FLI1 regulates radiotherapy resistance in nasopharyngeal carcinoma through TIE1-mediated PI3K/AKT signaling pathway.

BACKGROUND: Radiotherapy resistance is the main cause of treatment failure in nasopharyngeal carcinoma (NPC), which leads to poor prognosis. It is urgent to elucidate the molecular mechanisms underlying radiotherapy resistance. METHODS: RNA-seq analysis was applied to five paired progressive disease (PD) and complete response (CR) NPC tissues. Loss-and gain-of-function assays were used for oncogenic function of FLI1 both in vitro and in vivo. RNA-seq analysis, ChIP assays and dual luciferase reporter assays were performed to explore the interaction between FLI1 and TIE1. Gene expression with clinical information from tissue microarray of NPC were analyzed for associations between FLI1/TIE1 expression and NPC prognosis. RESULTS: FLI1 is a potential radiosensitivity regulator which was dramatically overexpressed in the patients with PD to radiotherapy compared to those with CR. FLI1 induced radiotherapy resistance and enhanced the ability of DNA damage repair in vitro, and promoted radiotherapy resistance in vivo. Mechanistic investigations showed that FLI1 upregulated the transcription of TIE1 by binding to its promoter, thus activated the PI3K/AKT signaling pathway. A decrease in TIE1 expression restored radiosensitivity of NPC cells. Furthermore, NPC patients with high levels of FLI1 and TIE1 were correlated with poor prognosis. CONCLUSION: Our study has revealed that FLI1 regulates radiotherapy resistance of NPC through TIE1-mediated PI3K/AKT signaling pathway, suggesting that targeting the FLI1/TIE1 signaling pathway could be a potential therapeutic strategy to enhance the efficacy of radiotherapy in NPC.

TERC promotes non-small cell lung cancer progression by facilitating the nuclear localization of TERT.

The core of telomerase consists of the protein subunit telomerase reverse transcriptase (TERT) and the telomerase RNA component (TERC). So far, the role of TERC in cancer development has remained elusive. Here, we found TERC expression elevated in non-small cell lung cancer (NSCLC) tissues, which was associated with disease progression and poor prognosis in patients. Using NSCLC cell lines and xenograft models, we showed that knockdown of TERC caused cell cycle arrest, and inhibition of cell proliferation and migration. Mechanistically, TERC was exported to the cytoplasm by nuclear RNA export factor 1 (NXF1), where it mediated the interaction of TERT with other telomerase subunits. Depletion of TERC hindered the assembly and subsequent nuclear localization of the telomerase complex, preventing TERT from functioning in telomere maintenance and transcription regulation. Our findings suggest that TERC is a potential biomarker for NSCLC diagnosis and prognosis and can be a target for NSCLC treatment.

FLI1 promotes IFN-γ-induced kynurenine production to impair anti-tumor immunity.

Nasopharyngeal carcinoma (NPC)-mediated immunosuppression within the tumor microenvironment (TME) frequently culminates in the failure of otherwise promising immunotherapies. In this study, we identify tumor-intrinsic FLI1 as a critical mediator in impairing T cell anti-tumor immunity. A mechanistic inquiry reveals that FLI1 orchestrates the expression of CBP and STAT1, facilitating chromatin accessibility and transcriptional activation of IDO1 in response to T cell-released IFN-γ. This regulatory cascade ultimately leads to augmented IDO1 expression, resulting in heightened synthesis of kynurenine (Kyn) in tumor cells. This, in turn, fosters CD8+ T cell exhaustion and regulatory T cell (Treg) differentiation. Intriguingly, we find that pharmacological inhibition of FLI1 effectively obstructs the CBP/STAT1-IDO1-Kyn axis, thereby invigorating both spontaneous and checkpoint therapy-induced immune responses, culminating in enhanced tumor eradication. In conclusion, our findings delineate FLI1-mediated Kyn metabolism as an immune evasion mechanism in NPC, furnishing valuable insights into potential therapeutic interventions.

The prognostic value and immune correlation of IL18 expression and promoter methylation in renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is not sensitive to immunotherapy and has poor prognosis. DNA methylation regulates gene expression, and its abnormal changes are related to many human diseases. Recently, DNA methylation has been found to participate in immune infiltration in various cancers. However, its pattern in RCC remains poorly understood. RESULTS: We found that IL18 was significantly over-expressed in RCC tumor tissues compared to normal adjacent tissues The IL18 promoter region was hypomethylated, which was strongly correlated with elevated IL18 mRNA expression, and predicted advanced clinicopathological characteristics and shorter overall survival. Furthermore, we found that IL18 promoter methylation was significantly related to the down-regulation of immune checkpoint molecules and increase of CD8 + T cell infiltration in RCC tumor tissues. CONCLUSIONS: We have identified the important role of IL18 promoter methylation and expression, which are associated with clinicopathological characteristics, overall survival, immune cell infiltration and expression of immune checkpoint molecules in RCC. We present the rationale for IL18 promoter methylation as a molecular biomarker for predicting the response of RCC to immune checkpoint inhibitors.

Prognostic value and immune landscapes of TERT promoter methylation in triple negative breast cancer.

Background: Treatment options for patients with triple-negative breast cancer (TNBC) remain limited to mainstay therapies owing to a lack of efficacious therapeutic targets. Accordingly, there is an urgent need to discover and identify novel molecular targets for the treatment and diagnosis of this disease. In this study, we analyzed the correlation of telomerase reverse transcriptase (TERT) methylation status with TERT expression, prognosis, and immune infiltration in TNBC and identified the role of TERT methylation in the regulation TNBC prognosis and immunotherapy. Methods: Data relating to the transcriptome, clinicopathological characteristics and methylation of TNBC patients were obtained from The Cancer Genome Atlas (TCGA) database. TERT expression levels and differential methylation sites (DMSs) were detected. The correlations between TERT expression and DMSs were calculated. Kaplan-Meier curves was plotted to analyze the relationship between the survival of TNBC patients and the DMSs. The correlations of DMSs and TERT expression with several immunological characteristics of immune microenvironment (immune cell infiltration, immunomodulators, immune-related biological pathways, and immune checkpoints) were assessed. The results were validated using 40 TNBC patients from Sun Yat-sen University Cancer Center (SYSUCC). Results: Six DMSs were identified. Among them, four sites (cg11625005, cg07380026, cg17166338, and cg26006951) were within the TERT promoter, in which two sites (cg07380026 and cg26006951) were significantly related to the prognosis of patients with TNBC. Further validation using 40 TNBC samples from SYSUCC showed that the high methylation of the cg26006951 CpG site was associated with poor survival prognosis (P=0.0022). TERT expression was significantly correlated with pathological N stage and clinical stage, and cg07380026 were significantly associated with pathological T and N stages in the TCGA cohort. Moreover, the methylation site cg26006951, cg07380026 and TERT expression were significantly correlated with immune cell infiltration, common immunomodulators, and the level of the immune checkpoint receptor lymphocyte activation gene 3 (LAG-3) in TNBC patients. Conclusion: TERT promotertypermethylation plays an important role in TERT expression regulation and tumor microenvironment in TNBC. It is associated with overall survival and LAG-3 expression. TERT promoter hypermethylation may be a potential molecular biomarker for predicting response to the TERT inhibitors and immune checkpoint inhibitors in TNBC.

A prognostic model based on DNA methylation-related gene expression for predicting overall survival in hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) continues to increase in morbidity and mortality among all types of cancer. DNA methylation, an important epigenetic modification, is associated with cancer occurrence and progression. The objective of this study was to establish a model based on DNA methylation risk scores for identifying new potential therapeutic targets in HCC and preventing cancer progression. Methods: Transcriptomic, clinical, and DNA methylation data on 374 tumor tissues and 50 adjacent normal tissues were downloaded from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma database. The gene expression profiles of the GSE54236 liver cancer dataset, which contains data on 161 liver tissue samples, were obtained from the Gene Expression Omnibus database. We analyzed the relationship between DNA methylation and gene expression levels after identifying the differentially methylated and expressed genes. Then, we developed and validated a risk score model based on the DNA methylation-driven genes. A tissue array consisting of 30 human hepatocellular carcinoma samples and adjacent normal tissues was used to assess the protein and mRNA expression levels of the marker genes by immunohistochemistry and qRT-PCR, respectively. Results: Three methylation-related differential genes were identified in our study: GLS, MEX3B, and GNA14. The results revealed that their DNA methylation levels were negatively correlated with local gene expression regulation. The gene methylation levels correlated strongly with the prognosis of patients with liver cancer. This was confirmed by qRT-PCR and immunohistochemical verification of the expression of these genes or proteins in tumors and adjacent tissues. These results revealed the relationship between the level of relevant gene methylation and the prognosis of patients with liver cancer as well as the underlying cellular and biological mechanisms. This allows our gene signature to provide more accurate and appropriate predictions for clinical applications. Conclusion: Through bioinformatics analysis and experimental validation, we obtained three DNA methylation marker: GLS, MEX3B, and GNA14. This helps to predict the prognosis and may be a potential therapeutic target for HCC patients.

CPT1A promotes anoikis resistance in esophageal squamous cell carcinoma via redox homeostasis.

Anoikis resistance was a prominent hallmark of cancer metastasis, and lipo-genic characteristics have been identified as another metabolic alteration during tumorigenesis. However, their crosstalk has not been fully elucidated, especially in advanced esophageal squamous cell carcinoma (ESCC). In this study, we showed, for the first time, that the key enzyme carnitine O-palmitoyl transferase 1 (CPT1A), which is involved in fatty acid oxidation (FAO), was markedly upregulated in ESCC cells upon detached culture via a metabolism PCR array. Overexpression of CPT1A was associated with poor survival of ESCC patients and could protect ESCC cells from apoptosis via maintaining redox homeostasis through supply of GSH and NADPH. Mechanistically, detached culture conditions enhanced the expression of the transcription factor ETV4 and suppressed the expression of the ubiquitin enzyme RNF2, which were responsible for the elevated expression of CPT1A at the mRNA and protein levels, respectively. Moreover, genetic or pharmacologic disruption of CPT1A switched off the NADPH supply and therefore prevented the anchorage-independent growth of ESCC cells in vitro and lung metastases of xenografted tumor models in vivo. Collectively, our results provide novel insights into how ESCC cancer cells exploit metabolic switching to form distant metastases and some evidence for the link between anoikis and FAO.

Prognostic value of JAK3 promoter methylation and mRNA expression in clear cell renal cell carcinoma.

INTRODUCTION: Janus kinase 3 (JAK3) is a well-established oncogene in clear cell renal cell carcinoma (ccRCC). The methylation status of oncogene promoters has emerged as biomarkers for cancer diagnosis and prognosis. OBJECTIVE: This study aims to investigate the biological and clinical significance of JAK3 promoter methylation in ccRCC. METHODS: We analyzed the relationship of JAK3 promoter methylation with its mRNA expression, overall survival, and immune cell infiltration in a cohort obtained from The Cancer Genome Atlas (TCGA), which was further validated by another independent cohort. We further validated correlations of JAK3 promoter methylation with JAK3 expression, overall survival, and immune cell infiltration in an independent ccRCC cohort (Sun Yat-sen University Cancer Center (SYSUCC) cohort) by methods of immunohistochemistry (IHC) and pyrosequencing. RESULTS: We found JAK3 promoter was significantly hypomethylated in tumor tissues compared to normal adjacent tissues in ccRCC, and JAK3 promoter hypomethylation was strongly correlated with high JAK3 mRNA expression in all three ccRCC cohorts we examined. JAK3 promoter hypomethylation predicted advanced clinicopathological characteristics and shorter overall survival (TCGA cohort and SYSUCC cohort). Furthermore, we found that JAK3 promoter methylation was significantly associated with immune cell infiltration and expression of immune checkpoint molecules (TCGA cohort and CPTAC cohort). Finally, our SYSUCC cohort validated that JAK3 promoter methylation was correlated with CD4+ and CD8+ T cell infiltration in ccRCC tumor tissues. CONCLUSION: Our data demonstrated that the crucial role of JAK3 promoter methylation in its expression regulation and tumor microenvironment. JAK3 promoter methylation and expression are associated with clinicopathological characteristics, overall survival, and immune cell infiltration in ccRCC. We propose a rationale for further validation of JAK3 promoter methylation as a molecular biomarker for predicting responses to immune checkpoint inhibitors in ccRCC.

TNF Patterns and Tumor Microenvironment Characterization in Head and Neck Squamous Cell Carcinoma.

Background: HNSCC is a heterogeneous disease, which arises from distinct anatomic subsites, associates with various risk factors and possesses diverse molecular pathological features. Generally, HNSCC is considered as an immunosuppressive disease, characterized by abnormal tumor immune microenvironment. The TNF family plays a crucial role in the survival, proliferation, differentiation, and effector functions in both immune and non-immune cells. However, the expression patterns of TNF in HNSCC remains to be systematically analyzed. Methods: We downloaded transcriptional profile data of HNSCC from TCGA and GEO datasets. Unsupervised clustering methods were used to identify different TNF patterns and classify patients for further analysis. PCA was conducted to construct a TNF relevant score, which we called risk score. Results: In this study, we systematically evaluated the patterns of TNF family and tumor immune microenvironment characteristics of HNSCC patients by clustering the expression of 46 members of TNF family. We identified two subtypes with distinct clinical and immune characteristics in HNSCC and constructed a risk scoring system based on the expression profile of TNF family genes. Conclusion: Risk score serves as a reliable predictor of overall survival, clinical characteristics, and immune cell infiltration, which has the potential to be applied as a valuable biomarker for HNSCC immunotherapy.