Comprehensive Analysis of FASN in Tumor Immune Infiltration and Prognostic Value for Immunotherapy and Promoter DNA Methylation.

Fatty acid synthase (FASN) promotes tumor progression in multiple cancers. In this study, we comprehensively examined the expression, prognostic significance, and promoter methylation of FASN, and its correlation with immune cell infiltration in pan-cancer. Our results demonstrated that elevated FASN expression was significantly associated with an unfavorable prognosis in many cancer types. Furthermore, FASN promoter DNA methylation can be used as a tumor prognosis marker. Importantly, high levels of FASN were significantly negatively correlated with tumor immune infiltration in 35 different cancers. Additionally, FASN was significantly associated with tumor mutational burden (TMB) and microsatellite instability (MSI) in multiple malignancies, suggesting that it may be essential for tumor immunity. We also investigated the effects of FASN expression on immunotherapy efficacy and prognosis. In up to 15 tumors, it was significantly negatively correlated with immunotherapy-related genes, such as PD-1, PD-L1, and CTLA-4. Moreover, we found that tumors with high FASN expression may be more sensitive to immunotherapy and have a good prognosis with PD-L1 treatment. Finally, we confirmed the tumor-suppressive effect of mir-195-5p through FASN. Altogether, our results suggested that FASN may serve as a novel prognostic indicator and immunotherapeutic target in various malignancies.

Ezh2 loss in hematopoietic stem cells predisposes mice to develop heterogeneous malignancies in an Ezh1-dependent manner.

Recent genome sequencing revealed inactivating mutations in EZH2, which encodes an enzymatic component of polycomb-repressive complex 2 (PRC2), in patients with myelodysplastic syndrome (MDS), myeloproliferative neoplasms (MPNs), and MDS/MPN overlap disorders. We herein demonstrated that the hematopoietic-specific deletion of Ezh2 in mice induced heterogeneous hematopoietic malignancies. Myelodysplasia was detected in mice following the deletion of Ezh2, and resulted in the development of MDS and MDS/MPN. Thrombocytosis was induced by Ezh2 loss and sustained in some mice with myelodysplasia. Although less frequent, Ezh2 loss also induced T-cell acute lymphoblastic leukemia and the clonal expansion of B-1a B cells. Gene expression profiling showed that PRC2 target genes were derepressed upon the deletion of Ezh2 in hematopoietic stem and progenitor cells, but were largely repressed during the development of MDS and MDS/MPN. Chromatin immunoprecipitation-sequence analysis of trimethylation of histone H3 at lysine 27 (H3K27me3) revealed a compensatory function of Ezh1, another enzymatic component of PRC2, in this process. The deletion of Ezh1 alone did not cause dysplasia or any hematologic malignancies in mice, but abolished the repopulating capacity of hematopoietic stem cells when combined with Ezh2 loss. These results clearly demonstrated an essential role of Ezh1 in the pathogenesis of hematopoietic malignancies induced by Ezh2 insufficiency, and highlighted the differential functions of Ezh1 and Ezh2 in hematopoiesis.

Depletion of Sf3b1 impairs proliferative capacity of hematopoietic stem cells but is not sufficient to induce myelodysplasia.

Numerous studies have recently reported mutations involving multiple components of the messenger RNA (mRNA) splicing machinery in patients with myelodysplastic syndrome (MDS). SF3B1 is mutated in 70% to 85% of refractory anemia with ringed sideroblasts (RARS) patients and is highly associated with the presence of RARS, although the pathological role of SF3B1 mutations in MDS-RARS has not been elucidated yet. Here, we analyzed the function of pre-mRNA splicing factor Sf3b1 in hematopoiesis. Sf3b1(+/-) mice maintained almost normal hematopoiesis and did not develop hematological malignancies during a long observation period. However, Sf3b1(+/-) cells had a significantly impaired capacity to reconstitute hematopoiesis in a competitive setting and exhibited some enhancement of apoptosis, but they did not show any obvious defects in differentiation. Additional depletion of Sf3b1 with shRNA in Sf3b1(+/-) hematopoietic stem cells (HSCs) severely compromised their proliferative capacity both in vitro and in vivo. Finally, we unexpectedly found no changes in the frequencies of sideroblasts in either Sf3b1(+/-) erythroblasts or cultured Sf3b1(+/-) erythroblasts expressing shRNA against Sf3b1. Our findings indicate that the level of Sf3b1 expression is critical for the proliferative capacity of HSCs, but the haploinsufficiency for Sf3b1 is not sufficient to induce a RARS-like phenotype.

[Influence of PAX2 gene silencing on renal interstitial fibrosis in rats].

OBJECTIVE: To investigate the influence of silencing PAX2 gene in vivo on epithelial-mesenchymal transition (EMT) of renal tubular cells in rats with renal interstitial fibrosis. METHODS: A total of 64 Wistar rats were anaesthetized, and unilateral ureteral obstruction (UUO) was performed to establish a rat model of renal interstitial fibrosis. The 64 rats were randomly divided into negative control and PAX2 gene silencing groups (n=32 each). The rats in the control group were transfected with 200 µL NC-siRNA-in vivo jetPEI(TM) solution. Those in the PAX2 gene silencing group were transfected with 200 µL PAX2-siRNA-in vivo jetPEI(TM) solution. Each group was further divided into 4 subgroups based on the post-transfection time (3, 5, 7 and 14 days after transfection), with 8 rats in each subgroup. Renal tissue samples were harvested in each group. Real-time PCR and Western blot were used to measure the mRNA and protein expression of PAX2 in the renal cortex, as well as the mRNA and protein expression of E-cadherin and α-SMA. RESULTS: Compared with the control group, the PAX2 gene silencing group showed significantly lower mRNA and protein expression of PAX2 (P<0.05). In the two groups, the mRNA and protein expression levels of E-cadherin were gradually reduced over the time of obstruction, while those of α-SMA gradually increased. At 14 days after transfection, the PAX2 gene silencing group had significantly higher mRNA and protein expression of E-cadherin but lower mRNA and protein expression of α-SMA compared with the control group (P<0.05). CONCLUSIONS: PAX2 gene silencing can significantly inhibit the process of EMT of renal tubular cells in rats with advanced fibrosis, suggesting that PAX2 gene silencing may have a therapeutic effect on renal interstitial fibrosis.

Disruption of the thymic microenvironment is associated with thymic involution of transitional cell cancer.

INTRODUCTION: During bladder tumorigenesis, thymopoiesis is usually downregulated. Considering that the thymus is the site of most T-cell development, this phenomenon may be related to thymic involution. However, the mechanisms involved in this phenomenon remain to be elucidated. MATERIALS AND METHODS: An MB 49 murine bladder tumor model was used to identify mechanisms that might underlie this process. RESULTS: The thymuses of tumor-bearing mice showed less cellularity than those of healthy mice. Involution was found to be associated with less proliferation and more apoptosis of thymic epithelial cells (TEC). Foxn1, KGF, and IL-7, three factors known to be involved in thymic development, were also downregulated in the thymuses of tumor bearers. When these mice were intravenously injected with KGF, the thymic microenvironment, thymopoiesis, and T-cell differentiation all returned to near normal status. CONCLUSIONS: The decreases in thymopoiesis and impaired T-cell differentiation may be attributable to changes in the thymic microenvironment. Improving the function of TEC, rather than T-cell progenitors, should be the focus of therapy.

The Role of Oxidative Stress in Tumorigenesis and Progression.

Oxidative stress refers to the imbalance between the production of reactive oxygen species (ROS) and the endogenous antioxidant defense system. Its involvement in cell senescence, apoptosis, and series diseases has been demonstrated. Advances in carcinogenic research have revealed oxidative stress as a pivotal pathophysiological pathway in tumorigenesis and to be involved in lung cancer, glioma, hepatocellular carcinoma, leukemia, and so on. This review combs the effects of oxidative stress on tumorigenesis on each phase and cell fate determination, and three features are discussed. Oxidative stress takes part in the processes ranging from tumorigenesis to tumor death via series pathways and processes like mitochondrial stress, endoplasmic reticulum stress, and ferroptosis. It can affect cell fate by engaging in the complex relationships between senescence, death, and cancer. The influence of oxidative stress on tumorigenesis and progression is a multi-stage interlaced process that includes two aspects of promotion and inhibition, with mitochondria as the core of regulation. A deeper and more comprehensive understanding of the effects of oxidative stress on tumorigenesis is conducive to exploring more tumor therapies.

S100A6 Activates Kupffer Cells via the p-P38 and p-JNK Pathways to Induce Inflammation, Mononuclear/macrophage Infiltration Sterile Liver Injury in Mice.

Noninfectious liver injury, including the effects of chemical material, drugs and diet, is a major cause of liver diseases worldwide. In chemical and drugs-induced liver injury, innate inflammatory responses are mediated by extracellular danger signals. The S100 protein can act as danger signals, which can promote the migration and chemotaxis of immune cells, promote the release of various inflammatory cytokines, and regulate the body's inflammatory and immune responses. However, the role of S100A6 in inflammatory response in chemical and drugs-induced sterile liver injury remains unclear. We constructed the model of sterile liver injury induced by carbon tetrachloride (CCl4)/Paracetamol (APAP) and performed RNA sequencing (RNA-seq) on the liver tissues after injury (days 2 and 5). We analyzed inflammatory protein secretion in the liver tissue supernatant by enzyme-linked immunosorbent assay (ELISA), determined the inflammation response by bioinformatic analysis during sterile liver injury, and assessed mononuclear/macrophage infiltration by immunohistochemistry and flow cytometry. Immunohistochemistry was used to analyze the location of S100A6. We conducted inflammatory factor expression analysis and molecular mechanistic studies in Kupffer cells (KCs) induced by S100A6 using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), ELISA, and western blot in vitro experiments. We performed chemokine CCL2 expression analysis and molecular mechanism studies using the same method. We used a Transwell assay to show the infiltration of mononuclear/macrophage. We here observed that aggravated inflammatory response was shown in CCl4 and APAP-administrated mice, as evidenced by enhanced production of inflammatory cytokines (TNF-α, IL-1ß), and elevated mononuclear/macrophage infiltration and activation of immunity. The expression of S100A6 was significantly increased on day 2 after sterile liver injury, which is primarily produced by injured liver cells. Mechanistic studies established that S100A6 activates Kupffer cells (KCs) via the p-P38, p-JNK and P65 pathways to induce inflammation in vitro. Furthermore, TNF-α can stimulate liver cells via the p-P38 and p-JNK pathways to produce CCL2 and promote the infiltration of mononuclear/macrophage. In summary, we showed that S100A6 plays an important role in regulating inflammation, thus influencing sterile liver injury. Our findings provide novel evidence that S100A6 can as a danger signal that contributes to pro-inflammatory activation through p-P38 and p-JNK pathways in CCl4 and APAP-induced sterile liver injury in mice. In addition, the inflammatory factor TNF-α induces a large amount of CCL2 production in normal liver cells surrounding the injured area through a paracrine action, which is chemotactic for blood mononuclear/macrophage infiltration.

Identification of specific prognostic markers for lung squamous cell carcinoma based on tumor progression, immune infiltration, and stem index.

Introduction: Lung squamous cell carcinoma (LUSC) is a unique subform of nonsmall cell lung cancer (NSCLC). The lack of specific driver genes as therapeutic targets leads to worse prognoses in patients with LUSC, even with chemotherapy, radiotherapy, or immune checkpoint inhibitors. Furthermore, research on the LUSC-specific prognosis genes is lacking. This study aimed to develop a comprehensive LUSC-specific differentially expressed genes (DEGs) signature for prognosis correlated with tumor progression, immune infiltration,and stem index. Methods: RNA sequencing data for LUSC and lung adenocarcinoma (LUAD) were extracted from The Cancer Genome Atlas (TCGA) data portal, and DEGs analyses were conducted in TCGA-LUSC and TCGA-LUAD cohorts to identify specific DEGs associated with LUSC. Functional analysis and protein-protein interaction network were performed to annotate the roles of LUSC-specific DEGs and select the top 100 LUSC-specific DEGs. Univariate Cox regression and least absolute shrinkage and selection operator regression analyses were performed to select prognosis-related DEGs. Results: Overall, 1,604 LUSC-specific DEGs were obtained, and a validated seven-gene signature was constructed comprising FGG, C3, FGA, JUN, CST3, CPSF4, and HIST1H2BH. FGG, C3, FGA, JUN, and CST3 were correlated with poor LUSC prognosis, whereas CPSF4 and HIST1H2BH were potential positive prognosis markers in patients with LUSC. Receiver operating characteristic analysis further confirmed that the genetic profile could accurately estimate the overall survival of LUSC patients. Analysis of immune infiltration demonstrated that the high risk (HR) LUSC patients exhibited accelerated tumor infiltration, relative to low risk (LR) LUSC patients. Molecular expressions of immune checkpoint genes differed significantly between the HR and LR cohorts. A ceRNA network containing 19 lncRNAs, 50 miRNAs, and 7 prognostic DEGs was constructed to demonstrate the prognostic value of novel biomarkers of LUSC-specific DEGs based on tumor progression, stemindex, and immune infiltration. In vitro experimental models confirmed that LUSC-specific DEG FGG expression was significantly higher in tumor cells and correlated with immune tumor progression, immune infiltration, and stem index. In vitro experimental models confirmed that LUSC-specific DEG FGG expression was significantly higher in tumor cells and correlated with immune tumor progression, immune infiltration, and stem index. Conclusion: Our study demonstrated the potential clinical implication of the 7- DEGs signature for prognosis prediction of LUSC patients based on tumor progression, immune infiltration, and stem index. And the FGG could be an independent prognostic biomarker of LUSC promoting cell proliferation, migration, invasion, THP-1 cell infiltration, and stem cell maintenance.

UTX inactivation in germinal center B cells promotes the development of multiple myeloma with extramedullary disease.

UTX/KDM6A, a histone H3K27 demethylase and a key component of the COMPASS complex, is frequently lost or mutated in cancer; however, its tumor suppressor function remains largely uncharacterized in multiple myeloma (MM). Here, we show that the conditional deletion of the X-linked Utx in germinal center (GC) derived cells collaborates with the activating BrafV600E mutation and promotes induction of lethal GC/post-GC B cell malignancies with MM-like plasma cell neoplasms being the most frequent. Mice that developed MM-like neoplasms showed expansion of clonal plasma cells in the bone marrow and extramedullary organs, serum M proteins, and anemia. Add-back of either wild-type UTX or a series of mutants revealed that cIDR domain, that forms phase-separated liquid condensates, is largely responsible for the catalytic activity-independent tumor suppressor function of UTX in MM cells. Utx loss in concert with BrafV600E only slightly induced MM-like profiles of transcriptome, chromatin accessibility, and H3K27 acetylation, however, it allowed plasma cells to gradually undergo full transformation through activation of transcriptional networks specific to MM that induce high levels of Myc expression. Our results reveal a tumor suppressor function of UTX in MM and implicate its insufficiency in the transcriptional reprogramming of plasma cells in the pathogenesis of MM.

Inhibition of PAX2 gene expression by siRNA (polyethylenimine) in experimental model of obstructive nephropathy.

OBJECTIVE: It was found that PAX2 (Paired Box 2) re-expression in renal tubular epithelial cells correlated with renal interstitial fibrosis of rats with obstructive nephropathy. The purpose of the present study was to identify whether RNA interference (RNAi) induced by polyethylenimine (jetPEI) could inhibit PAX2 gene re-expression and impact renal interstitial fibrosis of rats with obstructive nephropathy. METHODS: Four pairs of small interfering RNA (siRNA) interference sequences and a negative control were designed and synthesized according to the whole PAX2 gene mRNA sequence. siRNA was then transfected into renal capsule in a rodent model of unilateral ureteral obstruction (UUO), using in vivo jetPEI as delivery vector. The expression of PAX2 mRNA and protein in renal tissue was determined by real-time quantitative polymerase chain reaction (PCR) and Western blot, respectively. A carboxyfluorescein (FAM)-labeled negative control was also synthesized at the same time to identify transfection in vivo. Renal interstitial fibrosis was observed under light microscope after PAX2 gene silenced. RESULTS: Green fluorescence was observed around renal tubule epithelial cells by fluorescence microscopy 3 days after the procedure validating the success of transfection. While the PAX2 gene expression was inhibited by all siRNA interference sequences, the strongest inhibition was observed with siRNA3. The PAX2 mRNA and protein were inhibited by 55% and 81%, respectively. Renal tubular damage and renal interstitial fibrosis were remitted obviously after PAX2 gene silenced. CONCLUSION: siRNA was able to inhibit the expression of PAX2 in tubular epithelial cells in the UUO model. The siRNA may thus provide therapeutic potential for retarding the pathological progression of UUO.

The role of epigenetic modifications in Colorectal Cancer Metastasis.

Distant metastasis is the major contributor to the high mortality rate of colorectal cancer (CRC). To overcome the poor prognosis caused by distant metastasis, the mechanisms of CRC metastasis should be further explored. Epigenetic events are the main mediators of gene regulation and further affect tumor progression. Recent studies have found that some epigenetic enzymes are often dysregulated or mutated in multiple tumor types, which prompted us to study the roles of these enzymes in CRC metastasis. In this review, we summarized the alteration of enzymes related to various modifications, including histone modification, nonhistone modification, DNA methylation, and RNA methylation, and their epigenetic mechanisms during the progression of CRC metastasis. Existing data suggest that targeting epigenetic enzymes is a promising strategy for the treatment of CRC metastasis.

The Traditional Mongolian Medicine Qiqirigan-8 Effects on Lipid Metabolism and Inflammation in Obesity: Pharmacodynamic Evaluation and Relevant Metabolites.

Objective: Traditional Mongolian Medicine Qiqirigan-8 (MMQ-8) is a Chinese botanical drug with effective pharmacological properties in obesity. However, the pharmacological mechanism of MMQ-8 remains unclear. This study aimed to determine the active metabolites of MMQ-8 and its therapeutic effects on lipid metabolism and inflammation. Methods: The active metabolites of MMQ-8 were identified by ultrahigh-performance liquid chromatograph Q extractive mass spectrometry (UHPLC-QE-MS) assay and network analysis. An obesity rat model induced by high-fat diet was used in the study. Serum levels of lipids and inflammatory factors were detected using biochemical analysis and enzyme-linked immunosorbent assay (ELISA). Pathological analysis of liver tissues and arteries was conducted with hematoxylin and eosin (H&E) staining and immunohistochemistry. Protein expression of the tumor necrosis factor (TNF) signaling pathway was investigated by Western-blot. Simultaneously, bone marrow cells were used for RNA sequencing and relevant results were validated by cell culture and quantitative real-time polymerase chain reaction (RT-qPCR). Results: We identified 69 active metabolites and 551 target genes of MMQ-8. Of these, there are 65 active metabolites and 225 target genes closely related to obesity and inflammation. In vivo, we observed that MMQ-8 had general decreasing effects on body weight, white adipose tissue weight, and serum lipids. MMQ-8 treatment notably decreased the liver function markers and hepatic steatosis, and significantly decreased inflammation. In serum, it notably decreased TNF-α, interleukin (IL)-6, and inducible nitric oxide synthase (INOS), while elevating IL-10 levels. MMQ-8 treatment also significantly inhibited proteins phosphorylation of nuclear factor-kappa B inhibitor alpha (IκBα), mitogen-activated protein kinase (p38), extracellular regulated kinase 1/2(ERK1/2), and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and decreased vascular endothelium damage and macrophage infiltration and polarization to M1. These findings coincide with the RNA-sequencing data of bone marrow cells and results of in vitro experiments. Conclusion: We determined the pharmacological actions and relevant metabolites of MMQ-8 in obesity for the first time. Our study revealed MMQ-8 can optimize lipid metabolism and reduce chronic inflammation in obesity. However, more in-depth research is needed, for example, to understand the principle of compound compatibility and the inhibition effects on hepatic steatosis, T cell differentiation, and inflammatory signal transduction.

Traditional Mongolian medicine (HHQG) attenuates CCl4-induced acute liver injury through inhibiting monocyte/macrophage infiltration via the p-P38/p-JNK pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Honghua Qinggan 13 Flavor Pills (HHQG), whose Mongolian name is Guri Gumu-13, is a traditional Mongolian medicine, that was stated in the "Diagnosis and Treatment of Ming Medical Code". The HHQG has been included in the Mongolian Medicine Division of the Ministry of Health Drug Standards (1998 edition). Based on our clinical expertise, HHQG demonstrated satisfactory therapeutic effects in hepatitis and liver failure. However, the pharmacological effects and potential mechanisms of HHQG have not been investigated. AIM OF THE STUDY: In this study, we combined network pharmacology, transcriptomics, and molecular biology to detect the underlying mechanism for the effect of HHQG on acute liver injury in mice. MATERIALS AND METHODS: Network pharmacology was used to explore the pathways involved in the protective effect HHQG in acute liver injury. This effect was further verified by injecting carbon tetrachloride (CCl4; 10 mL/kg, i.p.) to induce acute liver injury in mice. Serum markers of liver injury, morphology, histology, and monocyte/macrophage infiltration in the liver tissue were investigated. Transcriptomics further defined the HHQG targets. Transwell analysis was performed to confirm that HHQG inhibited monocyte/macrophage RAW.264.7 infiltration. qPCR and Western blot were performed to explore the mechanism of action of HHQG. RESULTS: Network pharmacology showed that HHQG exerted anti-oxidative and anti-inflammatory effects and promoted metabolic effects against acute liver injury. Pretreatment of mice with HHQG significantly maintained their body weight and decreased serum tumor necrosis factor-alpha (TNF-α) levels induced by CCl4 treatment in vivo. Histopathological examination further confirmed that HHQG protected the liver cells from CCl4-induced damage. Importantly, HHQG significantly inhibited CCl4-induced monocyte/macrophage infiltration. Transcriptomic analysis revealed that HHQG significantly reduced the expression of chemokines and cell adhesion molecules. We determined that HHQG significantly downregulated the expression of the key chemokine (monocyte chemokine protein-1, CCL2) at the gene and protein levels. Further research showed that HHQG inhibited chemokine production in hepatocytes by inhibiting the p-P38 and p-JNK pathways, thereby reducing monocyte/macrophage infiltration. CONCLUSIONS: These combined data showed that HHQG alleviated acute liver injury in mice, and further verified that HHQG exerted protective effects by inhibiting the production of CCL2 and reducing the infiltration of monocyte/macrophage by inhibiting the p-P38 and p-JNK pathways.

Upregulated miR-322-5p regulates cell cycle and promotes cell proliferation and apoptosis by directly targeting Wee1 in mice liver injury.

Liver injury from any number of causes (e.g. chemical material, drugs and diet, viral infection) is a global health problem, and its mechanism is not clearly understood. MicroRNAs (miRNAs) expression profiling is gaining popularity because miRNAs, as key regulators in gene expression networks, can influence many biological processes and have also shown promise as biomarkers for disease. Previous studies reported the regulation effects of miRNAs in liver injury, whereas function and molecular mechanisms of miR-322-5p were still unclear. Therefore, our study focused on the biological role of miR-322-5p in carbon tetrachloride (CCl4)-induced liver injury proliferation, apoptosis, and cell cycle. A mouse model of CCl4-induced liver injury was established, and the transcriptomes and miRNAs transcriptomes of 2d and 5d liver tissues after injury were sequenced. The expression of miR-322-5p and the cell cycle genes were detected in liver tissues and Hepa1-6 cell line by miRNA RT-PCR, qRT-PCR. The effects of miR-322-5p on liver cell proliferation, cell cycle and apoptosis were evaluated using MTS assays and flow cytometry analysis. The relationship between miR-322-5p and Wee1 was predicted and confirmed by bioinformatics analysis and a dual luciferase reporter assay. Functional experiments, including an MTS assay and flow cytometric analysis, were performed to study the effects of Wee1. MiR-322-5p was upregulated in injury liver tissues, and downregulated miR-322-5p was proved to inhibit proliferation, apoptosis and arrest cell cycle at G2/M in vitro. The dual-luciferase reporter assay results indicated that miR-322-5p has a binding site at position 285 in the Wee1 3´UTR. The effects of miR-322-5p in proliferation and cell cycle regulation can be abolished by Wee1 through rescue experiments. By directly targeting Wee1 influenced the expression of several cell cycle factors, including Cyclin dependent kinase 1 (Cdk1), cyclin B1 (Ccnb1) and Cell division cyclin 25C (Cdc25C). MiR-322-5p may function as a suppressive factor by negatively controlling Wee1, thus, highlighting the potential role of miR-322-5p as a therapeutic target for liver injury.Abbreviations: ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; GSH: Glutathione, γ-glutamyl cysteinel + glycine; CCl4: Carbon tetrachloride; HE: Haematoxylin and eosin; KEGG: Kyoto Encyclopedia of Genes and Genomes.

Direct activation of STAT5 by ETV6-LYN fusion protein promotes induction of myeloproliferative neoplasm with myelofibrosis.

Myeloproliferative neoplasms (MPN), a group of haematopoietic stem cell (HSC) disorders, are often accompanied by myelofibrosis. We previously identified the fusion of the ETV6 gene to the LYN gene (ETV6-LYN) in idiopathic myelofibrosis with ins(12;8)(p13;q11q21). The introduction of ETV6-LYN into HSCs resulted in fatal MPN with massive myelofibrosis in mice, implicating the rearranged LYN kinase in the pathogenesis of MPN with myelofibrosis. However, the signalling molecules directly downstream from and activated by ETV6-LYN remain unknown. In this study, we demonstrated that the direct activation of STAT5 by ETV6-LYN is crucial for the development of MPN. ETV6-LYN was constitutively active as a kinase through autophosphorylation. ETV6-LYN, but not its kinase-dead mutant, supported cytokine-free proliferation of haematopoietic cells. STAT5 was activated in a JAK2-independent manner in ETV6-LYN-expressing cells. ETV6-LYN interacted with STAT5 and directly activated STAT5 both in vitro and in vivo. Of note, ETV6-LYN did not support the formation of colonies by Stat5-deficient HSCs under cytokine-free conditions and the capacity of ETV6-LYN to induce MPN with myelofibrosis was profoundly attenuated in a Stat5-null background. These findings define STAT5 as a direct target of ETV6-LYN and unveil the LYN-STAT5 axis as a novel pathway to augment proliferative signals in MPN and leukaemia.

Retrotransposon silencing by DNA methylation can drive mammalian genomic imprinting.

Among mammals, only eutherians and marsupials are viviparous and have genomic imprinting that leads to parent-of-origin-specific differential gene expression. We used comparative analysis to investigate the origin of genomic imprinting in mammals. PEG10 (paternally expressed 10) is a retrotransposon-derived imprinted gene that has an essential role for the formation of the placenta of the mouse. Here, we show that an orthologue of PEG10 exists in another therian mammal, the marsupial tammar wallaby (Macropus eugenii), but not in a prototherian mammal, the egg-laying platypus (Ornithorhynchus anatinus), suggesting its close relationship to the origin of placentation in therian mammals. We have discovered a hitherto missing link of the imprinting mechanism between eutherians and marsupials because tammar PEG10 is the first example of a differentially methylated region (DMR) associated with genomic imprinting in marsupials. Surprisingly, the marsupial DMR was strictly limited to the 5' region of PEG10, unlike the eutherian DMR, which covers the promoter regions of both PEG10 and the adjacent imprinted gene SGCE. These results not only demonstrate a common origin of the DMR-associated imprinting mechanism in therian mammals but provide the first demonstration that DMR-associated genomic imprinting in eutherians can originate from the repression of exogenous DNA sequences and/or retrotransposons by DNA methylation.

Liposomes Encapsulating Neoantigens and Black Phosphorus Quantum Dots for Enhancing Photothermal Immunotherapy.

Colorectal cancer frustrates with high relapse after the traditional treatment including surgery and chemotherapy. Neoantigen-based therapeutic vaccine has achieved high response rate in the clinical trials rising the immunotherapy as a promising alternative for colorectal cancer. Herein, colon cancer cells derived neoantigen peptide Adpgk were employed to be co-encapsulated with black phosphorus quantum dots into liposome (Adpgk-BPQDs-liposome) as therapeutic vaccine. Adpgk-BPQDs-liposome were dispersed in F127 gel containing GM-CSF. The heat generated by black phosphorus (BP) under 808 nm near-infrared laser irradiation accelerates the F127 gel ablation and the release of GM-CSF, which recruit APC cells and prime the native T cells. The tumor bearing mice received the programmed cell death protein 1 (PD-1) checkpoint blockade antibody combined with photo-thermal gel intensively prevented the tumor progress. Furthermore, the tumor infiltrating CD8+ T cells were significantly increased which lead to the elimination of the tumor.

Activin A and BMP4 Signaling Expands Potency of Mouse Embryonic Stem Cells in Serum-Free Media.

Inhibitors of Mek1/2 and Gsk3ß, known as 2i, and, together with leukemia inhibitory factor, enhance the derivation of embryonic stem cells (ESCs) and promote ground-state pluripotency (2i/L-ESCs). However, recent reports show that prolonged Mek1/2 suppression impairs developmental potential of ESCs, and is rescued by serum (S/L-ESCs). Here, we show that culturing ESCs in Activin A and BMP4, and in the absence of MEK1/2 inhibitor (ABC/L medium), establishes advanced stem cells derived from ESCs (esASCs). We demonstrate that esASCs contributed to germline lineages, full-term chimeras and generated esASC-derived mice by tetraploid complementation. We show that, in contrast to 2i/L-ESCs, esASCs display distinct molecular signatures and a stable hypermethylated epigenome, which is reversible and similar to serum-cultured ESCs. Importantly, we also derived novel ASCs (blASCs) from blastocysts in ABC/L medium. Our results provide insights into the derivation of novel ESCs with DNA hypermethylation from blastocysts in chemically defined medium.

Ezh2 loss propagates hypermethylation at T cell differentiation-regulating genes to promote leukemic transformation.

Early T cell precursor acute lymphoblastic leukemia (ETP-ALL) is a new pathological entity with poor outcomes in T cell ALL (T-ALL) that is characterized by a high incidence of loss-of-function mutations in polycomb repressive complex 2 (PRC2) genes. We generated a mouse model of ETP-ALL by deleting Ezh2, one of the PRC2 genes, in p53-null hematopoietic cells. The loss of Ezh2 in p53-null hematopoietic cells impeded the differentiation of ETPs and eventually induced ETP-ALL-like disease in mice, indicating that PRC2 functions as a bona fide tumor suppressor in ETPs. A large portion of PRC2 target genes acquired DNA hypermethylation of their promoters following reductions in H3K27me3 levels upon the loss of Ezh2, which included pivotal T cell differentiation-regulating genes. The reactivation of a set of regulators by a DNA-demethylating agent, but not the transduction of single regulator genes, effectively induced the differentiation of ETP-ALL cells. Thus, PRC2 protects key T cell developmental regulators from DNA hypermethylation in order to keep them primed for activation upon subsequent differentiation phases, while its insufficiency predisposes ETPs to leukemic transformation. These results revealed a previously unrecognized epigenetic switch in response to PRC2 dysfunction and provide the basis for specific rational epigenetic therapy for ETP-ALL with PRC2 insufficiency.