Objective: Tumor metastasis is a complex, multistep process that depends on tumor cells and their communication with the tumor microenvironment. A p53 gain-of-function mutant has been shown to enhance the tumorigenesi...Objective: Tumor metastasis is a complex, multistep process that depends on tumor cells and their communication with the tumor microenvironment. A p53 gain-of-function mutant has been shown to enhance the tumorigenesis, invasion, and metastasis abilities of tumor cells. This study aimed to investigate the roles of p53 R273 H mutation in the tumor microenvironment.Methods: The in vitro and in vivo effects of the p53 R273 H mutant on the invasion and metastasis of HCT116 cells were investigated. Exosomes from wild-type and HCT116-TP53(R273 H) cells were cocultured with mouse embryonic fibroblasts(MEFs). The roles of differentially expressed exosomal micro RNAs identified by microarray analysis were investigated. The functions of the p53 R273 H mutant in tumor cells were also investigated via gene expression microarray and quantitative polymerase chain reaction(q PCR) analyses.Results: Introducing p53 R273 H mutant into HCT116 cells significantly potentiated pulmonary metastasis in vivo. In the presence of exosomes derived from HCT116-TP53(R273 H) cells, the exosomes were taken up by MEFs and became activated. Microarray analysis showed that the p53 R273 H mutation increased the exosomal levels of mi R-21-3 p and mi R-769-3 p. Intriguingly, in clinical samples, mi R-21-3 p and mi R-769-3 p levels were significantly higher in patients with a p53 mutation than in those without this mutation. Furthermore, both mi R-21-3 p and mi R-769-3 p activated fibroblasts and exerted a synergistic effect via their target genes on the transforming growth factor-β(TGF-β)/Smad signaling pathway. The activated fibroblasts excreted cytokine TGF-β and may have reciprocally induced cancer cells to undergo epithelial-mesenchymal transition(EMT). Indeed, HCT116-TP53(R273 H) cells showed increased expression of ZEB1 and SNAI2 and decreased transcription of several cell adhesion molecules.Conclusions: The mutant p53-exosomal mi R-21-3 p/mi R-769-3 p-fibroblast-cytokine circuit appears to be responsible for communication between tumor and stromal cells, with exosomal mi RNAs acting as a bridge. mi R-21-3 p and mi R-769-3 p are potential predictive markers of pulmonary metastasis and candidate targets for therapeutic interventions.展开更多
基金supported by grants from the National Key R & D Program of China (No. 2017YFC0906601, No. 2017ZX10203205-003-001 and No. 2016YFC0901403)the National Natural Science Foundation (No. 81572840, No. 81572365, No. 81728015 and No. 81872033)+1 种基金the Nonprofit Central Research Institute Fund of CAMS (No. 2018RC310011)the CAMS Innovation Fund for Medical Sciences (No. 2016-I2M-1-001, No. 2017-I2M-3005 and No. 2019-I2M-1-003) in China
文摘Objective: Tumor metastasis is a complex, multistep process that depends on tumor cells and their communication with the tumor microenvironment. A p53 gain-of-function mutant has been shown to enhance the tumorigenesis, invasion, and metastasis abilities of tumor cells. This study aimed to investigate the roles of p53 R273 H mutation in the tumor microenvironment.Methods: The in vitro and in vivo effects of the p53 R273 H mutant on the invasion and metastasis of HCT116 cells were investigated. Exosomes from wild-type and HCT116-TP53(R273 H) cells were cocultured with mouse embryonic fibroblasts(MEFs). The roles of differentially expressed exosomal micro RNAs identified by microarray analysis were investigated. The functions of the p53 R273 H mutant in tumor cells were also investigated via gene expression microarray and quantitative polymerase chain reaction(q PCR) analyses.Results: Introducing p53 R273 H mutant into HCT116 cells significantly potentiated pulmonary metastasis in vivo. In the presence of exosomes derived from HCT116-TP53(R273 H) cells, the exosomes were taken up by MEFs and became activated. Microarray analysis showed that the p53 R273 H mutation increased the exosomal levels of mi R-21-3 p and mi R-769-3 p. Intriguingly, in clinical samples, mi R-21-3 p and mi R-769-3 p levels were significantly higher in patients with a p53 mutation than in those without this mutation. Furthermore, both mi R-21-3 p and mi R-769-3 p activated fibroblasts and exerted a synergistic effect via their target genes on the transforming growth factor-β(TGF-β)/Smad signaling pathway. The activated fibroblasts excreted cytokine TGF-β and may have reciprocally induced cancer cells to undergo epithelial-mesenchymal transition(EMT). Indeed, HCT116-TP53(R273 H) cells showed increased expression of ZEB1 and SNAI2 and decreased transcription of several cell adhesion molecules.Conclusions: The mutant p53-exosomal mi R-21-3 p/mi R-769-3 p-fibroblast-cytokine circuit appears to be responsible for communication between tumor and stromal cells, with exosomal mi RNAs acting as a bridge. mi R-21-3 p and mi R-769-3 p are potential predictive markers of pulmonary metastasis and candidate targets for therapeutic interventions.
