Project description:MCF7 breast cancer cell lines: drug-resistant (OHT and ICI) cell lines vs. drug-sensitive (wild type) cell lines. Assessment of association between gene expression and methylation. Two comparisons: OHT-resistant vs. wild type, and ICI-resistant vs. wild type. OHT: 4-hydroxytamoxifen ICI: fulvestrant ((ICI 182780) This submission represents the methylation component of the study.
Project description:MCF7 breast cancer cell lines: drug-resistant (OHT and ICI) cell lines vs. drug-sensitive (wild type) cell lines. Assessment of association between gene expression and methylation.
Project description:The heterogenicity of hepatocellular carcinoma (HCC) remains a key obstacle in turning the majority of ‘immune-cold’ tumors ‘hot’ for effective immune checkpoint inhibitors (ICIs). Through analyzing the naturally-existed ‘hot’ HCC variants, we identified fas-associated death domain (FADD) as a key molecule upregulated in patients with dense tumor-filtrating CD8+T cells and better response to ICIs. Apart from the canonical role in apoptosis pathway, our data showed that CRISPR knockout of hepatoma-intrinsic Fadd led to increased tumor weights in immunocompetent but not immunodeficient mice, accompanied with decreased numbers and IFN-γ/TNF-ɑ production of tumor-filtrating CD8+T cells. Mechanistically, phosphorylated FADD translocated into cell nucleus, where it interacted with Sam68 to upregulate NF-κB transcription of CCL5, thereby promoted CD8+T cell tumor infiltration. Interestingly, anti-PD1 triggered FADD phosphorylation by CD8+T cell-derived IFN-γ/TNF-ɑ in ICI-sensitive, but not resistant tumors. Sequential FADD activation through genetic or pharmacologic approaches to orchestrate p-FADD-CD8+T cell axis therefore overcame ICI resistance in ICI-resistant orthotopic and spontaneous HCC mouse models in vivo. Taken together, our findings may provide insights into the combinatory immunotherapy approaches for the majority of HCC patients in the future.
Project description:Immune checkpoint inhibitors (ICIs) have improved outcomes in advanced cancers, yet resistance remains a major obsticle. Here, we investigated the role of myeloid cells in shaping the immunosuppressive tumor microenvironment that contributes to ICI resistance. Using mutagenized ICI-sensitive and resistant 4T1 breast cancer clones, we performed single-cell RNA sequencing to characterize immune cell populations post-ICI therapy. We identified monocytic dendritic progenitors (MDPs) and common monocytic progenitors (cMOPs) enriched in sensitive tumors, which may differentiate into immunosuppressive cells in resistant tumors. Analysis of public datasets confirmed the presence of MDP-cMOPs in tumors and blood of breast, lung, and colorectal cancer patients. We found high expression of CXCR4 and IL6R in MDP-cMOPs, and inhibiting these pathways blocked their recruitment and differentiation. Combined targeting of CXCR4 and IL6 pathway with ICI improved responses in resistant tumors, highlighting MDP-cMOPs as contributors to immunotherapy resistance and potential therapeutic targets.
Project description:Immune checkpoint inhibitors (ICIs) provide clinical benefits for various advanced malignancies. However, the predictive factors that determine sensitivity to ICIs have not been fully elucidated. To identify the mechanisms underlying ICI resistance, we performed a microarray analysis to compare the IFN-γ-inducible genes between ICI-sensitive AB1-HA and ICI-resistant LLC in vitro.
Project description:One of the first-line treatments for advanced non-small cell lung cancer (NSCLC) are immune checkpoint inhibitors (ICI), which activate the antitumor immune response. Despite their success, ICI remain ineffective in many patients, highlighting the need for strategies to overcome resistance. Most efforts have focused on promoting immune cell infiltration into refractory tumors to improve ICI efficacy. In this work, we mobilize this approach by focusing on Argonaute 2 (Ago2), a pivotal member of the RNA interference pathway. Using two murine models of immunorefractory NSCLC, we demonstrate that tumoral Ago2 suppresses interferon signaling, leading to poor immunogenicity and failure of ICI therapy. Genetic deletion of Ago2 in cancer cells restores interferon signaling and supports immune infiltration of the tumor. Consequently, whereas wild-type tumors are resistant to ICI, tumors devoid of Ago2 become sensitive to treatment. In NSCLC patients treated with ICI, high Ago2 expression and a low interferon signature in tumors correlates with reduced survival. Ago2 is thus a driver of the immunorefractory phenotype observed in NSCLC and may represent a therapeutic target when aiming to sensitize patients to ICI.
Project description:One of the first-line treatments for advanced non-small cell lung cancer (NSCLC) are immune checkpoint inhibitors (ICI), which activate the antitumor immune response. Despite their success, ICI remain ineffective in many patients, highlighting the need for strategies to overcome resistance. Most efforts have focused on promoting immune cell infiltration into refractory tumors to improve ICI efficacy. In this work, we mobilize this approach by focusing on Argonaute 2 (Ago2), a pivotal member of the RNA interference pathway. Using two murine models of immunorefractory NSCLC, we demonstrate that tumoral Ago2 suppresses interferon signaling, leading to poor immunogenicity and failure of ICI therapy. Genetic deletion of Ago2 in cancer cells restores interferon signaling and supports immune infiltration of the tumor. Consequently, whereas wild-type tumors are resistant to ICI, tumors devoid of Ago2 become sensitive to treatment. In NSCLC patients treated with ICI, high Ago2 expression and a low interferon signature in tumors correlates with reduced survival. Ago2 is thus a driver of the immunorefractory phenotype observed in NSCLC and may represent a therapeutic target when aiming to sensitize patients to ICI.
Project description:ER-dependent gene expression was investigated in the LY2 endocrine resistant cell line by treatment with ICI 182780. Cells were steroid depleted for 3 days prior to treatment with ICI for 6 hours. Four biological replicates were processed and analysed.
Project description:Transcriptome analysis was used to identify changes in mouse kidney cancer cells (RENCA) resistant to sunitinib (SuR) and after short and long term sunitinib withdrawal in vitro (ST-W for 48 hours and LT-W for more than 2 months, respectively).