Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PR China.
Oncol Rep. 2011 Sep;26(3):543-50. doi: 10.3892/or.2011.1317. Epub 2011 May 25.
Invasive pituitary adenomas are usually refractory to routine neurosurgery, radiosurgery or medications, and alternative therapies are needed. The effects of temozolomide (TMZ) on the inhibition of gonadotroph adenoma cell viability and hormone secretion were evaluated. Cell viability and IC50 values were evaluated after αT3-1 cells were treated with TMZ (31.25-1000 µM) or vehicle for 0-72 h. Cell cycle changes and the extent of apoptosis were detected using flow cytometry, TUNEL and TEM. The molecular mechanism of TMZ action was investigated by the Caspase-Glo® assay and immunoblotting. Gonadotropin secretion was assessed using an immunoassay system. TMZ dose- and time-dependently suppressed cell proliferation (P<0.01 vs. control, 250 µM, 24 h) and induced S-phase accumulation and G2/M-phase arrest (P<0.05 vs. control, 250 µM, 24 h). Early apoptotic cells increased following a 24-h TMZ incubation (P<0.001 vs. control, 250 µM), consistent with TEM and TUNEL detection that exhibited morphological features of apoptosis. TMZ (250 µM) increased the level of caspase-3/7 by 6-fold, caspase-9 by 7-fold and caspase-8 by 3-fold after a 24-h incubation, while it attenuated Bcl-2 expression (P<0.001 vs. control) and raised the proteolysis of PARP. Both FSH and LH levels were significantly decreased by TMZ (P<0.01 vs. control, 250 µM, 24 h). TMZ inhibited cell proliferation and hormone secretion, and induced cell cycle arrest and apoptotic cell death in gonadotroph adenoma cells via both death receptor and mitochondrial pathways, suggesting that it may represent a useful medical management strategy of invasive gonadotroph adenomas.
侵袭性垂体腺瘤通常对常规神经外科、放射外科或药物治疗具有抗性，因此需要替代疗法。本文评估了替莫唑胺（TMZ）对促性腺激素腺瘤细胞活力和激素分泌抑制的作用。用 TMZ（31.25-1000μM）或载体处理αT3-1 细胞 0-72 h 后，评估细胞活力和 IC50 值。使用流式细胞术、TUNEL 和 TEM 检测细胞周期变化和凋亡程度。通过 Caspase-Glo®测定和免疫印迹研究 TMZ 作用的分子机制。使用免疫测定系统评估促性腺激素分泌。TMZ 呈剂量和时间依赖性地抑制细胞增殖（与对照组相比，P<0.01，250μM，24 h），并诱导 S 期积累和 G2/M 期阻滞（与对照组相比，P<0.05，250μM，24 h）。孵育 24 h 后，早期凋亡细胞增加（与对照组相比，P<0.001，250μM），与 TEM 和 TUNEL 检测到的凋亡形态特征一致。TMZ（250μM）孵育 24 h 后，caspase-3/7 水平增加 6 倍，caspase-9 增加 7 倍，caspase-8 增加 3 倍，而 Bcl-2 表达减少（与对照组相比，P<0.001），PARP 水解增加。TMZ 显著降低 FSH 和 LH 水平（与对照组相比，P<0.01，250μM，24 h）。TMZ 通过死亡受体和线粒体途径抑制促性腺激素腺瘤细胞的增殖和激素分泌，并诱导细胞周期停滞和凋亡细胞死亡，提示其可能是侵袭性促性腺激素腺瘤的一种有用的医学治疗策略。
