Poulaki Vassiliki, Mitsiades Constantine S, Kotoula Vassiliki, Negri Joseph, McMillin Douglas, Miller Joan W, Mitsiades Nicholas
Angiogenesis/Laser Laboratory, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA.
Invest Ophthalmol Vis Sci. 2007 Oct;48(10):4706-19. doi: 10.1167/iovs.06-1147.
To evaluate the potential of proteasome inhibitors, a novel class of antitumor agents, for the treatment of retinoblastoma. The proteasome inhibitor bortezomib (PS-341, Velcade; Millennium Pharmaceuticals, Cambridge, MA), approved by the US Food and Drug Administration for the treatment of multiple myeloma, is being studied for the treatment of several other malignancies. Among other effects, it inactivates the transcription factor nuclear factor-kappaB (NF-kappaB) by blocking the degradation of its inhibitor, IkappaB. NF-kappaB, which is constitutively active in human retinoblastoma cells and promotes their survival, represents a therapeutic target for patients with this malignancy.
The authors evaluated the effect of bortezomib on the retinoblastoma cell lines Y79 and WERI-Rb1 in vitro using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry with propidium iodide, gene expression profiling, RT-PCR, and immunoblotting.
Bortezomib induced caspase-dependent apoptosis in both retinoblastoma cell lines at clinically achievable concentrations. Bortezomib upregulated heat-shock proteins, other stress-response proteins, proapoptotic molecules, cell-cycle regulators, transcription factors, cytokines, and several proteasome subunits and solute carrier proteins, whereas it downregulated antiapoptotic and adhesion molecules. Bortezomib also induced cleavage of caspases, Bid and poly(ADP-ribose) polymerase (PARP), and sensitized retinoblastoma cells to doxorubicin.
Bortezomib induces a stress response and triggers caspase-dependent apoptosis in human retinoblastoma cells at clinically achievable concentrations. This study provides insight into the molecular mechanism(s) of the antitumor activity of bortezomib and a basis for future preclinical studies leading to clinical trials of bortezomib, alone or in combination with conventional chemotherapy, to improve patient outcomes in retinoblastoma.
评估蛋白酶体抑制剂（一类新型抗肿瘤药物）治疗视网膜母细胞瘤的潜力。蛋白酶体抑制剂硼替佐米（PS - 341，万珂；千禧制药公司，马萨诸塞州剑桥）已获美国食品药品监督管理局批准用于治疗多发性骨髓瘤，目前正被研究用于治疗其他几种恶性肿瘤。除其他作用外，它通过阻止其抑制剂IkappaB的降解来使转录因子核因子-κB（NF-κB）失活。NF-κB在人视网膜母细胞瘤细胞中持续激活并促进其存活，是这种恶性肿瘤患者的一个治疗靶点。
作者使用3 -（4,5 - 二甲基噻唑 - 2 - 基）- 2,5 - 二苯基四氮唑溴盐（MTT）法、碘化丙啶流式细胞术、基因表达谱分析、逆转录聚合酶链反应（RT - PCR）和免疫印迹法，在体外评估硼替佐米对视网膜母细胞瘤细胞系Y79和WERI - Rb1的作用。
在临床可达到的浓度下，硼替佐米在两种视网膜母细胞瘤细胞系中均诱导了半胱天冬酶依赖性凋亡。硼替佐米上调了热休克蛋白、其他应激反应蛋白、促凋亡分子、细胞周期调节因子、转录因子、细胞因子以及几种蛋白酶体亚基和溶质载体蛋白，而它下调了抗凋亡和黏附分子。硼替佐米还诱导了半胱天冬酶、Bid和聚（ADP - 核糖）聚合酶（PARP）的裂解，并使视网膜母细胞瘤细胞对多柔比星敏感。
在临床可达到的浓度下，硼替佐米在人视网膜母细胞瘤细胞中诱导应激反应并触发半胱天冬酶依赖性凋亡。本研究深入了解了硼替佐米抗肿瘤活性的分子机制，并为未来的临床前研究提供了基础，这些研究将导致硼替佐米单独或与传统化疗联合进行临床试验，以改善视网膜母细胞瘤患者的预后。
