ASC modulates HIF-1? stability and induces cell mobility in OSCC.
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ABSTRACT: High-level expression of ASC (Apoptosis-associated speck-like protein containing a CARD) leads to lymph node metastasis in OSCC, but the underlying mechanism remains unclear. Here, we show that HIF-1? participates in ASC-induced metastasis. We identified 195 cell-motion-associated genes that were highly activated in ASC-overexpressed SAS_ASC cells; of them, 14 representative genes were found to be overexpressed in OSCC tissues in our previously reported RNA-seq dataset, OSCC-Taiwan. Nine of the 14 genes were also upregulated in OSCC-TCGA samples. Among the nine genes, RRAS2, PDGFA, and VEGFA, were correlated with poor overall survival of patients in OSCC-TCGA dataset. We further demonstrated that the promoters of these 14 ASC-induced genes contained binding motifs for the transcription-regulating factor, HIF-1?. We observed that ASC interacted with and stabilized HIF-1? in both the cytoplasm and the nucleus under normoxia. Molecules involved in the HIF-1? pathway, such as VHL and PHD2, showed no difference in their gene and protein levels in the presence or absence of ASC, but the expression of HIF-1?-OH, and the ubiquitination of HIF-1? were both decreased in SAS_ASC cells versus SAS_con cells. The migration and invasion activities of SAS_ASC cells were reduced when cells were treated with the HIF-1? synthesis inhibitor, digoxin. Taken together, our results demonstrate that the novel ASC-HIF-1? regulatory pathway contributes to lymph node metastasis in OSCC, potentially suggesting a new treatment strategy for OSCC.
SUBMITTER: Wu CS
PROVIDER: S-EPMC7471912 | biostudies-literature | 2020 Sep
REPOSITORIES: biostudies-literature
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