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A G3BP1-Interacting lncRNA Promotes Ferroptosis and Apoptosis in Cancer via Nuclear Sequestration of p53.

ABSTRACT: Long noncoding RNAs (lncRNA) have been associated with various types of cancer; however, the precise role of many lncRNAs in tumorigenesis remains elusive. Here we demonstrate that the cytosolic lncRNA P53RRA is downregulated in cancers and functions as a tumor suppressor by inhibiting cancer progression. Chromatin remodeling proteins LSH and Cfp1 silenced or increased P53RRA expression, respectively. P53RRA bound Ras GTPase-activating protein-binding protein 1 (G3BP1) using nucleotides 1 and 871 of P53RRA and the RRM interaction domain of G3BP1 (aa 177-466). The cytosolic P53RRA-G3BP1 interaction displaced p53 from a G3BP1 complex, resulting in greater p53 retention in the nucleus, which led to cell-cycle arrest, apoptosis, and ferroptosis. P53RRA promoted ferroptosis and apoptosis by affecting transcription of several metabolic genes. Low P53RRA expression significantly correlated with poor survival in patients with breast and lung cancers harboring wild-type p53. These data show that lncRNAs can directly interact with the functional domain of signaling proteins in the cytoplasm, thus regulating p53 modulators to suppress cancer progression.Significance: A cytosolic lncRNA functions as a tumor suppressor by activating the p53 pathway. Cancer Res; 78(13); 3484-96. ©2018 AACR.

SUBMITTER: Mao C

PROVIDER: S-EPMC8073197 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundMetastasis is the key cause of death in ovarian cancer patients. To figure out the biological nature of cancer metastasis is essential for developing effective targeted therapy. Here we investigate how long non-coding RNA (lncRNA) SPOCD1-AS from ovarian cancer extracellular vesicles (EVs) remodel mesothelial cells through a mesothelial-to-mesenchymal transition (MMT) manner and facilitate peritoneal metastasis.MethodsEVs purified from ovarian cancer cells and ascites of patients were applied to mesothelial cells. The MMT process of mesothelial cells was assessed by morphology observation, western blot analysis, migration assay and adhesion assay. Altered lncRNAs of EV-treated mesothelial cells were screened by RNA sequencing and identified by qRT-PCR. SPOCD1-AS was overexpressed or silenced by overexpression lentivirus or shRNA, respectively. RNA pull-down and RNA immunoprecipitation assays were conducted to reveal the mechanism by which SPOCD1-AS remodeled mesothelial cells. Interfering peptides were synthesized and applied. Ovarian cancer orthotopic implantation mouse model was established in vivo.ResultsWe found that ovarian cancer-secreted EVs could be taken into recipient mesothelial cells, induce the MMT phenotype and enhance cancer cell adhesion to mesothelial cells. Furthermore, SPOCD1-AS embedded in ovarian cancer-secreted EVs was transmitted to mesothelial cells to induce the MMT process and facilitate peritoneal colonization in vitro and in vivo. SPOCD1-AS induced the MMT process of mesothelial cells via interacting with G3BP1 protein. Additionally, G3BP1 interfering peptide based on the F380/F382 residues was able to block SPOCD1-AS/G3BP1 interaction, inhibit the MMT phenotype of mesothelial cells, and diminish peritoneal metastasis in vivo.ConclusionsOur findings elucidate the mechanism associated with EVs and their cargos in ovarian cancer peritoneal metastasis and may provide a potential approach for metastatic ovarian cancer therapeutics.

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A G3BP1-Interacting lncRNA Promotes Ferroptosis and Apoptosis in Cancer via Nuclear Sequestration of p53.

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