Testicular expression of survivin and human telomerase reverse transcriptase(hTERT)associated with spermatogenic function in infertile patients

Aim： To characterize the coexpression of survivin, an inhibitor of apoptosis （IAF）, and human telomerase reverse transcriptase （hTERT） in human testes with varying spermatogenic function. Methods： Transcript levels of survivin mRNA and hTERT mRNA were determined in normal testes （n = 11） and testes with defective spermatogenesis （n = 28） using real-time reverse-transcription polymerase chain reaction （RT-PCR）. The histological work-up was performed according to a modified Johnsen score. Results： Expressions of both survivin and hTERT were highest at median levels of 96.8 and 709 in normal spermatogenesis and dropped to 53.3 and 534 in testes with postmeiotic spermatogenic arrest （n = 10）. In severe spermatogenic failure （n = 18）, survivin expression was lacking in most specimens （n = 16）, whereas at least low levels of testicular hTERT expression were largely detectable with a normalized expression of 73 in premeiotic spermatogenic arrest （n = 7） and 45 in patients with Sertoli cell-only syndrome （SCOS） （n = 3）. Both survivin and hTERT expressions increased with a progressing Johnsen score （P for trend = 0.001）. Conclusion： Although both survivin and hTERT are correlated with spermatogenic function, they show different expression patterns in testes of infertile patients. These findings substantiate results from studies in the rodent testis suggesting a predominant expression of survivin in meiotically dividing germ cells. （Asian J Andro12006 Jan; 8： 95-100）

Neuroprotective effects of human telomerase reverse transcriptase on beta-amyloid fragment 25-35-treated human embryonic cortical neurons

BACKGROUND： Numerous current studies have suggested that human telomerase reverse transcriptase （hTERT） gene has neuroprotective effects and can inhibit apoptosis induced by various cytotoxic stresses; however, the mechanism of action remains unknown. OBJECTIVE： To evaluate the neuroprotective effects and possible mechanism of action of hTERT gene transfection in human embryonic cortical neurons treated with beta-amyloid fragment 25-35 （AI325-35）. DESIGN, TIME AND SETTING： The randomized, controlled and molecular biological studies were performed at the Department of Anatomy and Brain Research, Zhongshan School of Medicine, Sun Yat-sen University, China, from September 2005 to June 2008. MATERIALS： AdEasy-1 Expression System was gifted by Professor Guoquan Gao from Sun Yat-Sen University, China. Human cortical neurons were derived from 12-20 week old aborted fetuses, obtained from the Guangzhou Maternal and Child Health Hospital, China. Mouse anti-Odk5 and mouse anti-p16 monoclonal antibodies （Lab Vision, USA）, and mouse anti-hTERT monoclonal antibody （Epitomics, USA）, were used in this study. METHODS： （1） Recombinant adenovirus vectors, encoding hTERT （Ad-hTERT） and green fluorescent protein （Ad-GFP）, were constructed using the AdEasy-1 Expression System. Human embryonic cortical neurons in the Ad-hTERT group were transfected with Ad-hTERT for 1-21 days. Likewise, human embryonic cortical neurons in the Ad-GFP group were transfected with Ad-GFP for 1-21 days. Human embryonic cortical neurons in the control group were cultured as normal. （2） Human embryonic cortical neurons in the Ad-hTERT group were treated with 10 pmol/L Aβ25-35 for 24 hours. Normal human embryonic cortical neurons treated with 10 pmol/Lβ25.35 for 24 hours served as a model group. Human embryonic cortical neurons in the Ad-GFP and control groups were not treated with Aβ25-35. MAIN OUTCOME MEASURES： Expression of hTERT in human embryonic cortical neurons was evaluated by immunocytochemical staining and Western blot assay. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol （TRAP） ELISA kit. Neural activity in human embryonic cortical neurons was examined by MTT assay; apoptosis was measured using TUNEL assay; and Cdk5 and p16 protein expressions were measured by Western blot. RESULTS： Expression of hTERT protein was significantly increased and peaked at day 3 post-transfection in the Ad-hTERT group. No hTERT expression was detected in the Ad-GFP and control groups. Telomerase activity was significantly greater in the Ad-hTERT group compared with the Ad-GFP and control groups （P 〈 0.01）. Compared with the control group, cell activity was significantly decreased （P 〈 0.05）, and cell apoptotic rate, Cdk5 and p16 expression were significantly increased （P 〈 0.01） in the model group. Compared with the model group, cell activity was increased in the Ad-hTERT group, and peaked at day 3 post-transfection （P 〈 0.05）. Neuroprotective effects also peaked at day 3 post-transfection; and the apoptotic rate, Cdk5 and p16 expression significantly decreased （P 〈 0.01）. CONCLUSION： Expression of hTERT in human embryonic cortical neurons can relieve Aβ25-35-induced neuronal apoptosis. The possible mechanism by which hTERT produces these neuroprotective effects may be associated with inhibition of Cdk5 and p16 expression.

Inhibition of telomerase with human telomerase reverse transcriptase antisense increases the sensitivity of tumor necrosis factor-α-induced apoptosis in prostate cancer cells

Aim： To investigate the effect of inhibition of telomerase with human telomerase reverse transcriptase （hTERT） antisense on tumor necrosis factor-α （TNF-α-induced apoptosis in prostate cancer cells （PC3）. Methods： Antisense phosphorothioate oligodeoxynucleotide （AS PS-ODN） was synthesized and purified. Telomerase activity was measured using the telomeric repeat amplification protocol （TRAP） and polymerase chain reaction enzyme-linked immunoassay （PCR-ELISA）. hTERT mRNA was measured by reverse transcription PCR （RT-PCR） assay and gel-image system, hTERT protein was detected by immunochemistry and flow cytometry. Cell viability was detected by 3-（4, 5-dimethylthiazol-2-yl）-2,5-Diphenyltetrazolium （MTT） assay. Cell apoptosis was observed by morphological method and determined by flow cytometry. Results： The telomerase activity decreased with time after hTERT AS PS-ODN treatment. The levels of hTERT mRNA decreased with time after hTERT AS PS-ODN treatment, which appeared before the decline of the telomerase activity. The percentage of positive cells of hTERT protein declined with time after hTERT AS PS-ODN treatment, which appeared after the decline of hTERT mRNA. There was no difference in telomerase activity, hTERT mRNA and protein levels between hTERT sense phosphorothioate oligodeoxynucleotide （S PS-ODN） and the control group. The cell viability decreased with time after hTERT AS PS-ODN combined with TNF-α treatment. The percentage of apoptosis increased with time after hTERT AS PS-ODN combined with TNF-α treatment. There was no difference in cell viability and the percentage of apoptosis between hTERT S PS-ODN and the control group. Conclusion： hTERT AS PS-ODN can significantly inhibit telomerase activity by downregulating the hTERT mRNA and protein expression, and inhibition of telomerase with hTERT antisense can enhance TNF-α- induced apoptosis of PC3 cells.

Unique case of oligoastrocytoma with recurrence and grade progression:Exhibiting differential expression of high mobility group-A1 and human telomerase reverse transcriptase

Mixed gliomas, primarily oligoastrocytomas, account for about 5%-10% of all gliomas. Distinguishing oligoastrocytoma based on histological features alone has limitations in predicting the exact biological behavior, necessitating ancillary markers for greater specificity. In this case report, human telomerase reverse transcriptase(hT ERT) and high mobility group-A1(HMGA1); markers of proliferation and stemness, have been quantitatively analyzed in formalin-fixed paraffin-embedded tissue samples of a 34 years old patient with oligoastrocytoma. Customized florescence-based immunohistochemistry protocol with enhanced sensitivity and specificity is used in the study. The patient presented with a history of generalized seizures and his magnetic resonance imaging scans revealed infiltrative ill-defined mass lesion with calcified foci within the left frontal white matter, suggestive of glioma. He was surgically treated at our center for four consecutive clinical events. Histopathologically, the tumor was identified as oligoastrocytoma-grade Ⅱ followed by two recurrence events and final progression to grade Ⅲ. Overall survival of the patient without adjuvant therapy was more than 9 years. Glial fibrillary acidic protein, p53, Ki-67, nuclear atypia index, pre-operative neutrophillymphocyte ratio, are the other parameters assessed. Findings suggest that hT ERT and HMGA1 are linked to tumor recurrence and progression. Established markers can assist in defining precise histopathological grade in conjuction with conventional markers in clinical setup.

Quantification of human telomerase RNA(hTR)and human telomerase reverse transcriptase(hTERT)mRNA in testicular tissue of infertile patients

Aim:To evaluate the quantitative detection of human telomerase RNA(hTR)and human telomerase reverse tran-scriptase(hTERT)mRNA as diagnostic parameters in the workup of testicular tissue specimens from patients presentingwith non-obstructive azoospermia.Methods:hTR and hTERT mRNA expression were quantified in 38 cryopre-served testicular tissue specimens by fluorescence real-time reverse transcription-polymerase chain reaction(RT-PCR)in a LightCycler(r).This was paralleled by conventional histological workup in all tissue specimens and additionalsemithin sectioning preparation in cases with maturation arrest(n=12)and Sertoli-cell-only syndrome(n=12).Re-sults;The average normalized hTERT expression(N_(hTERT))was 131.9±48.0 copies(mean±SD)in tissue speci-mens with full spermatogenesis,N_(hTERT)=51.2±17.2 copies in those with maturation arrest and N_(hTERT)=2.7±2.4copies in those with Sertoli-cell-only syndrome(SCOS).The discriminant analysis showed that detection of N_(hTERT)(N_(hTR))had a predictive value of 86.8%(55.3%)for correct classification in one of the three histological subgroups.Conclusion;Our results demonstrate that quantitative detection of hTERT mRNA expression in testicular tissue en-ables a molecular-diagnostic classification of gametogenesis.Quantitative detection of hTERT in testicular biopsies isthus well suited for supplementing the histopathological evaluation.

Trichostatin A Induces Apoptosis by Inhibiting Telomerase Activity and Expression of Telomerase Reverse Transcriptase in HL-60 Cells

Aim To investigate the effects of trichostatin A （TSA） on telomerase activity and the expression of human telomerase reverse transcriptase （hTERT） during apoptosis in vitro and the mechanisms in HL-60 cells. Methods The proliferative activity of HL-60 cells was assessed by MTT assay. Cell apoptosis was analyzed by flow cytometry. Telomerase activity was examined by TRAP-ELISA. The expression of telomerase subunits was analyzed by RT-PCR. Results A time- and dose-dependent inhibition was detected in HL-60 cells treated with TSA. After treatment with 600 nmol· L^-1 TSA for 48 h, the apoptosis rate in HL-60 cells was 42. 6% and telomerase activity decreased 1.95 ± 0.25, 1.73 ± 0. 12, and 1.52 ± 0. 09 for 12, 24, and 48 h, respectively. The expression of hTERTmRNA decreased. No significant changes were observed in the expression of hTRmRNA and hTPI mRNA. Condusion TSA inhibits telomerase activity and induces apoptosis in HL-60 cells. The underlying mechanism may be related to the down-regulation of hTERT transcription.

Expression of Telomerase Reverse Transcriptase during the Malignant Transformation of Cadmium-Induced Cells

The objective of the present study was to investigate human telomerase reverse transcriptase (hTERT) mRNA and protein expressions during the cadmium chloride-induced malignant transformation of human bronchial epithelial (16HBE) cells. Fluorescence quantitative PCR (FQ-PCR) and Western blot analyses were performed to detect the hTERT mRNA and protein expressions in normal 16HBE cells, cadmium chloride-transformed 16HBE cells, and tumorigenic cells from nude mice inoculated with cadmium chloride-transformed 16HBE cells. Under the inner standard of GAPDH, the hTERT mRNA expression was significantly higher at different stages of malignant transformation (cadmium chloride-transformed 16HBE cells at passages 15 and 35 and tumorigenic cells from nude mice) than in normal 16HBE cells, and increased with the development of malignancy (P < 0.01). In addition, hTERT protein expression increased with the development of malignancy. These findings demonstrate that hTERT expression is related to cadmium chlorideinduced malignant transformation. Cadmium chloride-induced malignant transformation is involved in changes in the hTERT activity, and might be an early event in cadmium chloride-induced malignant transformation.

子痫前期孕妇血清hTERT和Sirt6水平表达与疾病严重程度及妊娠结局评估中的价值研究

目的检测子痫前期孕妇血清中人端粒酶反转录酶(human telomerase reverse transcriptase,hTERT)、沉默信息调节因子6(silent information regulator 6,Sirt6)表达,并探究hTERT,Sirt6水平表达与疾病严重程度及妊娠结局评估中的价值。方法选取2018年1月~2022年12月在陕西省人民医院进行诊治的300例子痫前期孕妇作为子痫前期组,孕妇均符合《妊娠期高血压疾病诊治指南(2015)》中子痫前期诊断标准,选取同时期孕检的300例健康孕妇为对照组,根据病情严重程度将子痫前期组分为轻症子痫前期组(n=180)和重症子痫前期组(n=120),根据是否发生不良妊娠结局将子痫前期组分为正常妊娠组(n=165)和不良妊娠组(n=135)。酶联免疫吸附实验(enzyme-linked immunosorbnent assay,ELISA)法检测血清中hTERT和Sirt6水平,Spearman相关性分析血清中hTERT和Sirt6水平与子痫前期孕妇病情严重程度的相关性,利用受试者工作特征(receiver operating characteristic,ROC)曲线评估血清hTERT和Sirt6水平在子痫前期诊断及妊娠结局预测中的价值。结果与对照组比较,子痫前期组血清hTERT(22.15±5.82 ng/ml vs 30.12±9.56 ng/ml),Sirt6(5.26±1.62 ng/ml vs 7.06±2.29 ng/ml)水平降低,差异具有统计学意义(t=12.334,11.114,均P<0.001)。与轻症子痫前期组比较,重症子痫前期组孕妇血清hTERT(18.28±4.11 ng/ml vs 24.73±6.96 ng/ml),Sirt6(4.03±1.17 ng/ml vs 6.08±1.92 ng/ml)水平降低,差异具有统计学意义(t=9.142,10.469,均P<0.001)。与正常妊娠组比较,不良妊娠组子痫前期孕妇血清中hTERT(17.75±4.61 ng/ml vs 25.75±6.81 ng/ml),Sirt6(4.06±0.96 ng/ml vs 6.24±2.16 ng/ml)水平降低,差异具有统计学意义(t=11.639,10.878,均P<0.001)。Spearman相关性分析显示,血清hTERT,Sirt6水平与子痫前期孕妇疾病严重程度均呈负相关(r=-0.562,-0.604,均P<0.001)。ROC曲线分析结果显示,血清hTERT,Sirt6诊断子痫前期的曲线下面积(95%置信区间)[AUC(95%CI)]分别为0.711(0.673~0.747),0.727(0.689~0.762),两者联合诊断子痫前期的AUC(95%CI)为0.788(0.753~0.820),高于两者单独诊断(Z=2.719,2.154,P=0.007,0.031);血清hTERT,Sirt6预测子痫前期不良妊娠结局的AUC(95%CI)分别为0.786(0.735~0.831),0.783(0.732~0.829),两者联合预测子痫前期不良妊娠结局的AUC(95%CI)为0.849(0.804~0.888),高于两者单独预测(Z=1.855,1.861,P=0.032,0.031)。结论hTERT和Sirt6在子痫前期孕妇血清中水平较低,与子痫前期孕妇疾病严重程度均呈负相关,并对妊娠结局具有一定的评估价值。

hTRT反义基因转染对肝癌细胞端粒酶亚单位及细胞周期的影响

目的 探讨人端粒酶蛋白催化活性亚单位 (Humantelomerasereversetranscriptase ,hTRT)反义基因转染对HepG2 肝癌细胞株端粒酶亚单位及细胞周期的影响。方法 采用流式细胞仪检测hTRT正义基因转染的HepG2 细胞(HepG2 S)以及hTRT反义基因转染的HepG2 细胞 (HepG2 AS)的细胞周期 ,采用RT PCR法检测上述细胞hTRT、端粒酶RNA(hTR)、端粒酶相关蛋白 1(TP1)以及c myc和bcl 2基因的变化 ,同时采用Westernblot检测hTRT蛋白质的变化。结果 HepG2 AS出现G0 G1 期阻滞 ,增殖指数增加 ,凋亡率亦明显增加 ,进一步研究发现 ,HepG2 AS端粒酶亚单位hTRT在蛋白质和mRNA水平均表达减少 ,而TP1、hTR无明显变化 ,bcl 2和c mycmRNA的表达亦明显下调。结论 hTRT反义基因不仅可以下调HepG2 细胞hTRTmRNA和蛋白质的表达 ,而且可以下调c myc、bcl 2mRNA的表达 ,从而一方面降低端粒酶活性 ,另一方面一定程度增加凋亡细胞的比率 。

反义hTRT转染对SGC-7901胃癌细胞株形态学的影响

目的 探讨人端粒酶蛋白催化亚单位 (hTRT)反义基因转染对SGC 790 1胃癌细胞株形态学的影响 ;方法 采用脂质体法将hTRT正、反义真核表达载体导入SGC 790 1胃癌细胞株中 ,从光镜、电镜水平观察转染细胞形态学的变化。结果 与未转染细胞相比 ,光镜下hTRT反义基因转染的SGC 790 1胞体增大 ,胞浆丰富 ,分裂相减少 ,核浆比增大 ,异型性减小 ;透射电镜下反义基因转染细胞细胞器丰富 ,胞浆内出现分泌泡样结构及胞质内微囊 ;扫描电镜下反义基因转染细胞表面微绒毛增多 ,胞体周围可见大量颗粒样物质 ,根据AB/PAS染色结果 ,这些颗粒样物质有可能是其分泌的粘液颗粒。结论 hTRT反义基因有促进SGC 790 1细胞分化的作用。

重组端粒酶pEGFP-hTRT质粒的构建

目的 构建具有绿色荧光蛋白报道 (GFP)基因的端粒酶真核质粒载体 ,为转染细胞、延长细胞寿命提供基础。 方法 酶切含人端粒酶逆转录酶 (h TRT)基因的 p GRN14 5质粒获取 h TRT片段 ,插入经酶切及磷酸化处理的 GFP载体 p EGFP- C1,形成 8.1kb质粒 ,经 Hind 、Not 酶切电泳筛选、鉴定并测序。 结果 经酶切电泳分析得到3.4 kb及 4 .7kb大小的两片段 ;测序结果显示接头两端序列正确。 结论 重组端粒酶 p EGFP- h TRT质粒的成功构建 ,可用于细胞转染 ,对进一步研究组织工程种子细胞的衰老问题具有重要意义。

口腔鳞癌中hTRT mRNA的表达及其与PCNA关系的探讨

目的 :探讨端粒酶逆转录酶 (hTRT)在口腔鳞癌、癌旁组织的表达及其与增殖细胞核抗原 (PCNA)之间的关系。方法 :用原位杂交技术及免疫组化方法检测 5 2例口腔鳞癌标本。结果 :正常癌旁上皮、上皮异常增生组织及鳞癌hTRTmRNA阳性率分别为 2 0 %、41.7%、82 .7%。PCNA阳性组与阴性组间hTRT表达水平有显著差异 (P <0 .0 5 )。结论 :hTRT在口腔鳞癌发生、发展中起重要作用 ,hTRT与PCNA阳性表达呈正相关 ,表明hTRT激活细胞多处于高增殖状态。

Inhibition of Telomerase with hTERT Antisense Increases Susceptibility of Leukemic Cells to CDDP-induced Apoptosis

Objective: To investigated the e?ect of inhibition of telomerase with hTERT antisense on leukemic cells (HL-60 and K562) to CDDP-induced apoptosis. Methods: Antisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and puri?ed. Telomerase activity was detected by Telomerase PCR ELASA kit and cell apoptosis was observed by morphological method and determined by ?owcytometry. Results: AS PS-ODN could signi?cantly inhibit telomerase activity by down regulat- ing the hTERT expression, and increase the susceptibility of leukemic cells to CDDP-induced apoptosis. Conclusion: Inhibition of telomerase with hTERT antisense can increases the susceptibility of leukemic cells to CDDP-induced apoptosis.

肝癌端粒酶hTRT表达与临床病理因素及预后的关系

目的 :研究原发性肝细胞癌端粒酶hTRT(humantelomerasereversetranscriptase ,hTRT)的表达与临床病理因素的关系 ,及预后判断的价值。方法 :采用原位杂交法检测 4 0例原发性肝细胞癌中端粒酶hTRT的表达。结果 :hTRT阳性表达率与原发性肝癌病理分级呈正相关 ;伴肝硬化者hTRT阳性率比无肝硬化者高 ;而与肿瘤病理巨体分类、TNM分期、肿块大小、病灶数目、有否包膜及合并门静脉瘤栓、患者年龄及性别、HBsAg、AFP等其他临床及病理因素无密切相关 ;hTRT阳性组患者术后 1年、3年、5年累计生存率、中位生存期分别为 5 2 .38%、 2 4 .4 5 %、4 .19%、2 1个月 ,阴性组患者分别为 85 .0 0 %、6 6 .0 0 %、33.12 %、4 6 .0 0个月 ,有显著差异。hTRT阳性组与阴性组复发转移的中位时间分别为 2 6 .4 2个月和 4 5 .71个月 ,有显著差异。结论 :端粒酶hTRT阳性表达率与原发性肝细胞癌病理分级、有否伴肝硬化者呈密切相关 ,原发性肝癌hTRT表达阳性者 ,更有恶性潜能、更早复发、生存率低 ,hTRT对判断原发性肝癌预后有一定价值。

hTRT反义基因转染对人结肠癌细胞生长的抑制作用

利用基因重组技术,hTRT基因反向插入真核表达载体pcDNA3.0,获得重组体pcDRTRT,通过脂质体法导入人结肠癌细胞株SW-111C,获得稳定转染细胞系,即反义细胞,该细胞易脱落,出现明显生长抑制现象;失去叠落生长能力;流式细胞仪(FCM)证实导入反义hTRT后,G0/1期细胞增加,G,M和S期细胞减少,增殖指数(PI)降低;且不能在软琼脂中形成集落;并发现反义细胞中hTRT表达水平明显下降。说明反义hTRT基因体外导入结肠癌细胞株SW-111C可以明显降低端粒酶活性,抑制结肠癌细胞的生长、增殖且能使其恶性表型发生逆转。

Inhibitory Effects of Selenium on Telomerase Activity and hTERT Expression in Cadmium-transformed 16HBE Cells

To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells. Methods Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses （0.625, 1.25, 2.50, 5.00 pmol/L） for 24 hours. Results Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of madl mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group. Conclusion Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing madl mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

Antitumor activity of an hTERT promoter-regulated tumor-selective oncolytic adenovirus in human hepatocellular carcinoma

AIM: To construct a tumor-selective replication-competent adenovirus (RCAd), SG300, using a modified promoter of human telomerase reverse transcriptase (hTERT). METHODS: The antitumor efficacy of SG300 in hepatocellular carcinoma was assessed in vitro and in vivo. In vitro cell viability by MTT assay was used to assess the tumor-selective oncolysis and safety features of SG300, and in vivo antitumor activity of SG300 was assessed in established hepatocellular carcinoma models in nude mice. RESULTS: SG300 could lyse hepatocellular carcinoma cells at a low multiplicity of infection (MOI), but could not affect growth of normal cells even at a high MOI. Both in Hep3B and SMMC-7721 xenograft models of hepatocellular carcinoma, SG300 had an obvious antitumor effect, resulting in a decrease in tumor volume. Its selective oncolysis to tumor cells and safety to normal cells was also superior to that of ONYX-015. Pathological examination of tumor specimens showed that SG300 replicated selectively in cancer cells and resulted in apoptosis and necrosis of cancer cells. CONCLUSION: hTERT promoter-regulated replicativeadenovirus SG300 has a better cancer-selective replication-competent ability, and can specifically kill a wide range of cancer cells with positive telomerase activity, and thus has better potential for targeting therapy of hepatocellular carcinoma.

Telomerase and hTERT: Can they serve as markers for gastric cancer diagnosis?

AIM: To investigate telomerase activity and human telomerase reverse transcriptase (hTERT) expression in normal human gastric mucosal epithelial cells (nhGMECs) and fibroblasts (nhGMFs).

Effects of Combined siRNA-TR and-TERT on Telomerase Activity and Growth of Bladder Transitional Cell Cancer BIU-87 Cells

The effects of combined RNA interference(RNAi) of human telomerase RNA(hTR) and human telomerase reverse transcriptase(hTERT) genes on telomerase activity in a bladder cancer cell line(BIU-87 cells) were investigated by using gene chip technology in vitro with an attempt to evaluate the role of RNAi in the gene therapy of bladder transitional cell cancer(BTCC).Three TR-specific double-stranded small interfering RNAs(siRNAs) and three TERT-specific double-stranded siRNAs were designed to target different regions of TR and TERT mRNA.The phTR-siRNA,phTERT-siRNA,and the combination of both plasmids phTR+phTERT-siRNA were transfected into BIU-87 cells.The expression of hTR and hTERT mRNA was detected by quantitative fluorescent reverse transcription-polymerase chain reaction,and a telomeric repeat amplification protocol was applied to detect telomerase activity.Growth inhibition of BIU-87 cells was measured by MTT assay.Gene chip analysis was performed to evaluate the effects of the combined RNAi of hTR+hTERT genes on telomerase activity and growth of BIU-87 cells in vitro.The results showed that the expression of hTERT and hTR mRNA was inhibited by pRNAT-hTERT-Ⅲ,pRNAT-hTR-Ⅲ,and pRNAT-hTR-Ⅲ+hTERT-Ⅲ in BIU-87 cells.The inhibition efficiency of pRNAT-hTERT-Ⅲ,pRNAT-hTR-Ⅲ,pRNAT-hTERT-Ⅲ+pRNAT-hTR-Ⅲ was 67% for TERT mRNA,41% for TR mRNA,57% for TR mRNA and 70% for TERT mRNA in BIU-87 cells respectively.The growth of BIU-87 cells was inhibited and telomerase activity was considerably decreased,especially in the cells treated with combined RNAi-hTR and-hTERT.Gene chip analysis revealed that 21 genes were down-regulated(ATM,BAX,BCL2,BCL2L1,BIRC5,CD44,CTNNB1,E2F1,JUN,MCAM,MTA1,MYC,NFKB1,NFKBIA,NME4,PNN,PNN,SERPINE1,THBS1,TNFRSF1A,and UCC1).The results indicated that hTR-siRNA and hTERT-siRNA,especially their combination,siRNA hTR+hTERT,specifically and effectively suppressed the expression of both hTR and hTERT mRNA and telomerase activity.Molecular biological mechanism by which combined siRNA-TR and-TERT inhibited telomerase activity and growth of BIU-87 cells in vitro may involve the down-regulation of the 21 genes.