Similar Datasets
Project description:N6-methyladenosine (m6A) is an abundant nucleotide modification in mRNA, known to regulate mRNA stability, splicing, and translation, but it is unclear whether it is also has a physiological role in the intratumoral microenvironment and cancer drug resistance. Here, we find that METTL3, a primary m6A methyltransferase, is significantly down-regulated in human sorafenib-resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promotes sorafenib resistance and expression of angiogenesis genes in cultured HCC cells, and activates autophagy-associated pathways. Mechanistically, we have identified FOXO3 as a key downstream target of METTL3, with m6A modification of the FOXO3 mRNA 3'-untranslated region increasing its stability through a YTHDF1-dependent mechanism. Analysis of clinical samples furthermore showed that METTL3 and FOXO3 levels are tightly correlated in HCC patients. In mouse xenograft models, METTL3 depletion significantly enhances sorafenib resistance of HCC by abolishing the identified METTL3-mediated FOXO3 mRNA stabilization, and overexpression of FOXO3 restores m6A-dependent sorafenib sensitivity. Collectively, our work reveals a critical function for METTL3-mediated m6A modification in the hypoxic tumor microenvironment, and identifies FOXO3 as an important target of m6A modification in the resistance of HCC to sorafenib therapy.
| S-SCDT-EMBOJ-2019-103181 | biostudies-other
Project description:N6-methyladenosine (m6A) is a type of nucleotide modification abundant in mRNA, which regulates mRNA stability, splicing and translation. However, its physiological role in intratumoral microenvironment and drug resistancehave not been fully understood. We demonstrated that METTL3,a primary m6A methyltransferase, was significantly down-regulated in human sorafenib-resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promoted sorafenib-resistance and angiogenesis and exacerbated progression by activating autophagy-associated pathway. Mechanistically, we identified FOXO3 as a key downstream target of the METTL3-mediated m6A modification. The m6A modification of FOXO3 at the 3'-untranslated region increased FOXO3 mRNA stability. Analysis of clinical samples showed that METTL3levels aretightly correlated with FOXO3levels in patients with HCC, and suppression of FOXO3 predicted poor clinical outcomes. Importantly, METTL3-depletion significantly enhanced sorafenib-resistance of HCC via a METTL3-FOXO3 axis, whereasoverexpression of FOXO3 restored the m6A-dependent sorafenib-sensitivity. Collectively, our work revealedthe critical function of the METTL3-mediated m6A modification in HCC in hypoxic tumor microenvironment, and provided insights into the molecular mechanism of the m6A modification in the resistance of HCC to sorafenib therapy.
2020-04-03 | GSE143234 | GEO
Project description:N6-methyladenosine (m6A) is a type of nucleotide modification abundant in mRNA, which regulates mRNA stability, splicing and translation. However, its physiological role in intratumoral microenvironment and drug resistancehave not been fully understood. We demonstrated that METTL3,a primary m6A methyltransferase, was significantly down-regulated in human sorafenib-resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promoted sorafenib-resistance and angiogenesis and exacerbated progression by activating autophagy-associated pathway. Mechanistically, we identified FOXO3 as a key downstream target of the METTL3-mediated m6A modification. The m6A modification of FOXO3 at the 3'-untranslated region increased FOXO3 mRNA stability. Analysis of clinical samples showed that METTL3levels aretightly correlated with FOXO3levels in patients with HCC, and suppression of FOXO3 predicted poor clinical outcomes. Importantly, METTL3-depletion significantly enhanced sorafenib-resistance of HCC via a METTL3-FOXO3 axis, whereasoverexpression of FOXO3 restored the m6A-dependent sorafenib-sensitivity. Collectively, our work revealedthe critical function of the METTL3-mediated m6A modification in HCC in hypoxic tumor microenvironment, and provided insights into the molecular mechanism of the m6A modification in the resistance of HCC to sorafenib therapy.
2020-04-03 | GSE143233 | GEO
Project description:N6-methyladenosine (m6 A) is an abundant nucleotide modification in mRNA, known to regulate mRNA stability, splicing, and translation, but it is unclear whether it is also has a physiological role in the intratumoral microenvironment and cancer drug resistance. Here, we find that METTL3, a primary m6 A methyltransferase, is significantly down-regulated in human sorafenib-resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promotes sorafenib resistance and expression of angiogenesis genes in cultured HCC cells and activates autophagy-associated pathways. Mechanistically, we have identified FOXO3 as a key downstream target of METTL3, with m6 A modification of the FOXO3 mRNA 3'-untranslated region increasing its stability through a YTHDF1-dependent mechanism. Analysis of clinical samples furthermore showed that METTL3 and FOXO3 levels are tightly correlated in HCC patients. In mouse xenograft models, METTL3 depletion significantly enhances sorafenib resistance of HCC by abolishing the identified METTL3-mediated FOXO3 mRNA stabilization, and overexpression of FOXO3 restores m6 A-dependent sorafenib sensitivity. Collectively, our work reveals a critical function for METTL3-mediated m6 A modification in the hypoxic tumor microenvironment and identifies FOXO3 as an important target of m6 A modification in the resistance of HCC to sorafenib therapy.
| S-EPMC7298296 | biostudies-literature
Project description:RNA m6A methylation regulates sorafenib-resistance in liver cancer through FOXO3-mediated autophagy
| PRJNA599368 | ENA
Project description:RNA m6A methylation regulates sorafenib-resistance in liver cancer through FOXO3-mediated autophagy [m6A RIP-seq]
| PRJNA599374 | ENA
Project description:RNA m6A methylation regulates sorafenib-resistance in liver cancer through FOXO3-mediated autophagy [RNA-seq]
| PRJNA599373 | ENA
Project description:Translation machinery associated 7 homolog (TMA7) is closely related to proliferation-related diseases. However, the function and regulatory mechanism of TMA7 in laryngeal squamous cell carcinoma (LSCC) remain unclear. The present study aimed to investigate the effect of TMA7 on the occurrence and development of LSCC and to study the mechanism of TMA7. TMA7 is upregulated in LSCC tissues and associated with poor prognosis. After TMA7 downregulation, the autophagy level was increased, and the proliferation, migration, and invasion of LSCC cells were inhibited. The m6A methylated reader IGF2BP3 enhanced the stability of TMA7 and reduced the level of autophagy. TMA7 interacted directly with UBA2. Furthermore, the activation of the IGF2BP3-regulated TMA7-UBA2-PI3K pathway is the primary mechanism by which TMA7 inhibits autophagy and promotes the progression of LSCC. The current study revealed that IGF2BP3-mediated TMA7 m6A modification promotes LSCC progression and cisplatin-resistance through UBA2-PI3K pathway, providing new insights into the autophagy-related mechanism, potential biomarkers, and therapeutic targets for LSCC.
| S-EPMC10086756 | biostudies-literature
Project description:Hepatocyte nuclear factor 3γ (HNF3γ) is a hepatocyte nuclear factor, but its role and clinical significance in hepatocellular carcinoma (HCC) remain unclear. Herein, we report that HNF3γ expression is downregulated in patient HCC and inversely correlated with HCC malignancy and patient survival. Moreover, our data suggested that the HNF3γ reduction in HCC could be mediated by METTL14-dependent m6A methylation of HNF3γ mRNA. HNF3γ expression was increased during hepatic differentiation and decreased in dedifferentiated HCC cells. Interestingly, HNF3γ delivery promoted differentiation of not only HCC cells but also liver CSCs, which led to suppression of HCC growth. Mechanistic analysis suggested an HNF3γ-centered regulatory network that includes essential liver differentiation-associated transcription factors and functional molecules, which could synergistically facilitate HCC cell differentiation. More importantly, enforced HNF3γ expression sensitized HCC cells to sorafenib-induced growth inhibition and cell apoptosis through transactivation of OATP1B1 and OATP1B3 expression, which are major membrane transporters for sorafenib uptake. Clinical investigation showed that patient-derived HCC xenografts with high HNF3γ expression exhibited a sorafenib response and patients with high HCC HNF3γ levels benefited from sorafenib therapy. Together, these results suggest that HNF3γ plays an essential role in HCC differentiation and may serve as a therapeutic target and predictor of sorafenib benefit in patients.
| S-EPMC7762754 | biostudies-literature
Project description:Hepatocellular carcinoma is one of most common solid cancers worldwide. Sorafenib is indicated as a treatment for advanced hepatocellular carcinoma (HCC). However, the clinical efficacy of sorafenib has been severely compromised by the development of drug resistance, and the precise mechanisms of drug resistance remain largely unknown. Here we found that a cell surface molecule, CD24, is overexpressed in tumor tissues and sorafenib-resistant hepatocellular carcinoma cell lines. Moreover, there is a positive correlation between CD24 expression levels and sorafenib resistance. In sorafenib-resistant HCC cell lines, depletion of CD24 caused a notable increase of sorafenib sensitivity. In addition, we found that CD24-related sorafenib resistance was accompanied by the activation of autophagy and can be blocked by the inhibition of autophagy using either pharmacological inhibitors or essential autophagy gene knockdown. In further research, we found that CD24 overexpression also leads to an increase in PP2A protein production and induces the deactivation of the mTOR/AKT pathway, which enhances the level of autophagy. These results demonstrate that CD24 regulates sorafenib resistance via activating autophagy in HCC. This is the first report to describe the relationships among CD24, autophagy, and sorafenib resistance. In conclusion, the combination of autophagy modulation and CD24 targeted therapy is a promising therapeutic strategy in the treatment of HCC.
| S-EPMC5974417 | biostudies-literature