Masawa Meitetsu, Sato-Yazawa Hanako, Kashiwagi Korehito, Ishii Jun, Miyata-Hiramatsu Chie, Iwamoto Masami, Kohno Kakeru, Miyazawa Tadasuke, Onozaki Masato, Noda Shuhei, Shimizu Yasuo, Niho Seiji, Yazawa Takuya
Department of Respiratory Medicine, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Japan.
Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Japan.
Am J Pathol. 2022 Jun;192(6):847-861. doi: 10.1016/j.ajpath.2022.03.007. Epub 2022 Mar 30.
Although recent reports have revealed the importance of the inactivation of both RB1 and TP53 in the transformation from lung adenocarcinoma into neuroendocrine carcinoma (NEC), the requirements for complete transformation into NEC have not been elucidated. To investigate alterations in the characteristics associated with the inactivation of RB1/TP53 and define the requirements for transformation into NEC cells, RB1/TP53 double-knockout A549 lung adenocarcinoma cells were established, and additional knockout of REST and transfection of ASCL1 and POU class 3 homeobox transcription factors (TFs) was conducted. More than 60 genes that are abundantly expressed in neural cells and several genes associated with epithelial-to-mesenchymal transition were up-regulated in RB1/TP53 double-knockout A549 cells. Although the expression of chromogranin A and synaptophysin was induced by additional knockout of REST (which mimics the status of most NECs), the expression of another neuroendocrine marker, CD56, and proneural TFs was not induced. However, coexpression of ASCL1 and POU3F4 in RB1/TP53/REST triple-knockout A549 cells induced the expression of not only CD56 but also other proneural TFs (NEUROD1 and insulinoma-associated 1) and induced NEC-like morphology. These findings suggest that the inactivation of RB1 and TP53 induces a state necessary for the transformation of lung adenocarcinoma into NEC and that further inactivation of REST and coexpression of ASCL1 and POU3F4 are the triggers for complete transformation into NEC.
尽管最近的报告揭示了RB1和TP53失活在肺腺癌向神经内分泌癌（NEC）转变中的重要性，但完全转变为NEC的必要条件尚未阐明。为了研究与RB1/TP53失活相关的特征变化，并确定向NEC细胞转变的必要条件，我们建立了RB1/TP53双敲除A549肺腺癌细胞，并进行了REST的额外敲除以及ASCL1和POU3类同源框转录因子（TFs）的转染。在RB1/TP53双敲除A549细胞中，60多个在神经细胞中大量表达的基因以及几个与上皮-间质转化相关的基因上调。尽管通过额外敲除REST（模拟大多数NEC的状态）诱导了嗜铬粒蛋白A和突触素的表达，但另一种神经内分泌标志物CD56和神经源性TFs的表达并未被诱导。然而，在RB1/TP53/REST三敲除A549细胞中共表达ASCL1和POU3F4不仅诱导了CD56的表达，还诱导了其他神经源性TFs（NEUROD1和胰岛素瘤相关蛋白1）的表达，并诱导了NEC样形态。这些发现表明，RB1和TP53的失活诱导了肺腺癌向NEC转变所需的状态，而REST的进一步失活以及ASCL1和POU3F4的共表达是完全转变为NEC的触发因素。
