering RNAs silencing the cyclin-dependent kinase inhibitor p21 improve proliferation of Duchenne muscular dystrophy patients’ primary skeletal myoblasts

Increased levels of the cyclin-dependent kinase inhibitor p21 associated with decreased myoblast proliferation may be involved in the dystrophic process in Duchenne muscular dystrophy (DMD). Therefore we are interested to improve the proliferation of primary myoblasts of DMD patients by a reduction in p21 using either antisense oligonucleotides (ASO) or short interfering RNAs (siRNA). After transient transfection of myoblasts in cell culture proliferation was analyzed using a 5-bromo-2-deoxyuridine assay comparing specific transfected cells with untransfected cells and cells transfected with scrambled ASO and luciferase siRNA, respectively. Four of five Dystrophin-deficient (Dys^–) cell culture samples revealed an increase in proliferation between 7% and 18% compared to untransfected cells and between 8% and 36% compared to cells transfected with scrambled ASO. Transfection with siRNA was performed for selected samples to determine whether siRNA is more effective in gene silencing than ASO. The increase in proliferation using luciferase siRNA as reference was comparable to or less than ASO data using scrambled ASO as reference. Using untransfected cells as reference, the increase in proliferation was higher for siRNA than ASO (20–47% vs. 7–18%), but the data must be carefully interpreted with respect to nonspecific effects on gene expression by siRNA. Our findings of transient p21 gene silencing represent a basis for viral vector-mediated drug-inducible p21 shRNA expression in Dys^– myoblasts which might enhance, prolong and regulate the proliferation effect.S. Endesfelder and A. Kliche contributed equally to this work