Evading TGF-β-mediated growth inhibition is often associated with tumorigenesis in liver, including hepatocellular carcinoma （HCC）. To better understand the functions and the underlying molecular mechanisms of TGF-...Evading TGF-β-mediated growth inhibition is often associated with tumorigenesis in liver, including hepatocellular carcinoma （HCC）. To better understand the functions and the underlying molecular mechanisms of TGF-β in HCC initiation and progression, we carried out transcriptome sequencing （RNA-Seq） to identify the target genes of TGF-β. CXXCS, a member of the CXXC-type zinc finger domain-containing protein family, was identified as a novel TGF-β target gene in Hep3B HCC cells. Knockdown of CXXC5 attenuated the expression of a substantial portion of TGF-p target genes and ameliorated TGF-13-induced growth inhibition or apoptosis of Hep3B cells, suggesting that CXXC5 is required for TGF-p-mediated inhibition of HCC progression. Analysis of the TCGA database indicated that CXXC5 expression is reduced in the majority of HCC tissue samples in comparison to that in normal tissues. Furthermore, CXXC5 associates with the histone deacetylase HDAC1 and competes its interaction with Smad2/3, thereby abolishing the inhibitory effect of HDAC1 on TGF-β signaling. These observations together suggest that CXXC5 may act as a tumor suppressor by promoting TGF-β signaling via a positive feedback loop, and reveal a strategy for HCC to bypass TGF-β-mediated cytostasis by disrupting the positive feedback regulation. Our findings shed new light on TGF-β signaling regulation and demon- strate the function of CXXC5 in HCC development.展开更多
Some HIV-infected individuals receiving ART develop low-level viremia(LLV),with a plasma viral load of 50-1000 copies/mL.Persistent low-level viremia is associated with subsequent virologic failure.The peripheral bloo...Some HIV-infected individuals receiving ART develop low-level viremia(LLV),with a plasma viral load of 50-1000 copies/mL.Persistent low-level viremia is associated with subsequent virologic failure.The peripheral blood CD4^(+)T cell pool is a source of LLV.However,the intrinsic characteristics of CD4^(+)T cells in LLV which may contribute to low-level viremia are largely unknown.We analyzed the transcriptome profiling of peripheral blood CD4^(+)T cells from healthy controls(HC)and HIV-infected patients receiving ART with either virologic sup-pression(VS)or LLV.To identify pathways potentially responding to increasing viral loads from HC to VS and to LLV,KEGG pathways of differentially expressed genes(DEGs)were acquired by comparing VS with HC(VS-HC group)and LLV with VS(LLV-VS group),and overlapped pathways were analyzed.Characterization of DEGs in key overlapping pathways showed that CD4^(+)T cells in LLV expressed higher levels of Th1 signature transcription factors(TBX21),toll-like receptors(TLR-4,-6,-7 and-8),anti-HIV entry chemokines(CCL3 and CCL4),and anti-IL-1βfactors(ILRN and IL1R2)compared to VS.Our results also indicated activation of the NF-κB and TNF signaling pathways that could promote HIV-1 transcription.Finally,we evaluated the effects of 4 and 17 tran-scription factors that were upregulated in the VS-HC and LLV-VS groups,respectively,on HIV-1 promoter activity.Functional studies revealed that CXXC5 significantly increased,while SOX5 markedly suppressed HIV-1 tran-scription.In summary,we found that CD4^(+)T cells in LLV displayed a distinct mRNA profiling compared to that in VS,which promoted HIV-1 replication and r+eactivation of viral latency and may eventually contribute to virologic failure in patients with persistent LLV.CXXC5 and SOX5 may serve as targets for the development of latency-reversing agents.展开更多
文摘Evading TGF-β-mediated growth inhibition is often associated with tumorigenesis in liver, including hepatocellular carcinoma （HCC）. To better understand the functions and the underlying molecular mechanisms of TGF-β in HCC initiation and progression, we carried out transcriptome sequencing （RNA-Seq） to identify the target genes of TGF-β. CXXCS, a member of the CXXC-type zinc finger domain-containing protein family, was identified as a novel TGF-β target gene in Hep3B HCC cells. Knockdown of CXXC5 attenuated the expression of a substantial portion of TGF-p target genes and ameliorated TGF-13-induced growth inhibition or apoptosis of Hep3B cells, suggesting that CXXC5 is required for TGF-p-mediated inhibition of HCC progression. Analysis of the TCGA database indicated that CXXC5 expression is reduced in the majority of HCC tissue samples in comparison to that in normal tissues. Furthermore, CXXC5 associates with the histone deacetylase HDAC1 and competes its interaction with Smad2/3, thereby abolishing the inhibitory effect of HDAC1 on TGF-β signaling. These observations together suggest that CXXC5 may act as a tumor suppressor by promoting TGF-β signaling via a positive feedback loop, and reveal a strategy for HCC to bypass TGF-β-mediated cytostasis by disrupting the positive feedback regulation. Our findings shed new light on TGF-β signaling regulation and demon- strate the function of CXXC5 in HCC development.
基金the Ethics Committee of Guangzhou Eighth People's Hospital(202033166),and all participants provided written informed consent.
文摘Some HIV-infected individuals receiving ART develop low-level viremia(LLV),with a plasma viral load of 50-1000 copies/mL.Persistent low-level viremia is associated with subsequent virologic failure.The peripheral blood CD4^(+)T cell pool is a source of LLV.However,the intrinsic characteristics of CD4^(+)T cells in LLV which may contribute to low-level viremia are largely unknown.We analyzed the transcriptome profiling of peripheral blood CD4^(+)T cells from healthy controls(HC)and HIV-infected patients receiving ART with either virologic sup-pression(VS)or LLV.To identify pathways potentially responding to increasing viral loads from HC to VS and to LLV,KEGG pathways of differentially expressed genes(DEGs)were acquired by comparing VS with HC(VS-HC group)and LLV with VS(LLV-VS group),and overlapped pathways were analyzed.Characterization of DEGs in key overlapping pathways showed that CD4^(+)T cells in LLV expressed higher levels of Th1 signature transcription factors(TBX21),toll-like receptors(TLR-4,-6,-7 and-8),anti-HIV entry chemokines(CCL3 and CCL4),and anti-IL-1βfactors(ILRN and IL1R2)compared to VS.Our results also indicated activation of the NF-κB and TNF signaling pathways that could promote HIV-1 transcription.Finally,we evaluated the effects of 4 and 17 tran-scription factors that were upregulated in the VS-HC and LLV-VS groups,respectively,on HIV-1 promoter activity.Functional studies revealed that CXXC5 significantly increased,while SOX5 markedly suppressed HIV-1 tran-scription.In summary,we found that CD4^(+)T cells in LLV displayed a distinct mRNA profiling compared to that in VS,which promoted HIV-1 replication and r+eactivation of viral latency and may eventually contribute to virologic failure in patients with persistent LLV.CXXC5 and SOX5 may serve as targets for the development of latency-reversing agents.
