Department of Respiratory Medicine, Xiangya Hospital, Central South University , Changsha, Hunan, China.
Cell Cycle. 2020 Oct;19(20):2701-2719. doi: 10.1080/15384101.2020.1826236. Epub 2020 Oct 5.
Fibrotic microenvironment has been reported to have a pro-metastasis effect on tumor cells, but the mechanism remains unclear. The current study aimed to explore the underlying mechanism by which the fibrotic microenvironment affects tumor cells. A tumor metastasis model was established by injecting tumor cells containing GFP into mice with pulmonary fibrosis. Lung tissues and fibroblasts were harvested, and conditioned medium (CM) were collected from fibrotic lungs and fibroblasts. Hematoxylin & eosin staining and immunohistochemistry were used to detect pulmonary metastasis and FSP1 expression, respectively. Bioinformatics and dual-luciferase reporter assay proved that the target genes of ZEB1-AS1 and miR-200b-3p were miR-200b-3p and ZEB1, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expressions of GFP, ZEB1-AS1, and miR-200b-3p. Transwell assay, Annexin V/PI assay, and colorimetry were performed to examine the effects of CM, ZEB1-AS1, miR-200b-3p, and ZEB1 on cell invasion, apoptosis, and the activity level of caspase-3/-9. Pulmonary metastasis was promoted and the expressions of FSP1 and GFP were increased in mice with pulmonary fibrosis. CM enhanced the invasion and inhibited the apoptosis of tumor cells. SiZEB1-AS1 and siZEB1 inhibited the invasion and apoptosis of tumor cells, while miR-200b-3p inhibitor had the opposite effect of SiZEB1-AS1 and siZEB1, and further reversed the effect of siZEB1 on tumor cell invasion and apoptosis. SiZEB1-AS1 reversed the effects of both miR-200b-3p inhibitor and miR-200b-3p inhibitor+siZEB1 on tumor cell invasion and apoptosis. Fibrotic microenvironment promoted the metastatic seeding of tumor cells into the lungs via mediating the ZEB1-AS1/miR-200b-3p/ZEB1 signaling.
纤维化微环境已被报道对肿瘤细胞具有促转移作用，但具体机制尚不清楚。本研究旨在探索纤维化微环境影响肿瘤细胞的潜在机制。通过将含有 GFP 的肿瘤细胞注射到患有肺纤维化的小鼠中，建立肿瘤转移模型。采集肺组织和成纤维细胞，收集来自纤维化肺和成纤维细胞的条件培养基（CM）。苏木精和伊红染色和免疫组织化学分别用于检测肺转移和 FSP1 表达。生物信息学和双荧光素酶报告基因检测证明，ZEB1-AS1 和 miR-200b-3p 的靶基因分别是 miR-200b-3p 和 ZEB1。实时定量聚合酶链反应（qRT-PCR）用于检测 GFP、ZEB1-AS1 和 miR-200b-3p 的表达。Transwell 测定、Annexin V/PI 测定和比色法用于检测 CM、ZEB1-AS1、miR-200b-3p 和 ZEB1 对细胞侵袭、凋亡和 caspase-3/-9 活性的影响。肺纤维化小鼠的肺转移得到促进，FSP1 和 GFP 的表达增加。CM 增强了肿瘤细胞的侵袭并抑制了其凋亡。SiZEB1-AS1 和 siZEB1 抑制了肿瘤细胞的侵袭和凋亡，而 miR-200b-3p 抑制剂则对 SiZEB1-AS1 和 siZEB1 具有相反的作用，并进一步逆转了 SiZEB1 对肿瘤细胞侵袭和凋亡的影响。SiZEB1-AS1 逆转了 miR-200b-3p 抑制剂和 miR-200b-3p 抑制剂+siZEB1 对肿瘤细胞侵袭和凋亡的影响。纤维化微环境通过介导 ZEB1-AS1/miR-200b-3p/ZEB1 信号促进肿瘤细胞向肺部转移。
