ABSTRACT: Gene expression in human endometrial cancer tissues and serous papillary endometrial cancer cell line, SPAC-1L, treated by STAT1-siRNA and/or IFN-gamma
Project description:Gene expression in human endometrial cancer tissues and serous papillary endometrial cancer cell line, SPAC-1L, treated by STAT1-siRNA and/or IFN-gamma
Project description:Endometrial cancer is one of the most common gynecologic malignancies, and patients with high grade disease, especially serous papillary subtype (SPEC) are often related to the poor outcomes. Recent genome-wide analyses have revealed that SPEC exhibits gene expression profiles that are distinct from the endometrioid histologic subtype; therefore, it is important to identify the SPEC driver genes or pathways responsible for the inherently aggressive phenotypes and to develop SPEC-specific therapies to target these driver genes or pathways. Through array-based analysis and immunohistochemical staining of human endometrial cancer tissue, STAT1 is identified high expressed, and can distinguish SPEC from other subtypes of endometrial cancer. In vitro and in vivo experiments show STAT1 role as a pro-survival factor in SPEC. STAT1 was identified as a master gene modulating “transcriptional pro-survival pathways” to enhance multiple malignant characteristics These finding may suggest that targeting of STAT1, the SPEC driver gene, may provide the means to improve poor outcomes for patients with SPEC. We used microarrays to clarify the changes of gene expression along with STAT1-siRNA treatment and to confirm whether there are any changes on genes expression related to STAT1 pathway. We also used the microarray data to clarify genes signatures which can distinguish subtype of human endometrial cancers.
Project description:Endometrial cancer is one of the most common gynecologic malignancies, and patients with high grade disease, especially serous papillary subtype (SPEC) are often related to the poor outcomes. Recent genome-wide analyses have revealed that SPEC exhibits gene expression profiles that are distinct from the endometrioid histologic subtype; therefore, it is important to identify the SPEC driver genes or pathways responsible for the inherently aggressive phenotypes and to develop SPEC-specific therapies to target these driver genes or pathways. Through array-based analysis and immunohistochemical staining of human endometrial cancer tissue, STAT1 is identified high expressed, and can distinguish SPEC from other subtypes of endometrial cancer. In vitro and in vivo experiments show STAT1 role as a pro-survival factor in SPEC. STAT1 was identified as a master gene modulating “transcriptional pro-survival pathways” to enhance multiple malignant characteristics These finding may suggest that targeting of STAT1, the SPEC driver gene, may provide the means to improve poor outcomes for patients with SPEC.
Project description:Classically, there are two types of endometrial cancer, endometrioid adenocarcinoma (EAC), or Type I; and uterine papillary serous carcinoma (UPSC), or Type II. These two types of cancers exhibit distinct DNA methylation levels in promoters of many genes. In EAC, many tumor suppressor genes were silenced due to DNA hypermethylation at their promoter region. However, promoters of many of these genes remained unmethylated in UPSC. Here, we described complete DNA methylome maps of endometrioid adenocarcinoma, uterine papillary serous carcinoma, and normal endometrium, by applying a combined strategy of methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylation-sensitive restriction enzyme sequencing (MRE-seq). We took a complementary and orthogonal approach to identify DNA methylation changes unique to the two endometrial cancer subtypes in an unbiased fashion. We generated complete DNA methylome maps for endometrioid adenocarcinoma (EAC, three samples), uterine papillary serous carcinomas (UPSC, three samples), and normal endometrium (pooled samples) by integrating data from methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylation-sensitive restriction enzyme sequencing (MRE-seq).
Project description:Tumor cells frequently develop immune resistance through interferon-γ (IFN-γ)–induced PD-L1 expression, acquisition of cancer stem cell (CSC)–like features, and adaptation to hypoxia within the tumor microenvironment (TME). Although IFN-γ activates both STAT1 and STAT3, how these pathways interact to regulate immune evasion under hypoxia remains unclear. Using the MC38 murine colorectal cancer model and T cell–tumor spheroid co-culture assays, we examined how IFN-γ signaling through STAT1 and STAT3 regulates PD-L1 expression, CSC plasticity, and cytotoxic T cell function under normoxic and hypoxic conditions. Pharmacologic inhibitors and siRNA-mediated knockdown were used to dissect pathway function, and Niclosamide, an FDA-approved anthelmintic, was evaluated as a dual STAT1/STAT3 inhibitor. We found that IFN-γ primarily induced PD-L1 expression through STAT1 activation, whereas CSC plasticity was associated with STAT3 signaling. STAT1 and STAT3 displayed reciprocal regulation—blocking one enhanced activation of the other. Niclosamide effectively inhibited phosphorylation of both STAT1 and STAT3, resulting in suppressed PD-L1 upregulation and reduced CSC enrichment. In addition, it also partially inhibited hypoxia-induced HIF-1α expression. In co-culture assays, Niclosamide enhanced T cell infiltration and reduced exhaustion under hypoxic conditions, resulting in improved T cell killing. Our findings identified Niclosamide as a potent dual STAT1/3 inhibitor capable of reversing IFN-γ and hypoxia-driven immune evasion. Repurposing Niclosamide may represent a promising strategy to enhance the efficacy of immune checkpoint blockade in solid tumors.
Project description:While the IFN-γ-STAT1 signaling pathway is well-characterized in promoting MHC class II (MHC-II)-dependent antigen presentation within pro-inflammatory macrophages during acute infections, its functional dynamics in tumor-associated macrophages (TAMs) remain poorly understood. Here, we systematically investigated the immunomodulatory role of IFN-γ-STAT1 axis in TAMs through integrative bioinformatics and experimental validation. Transcriptomic analysis of tumor-infiltrating myeloid cells across multiple cancer cohorts revealed a strong correlation between STAT1 activation and MHC-II pathway enrichment, particularly in IFN-γ-high TAM subsets. To mechanistically dissect this relationship, we employed bone marrow-derived macrophages (BMDMs) polarized under tumor-conditioned media and subjected them to IFN-γ stimulation. Single-cell RNA sequencing demonstrated that IFN-γ triggered STAT1 nuclear translocation, upregulating MHC-II genes. Our findings establish IFN-γ-STAT1 as a master regulator of TAM immunogenicity, proposing targeted STAT1 activation as a strategy to overcome myeloid-driven immunosuppression in cancer.
Project description:Gene regulation by cytokine-activated STAT transcription factors requires serine phosphorylation within the transactivation domain (TAD). STAT1 and STAT3 TAD phosphorylation was reported to occur upon promoter binding by an unknown kinase. Here we show that the Mediator CDK8 module phosphorylates S727 of the STAT1 TAD in the interferon (IFN) signaling pathway as well as the TADs of other STATs. Microarray analysis reveals that CDK8-mediated STAT1 TAD phosphorylation positively or negatively regulates over 40% of IFN-gamma-responsive genes, and RNA polymerase II occupancy correlates with gene expression changes. This selective regulation occurs despite CDK8 occupancy and STAT1 S727 phosphorylation at both S727 phosphorylation-dependent and -independent IFN-gamma target genes. Independently of its role as STAT1 S727 kinase CDK8 acts as a positive regulator of IFN-gamma responses. These data reveal a dual input of CDK8 in STAT1-controlled transcription and propose a key role for CDK8 in TAD phosphorylation of other STATs during cytokine responses. STAT1 WT and STAT1 S727A mouse fibroblasts were treated with siRNA to CDK8 (siCdk8 smart pool, On Target Plus, Dharmacon) and control siRNA (siCtrl) and stimulated with IFN-gamma for 4 h or left untreated. Total RNA from three independent experiments for each treatment and each genotype was isolated from cells using Trizol reagent (Invitrogen) following the manufactures protocol and used for expression analysis using Agilent Whole Mouse Genome Microarrays, 8x60K. Standard protocols for labeling and hybridization were followed. In brief, fluorescent cRNA was generated using Low Input Quick Amp Labeling Kit (Agilent). The amplified cyanine 3-labeled cRNA samples were then purified using SV Total RNA Isolation System (Promega) and hybridized to microarray slides. Microarray slides were washed and scanned with an Agilent Scanner. Note: The outlier array #10 [SA.CDK.gamma.R3] was removed from subsequent analysis and its processed data was not provided. However, its raw data file has been linked as a supplementary file at the foot of the Series record.
Project description:Classically, there are two types of endometrial cancer, endometrioid adenocarcinoma (EAC), or Type I; and uterine papillary serous carcinoma (UPSC), or Type II. These two types of cancers exhibit distinct DNA methylation levels in promoters of many genes. In EAC, many tumor suppressor genes were silenced due to DNA hypermethylation at their promoter region. However, promoters of many of these genes remained unmethylated in UPSC. Here, we described complete DNA methylome maps of endometrioid adenocarcinoma, uterine papillary serous carcinoma, and normal endometrium, by applying a combined strategy of methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylation-sensitive restriction enzyme sequencing (MRE-seq).
Project description:Type I interferons (IFN-I) are critical in antimicrobial and antitumor defense. Although IFN-I signal via the interferon-stimulated gene factor 3 (ISGF3) complex consisting of STAT1, STAT2 and IRF9, IFN-I can mediate significant biological effects via ISGF3-independent pathways. For example, absence of STAT1, STAT2 or IRF9 exacerbates neurological disease in transgenic mice with CNS-production of IFN-gamma. Here we determined the role of IFN-I-driven, ISGF3-independent signaling in regulating global gene expression in STAT1, STAT2 or IRF9-deficient murine mixed glial cell cultures (MGCs). Compared with WT, the expression of IFN-gamma-stimulated genes (ISGs) was reduced in number and magnitude in MGCs that lacked STAT1, STAT2 or IRF9. There were significantly fewer ISGs in the absence of STAT1 or STAT2 versus the absence of IRF9. The majority of ISGs regulated in the STAT1-, STAT2- or IRF9-deficient MGCs individually were shared with WT. However, only a minor number of ISGs were common to WT, STAT1-, STAT2- and IRF9-deficient MGCs. While signal pathway activation in response to IFN-gamma was rapid and transient in WT MGCs, this was delayed and prolonged and correlated with increased numbers of ISGs expressed at 12 h versus 4 h IFN-gamma exposure in all three IFN-I-signaling-deficient MGCs. In conclusion, (1) IFN-I can mediate ISG expression in MGCs via ISGF3-independent signaling pathways but with reduced efficiency, with delayed and prolonged kinetics and is more dependent on STAT1 and STAT2 than IRF9, and (2) signaling pathways not involving STAT1, STAT2 or IRF9 play a minor role only in mediating ISG expression in MGCs.
Project description:Intracellular pathogens including the apicomplexan and opportunistic parasite Toxoplasma gondii profoundly modify their host cells in order to establish infection. We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites’ replication. Using genome-wide transcriptome analysis we show herein that infection with T. gondii leads to global unresponsiveness of murine macrophages to IFN-γ. More than 61% and 89% of the transcripts, which were induced or repressed by IFN-γ in non-infected MΦ, respectively, were not altered after stimulation of T. gondii-infected cells with IFN-γ. These genes are involved in a variety of biological processes, which are mostly but not exclusively related to immune responses. Analyses of the underlying mechanisms revealed that IFN-γ-triggered nuclear translocation of STAT1 still occurred in Toxoplasma-infected MΦ. However, STAT1 bound aberrantly to oligonucleotides containing the IFN-γ-responsive gamma-activated site (GAS) consensus sequence. Conversely, IFN-γ did not induce formation of active GAS-STAT1 complexes in nuclear extracts from infected MΦ. Mass spectrometry of protein complexes bound to GAS oligonucleotides showed that T. gondii-infected MΦ are unable to recruit non-muscle actin to IFN-γ-responsive DNA sequences, which appeared to be independent of stimulation with IFN-γ and of STAT1 binding. IFN-γ-induced recruitment of BRG-1 and acetylation of core histones at the IFN-γ-regulated CIITA promoter IV, but not β-actin was diminished by >90% in Toxoplasma-infected MΦ as compared to non-infected control cells. Remarkably, treatment with histone deacetylase inhibitors restored the ability of infected macrophages to express the IFN-γ regulated genes H2-A/E and CIITA. Taken together, these results indicate that Toxoplasma-infected MΦ are unable to respond to IFN-γ due to disturbed chromatin remodelling, but can be rescued using histone deacetylase inhibitors. Comparison of 4 different RNA pools with a 2-Color-Loop Design including 10 microarrays: [1] T. gondii infected and IFN-gamma treated, [2] T. gondii infected and untreated, [3] Non-infected and IFN-gamma treated, and [4] Non-infected and untreated.