Conditional expression of a dominant negative-TEAD2 construct modulates YAP1/TEAD-dependent transcription and arrests growth of human malignant mesothelioma MSTO-211H [TEAD2-dn] xenografts.

We investigate the dependence of human malignant pleural mesothelioma on a functional YAP1-TEAD transcription factor complex to maintain fully established tumors in vivo. We show that, in a dysfunctional Hippo genetic background, expression of a dominant negative TEAD2 modulates YAP1/TEAD-dependent gene expression and inhibits growth of established tumor xenografts. Our data demonstrate that, in the context of a mutated Hippo pathway, TEAD2 activity is essential to maintain the growth of mesothelioma tumors in vivo, thus validating the concept of inhibiting the activated YAP1/TEAD complex for the treatment of malignant pleural mesothelioma patients. Human malignant mesothelioma MSTO-211H cells transfected with a doxycycline-dependent dominant negative-TEAD2 (dn-TEAD2) construct were inoculated subcutaneously in mice and allowed to grow to about 300 mm3 under glucose supplementation. At time 0, the mice were split into groups receiving doxycycline or not. The effects of doxycycline (dn-TEAD2 expression) on tumor size and gene expression (transcriptome) were evaluated times 0, 24, 96, or 216 hours of treatment.

本研究探讨了人恶性胸膜间皮瘤（human malignant pleural mesothelioma）依赖功能性YAP1-TEAD转录因子复合物（YAP1-TEAD transcription factor complex）以维持体内已完全建立肿瘤的分子机制。研究发现，在Hippo通路（Hippo pathway）功能异常的遗传背景下，显性负性TEAD2（dominant negative TEAD2）的表达可调控YAP1/TEAD依赖的基因表达，并抑制已建立的肿瘤异种移植物（tumor xenografts）的生长。本研究数据证实，在Hippo通路发生突变的背景下，TEAD2活性对于体内维持间皮瘤的生长至关重要，从而验证了通过抑制活化的YAP1/TEAD复合物治疗恶性胸膜间皮瘤患者的理念。
将转染了多西环素（doxycycline）诱导型显性负性TEAD2（dn-TEAD2）载体的人恶性胸膜间皮瘤MSTO-211H细胞经皮下接种至小鼠体内，并在葡萄糖补充条件下培养至肿瘤体积约300 mm³。于0时刻将小鼠分为给予多西环素与不予多西环素两组。分别于给药后0、24、96、216小时，评估多西环素（即dn-TEAD2表达）对肿瘤体积及基因表达（转录组transcriptome）的影响。