Nan Yang, Guo Liyun, Song Yunpeng, Wang Le, Yu Kai, Huang Qiang, Zhong Yue
Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.
Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin, 300052, People's Republic of China.
J Cancer Res Clin Oncol. 2017 Aug;143(8):1477-1487. doi: 10.1007/s00432-017-2415-5. Epub 2017 Apr 11.
Glioblastoma is a highly invasive and challenging tumor of the central nervous system. The mutation/deletion of the tumor suppressor phosphatase and tensin homolog (PTEN) gene is the main genetic change identified in glioblastomas. PTEN plays a critical role in tumorigenesis and has been shown to be an important therapeutic target. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 is commonly used to inhibit glioma cell growth via regulation of the PI3K/AKT signaling pathway. In this study, we examined the growth inhibitory effects of a combinatorial therapy of adenoviral-mediated PTEN (Ad-PTEN) and LY294002 on LN229 and U251 glioma cells in vitro and on tumor xenografts in vivo.
In vitro, LN229 and U251 glioma cells were treated by combinatorial therapy with Ad-PTEN and LY294002. The growth ability was determined by MTT assay. The cell cycle distribution was analyzed by flow cytometry. Cell invasive ability was analyzed by transwell invasion assay and cell apoptosis analysis via FITC-Annexin V analysis. In vivo, U251 subcutaneous glioblastoma xenograft was used to assay anti-tumor effect of combinatorial therapy with Ad-PTEN and LY294002 by mean volume of tumors, immunohistochemistry and TUNEL method.
The combinatorial treatment clearly suppressed cell proliferation, arrested the cell cycle, reduced cell invasion and promoted cell apoptosis compared with the Ad-PTEN or LY294002 treatment alone. The treatment worked by inhibiting the PI3K/AKT pathway. In addition, the growth of U251 glioma xenografts treated with the combination of Ad-PTEN and LY294002 was significantly inhibited compared with those treated with Ad-PTEN or LY294002 alone.
Our data indicated that the combination of Ad-PTEN and LY294002 effectively suppressed the malignant growth of human glioma cells in vitro and in tumor xenografts, suggesting a promising new approach for glioma gene therapy that warrants further investigation.
胶质母细胞瘤是中枢神经系统中一种具有高度侵袭性且极具挑战性的肿瘤。肿瘤抑制磷酸酶和张力蛋白同源物（PTEN）基因的突变/缺失是在胶质母细胞瘤中鉴定出的主要基因变化。PTEN在肿瘤发生中起关键作用，并且已被证明是一个重要的治疗靶点。磷脂酰肌醇3-激酶（PI3K）抑制剂LY294002通常用于通过调节PI3K/AKT信号通路来抑制胶质瘤细胞生长。在本研究中，我们检测了腺病毒介导的PTEN（Ad-PTEN）与LY294002联合治疗对体外LN229和U251胶质瘤细胞以及体内肿瘤异种移植的生长抑制作用。
在体外，用Ad-PTEN和LY294002联合治疗LN229和U251胶质瘤细胞。通过MTT法测定生长能力。通过流式细胞术分析细胞周期分布。通过Transwell侵袭试验分析细胞侵袭能力，并通过FITC-Annexin V分析进行细胞凋亡分析。在体内，使用U251皮下胶质母细胞瘤异种移植模型，通过肿瘤平均体积、免疫组织化学和TUNEL法检测Ad-PTEN与LY294002联合治疗的抗肿瘤效果。
与单独使用Ad-PTEN或LY294002治疗相比，联合治疗明显抑制细胞增殖、使细胞周期停滞、降低细胞侵袭并促进细胞凋亡。该治疗通过抑制PI3K/AKT通路起作用。此外，与单独用Ad-PTEN或LY294002治疗的相比，用Ad-PTEN和LY294002联合治疗的U251胶质瘤异种移植瘤的生长受到显著抑制。
我们的数据表明，Ad-PTEN和LY294002联合有效地抑制了体外人胶质瘤细胞和肿瘤异种移植瘤的恶性生长，提示这是一种有前景的胶质瘤基因治疗新方法，值得进一步研究。
