Themis: advancing precision oncology through comprehensive molecular subtyping and optimization.

Recent advances in tumor molecular subtyping have revolutionized precision oncology, offering novel avenues for patient-specific treatment strategies. However, a comprehensive and independent comparison of these subtyping methodologies remains unexplored. This study introduces 'Themis' (Tumor HEterogeneity analysis on Molecular subtypIng System), an evaluation platform that encapsulates a few representative tumor molecular subtyping methods, including Stemness, Anoikis, Metabolism, and pathway-based classifications, utilizing 38 test datasets curated from The Cancer Genome Atlas (TCGA) and significant studies. Our self-designed quantitative analysis uncovers the relative strengths, limitations, and applicability of each method in different clinical contexts. Crucially, Themis serves as a vital tool in identifying the most appropriate subtyping methods for specific clinical scenarios. It also guides fine-tuning existing subtyping methods to achieve more accurate phenotype-associated results. To demonstrate the practical utility, we apply Themis to a breast cancer dataset, showcasing its efficacy in selecting the most suitable subtyping methods for personalized medicine in various clinical scenarios. This study bridges a crucial gap in cancer research and lays a foundation for future advancements in individualized cancer therapy and patient management.

Prmt5 deficient mouse B cells display RNA processing complexity and slower colorectal tumor progression.

Protein arginine methyltransferase 5 (Prmt5) is essential for normal B-cell development; however, the roles of Prmt5 in tumor-infiltrating B cells in tumor therapy have not been well elucidated. Here, we revealed that CD19-cre-Prmt5fl/fl (Prmt5cko) mice showed smaller tumor weights and volumes in the colorectal cancer mouse model; B cells expressed higher levels of Ccl22 and Il12a, which attracted T cells to the tumor site. Furthermore, we used direct RNA sequencing to comprehensively profile RNA processes in Prmt5 deletion B cells to explore underline mechanisms. We found significantly differentially expressed isoforms, mRNA splicing, poly(A) tail lengths, and m6A modification changes between the Prmt5cko and control groups. Cd74 isoform expressions might be regulated by mRNA splicing; the expression of two novel Cd74 isoforms was decreased, while one isoform was elevated in the Prmt5cko group, but the Cd74 gene expression showed no changes. We observed Ccl22, Ighg1, and Il12a expression was significantly increased in the Prmt5cko group, whereas Jak3 and Stat5b expression was decreased. Ccl22 and Ighg1 expression might be associated with poly(A) tail length, Jak3, Stat5b, and Il12a expression might be modulated by m6A modification. Our study demonstrated that Prmt5 regulates B-cell function through different mechanisms and supported the development of Prmt5-targeted antitumor treatments.

PRMT5 Deficiency Enforces the Transcriptional and Epigenetic Programs of Klrg1+CD8+ Terminal Effector T Cells and Promotes Cancer Development.

Protein arginine methyltransferase 5 (PRMT5) participates in the symmetric dimethylation of arginine residues of proteins and contributes to a wide range of biological processes. However, how PRMT5 affects the transcriptional and epigenetic programs involved in the establishment and maintenance of T cell subset differentiation and roles in antitumor immunity is still incompletely understood. In this study, using single-cell RNA and chromatin immunoprecipitation sequencing, we found that mouse T cell-specific deletion of PRMT5 had greater effects on CD8+ than CD4+ T cell development, enforcing CD8+ T cell differentiation into Klrg1+ terminal effector cells. Mechanistically, T cell deficiency of PRMT5 activated Prdm1 by decreasing H4R3me2s and H3R8me2s deposition on its loci, which promoted the differentiation of Klrg1+CD8+ T cells. Furthermore, effector CD8+ T cells that transited to memory precursor cells were decreased in PRMT5-deficient T cells, thus causing dramatic CD8+ T cell death. In addition, in a mouse lung cancer cell line-transplanted tumor mouse model, the percentage of CD8+ T cells from T cell-specific deletion of PRMT5 mice was dramatically lost, but CD8+Foxp3+ and CD8+PDL1+ regulatory T cells were increased compared with the control group, thus accelerating tumor progression. We further verified these results in a mouse colon cancer cell line-transplanted tumor mouse model. Our study validated the importance of targeting PRMT5 in tumor treatment, because PRMT5 deficiency enforced Klrg1+ terminal CD8+ T cell development and eliminated antitumor activity.

Prmt5 deficiency inhibits CD4+ T-cell Klf2/S1pr1 expression and ameliorates EAE disease.

BACKGROUND: Protein arginine methyltransferase 5 (Prmt5) is the main type II methyltransferase, catalyzes protein arginine residue symmetric dimethylation, and modulates normal cellular physiology and disease progression. Prmt5 inhibition or deletion in CD4+ T cells has been reported to ameliorate experimental autoimmune encephalomyelitis (EAE), but the detailed molecular mechanisms have not yet been elucidated. METHODS: EAE was induced by administration of myelin oligodendrocyte glycoprotein (MOG35-55) in T cells Prmt5 conditional knockout (CD4-cre-Prmt5fl/fl, Prmt5cko) and Prmt5fl/fl (WT) mice. Flow cytometry, single-cell RNA sequencing, ATAC sequencing and chromatin immunoprecipitation assay (ChIP) approaches were used to explore the detail mechanisms. RESULTS: We find that Prmt5cko mice are resistant to EAE; infiltrating inflammatory CD4+ T cells in the central nervous system (CNS) are greatly reduced. However, in Prmt5cko mice, T cells in the spleen show much more proliferation and activation properties, the total number of CD4+ T cells in the spleen is not reduced, and the percentage of Rora+ CD4+ T cells is elevated. Also, CD4+ T cells express lower levels of S1pr1 and Klf2 than WT mice, which may influence pathogenic CD4+ T-cell egress from the spleen and migration to the CNS. Moreover, the single-cell ATAC sequence and ChIP assay reveal that the transcription factor Klf2 is enriched at the S1pr1 promoter and that Klf2 motif activity is reduced in Prmt5cko mice. CONCLUSIONS: Our study delineates the undiscovered role of Prmt5 in T-cell biology in which Prmt5 may inhibit Klf2-S1pr1 pathway to ameliorate EAE disease. Controlling T-cell Prmt5 expression may be helpful for the treatment of autoimmune diseases.

Gastric cancer-secreted exosomal X26nt increases angiogenesis and vascular permeability by targeting VE-cadherin.

Angiogenesis is closely associated with tumorigenesis, invasion, and metastasis by providing oxygen and nutrients. Recently, increasing evidence indicates that cancer-derived exosomes which contain proteins, coding, and noncoding RNAs (ncRNAs) were shown to have proangiogenic function in cancer. A 26-nt-long ncRNA (X26nt) is generated in the process of inositol-requiring enzyme 1 alpha (IRE1α)-induced unspliced XBP1 splicing. However, the role of X26nt in the angiogenesis of gastric cancer (GC) remains largely unknown. In the present study, we found that X26nt was significantly elevated in GC and GC exosomes. Then, we verified that X26nt could be delivered into human umbilical vein endothelial cells (HUVECs) via GC cell exosomes and promote the proliferation, migration, and tube formation of HUVECs. We revealed that exosomal X26nt decreased vascular endothelial cadherin (VE-cadherin) by directly combining the 3'UTR of VE-cadherin mRNA in HUVECs, thereby increasing vascular permeability. We further demonstrated that X26nt accelerates the tumor growth and angiogenesis in a mouse subcutaneous tumor model. Our findings investigate a unique intercellular communication mediated by cancer-derived exosomes and reveal a novel mechanism of exosomal X26nt in the regulation of tumor vasculature.

BACH2 regulates the function of human CD4+ CD45RA- Foxp3l ° cytokine-secreting T cells and promotes B-cell response in systemic lupus erythematosus.

Although CD4+ CD45RA- Foxp3l ° cytokine-secreting T cells (Fr.III cells) have been reported to be increased in systemic lupus erythematosus (SLE), their function and effects on response of B cells are still unclear. Here, we dissect how BACH2 regulates Fr.III cells function and promotes B-cell response in active SLE patients. We measured cytokines and BACH2 expression, and found that Fr.III cells from SLE patients produce much more inflammatory cytokines and were more able to promote B- cell proliferation, IgG, IgA, and TNF-α production than controls in a co-culture system. Fr.III cells expressed high levels of ICOS and CD154, but a low level of Tfr and BACH2, BACH2 expression was negatively correlated with SLE Disease Activity Index. Overexpressed of BACH2 in Fr.III cells, decreased cytokines expression and reduced B-cell response. Furthermore, we identified a reduction of H3K27ac level binding at the BACH2 locus in the SLE Fr.III cells and SLE serum stimulation decreased H3K27ac binding at the BACH2 locus, which could be restored using trichostatin A (TSA). In conclusion, BACH2 was associated with SLE disease activity, regulated the function of Fr.III cells, and promoted B-cells response. Targeting BACH2 may be a new immune intervention therapy of SLE.

Mechanisms for propofol in inhibiting the proliferation and invasion of glioma U87 cells and its effect on miR-134 expression. / å¼‚ä¸™é šæŠ‘åˆ¶èƒ¶è´¨ç˜¤U87ç»†èƒžå¢žæ®–å’Œä¾µè¢­çš„ä½œç”¨æœºåˆ¶åŠå ¶å¯¹miR-134表达的影响.

OBJECTIVES: To investigate the effects of propofol on the proliferation and invasion of glioma U87 cells and to explore the possible anti-tumor mechanisms. METHODS: The glioma U87 cells was divided into a blank group, a positive control group, and the propofol groups (1.00, 2.00 or 5.00 mmol/L). Cell counting kit-8 (CCK-8) was used to detect cell proliferation; Transwell method was used to detect the effect of propofol on invasion and migration of U87 cells; real-time PCR was used to detect the expression of microRNA-134 (miR-134); Western blotting was used to detect the expression levels of reproduction-related protein Ki-67, invasion-related protein metalloproteinase-2 (MMP-2), metalloproteinase-9 (MMP-9) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway-related protein. RESULTS: Compared with the blank group, the proliferation, invasion and migration capacity of U87 cells were reduced in the positive control group and the propofol groups after 48 hours (all P<0.05), along with the decreased expression of Ki-67, MMP-2 and MMP-9 and the ratio of p-PI3K/PI3K and p-Akt/Akt (all P<0.05), while the level of miR-134 was increased significantly (P<0.05). Compared with the positive control group and the 1.00 mmol/L propofol-treated group, the proliferation, invasion and migration capacity of U87 cells, the expression of Ki-67, MMP-2 and MMP-9, and the ratio of p-PI3K/PI3K and p-Akt/Akt was decreased significantly after 48 hours (all P<0.05), while the level of miR-134 was increased significantly in the 2.00 and 5.00 mmol/L propofol-treated groups (both P<0.05). Compared with the 2.00 mmol/L propofol-treated group, the proliferation, invasion and migration capacity of U87 cells, the expression of Ki-67, MMP-2 and MMP-9, and the ratio of p-PI3K/PI3K and p-Akt/Akt was decreased significantly after 48 hours in the 5.00 mmol/L propofol-treated group (all P<0.05), while the level of miR-134 was increased significantly (P<0.05). CONCLUSIONS: Propofol can decrease the proliferation rate, and the invasion and migration abilities of U87 cells, which may be achieved by up-regulation of miR-134 and suppression of PI3K/Akt signaling pathway.

Prognostic value of YKL-40 in solid tumors: a meta-analysis of 41 cohort studies.

BACKGROUND: Serum/plasma YKL-40 can be a useful index that is associated with tumor development. However, the prognostic value of serum/plasma YKL-40 in patients with solid tumors is still unclear. We aimed to utilize the existing literature to investigate the prognostic value of serum/plasma YKL-40 in solid tumors. METHODS: An extensive literature search for relevant studies was conducted with the Embase, Medline and Web of Science databases. The effect on survival was measured with the hazard ratio (HR). Then, pooled HRs and 95% confidence intervals (CIs) were calculated using the random and fixed-effects models according to the heterogeneity of the included studies. RESULTS: This meta-analysis was based on 41 publications and comprised a total of 7762 patients with solid tumors. The pooled HR showed that elevated serum/plasma YKL-40 was significantly associated with poor OS (HR, 1.44; 95% CI 1.33-1.56). We also found that elevated serum/plasma YKL-40 had significant prognostic effects on OS in various cancer subgroups such as gastrointestinal tumors (HR, 1.37; 95% CI 1.18-1.58), ovarian cancer (HR, 2.27; 95% CI 1.69-3.06), melanoma (HR, 1.77; 95% CI 1.18-2.67), lung cancer (HR, 1.73; 95% CI 1.35-2.23), urologic neoplasms (HR, 1.61; 95% CI 1.08-2.40) and glioblastoma (HR, 1.23; 95% CI 1.07-1.42); in contrast, the prognostic effect of serum/plasma YKL-40 was not statistically significant in breast cancer (HR, 1.07; 95% CI 0.98-1.17). CONCLUSIONS: The available evidence supports the hypothesis that elevated serum/plasma YKL-40 is associated with poor survival in patients with solid tumors and that serum/plasma YKL-40 may serve as a novel prognostic biomarker.

Modulation of STAT3 and STAT5 activity rectifies the imbalance of Th17 and Treg cells in patients with acute coronary syndrome.

The signal transducer and activator of transcription (STAT) activity plays an important role in the differentiation and imbalance of Th17 and Treg cells in acute coronary syndrome (ACS) patients. We determined that the basal STAT3 phosphorylation level was significantly increased and exhibited a positive relationship with Th17 cells but was negatively correlated with Treg cells in ACS patients. Opposite effects were observed for STAT5 activity. Using the pharmaceutical inhibitor TG101348 or knockdown of STAT3 reduced the number of Th17 cells while promoting the number and function of Treg cells via the Janus kinase2 (JAK2)/STAT3 pathway in ACS patients. Significantly more STAT5 bound to the Foxp3 locus when STAT3 was knocked down, and overexpression of STAT5 led to an increased number of Treg cells but a decreased number of Th17 cells in ACS patients. Our findings demonstrate that modulation of STAT3/STAT5 activity rectifies the imbalance of Th17/Treg cells in ACS patients.

Osteopontin promotes inflammation in patients with acute coronary syndrome through its activity on IL-17 producing cells.

Atherosclerosis is a progressive disease with a strong inflammatory component. Here we confirm the existence of a critical imbalance in the ratio of Th17 to Treg-cell populations in peripheral CD4(+) T cells from patients with acute coronary syndrome (ACS), which favors inflammation. This was concurrent with increased IL-17 production from the CD4(+) CD45RA(-) FOXP3(lo) Treg-cell subset, and elevated osteopontin (OPN) levels in serum from ACS patients. We demonstrate a direct effect of OPN in serum from ACS patients on increased IL-17 production by CD4(+) CD45RA(-) FOXP3(lo) T cells, mediated through recruitment of the OPN receptors CD29 and CD44, and dependent on STAT3 and the nuclear hormone receptor retinoic-acid-related orphan receptor-γt (RORγt) pathway, but not IL-6 production. To our knowledge and beyond the disease context of ACS, this study constitutes the first demonstration of a critical role for OPN in the positive regulation of inflammation through increased IL-17 production by CD4(+) CD45RA(-) FOXP3(lo) cells.

Urinary exosomal long non-coding RNAs as noninvasive biomarkers for diagnosis of bladder cancer by RNA sequencing.

Introduction: Cystoscopy is the standard methodology for diagnosis of bladder cancer (BC), but it is invasive and relatively expensive. Previous studies have found that urinary exosomal long non-coding RNAs (lncRNAs) may act as potential noninvasive biomarkers for diagnosis. Here we identified urinary exosomal lncRNAs that are differentially expressed between BC and controls, and established a panel for diagnosis of BC. Methods: We performed RNA sequencing in urinary exosomes of 7 controls and 7 patients, subsequently the differentially expressed lncRNAs were detected in training cohort (50 controls and 50 patients) and validation cohort (43 controls and 43 patients). The diagnostic power of lncRNAs for BC was calculated by the area under curve (AUC). The panel for diagnosis of BC was calculated by logistic regression. Results: The results of RNA sequencing in urinary exosomes showed that 240 upregulated lncRNAs and 275 downregulated lncRNAs were differentially expressed. The levels of MKLN1-AS, TALAM1, TTN-AS1 and UCA1 in BC patients were higher than that in controls in the training and validation cohort by real-time PCR. Using logistic regression, with the combination of these four lncRNAs and NMP22, we identified a panel of five parameters capable of classifying BC patients versus controls on the basis of the training cohort (AUC=0.850). Moreover, the performance of the panel exhibited better performance than either single parameter in the validation cohort. Conclusion: Collectively, this study confirmed the diagnostic value of lncRNAs for BC by high-throughout urinary exosomal RNA sequencing.

PD-L1+CD8+ T cells enrichment in lung cancer exerted regulatory function and tumor-promoting tolerance.

Immunotherapy targeting checkpoint blockade to rescue T cells from exhaustion has become an essential therapeutic strategy in treating cancers. Till now, little is known about the PD-L1 graphic pattern and characteristics in CD8+ T cells. We combined cytometry by time-of-flight (CyTOF) and imaging mass cytometry (IMC) approaches to analyze CD8+ T cells from primary lung cancers and discovered that PD-L1+CD8+ T cells were enriched in tumor lesions, spatially localized with PD-1+CD8+ T cells. Furthermore, PD-L1+CD8+ T cells exerted regulatory functions that inhibited CD8+ T cells proliferation and cytotoxic abilities through the PD-L1/PD-1 axis. Moreover, tumor-derived IL-27 promotes PD-L1+CD8+ T cells development through STAT1/STAT3 signaling. Single-cell RNA sequencing data analysis further clarified PD-L1+CD8+ T cells elevated in the components related to downregulation of adaptive immune response. Collectively, our data demonstrated that PD-L1+CD8+ T cells enriched in lung cancer engaged in tolerogenic effects and may become a therapeutic target in lung cancer.

Role of osteopontin in synovial Th17 differentiation in rheumatoid arthritis.

OBJECTIVE: Osteopontin (OPN) that is aberrantly produced in rheumatoid synovium is thought to play an important role in rheumatoid arthritis (RA). This study was undertaken to investigate the role of OPN in the differentiation and accumulation of Th17 cells in rheumatoid synovium. METHODS: Peripheral blood mononuclear cells and purified CD4+ T cells derived from patients with RA or healthy controls were used to test the effect of OPN in vitro. Cytokine expression was determined by enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. Intracellular staining and flow cytometry were used to detect the percentages of Th17 cells and OPN receptors. Signaling and molecular events were analyzed by immunoblotting and chromatin immunoprecipitation. RESULTS: The levels of OPN correlated significantly with interleukin-17 (IL-17) production and the frequency of Th17 cells in the synovial fluid (SF) of RA patients. Endogenous OPN produced in RA SF was responsible for markedly increased production of IL-17 in T cells, which was blocked by OPN antibody. The effect of OPN in Th17 differentiation was mediated through a mechanism independent of the IL-6/STAT-3 pathway or other cytokines and specifically involved the OPN receptors CD44 and CD29 and the transcription factor retinoic acid-related orphan receptor (ROR). Furthermore, OPN was found to induce H3 acetylation of the IL17A gene promoter, mainly through the CD44 binding domain in CD4+ T cells, allowing the interaction of the IL17A gene locus with ROR. CONCLUSION: This study reveals new evidence of the critical role of OPN in Th17 differentiation in rheumatoid synovitis.

Interleukin 32 Promotes Foxp3+ Treg Cell Development and CD8+ T Cell Function in Human Esophageal Squamous Cell Carcinoma Microenvironment.

Proinflammatory cytokine interleukin 32 (IL-32) is involved in infectious diseases and cancer, but what subtypes of immune cells express IL-32 and its roles in tumor microenvironment (TME) have not been well discussed. In this study, we applied bioinformatics to analyze single-cell RNA sequencing data about tumor-infiltrating immune cells from esophageal squamous cell carcinoma (ESCC) TME and analyzed IL-32 expression in different immune cell types. We found CD4+ regulatory T cells (Treg cells) express the highest level of IL-32, while proliferating T and natural killer cells expressed relatively lower levels. Knocking down of IL-32 reduced Foxp3 and interferon gamma (IFNγ) expressions in CD4+ and CD8+ T cells, respectively. IL-32 was positively correlated with Foxp3, IFNG, and GZMB expression but was negatively correlated with proliferation score. IL-32 may have a contradictory role in the TME such as it promotes IFNγ expression in CD8+ T cells, which enhances the antitumor activity, but at the same time induces Foxp3 expression in CD4+ T cells, which suppresses the tumor immune response. Our results demonstrate different roles of IL-32 in Treg cells and CD8+ T cells and suggest that it can potentially be a target for ESCC cancer immunosuppressive therapy.

PRMT5 Inhibition Promotes PD-L1 Expression and Immuno-Resistance in Lung Cancer.

Protein arginine transferase 5 (PRMT5) has been implicated as an important modulator of tumorigenesis as it promotes tumor cell proliferation, invasion, and metastasis. Studies have largely focused on PRMT5 regulating intrinsic changes in tumors; however, the effects of PRMT5 on the tumor microenvironment and particularly immune cells are largely unknown. Here we found that targeting PRMT5 by genetic or pharmacological inhibition reduced lung tumor progression in immunocompromised mice; however, the effects were weakened in immunocompetent mice. PRMT5 inhibition not only decreased tumor cell survival but also increased the tumor cell expression of CD274 in vitro and in vivo, which activated the PD1/PD-L1 axis and eliminated CD8+T cell antitumor immunity. Mechanistically, PRMT5 regulated CD274 gene expression through symmetric dimethylation of histone H4R3, increased deposition of H3R4me2s on CD274 promoter loci, and inhibition of CD274 gene expression. Targeting PRMT5 reduced this inhibitory effect and promoted CD274 expression in lung cancer. However, PRMT5 inhibitors represent a double-edged sword as they may selectively kill cancer cells but may also disrupt the antitumor immune response. The combination of PRMT5 inhibition and ani-PD-L1 therapy resulted in an increase in the number and enhanced the function of tumor-infiltrating T cells. Our findings address an unmet clinical need in which combining PRMT5 inhibition with anti-PD-L1 therapy could be a promising strategy for lung cancer treatment.

Decreased expression of ATF3, orchestrated by ß-catenin/TCF3, miR-17-5p and HOXA11-AS, promoted gastric cancer progression via increased ß-catenin and CEMIP.

ATF3 has been reported to be dysregulated in various cancers and involved in various steps of tumorigenesis. However, the mechanisms underlying the abnormal expression of ATF3 and its biological function in gastric cancer (GC) have not been well investigated. Here, we report ATF3 as one of the key regulators of GC development and progression. Patients with low ATF3 expression had shorter survival and a poorer prognosis. In vitro and in vivo assays investigating ATF3 alterations revealed a complex integrated phenotype that affects cell growth and migration. Strikingly, high-throughput sequencing and microarray analysis of cells with ATF3 silencing or of ATF3-low GC tissues indicated alterations in the Wnt signaling pathway, focal adhesions and adherens junctions. Mechanistically, the expression of ß-catenin and cell migration inducing hyaluronidase 1 (CEMIP) was significantly upregulated in GC cells with downregulated ATF3, which was synergistically repressed by the ß-catenin/TCF3 signaling axis and noncoding RNA miR-17-5p and HOXA11-AS. In addition, we found that WDR5 expression was promoted by TCF3 and is involved in miR-17-5p and HOXA11-AS activation in GC cells. Taken together, our findings revealed the mechanism of ATF3 downregulation and its biological role in regulating the expression of Wnt signaling-related genes during GC progression, suggesting new informative biomarkers of malignancy and therapeutic directions for GC patients.

PRMT5 disruption drives antitumor immunity in cervical cancer by reprogramming T cell-mediated response and regulating PD-L1 expression.

Rationale: Protein arginine methyltransferase 5 (PRMT5) is an oncogene that promotes tumor cell proliferation, invasion and metastasis. However, the underlying mechanisms by which PRMT5 contributes to the progression of cervical cancer and especially the tumor microenvironment remain poorly understood. Methods: PRMT5 expression level was analyzed by Q-PCR, western blot, immunohistochemistry, and TCGA database. The role of PRMT5 in tumor growth was observed by transplanted tumor models, and the function of T cells in tumor microenvironment and in vitro co-culture system was investigated through flow cytometry. The transcriptional regulation of PRMT5 was analyzed using luciferase reporter and chromatin immunoprecipitation (ChIP) assay. The therapeutic effect of PRMT5 inhibitor was evaluated in a cervical cancer cell line transplanted tumor model. Results: We observed that the mRNA and protein expression levels of PRMT5 were increased in cervical cancer tissues, and the high expression of PRMT5 was associated with poor outcomes in cervical cancer patients. The absence of PRMT5 significantly inhibited tumor growth in a cervical cancer transplanted tumor model, and importantly, PRMT5 absence in tumors led to increase the number and enhance the function of tumor infiltrating T cells. Mechanistically, PRMT5 enhanced the transcription of STAT1 through symmetric dimethylation of histone H3R2 and thus promoted PD-L1 expression in cervical cancer cells. Moreover, in an in vitro co-culture system, knockdown of PRMT5 in tumor cells could directly enhance the expression of IFN-γ, TNF-α and granzyme B in T cells. These results suggested that PRMT5 promoted the development of cervical cancer by the crosstalk between tumor cells and T cells. Furthermore, the PRMT5 inhibitor EPZ015666 treatment could suppress tumor growth in a cervical cancer transplanted tumor model. Conclusion: Our results clarify a new mechanism which PRMT5 knockdown in cervical cancer cells drives an antitumor function via reprogramming T cell-mediated response and regulating PD-L1 expression. Thus, our study highlights that PRMT5 may be a potential target for cervical cancer therapy.

Immune suppressive landscape in the human esophageal squamous cell carcinoma microenvironment.

Cancer immunotherapy has revolutionized cancer treatment, and it relies heavily on the comprehensive understanding of the immune landscape of the tumor microenvironment (TME). Here, we obtain a detailed immune cell atlas of esophageal squamous cell carcinoma (ESCC) at single-cell resolution. Exhausted T and NK cells, regulatory T cells (Tregs), alternatively activated macrophages and tolerogenic dendritic cells are dominant in the TME. Transcriptional profiling coupled with T cell receptor (TCR) sequencing reveal lineage connections in T cell populations. CD8 T cells show continuous progression from pre-exhausted to exhausted T cells. While exhausted CD4, CD8 T and NK cells are major proliferative cell components in the TME, the crosstalk between macrophages and Tregs contributes to potential immunosuppression in the TME. Our results indicate several immunosuppressive mechanisms that may be simultaneously responsible for the failure of immuno-surveillance. Specific targeting of these immunosuppressive pathways may reactivate anti-tumor immune responses in ESCC.

DKK2 imparts tumor immunity evasion through ß-catenin-independent suppression of cytotoxic immune-cell activation.

Immunotherapy offers new options for cancer treatment, but efficacy varies across cancer types. Colorectal cancers (CRCs) are largely refractory to immune-checkpoint blockade, which suggests the presence of yet uncharacterized immune-suppressive mechanisms. Here we report that the loss of adenomatosis polyposis coli (APC) in intestinal tumor cells or of the tumor suppressor PTEN in melanoma cells upregulates the expression of Dickkopf-related protein 2 (DKK2), which, together with its receptor LRP5, provides an unconventional mechanism for tumor immune evasion. DKK2 secreted by tumor cells acts on cytotoxic lymphocytes, inhibiting STAT5 signaling by impeding STAT5 nuclear localization via LRP5, but independently of LRP6 and the Wnt-ß-catenin pathway. Genetic or antibody-mediated ablation of DKK2 activates natural killer (NK) cells and CD8+ T cells in tumors, impedes tumor progression, and enhances the effects of PD-1 blockade. Thus, we have identified a previously unknown tumor immune-suppressive mechanism and immunotherapeutic targets particularly relevant for CRCs and a subset of melanomas.

miR-155 Regulates IL-10-Producing CD24hiCD27+ B Cells and Impairs Their Function in Patients with Crohn's Disease.

Regulatory interleukin-10 (IL-10)-producing B cells (B10 cells) play a critical role in preventing and curing autoimmune diseases in experimental mouse models. However, the precise cellular and molecular mechanisms of action of B10 cells in humans, especially in patients with Crohn's disease (CD), remain to be determined. miR-155 regulates many physiological and pathological conditions, including inflammation such as that in CD. In this study, we aimed to explore the effect of miRNA-155 on IL-10 production by B cells in healthy controls (HCs) and CD patients. Interestingly, we found that CD24hiCD27+ B cells express high levels of miRNA-155 and IL-10, which are positively correlated. Additionally, CD24hiCD27+ B cells express higher levels of Toll-like receptor 9 than those found in other B cell subsets. Overexpression of miRNA-155 promotes IL-10 production, while inhibition of miRNA-155 decreases IL-10 production. We determined that miR-155 directly inhibits the expression of Jarid2, which reduces H3K27me3 binding to the IL10 promoter and increases IL-10 gene expression. In coculture systems, the CD24hiCD27+ B cells from HCs suppressed the secretion of TNFα and IFNγ by monocytes and T cells, respectively. However, the number and function of CD24hiCD27+ B cells from CD patients were decreased. Moreover, we found that miR-155 induces CD24hiCD27+ B cells to produce higher levels of TNFα instead of IL-10 in CD patients than in the controls and that the increased number of IL-10+TNFα+ B cells reduces the induction of Foxp3 expression and the inhibition of IFNγ production by CD4+CD25- T cells, as well as TNFα production by monocytes. Our study demonstrates the critical role of miRNA-155 in the regulation of IL-10 production by B cells and reveals the novel molecular mechanism underlying the functional impairment of B10 cells in CD patients. Our study has the potential to drive the development of B10 cell-based strategies to ameliorate disease progression in CD patients.