Project description:iRNAs targeting METTL3 used to deplete METTL3 in castrate resistant LNCaP:C42 and 22Rv1 prosate cancer cells and the effect on basal and androgen regulated gene expression and splicing determined.
Project description:To investigate the function of METTL3 in the regulation of Treg cell differentiation, we treated inducd Tregs with STM2457 in which the catalytic activity of METTL3 has been phrmacologically inhibited. We then performed gene expression profiling analysis using data obtained from RNA-seq of 8 different cells at one time point.
Project description:Genomic and transcriptomic alterations are insufficient to explain the variance in protein expression seen in cancer. Recent evidence has highlighted the role of N6-methyladenosine (m6A) in the regulation of mRNA expression, stability and translation, supporting a potential role for post-transcriptional regulation mediated by m6A in cancer. Here we explore prostate cancer as an exemplar cancer and generate the first prostate m6A maps, and further examined how low levels of N6-adenosine-methyltransferase (METTL3) associates with advanced prostate cancer and results in altered expression at the level of transcription, translation, and protein. In particular extracellular matrix proteins have a high number of m6A sites and show significant changes in expression with METTL3 knock-down. We also discovered the upregulation of a hepatocyte nuclear factor-driven gene signature that is associated with therapy resistance in prostate cancer. Significantly, METTL3 knock-down rendered the cells resistant to androgen receptor antagonists, implicating changes in m6A as a mechanism for therapy resistance in metastatic prostate cancer.
Project description:Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor of hepatocellular carcinoma (HCC). However, the mechanism and target therapy on NAFLD-HCC are still unclear. Here, we identify that the N6-methyladenosine (m6A) methyltransferase METTL3 promotes NAFLD-HCC. Hepatocyte-specific Mettl3 knockin exacerbated NAFLD-HCC formation while Mettl3 knockout exerted an opposite effect in mice. Single-cell RNA-seq revealed that METTL3 suppressed antitumor immune response by reducing infiltration of Gzmb+ and IFN-γ+ CD8+ T-cell, thereby facilitating immune escape. Mechanistically, METTL3 mediates SCAP mRNA m6A to promote its translation, leading to the activation of cholesterol biosynthesis. This enhanced secretion of cholesterol and cholesteryl esters, lipotoxins that impaired CD8+ T cell function in tumor microenvironment. Targeting of METTL3 by sgRNA, nanoparticle-siRNA, or pharmacological inhibitor (STM2457) in combination with anti-PD1 synergized to reinvigorate cytotoxic CD8+ T cells and mediate tumor regression. Together, METTL3 is a therapeutic target in NAFLD-HCC, especially in conjunction with immune checkpoint blockade (ICB) therapy.
Project description:Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor of hepatocellular carcinoma (HCC). However, the mechanism and target therapy on NAFLD-HCC are still unclear. Here, we identify that the N6-methyladenosine (m6A) methyltransferase METTL3 promotes NAFLD-HCC. Hepatocyte-specific Mettl3 knockin exacerbated NAFLD-HCC formation while Mettl3 knockout exerted an opposite effect in mice. Single-cell RNA-seq revealed that METTL3 suppressed antitumor immune response by reducing infiltration of Gzmb+ and IFN-γ+ CD8+ T-cell, thereby facilitating immune escape. Mechanistically, METTL3 mediates SCAP mRNA m6A to promote its translation, leading to the activation of cholesterol biosynthesis. This enhanced secretion of cholesterol and cholesteryl esters, lipotoxins that impaired CD8+ T cell function in tumor microenvironment. Targeting of METTL3 by sgRNA, nanoparticle-siRNA, or pharmacological inhibitor (STM2457) in combination with anti-PD1 synergized to reinvigorate cytotoxic CD8+ T cells and mediate tumor regression. Together, METTL3 is a therapeutic target in NAFLD-HCC, especially in conjunction with immune checkpoint blockade (ICB) therapy.