Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina 29209, USA.
Clin Cancer Res. 2009 Dec 1;15(23):7186-95. doi: 10.1158/1078-0432.CCR-09-1425. Epub 2009 Nov 24.
The limitless invasive and proliferative capacities of tumor cells are associated with telomerase and expression of its catalytic component, human telomerase reverse transcriptase (hTERT). IFN-gamma modulates several cellular activities, including signaling pathways and cell cycle, through transcriptional regulation.
Using a recombinant plasmid with hTERT siRNA cDNA, we downregulated hTERT during IFN-gamma treatment in human glioblastoma SNB-19 and LN-18 cell lines and examined whether such a combination could inhibit angiogenesis and tumor growth in nude mice. In vitro angiogenesis assay was done using coculture of tumor cells with human microvascular endothelial cells. In vivo angiogenesis assay was done using diffusion chambers under the dorsal skin of nude mice. In vivo imaging of intracerebral tumorigenesis and longitudinal solid tumor development studies were conducted in nude mice.
In vitro and in vivo angiogenesis assays showed inhibition of capillary-like network formation of microvascular endothelial cells and neovascularization under dorsal skin of nude mice, respectively. We observed inhibition of intracerebral tumorigenesis and s.c. solid tumor formation in nude mice after treatment with combination of hTERT siRNA and IFN-gamma. Western blotting of solid tumor samples showed significant downregulation of the molecules that regulate cell invasion, angiogenesis, and tumor progression.
Our study showed that the combination of hTERT siRNA and IFN-gamma effectively inhibited angiogenesis and tumor progression through the downregulation of molecules involved in these processes. Therefore, the combination of hTERT siRNA and IFN-gamma is a promising therapeutic strategy for controlling the growth of human glioblastoma.
肿瘤细胞具有无限的侵袭和增殖能力，这与端粒酶及其催化成分人端粒酶逆转录酶（hTERT）的表达有关。IFN-γ 通过转录调控调节多种细胞活动，包括信号通路和细胞周期。
使用带有 hTERT siRNA cDNA 的重组质粒，我们在人胶质母细胞瘤 SNB-19 和 LN-18 细胞系中在 IFN-γ 治疗期间下调 hTERT，并检查这种组合是否可以抑制裸鼠中的血管生成和肿瘤生长。体外血管生成实验通过肿瘤细胞与人微血管内皮细胞的共培养进行。体内血管生成实验通过在裸鼠背部皮肤下的扩散室进行。在裸鼠中进行颅内肿瘤发生和纵向实体瘤发展研究的体内成像。
体外和体内血管生成实验分别显示抑制微血管内皮细胞的毛细血管样网络形成和裸鼠背部皮肤下的新血管形成。我们观察到在 hTERT siRNA 和 IFN-γ 联合治疗后，抑制了裸鼠颅内肿瘤发生和皮下实体瘤形成。对实体瘤样本的 Western 印迹分析显示，参与这些过程的调节分子明显下调。
我们的研究表明，hTERT siRNA 和 IFN-γ 的联合有效地通过下调参与这些过程的分子来抑制血管生成和肿瘤进展。因此，hTERT siRNA 和 IFN-γ 的联合是控制人胶质母细胞瘤生长的有前途的治疗策略。
