Project description:Cholangiocarcinoma (CCA) is the second most common type of hepatocellular carcinoma characterized by high aggressiveness and extremely poor patient prognosis. The germ cell‑specific gene 2 protein (GSG2) is a histone H3 threonine‑3 kinase required for normal mitosis. Nevertheless, the role and mechanism of GSG2 in the progression and development of CCA remain elusive. In the present study, the association between GSG2 and CCA was elucidated. Firstly, we demonstrated that GSG2 was overexpressed in CCA specimens and HCCC‑9810 and QBC939 cells by immunohistochemical (IHC) staining. It was further revealed that high expression of GSG2 in CCA had significant clinical significance in predicting disease deterioration. Subsequently, cell proliferation, apoptosis, cell cycle distribution and migration were measured by MTT, flow cytometry, and wound healing assays, respectively in vitro. The results demonstrated that downregulation of GSG2 decreased proliferation, promoted apoptosis, arrested the cell cycle and weakened migration in the G2 phase of CCA cells. Additionally, GSG2 knockdown inhibited CCA cell migration by suppressing epithelial‑mesenchymal transition (EMT)‑related proteins, such as N‑cadherin and vimentin. Mechanistically, GSG2 exerted effects on CCA cells by modulating the PI3K/Akt, CCND1/CDK6 and MAPK9 signaling pathways. In vivo experiments further demonstrated that GSG2 knockdown suppressed tumor growth. In summary, GSG2 was involved in the progression of CCA, suggesting that GSG2 may be a potential therapeutic target for CCA patients.
Project description:Resistance to immunotherapy is one of the biggest problems of current oncotherapeutics. WhileT cell abundance is essential for tumor responsiveness to immunotherapy, factors that define the T cell inflamed tumor microenvironment are not fully understood. We conducted an unbiased approach to identify tumor-intrinsic mechanisms shaping the immune tumor microenvironment(TME), focusing on pancreatic adenocarcinoma because it is refractory to immunotherapy and excludes T cells from the TME. From human tumors, we identified EPHA2 as a candidate tumor intrinsic driver of immunosuppression. Epha2 deletion reversed T cell exclusion and sensitized tumors to immunotherapy. We found that PTGS2, the gene encoding cyclooxygenase-2, lies downstream of EPHA2 signaling through TGFβ and is associated with poor patient survival. Ptgs2 deletion reversed T cell exclusion and sensitized tumors to immunotherapy; pharmacological inhibition of PTGS2 was similarly effective. Thus, EPHA2-PTGS2 signaling in tumor cells regulates tumor immune phenotypes; blockade may represent a novel therapeutic avenue for immunotherapy-refractory cancers. Our findings warrant clinical trials testing the effectiveness of therapies combining EPHA2-TGFβ-PTGS2 pathway inhibitors with anti-tumor immunotherapy, and may change the treatment of notoriously therapy-resistant pancreatic adenocarcinoma.
Project description:The acidic leucine-rich nuclear phosphoprotein 32B (ANP32B) is reported to impact normal development, with Anp32b-knockout mice exhibiting smaller size and premature aging. However, its cellular and molecular mechanisms, especially its potential roles in tumorigenesis, remain largely unclear. Here, we utilize 'knockout' models, RNAi silencing and clinical cohorts to more closely investigate the role of this enigmatic factor in cell proliferation and cancer phenotypes. We report that, compared with Anp32b wild-type (Anp32b(+/+)) littermates, a broad panel of tissues in Anp32b-deficient (Anp32b(-/-)) mice are demonstrated hypoplasia. Anp32b(-/-) mouse embryo fibroblast cell has a slower proliferation, even after oncogenic immortalization. ANP32B knockdown also significantly inhibits in vitro and in vivo growth of cancer cells by inducing G1 arrest. In line with this, ANP32B protein has higher expression in malignant tissues than adjacent normal tissues from a cohort of breast cancer patients, and its expression level positively correlates with their histopathological grades. Moreover, ANP32B deficiency downregulates AKT phosphorylation, which involves its regulating effect on cell growth. Collectively, our findings suggest that ANP32B is an oncogene and a potential therapeutic target for breast cancer treatment.
Project description:Cleavage of the gasdermin proteins to produce pore-forming amino-terminal fragments causes inflammatory cell death (pyroptosis)1. Gasdermin E (GSDME, also known as DFNA5)-mutated in familial ageing-related hearing loss2-can be cleaved by caspase 3, thereby converting noninflammatory apoptosis to pyroptosis in GSDME-expressing cells3-5. GSDME expression is suppressed in many cancers, and reduced GSDME levels are associated with decreased survival as a result of breast cancer2,6, suggesting that GSDME might be a tumour suppressor. Here we show that 20 of 22 tested cancer-associated GSDME mutations reduce GSDME function. In mice, knocking out Gsdme in GSDME-expressing tumours enhances, whereas ectopic expression in Gsdme-repressed tumours inhibits, tumour growth. This tumour suppression is mediated by killer cytotoxic lymphocytes: it is abrogated in perforin-deficient mice or mice depleted of killer lymphocytes. GSDME expression enhances the phagocytosis of tumour cells by tumour-associated macrophages, as well as the number and functions of tumour-infiltrating natural-killer and CD8+ T lymphocytes. Killer-cell granzyme B also activates caspase-independent pyroptosis in target cells by directly cleaving GSDME at the same site as caspase 3. Uncleavable or pore-defective GSDME proteins are not tumour suppressive. Thus, tumour GSDME acts as a tumour suppressor by activating pyroptosis, enhancing anti-tumour immunity.
Project description:A large number of pseudogenes as well as long non-coding RNAs (lncRNAs) have been identified as important regulators in human tumors. However, the clinical role and potential functional effects of the double homeobox A pseudogene 8 (DUXAP8) in glioma remains unknown. In the present study, it was revealed that pseudogene DUXAP8 is significantly upregulated in glioma tissues, compared with adjacent normal tissues. Patients with increased DUXAP8 expression were associated with higher Karnofsky Performance Status, advanced World Health Organization grade, poor disease-free survival and overall survival rates of patients with glioma. Furthermore, in vitro assays, Cell-Counting Kit-8 cell viability and cell colony forming assays demonstrated that reduced DUXAP8 expression significantly suppressed proliferation capacity. Therefore, the results of the present study indicate that pseudogene DUXAP8 is an oncogenic lncRNA and may serve as a potentially prognostic biomarker and novel target of glioma treatment.
Project description:Circular RNAs (circRNA) are a class of covalently closed single-stranded RNAs that have been implicated in cancer progression. Here we identify circNDUFB2 to be downregulated in non-small cell lung cancer (NSCLC) tissues, and to negatively correlate with NSCLC malignant features. Elevated circNDUFB2 inhibits growth and metastasis of NSCLC cells. Mechanistically, circNDUFB2 functions as a scaffold to enhance the interaction between TRIM25 and IGF2BPs, a positive regulator of tumor progression and metastasis. This TRIM25/circNDUFB2/IGF2BPs ternary complex facilitates ubiquitination and degradation of IGF2BPs, with this effect enhanced by N6-methyladenosine (m6A) modification of circNDUFB2. Moreover, circNDUFB2 is also recognized by RIG-I to activate RIG-I-MAVS signaling cascades and recruit immune cells into the tumor microenvironment (TME). Our data thus provide evidences that circNDUFB2 participates in the degradation of IGF2BPs and activation of anti-tumor immunity during NSCLC progression via the modulation of both protein ubiquitination and degradation, as well as cellular immune responses.
Project description:NAA25 gene variants were reported as risk factors for type 1 diabetes, rheumatoid arthritis and acute arterial stroke. But it's unknown whether it could contribute to breast cancer. We identified rs11066150 in lncHSAT164, which contributes to breast cancer, in our earlier genome-wide long non-coding RNA association study on Han Chinese women. However, rs11066150 A/G variant is also located in NAA25 intron. Based on the public database, such as TCGA and Curtis dataset, NAA25 gene is highly expressed in breast cancer tissues and this result has also been proved in our samples and cell lines through RT-qPCR and western blot analysis. To better understand the function of NAA25 in breast cancer, we knocked down the expression of NAA25 in breast cancer cell lines, FACS was used to detect cell apoptosis and cell cycle and colony formation assay was used to detect cell proliferation. We found that NAA25-deficient cells could increase cell apoptosis, delay G2/M phase cell and decrease cell clone formation. RNA sequencing was then applied to analyze the molecular profiles of NAA25-deficient cells, and compared to the control group, NAA25 knockdown could activate apoptosis-related pathways, reduce the activation of tumor-associated signaling pathways and decrease immune response-associated pathways. Additionally, RT-qPCR was employed to validate these results. Taken together, our results revealed that NAA25 was highly expressed in breast cancer, and NAA25 knockdown might serve as a therapeutic target in breast cancer.
Project description:BackgroundDysregulation of circular RNAs (circRNAs) is associated with bladder cancer progression. Nevertheless, the mechanisms of circRNA centrosomal protein 128 (circCEP128) underlying bladder cancer progression remain poorly understood.MethodsThe levels of circCEP128, microRNA-515-5p (miR-515-5p) and syndecan-1 (SDC1) were determined via reverse transcription-quantitative polymerase chain reaction or Western blot. The effects of circCEP128, miR-515-5p and SDC1 on bladder cancer progression were investigated via MTT and colony formation assays, flow cytometry and transwell analysis and subcutaneous xenograft experiments. The interactions between miR-515-5p and circCEP128 or SDC1 were examined through bioinformatics prediction and luciferase reporter assay.ResultscircCEP128 and SDC1 were highly expressed and miR-515-5p was low expressed in bladder cancer tissues and cells. circCEP128 knockdown hindered cell proliferation, migration and invasion and promoted cell apoptosis in bladder cancer. circCEP128 loss increased miR-515-5p expression through direct interaction in bladder cancer cells. MiR-515-5p depletion mitigated the influences of circCEP128 knockdown on bladder cancer cell phenotypes. SDC1 was a direct target of miR-515-5p. circCEP128 positively regulated SDC1 expression via miR-515-5p. MiR-515-5p restrained the malignant progression of bladder cancer cells by decreasing SDC1 expression. circCEP128 knockdown hindered the growth of bladder cancer xenograft tumors by up-regulating miR-515-5p and down-regulating SDC1.ConclusioncircCEP128 knockdown hampered the tumorigenesis and progression of bladder cancer by regulating miR-515-5p/SDC1 axis in vitro and in vivo, deepening our understanding on the molecular mechanisms of circCEP128 in bladder cancer.
Project description:PRMT1 is known as a regulator of immune function by directly interacting with interferon receptors, methylating STAT1, and promoting B cell and macrophage differentiation by methylating CDK4 or B cell antigen receptor However, the function of PRMT1 as a therapeutic target of cancer remains largely elusive, particularly for its role in cancer immunosurveillance. Here, we performed bulk RNA-seq for CT26, a mouse tumor cell line, after either knocking down of endogeneous Prmt1 or blocking PRMT1 by two specific inhibitors, namely MS023 and GSK3368715.