FOXP3+ regulatory T cell perturbation mediated by the IFNγ-STAT1-IFITM3 feedback loop is essential for anti-tumor immunity.

Targeting tumor-infiltrating regulatory T cells (Tregs) is an efficient way to evoke an anti-tumor immune response. However, how Tregs maintain their fragility and stability remains largely unknown. IFITM3 and STAT1 are interferon-induced genes that play a positive role in the progression of tumors. Here, we showed that IFITM3-deficient Tregs blunted tumor growth by strengthening the tumor-killing response and displayed the Th1-like Treg phenotype with higher secretion of IFNγ. Mechanistically, depletion of IFITM3 enhances the translation and phosphorylation of STAT1. On the contrary, the decreased IFITM3 expression in STAT1-deficient Tregs indicates that STAT1 conversely regulates the expression of IFITM3 to form a feedback loop. Blocking the inflammatory cytokine IFNγ or directly depleting STAT1-IFITM3 axis phenocopies the restored suppressive function of tumor-infiltrating Tregs in the tumor model. Overall, our study demonstrates that the perturbation of tumor-infiltrating Tregs through the IFNγ-IFITM3-STAT1 feedback loop is essential for anti-tumor immunity and constitutes a targetable vulnerability of cancer immunotherapy.

Cutting Edge: Bach2 Integrates Cytokine Signals to Arbitrate Differentiation Decisions between T Follicular Helper and Th17 Lineages.

CXCR5 is a hallmark of T follicular helper (Tfh) cells. The mechanism of CXCR5 induction, however, is still incompletely understood. In this study, we report that in mice with the absence of transcription factor Bach2, the Th17-inducing cytokines IL-6 and TGF-ß together induced CXCR5 expression in vitro. Mechanistically, IL-6/STAT3 drove Cxcr5 promoter activity via the upstream site 1 regulatory element, whereas TGF-ß enhanced permissive histone modifications, and the STAT3 binding to the site 1 regulatory element was higher in the absence of Bach2. Subsequently, despite previous studies showing enhanced Th17 cell differentiation in the absence of Bach2 in vitro, we found that in vivo, the Bach2 deficiency led to an enhanced Tfh cell response at the expense of the Th17 cell response. These findings suggest that Bach2 helps integrate cytokine signals to arbitrate differentiation decisions between Tfh and Th17 lineages.

Spatiotemporal resolution of germinal center Tfh cell differentiation and divergence from central memory CD4+ T cell fate.

Follicular helper T (Tfh) cells are essential for germinal center (GC) B cell responses. However, it is not clear which PD-1+CXCR5+Bcl6+CD4+ T cells will differentiate into PD-1hiCXCR5hiBcl6hi GC-Tfh cells and how GC-Tfh cell differentiation is regulated. Here, we report that the sustained Tigit expression in PD-1+CXCR5+CD4+ T cells marks the precursor Tfh (pre-Tfh) to GC-Tfh transition, whereas Tigit-PD-1+CXCR5+CD4+ T cells upregulate IL-7Rα to become CXCR5+CD4+ T memory cells with or without CCR7. We demonstrate that pre-Tfh cells undergo substantial further differentiation at the transcriptome and chromatin accessibility levels to become GC-Tfh cells. The transcription factor c-Maf appears critical in governing the pre-Tfh to GC-Tfh transition, and we identify Plekho1 as a stage-specific downstream factor regulating the GC-Tfh competitive fitness. In summary, our work identifies an important marker and regulatory mechanism of PD-1+CXCR5+CD4+ T cells during their developmental choice between memory T cell fate and GC-Tfh cell differentiation.

Synthesis of ultrahigh-molecular-weight ethylene/1-octene copolymers with salalen titanium(iv) complexes activated by methyaluminoxane.

Two salalen titanium(iv) complexes ((H-salalen)TiCl2 and (F-salalen)TiCl2) containing hydrogen and fluorine respectively on the phenolate ring close to the imine were synthesized for the copolymerization of ethylene with 1-octene to prepare poly(ethylene-co-1-octene) in the presence of methylaluminoxane (MAO). The (F-salalen)TiCl2/MAO showed higher catalytic activity and better copolymer characteristics such as a higher molecular weight, narrower molecular weight distribution, and higher 1-octene incorporation than (H-salalen)TiCl2/MAO, which revealed that the electron-withdrawing conjugated effect introduced by fluorine substituents led to improvements on catalytic performance and thermal stability. The influences of copolymerization conditions including temperature, Al/Ti molar ratios and comonomer feed ratios on the copolymerization behavior of (F-salalen)TiCl2/MAO and the copolymer microstructure were investigated in detail. Under the activation of MAO, the (F-salalen)TiCl2 could produce ultrahigh molecular weight poly(ethylene-co-1-octene) with 1-octene incorporation ratios in the range of 0.9-3.1 mol% and exhibit relatively high activity. It could be inferred that long ethylene sequences in the copolymer were segregated by the isolated 1-octene units based on the 13C NMR characterization of the copolymer. Moreover, the thermal properties and crystallization of copolymers were determined by DSC and XRD and correlated to the ethylene sequence length distribution. The reactivity ratios calculated by the triad distribution in 13C NMR revealed the random comonomer distribution in the copolymer chain.

MondoA-Thioredoxin-Interacting Protein Axis Maintains Regulatory T-Cell Identity and Function in Colorectal Cancer Microenvironment.

BACKGROUND & AIMS: The metabolic features and function of intratumoral regulatory T cells (Tregs) are ambiguous in colorectal cancer. Tumor-infiltrating Tregs are reprogrammed to exhibit high glucose-depleting properties and adapt to the glucose-restricted microenvironment. The glucose-responsive transcription factor MondoA is highly expressed in Tregs. However, the role of MondoA in colorectal cancer-infiltrating Tregs in response to glucose limitation remains to be elucidated. METHODS: We performed studies using mice, in which MondoA was conditionally deleted in Tregs, and human colorectal cancer tissues. Seahorse and other metabolic assays were used to assess Treg metabolism. To study the role of Tregs in antitumor immunity, we used a subcutaneous MC38 colorectal cancer model and induced colitis-associated colorectal cancer in mice by azoxymethane and dextran sodium sulfate. RESULTS: Our analysis of single-cell RNA sequencing data of patients with colorectal cancer revealed that intratumoral Tregs featured low activity of the MondoA-thioredoxin-interacting protein (TXNIP) axis and increased glucose uptake. Although MondoA-deficient Tregs were less immune suppressive and selectively promoted T-helper (Th) cell type 1 (Th1) responses in a subcutaneous MC38 tumor model, Treg-specific MondoA knockout mice were more susceptible to azoxymethane-DSS-induced colorectal cancer. Mechanistically, suppression of the MondoA-TXNIP axis promoted glucose uptake and glycolysis, induced hyperglycolytic Th17-like Tregs, which facilitated Th17 inflammation, promoted interleukin 17A-induced of CD8+ T-cell exhaustion, and drove colorectal carcinogenesis. Blockade of interleukin 17A reduced tumor progression and minimized the susceptibility of MondoA-deficient mice to colorectal carcinogenesis. CONCLUSIONS: The MondoA-TXNIP axis is a critical metabolic regulator of Treg identity and function in the colorectal cancer microenvironment and a promising target for cancer therapy.

Impaired AGO2/miR-185-3p/NRP1 axis promotes colorectal cancer metastasis.

Increasing evidence suggests that global downregulation of miRNA expression is a hallmark of human cancer, potentially due to defects in the miRNA processing machinery. In this study, we found that the protein expression of Argonaute 2 (AGO2), a key regulator of miRNA processing, was downregulated in colorectal cancer (CRC) tissues, which was also consistent with the findings of the Clinical Proteomic Tumor Analysis Consortium (CPTAC). Furthermore, the correlation between the levels of AGO2 and epithelial-mesenchymal transition (EMT) markers (E-cadherin and vimentin) indicated that reduced levels of AGO2 promoted EMT in CRC. Low expression of AGO2 was an indicator of a poor prognosis among CRC patients. Knockdown of AGO2 in CRC cells promoted migration, invasion and metastasis formation in vitro and in vivo but had no influence on proliferation. To provide detailed insight into the regulatory roles of AGO2, we performed integrated transcriptomic, quantitative proteomic and microRNA sequencing (miRNA-seq) analyses of AGO2 knockdown cells and the corresponding wild-type cells and identified neuropilin 1 (NRP1) as a new substrate of AGO2 via miR-185-3p. Our data provided evidence that knockdown of AGO2 resulted in a reduction of miR-185-3p expression, leading to the upregulation of the expression of NRP1, which is a direct target of miR-185-3p, and elevated CRC cell metastatic capacity. Inhibition of NRP1 or treatment with a miR-185-3p mimic successfully rescued the phenotypes of impaired AGO2, which suggested that therapeutically targeting the AGO2/miR-185-3p/NRP1 axis may be a potential treatment approach for CRC.

Mouse Double Minute 2 Homolog-Mediated Ubiquitination Facilitates Forkhead Box P3 Stability and Positively Modulates Human Regulatory T Cell Function.

Regulatory T cells (Treg cells) are essential for maintaining immune tolerance, and the dysfunction of Treg cells may cause autoimmune diseases and tumors. Forkhead box P3 (FOXP3) is the key transcription factor controlling Treg cell development and suppressive function. Mouse double minute 2 homolog (MDM2), an E3 ubiquitin ligase, has been identified as an oncoprotein that mediates the ubiquitination and degradation of tumor suppressor p53; however, whether it has functions in Treg cells remains unknown. Here, we demonstrate that MDM2 positively regulates human Treg cell suppressive function via its mediated ubiquitination and stabilization of FOXP3. Knockdown of MDM2 with shRNA in human primary Treg cells leads to the impaired ability of FOXP3 to regulate the expression levels of downstream genes and the attenuated suppressive capacity of Treg cells, due to FOXP3 instability. Consistently, MDM2 overexpression in human Treg cells enhances FOXP3 stability and Treg cell suppressive capacity. Mechanistically, MDM2 interacts with FOXP3, and mainly mediates monoubiquitination and polyubiquitination of FOXP3, thus stabilizing the protein level of FOXP3. We have also found lysine residues in FOXP3 required for MDM2-mediated ubiquitination. In addition, TCR/CD28 signaling upregulates the expression level of MDM2 and its mediated FOXP3 ubiquitination in human Treg cells. Therefore, our findings reveal that MDM2 in Treg cells could be a potential therapeutic target for treating autoimmune diseases and tumors.

RNA-binding protein Musashi2 stabilizing androgen receptor drives prostate cancer progression.

The androgen receptor (AR) pathway is critical for prostate cancer carcinogenesis and development; however, after 18-24 months of AR blocking therapy, patients invariably progress to castration-resistant prostate cancer (CRPC), which remains an urgent problem to be solved. Therefore, finding key molecules that interact with AR as novel strategies to treat prostate cancer and even CRPC is desperately needed. In the current study, we focused on the regulation of RNA-binding proteins (RBPs) associated with AR and determined that the mRNA and protein levels of AR were highly correlated with Musashi2 (MSI2) levels. MSI2 was upregulated in prostate cancer specimens and significantly correlated with advanced tumor grades. Downregulation of MSI2 in both androgen sensitive and insensitive prostate cancer cells inhibited tumor formation in vivo and decreased cell growth in vitro, which could be reversed by AR overexpression. Mechanistically, MSI2 directly bound to the 3'-untranslated region (UTR) of AR mRNA to increase its stability and, thus, enhanced its transcriptional activity. Our findings illustrate a previously unknown regulatory mechanism in prostate cancer cell proliferation regulated by the MSI2-AR axis and provide novel evidence towards a strategy against prostate cancer.

PD1Hi CD8+ T cells correlate with exhausted signature and poor clinical outcome in hepatocellular carcinoma.

BACKGROUND: CD8+ T cells differentiate into exhausted status within tumors, including hepatocellular carcinoma (HCC), which constitutes a solid barrier to effective anti-tumor immunity. A detailed characterization of exhausted T cells and their prognostic value in HCC is lacking. METHODS: We collected fresh tumor tissues with adjacent non-tumor liver tissues and blood specimens of 56 HCC patients, as well as archived samples from two independent cohorts of HCC patients (n = 358 and n = 254), who underwent surgical resection. Flow cytometry and multiplex immunostaining were used to characterize CD8+ T cells. Patient prognosis was evaluated by Kaplan-Meier analysis and Cox regression analysis. RESULTS: CD8+ T cells were classified into three distinct subpopulations: PD1Hi, PD1Int and PD1-. PD1Hi CD8+ T cells were significantly enriched in tumor compared to adjacent non-tumor liver tissues. PD1Hi CD8+ T cells highly expressed exhaustion-related inhibitory receptors (TIM3, CTLA-4, etc.) and transcription factors (Eomes, BATF, etc.). In addition, PD1Hi CD8+ T cells expressed low levels of cytotoxic molecules and displayed a compromised capacity to produce pro-inflammatory cytokines while the expression of anti-inflammatory IL-10 was up-regulated following mitotic stimulation. Furthermore, PD1Hi CD8+ T cells shared features with tissue resident memory T cells and were also characterized in an aberrantly activated status with an apoptosis-prone potential. In two independent cohorts of HCC patients (n = 358 and n = 254), we demonstrated that PD1Hi or TIM3+PD1Hi CD8+ T cells were significantly correlated with poor prognosis, and the latter was positioned in close proximity to PD-L1+ tumor associated macrophages. CONCLUSION: The current study unveils the unique features of PD1Hi CD8+ exhausted T cells in HCC, and also suggests that exhausted T cells could act as a biomarker to select the most care-demanding patients for tailored therapies.

CD4+T Cell Subset Profiling in Biliary Atresia Reveals ICOS- Regulatory T Cells as a Favorable Prognostic Factor.

Biliary atresia (BA) is a destructive pediatric liver disease and CD4+T cell activation is demonstrated to play an important role in BA. However, a comprehensive scenario regarding the involvement of CD4+T cell subsets to the development of BA remains unclear. Here, we aim to explore the infiltration of CD4+T cell subsets and their clinical significance in BA. In the present study, thirty BA liver samples were collected during surgery and were divided into good (BA1, n = 16) and poor prognosis (BA2, n = 14), with samples from choledochal cyst patients (n = 8) as control. By using multiplex immunohistochemistry, we evaluated the infiltration level of CD4+T cell subsets in the portal areas. RT-qPCR and flow cytometry were further applied to explore detailed features of Treg subsets. We revealed that hepatic infiltrating Th1, Th2, Th17, and ICOS+Treg cells were significantly increased in BA patients compared to controls and were negatively associated with prognosis, while high infiltrating ICOS-Tregs showed a favorable outcome. Phenotypic analysis indicated that, in contrast to ICOS+Tregs, ICOS-Tregs were mainly CD45RAhiCD45ROlow, and preferentially expressed more CD73. Besides, RT-qPCR revealed elevated expression of CD25, CD73, TGF-ß, and BCL-2 genes in ICOS-Tregs. Finally, functional assay confirmed that ICOS-Tregs had a higher suppressive capacity to cytokine secretion and were more resistant to apoptosis in vitro. Collectively, we demonstrate that a mixed immune response is involved in BA pathogenesis, and the globally enhanced effector CD4+T cell response is associated with unfavorable prognosis, highly suppressive ICOS-Tregs is a protective factor and may serve an important reference to predict prognosis.

Co-delivery of metformin and levofloxacin hydrochloride using biodegradable thermosensitive hydrogel for the treatment of corneal neovascularization.

Corneal neovascularization (CNV) is one of the major causes of severe disorders in ocular surface. Subconjunctival administration provides a localized and effective delivery of anti-angiogenic agents to inhibit neovascularization. In the present study, the ABA triblock copolymer of poly(D,L-lactic-co-glycolic acid)-block-poly(ethylene glycol)-block-poly(D,L-lactic-co-glycolic acid) (PLGA-PEG-PLGA) was used as a sustained drug delivery carrier for metformin (MET) and levofloxacin hydrochloride (LFH). Both drugs and PLGA-PEG-PLGA copolymers could be easily dissolved in water at low or room temperature and the mixed solution could form a drug-loaded thermosensitive hydrogel in terms of body temperature response. The in vitro release investigation displayed a sustained release of MET and LFH from the formulation for one month. The in vivo efficacy of subconjunctival injection of the MET + LFH loaded thermosensitive hydrogel in inhibiting CNV was evaluated on a mouse model of corneal alkali burn. Compared with the single administration of MET or LFH loaded thermosensitive hydrogel, the MET + LFH loaded thermosensitive hydrogel remarkably inhibited the formation of CNV. The sustained release of MET and an antibiotic (LFH) provides synergistic therapeutic outcome. As a result, the co-delivery of MET and LFH using PLGA-PEG-PLGA thermosensitive hydrogel by subconjunctival injection has great potential for ocular anti-angiogenic therapy.

Regulation of T cell differentiation and function by ubiquitin-specific proteases.

T cells play critical roles in immune responses to pathogens, autoimmunity, and antitumor immunity. During the past few decades, increasing numbers of studies have demonstrated the significance of protein ubiquitination in T cell-mediated immunity. Several E3 ubiquitin ligases and deubiquitinases (DUBs) have been identified as either positive or negative regulators of T cell development and function. In this review, we mainly focus on the roles of DUBs (especially ubiquitin-specific proteases (USPs)) in modulating T cell differentiation and function, as well as the molecular mechanisms. Understanding how T cell development and function is regulated by ubiquitination and deubiquitination will provide novel strategies for treating infection, autoimmune diseases, and cancer.

Tacrolimus-loaded methoxy poly(ethylene glycol)-block-poly(D,L)-lactic-co-glycolic acid micelles self-assembled in aqueous solution for treating cornea immune rejection after allogenic penetrating keratoplasty in rats.

This study aimed to develop a stable and biodegradable tacrolimus loaded nanocarrier that enhanced tacrolimus corneal penetration and delivered in a sustained manner, thus to create a promising treatment to prevent immune rejection after corneal allografts. Spherical tacrolimus loaded methoxy poly (ethylene glycol)-block-poly (D,L)-lactic-co-glycolic acid (mPEG-b-PLGA) micelles with a mean diameter of 81.3 ±â€¯1.3 nm were prepared by the solvent-evaporation-induced self-assembly. The physicochemical properties of tacrolimus loaded mPEG-b-PLGA micelles were evaluated, and the in vitro release behavior, degradation, cytotoxicity and bio-safety were all assessed. The ex vivo permeation of tacrolimus using rabbit corneas was also performed, and the cumulative permeation amount of tacrolimus from mPEG-b-PLGA micelles was significantly higher than 0.05% tacrolimus eye drops (p < 0.05). These results indicated that the formulations were feasible for intraocular drug delivery. Compared with 0.05% tacrolimus eye drops, the in vivo immunofluorescence analysis indicated the tacrolimus loaded mPEG-b-PLGA micelles remarkably inhibit the immune rejection after corneal allograft, with the lower expression levels of nuclear factor of activated T cells (NFAT), cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8). In conclusion, we provided evidences that tacrolimus loaded mPEG-b-PLGA micelles would be a promising treatment for immune rejection after corneal transplantation.

A novel FK506 loaded nanomicelles consisting of amino-terminated poly(ethylene glycol)-block-poly(D,L)-lactic acid and hydroxypropyl methylcellulose for ocular drug delivery.

FK506 (tacrolimus) is an effective immunosuppressant, but its poor water solubility and low bioavailability impose barriers to ocular drug delivery. The nanomicelles (NMs) formulations comprised of amino-terminated poly(ethylene glycol-block-poly(D,L)-lactic acid) (NH2-PEG-b-PLA) and hydroxypropyl methylcellulose (HPMC) were developed to increase the penetration of hydrophobic drugs in the eye and enhance the drug bioavailability for ocular disorder therapy. Spherical FK506/NH2-PEG-b-PLA/HPMC NMs with mean diameter of 101.4 ±â€¯1.3 nm were prepared by solvent-evaporation-induced self-assembly in aqueous solution. The NMs that sufficiently solubilized FK506 were evaluated in terms of stability, drug loading, encapsulation efficiency, surface tension, cellular cytotoxicity and in vitro release, and the results revealed the NMs were suitable for intraocular drug delivery. Compared with the 0.05% FK506 suspension drops, the in vitro permeation amount of FK506 from NMs exhibited significant increase. Besides, the higher concentration and longer retention of FK506 in ocular tissue were also confirmed in vivo. Furthermore, the FK506/NH2-PEG-b-PLA/HPMC NMs obviously inhibited the allograft rejection after corneal transplantation in rats. In conclusion, FK506/NH2-PEG-b-PLA/HPMC NMs formulations as a promising ocular drug delivery system would be able to improve the bioavailability and efficacy of FK506 in anti-allograft rejection.

USP10 regulates Musashi-2 stability via deubiquitination and promotes tumour proliferation in colon cancer.

Recent studies have demonstrated that ubiquitin-specific protease 10 (USP10) plays a catalytic role in tumour suppression mainly by deubiquitinating its target proteins to enhance their stabilities. However, we found that USP10 could interact with and regulate the expression of oncogenic factor Musashi-2 (MSI2). We investigated whether USP10 positively regulates the expression of MSI2 by deubiquitination and confirmed the type of polyubiquitin chain that is linked to MSI2. We also explored the role of USP10 in regulating the proliferation of colon cancer through different experiments. This study provides a completely new perspective in understanding the role of USP10 in deubiquitination. In the future, USP10 may serve as a target for colon cancer treatment.

Titanium complex with an [OSSO]-type bis(phenolate) ligand for ethylene copolymerization with vinyl polar monomer based on group protection.

The [OSSO]-type bis(phenolate) titanium complex 1 activated by methylaluminoxane (MAO) was tested as a homogeneous catalyst for ethylene coordination copolymerization with protected vinyl polar monomer of p-tert-butyl-dimethylsilyloxystyrene (p-TBDMSOS). The results showed that the active species were almost not poisonous to the catalyst by the protected vinyl polar monomer. Moreover, the composition and sequence length as well as sequence distribution in the copolymers were investigated by theoretical calculation and 13C nuclear magnetic resonance (13C NMR) characterization. Especially, the incorporation ratio of p-TBDMSOS into the polyethylene chain could be controlled by changing p-TBDMSOS concentration in the feed. Interestingly, an approximate alternating copolymer of poly(E-alt-(p-TBDMSOS)) could be formed when the p-TBDMSOS feed concentration increased to 1.0 mol L-1. Subsequently, the poly(ethylene-co-(p-hydroxystyrene)) (poly(E-co-(p-HOS))) could be prepared by a facile deprotection in terms of desilylation of tert-butyldimethylsilyl ether. The hydrophilicity of poly(E-co-(p-HOS)) films were investigated by water contact angle measurements.

The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane.

Herein, two salalen titanium(iv) complexes were synthesized and characterized. These complexes coexisted as two isomers in certain conditions and underwent isomerization, as evidenced by 1H NMR spectroscopy. Furthermore, the molar ratio of the two isomers ranged from 100 : 15 at 30 °C to 100 : 34 at 120 °C, driven by thermal energy, based on variable temperature 1H NMR characterization. Both complexes were employed as catalysts for ethylene polymerization in the presence of methylaluminoxane (MAO). The influence of the electronic effects of different substituent groups at the ortho position of the phenolate on ethylene polymerization behaviors, molecular weight and molecular weight distributions of the resulting polyethylene was investigated. The fluorinated salalen titanium(iv) complex revealed relatively high catalytic activity and thermal stability owing to the electron-withdrawing inductive effect. Moreover, disentangled linear polyethylene with ultrahigh molecular weight (M w up to 3000 kDa) and narrow molecular weight distribution (M w/M n ∼ 2) was obtained in the polymerization temperature range of 30 °C to 50 °C.

Ring finger protein 31-mediated atypical ubiquitination stabilizes forkhead box P3 and thereby stimulates regulatory T-cell function.

The CD4+CD25+FOXP3+ regulatory T (Treg) cells are critical for maintaining immune tolerance in healthy individuals and are reported to restrict anti-inflammatory responses and thereby promote tumor progression, suggesting them as a target in the development of antitumor immunotherapy. Forkhead box P3 (FOXP3) is a key transcription factor governing Treg lineage differentiation and their immune-suppressive function. Here, using Treg cells, as well as HEK-293T and Jurkat T cells, we report that the stability of FOXP3 is directly and positively regulated by the E3 ubiquitin ligase ring finger protein 31 (RNF31), which catalyzes the conjugation of atypical ubiquitin chains to the FOXP3 protein. We observed that shRNA-mediated RNF31 knockdown in human Treg cells decreases FOXP3 protein levels and increases levels of interferon-γ, resulting in a Th1 helper cell-like phenotype. Human Treg cells that ectopically expressed RNF31 displayed stronger immune-suppressive capacity, suggesting that RNF31 positively regulates both FOXP3 stability and Treg cell function. Moreover, we found that RNF31 is up-regulated in Treg cells that infiltrate human gastric tumor tissues compared with their counterparts residing in peripheral and normal tissue. We also found that elevated RNF31 expression in intratumoral Treg cells is associated with poor survival of gastric cancer patients, suggesting that RNF31 supports the immune-suppressive functions of Treg cells. Our results suggest that RNF31 could be a potential therapeutic target in immunity-based interventions against human gastric cancer.

Cartilage oligomeric matrix protein is a prognostic factor and biomarker of colon cancer and promotes cell proliferation by activating the Akt pathway.

PURPOSE: Recent studies have determined that cartilage oligomeric matrix protein (COMP) plays a vital role in carcinogenesis. We sought to clarify the role of COMP in colon cancer. METHODS: We investigated gene expression data from The Cancer Genome Atlas (TCGA) dataset. Tissue microarrays (TMA) containing paired samples from 253 patients with colon cancer were subjected to immunostaining. COMP levels in serum of colon cancer patients and healthy donors were measured with ELISA. We established COMP-knockout cells using the CRISPR/Cas9 system and COMP-overexpressing cells using lentiviral vectors to detect the effects of COMP on colon cancer cells using Cell Counting Kit-8 (CCK8), colony formation, apoptosis detection kit, and tumorigenesis assays in nude mice. RESULTS: The analysis of TCGA dataset and the results of the TMA suggested that COMP expression levels were significantly higher in cancer tissues than in adjacent normal tissues. Moreover, high COMP expression was correlated with the poor outcome of colon cancer patients. COMP levels in the sera of preoperative patients with colon cancer were much higher than those in healthy donors and were significantly reduced after colectomy. Colon cancer cells without COMP were defective with respect to the ability to proliferate, colony formation, the ability to resist 5-Fluorouracil-induced apoptosis and the growth of xenograft tumors in mice. Contrasting results were observed in COMP overexpressed cells. COMP promoted colon cancer cell proliferation partially through the activation of PI3K/ Akt/ mTOR/ p70S6K pathway. CONCLUSIONS: COMP may be a novel prognostic indicator and biomarker and also a potential therapeutic target for colon cancer.

Synthesis and self-assembly of a novel amphiphilic diblock copolymer consisting of isotactic polystyrene and 1,4-trans-polybutadiene-graft-poly(ethylene oxide).

Herein, a novel amphiphilic diblock copolymer consisting of isotactic polystyrene (iPS) and 1,4-trans-polybutadiene-graft-poly(ethylene oxide) (1,4-trans-PBD-g-PEO), iPS-b-(1,4-trans-PBD-g-PEO), was synthesized by the combination of living coordination copolymerization and graft copolymerization. iPS-b-1,4-trans-PBD was firstly synthesized via sequential monomer addition in the presence of 1,4-dithiabutandiyl-2,2'-bis(6-cumenyl-4-methylphenoxy) titanium dichloride (complex 1) activated by triisobutyl aluminum modified methylaluminoxane (MMAO). Moreover, hydroboration of double bonds in the 1,4-trans-PBD blocks were performed with 9-borabicyclo[3.3.1]nonane (9-BBN) and subsequent oxidation by NaOH/H2O2 to form hydroxyls. Consequently, PEO was grafted into the hydroxylated 1,4-trans-PBD block in terms of ring-opening polymerization of ethylene oxide with potassium/naphthalide as initiatior. We also described solvent-evaporation-induced self-assembly of iPS-b-1,4-trans-PBD in n-dodecane and iPS-b-1,4-trans-PBD-g-PEO in aqueous solution, which were selective solvent for 1,4-trans-PBD and for 1,4-trans-PBD-g-PEO blocks, respectively. In these cases, tetrahydrofuran (THF) was used as good and volatile solvent. These resultant iPS-containing diblock copolymers could self-assemble into spherical nano-micelles with an iPS core as amorphous agglomeration or a very low degree of crystallinity resulting from slow crystallization rate and nanoconfinement. In addition, after isothermal crystallization of iPS in the micellar cores self-assembled in n-dodecane at 120 °C for 3 hours, the micellar morphology changed from sphere-like to platelet-like. It was believed that isothermal crystallization of iPS induced the deformation of the micelles.