101. Phosphorylation of RelA/p65 Ser536 inhibits the progression and metastasis of hepatocellular carcinoma by mediating cytoplasmic retention of NF-κB p65.
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Zuo W, Ma H, Bi J, Li T, Mo Y, Yu S, Wang J, Li B, Huang J, Li Y, and Li L
- Abstract
Background: Intrahepatic and extrahepatic metastases contribute to the high recurrence rate and mortality of hepatocellular carcinoma (HCC). Constitutive activation of nuclear factor-κB (NF-κB) is a crucial feature of HCC. NF-κB p65 (p50-p65) is the most common dimeric form. Ser536 acts as an essential phosphorylation site of RelA/p65. However, the effect of RelA/p65 Ser536 phosphorylation on progression and metastases during intermediate and advanced HCC has not been reported., Methods: Phosphorylation of RelA/p65 (p-p65 Ser536) and NF-κB p65 were detected by using immunohistochemical staining in HCC tissue samples. The biological effects of RelA/p65 Ser536 phosphorylation were evaluated by using xenograft and metastasis models. NF-κB p65 nuclear translocation was detected by using Western blotting. The binding of NF-κB p65 to the BCL2 , SNAIL , and MMP9 promoters was detected by using chromatin immunoprecipitation. The biological effects on proliferation, migration, invasion, and epithelial-mesenchymal transition were assessed by using tetrazolium-based colorimetry, colony formation, EdU incorporation, flow cytometry, cell wound healing, and transwell assay., Results: NF-κB p65 is highly expressed, while p-p65 Ser536 is not well expressed in intermediate and advanced HCC tissues. In vivo experiments demonstrated that a phosphorylation-mimetic mutant of RelA/p65 Ser536 (p65/S536D) prevents tumor progression and metastasis. In vitro experiments showed that p65/S536D inhibits proliferation, migration, and invasion. Mechanistically, RelA/p65 Ser536 phosphorylation inhibits NF-κB p65 nuclear translocation and reduces NF-κB p65 binding to the BCL2 , SNAIL , and MMP9 promoters., Conclusions: RelA/p65 Ser536 phosphorylation was detrimental to NF-κB p65 entry into the nucleus and inhibited HCC progression and metastasis by reducing BCL2 , SNAIL , and MMP9 . The phosphorylation site of RelA/p65 Ser536 has excellent potential to be a promising target for NF-κB-targeted therapy in HCC., Competing Interests: The authors declare no conflict of interest., (© The Author(s) 2024. Published by Oxford University Press and Sixth Affiliated Hospital of Sun Yat-sen University.)
- Published
- 2024
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