The antiretroviral agent saquinavir enhances hTERT expression and telomerase activity in human T leukaemia cells in vitro.
The antiretroviral agent saquinavir enhances hTERT expression and telomerase activity in human T leukaemia cells in vitro.
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DOI：
10.1186/1756-9966-32-38
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发表时间：
2013-06-08
期刊：
影响因子：
--
通讯作者：
Franzese O
中科院分区：
文献类型：
--
作者：
Adamo R;Comandini A;Aquino A;Bonmassar L;Guglielmi L;Bonmassar E;Franzese O
沙奎那韦是一种用于HIV感染的蛋白酶抑制剂，在各种实验模型中显示出抗肿瘤活性。在我们实验室进行的先前研究中，发现该药物可诱导正常外周血单个核细胞端粒酶活性的大幅增加。本研究的目的是检测沙奎那韦是否能够提高人恶性造血细胞端粒酶活性和端粒酶催化亚基hTERT的表达。在本研究中使用的是人类Jurkat CD4+ T细胞白血病细胞系。采用MTT法检测沙奎那韦的抗增殖作用。根据端粒重复扩增协议测定端粒酶活性。采用RT-PCR和Real Time定量PCR半定量检测hTERT mRNA的表达。用EMSA分析了转录因子c-Myc与hTERT启动子特异性E-Box DNA结合位点的结合。Western Blot检测白血病细胞细胞质和细胞核中c-Myc的含量，转染siRNA获得c-Myc下调。沙奎那韦使体外Jurkat细胞端粒酶活性显著增加，但不增加靶细胞增殖率，反而降低了靶细胞增殖率。端粒酶上调似乎是hTERT表达增强的结果。沙奎那韦介导的hTERT基因上调是蛋白质与启动子E-Box序列结合增加的结果。此外，沙奎那韦可扩增c-Myc的表达，特别是在核细胞部分。沙奎那韦对siRNA诱导的c-Myc抑制的拮抗作用也证明了沙奎那韦对该转录因子的直接影响。由于c-Myc主要负责hTERT转录，这些研究结果表明，沙奎那韦诱导的端粒酶激活的主要机制是由c-Myc上调介导的。沙奎那韦在抑制白血病细胞生长的同时增加hTERT的表达。实验证据表明，这种作用是由沙奎那韦影响的c-Myc水平升高介导的。这可能与增强的htert依赖性肿瘤细胞免疫原性有关，并提出了干扰c-Myc依赖性途径的新药理学方法。
Saquinavir, a protease inhibitor utilized in HIV infection, shows antitumor activity in various experimental models. In previous studies performed in our laboratory the drug was found to induce a substantial increase of telomerase activity in normal peripheral blood mononuclear cells. Aim of the present investigation was to test whether saquinavir was able to increase telomerase activity and the expression of the catalytic subunit of telomerase, hTERT, in human malignant hematopoietic cells. Human Jurkat CD4+ T cell leukaemia cell line was used throughout the present study. The antiproliferative effect of saquinavir was tested by the MTT assay. Telomerase activity was determined according to the telomeric repeat amplification protocol. The expression of hTERT mRNA was semi-quantitative evaluated by RT-PCR amplification and quantitative Real Time PCR. The binding of the transcription factor c-Myc to its specific E-Box DNA binding-site of hTERT promoter was analyzed by Electophoretic Mobility Shift Assay (EMSA). The amount of c-Myc in cytoplasm and nucleus of leukemia cells was determined by Western Blot analysis, and c-Myc down-regulation was obtained by siRNA transfection. Saquinavir produced a substantial increase of telomerase activity in Jurkat cells in vitro without increasing but rather reducing target cell proliferation rate. Telomerase up-regulation appeared to be the result of enhanced expression of hTERT. Saquinavir-mediated up-regulation of hTERT gene was the result of the increased binding of proteins to the E-Box sequence of the promoter. Moreover, saquinavir amplified the expression of c-Myc especially in the nuclear cell fraction. The direct influence of saquinavir on this transcription factor was also demonstrated by the antagonistic effect of the drug on siRNA induced c-Myc suppression. Since c-Myc is the main responsible for hTERT transcription, these findings suggest that the main mechanism underlying saquinavir-induced telomerase activation is mediated by c-Myc up-regulation. Saquinavir augments hTERT expression while inhibiting leukemic cell growth. Experimental evidences show that this effect is mediated by saquinavir-influenced increase of c-Myc levels. This could have relevance in terms of enhanced hTERT-dependent tumor cell immunogenicity and suggests new paharmacological approaches interfering with c-Myc dependent pathways.
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影响因子：
14.5
作者：
Shay JW;Wright WE
通讯作者：
Wright WE
DOI：
10.1097/jto.0b013e31820c9e3c
发表时间：
2011-04
期刊：
Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer
影响因子：
--
作者：
Srirangam A;Milani M;Mitra R;Guo Z;Rodriguez M;Kathuria H;Fukuda S;Rizzardi A;Schmechel S;Skalnik DG;Pelus LM;Potter DA
通讯作者：
Potter DA
影响因子：
2
作者：
Simsek, Bengu Cobanoglu;Pehlivan, Sultan;Karaoglu, Aziz
通讯作者：
Karaoglu, Aziz
影响因子：
5.5
作者：
Niu, Bai-lin;Du, Hui-min;Gong, Jian-ping
通讯作者：
Gong, Jian-ping
影响因子：
5.2
作者：
Furuya, Momoko;Tsuji, Naoki;Watanabe, Naoki
通讯作者：
Watanabe, Naoki