Targeting the KAT8/YEATS4 Axis Represses Tumor Growth and Increases Cisplatin Sensitivity in Bladder Cancer.

Bladder cancer (BC) is one of the most common tumors characterized by a high rate of relapse and a lack of targeted therapy. Here, YEATS domain-containing protein 4 (YEATS4) is an essential gene for BC cell viability using CRISPR-Cas9 library screening is reported, and that HUWE1 is an E3 ligase responsible for YEATS4 ubiquitination and proteasomal degradation by the Protein Stability Regulators Screening Assay. KAT8-mediated acetylation of YEATS4 impaired its interaction with HUWE1 and consequently prevented its ubiquitination and degradation. The protein levels of YEATS4 and KAT8 are positively correlated and high levels of these two proteins are associated with poor overall survival in BC patients. Importantly, suppression of YEATS4 acetylation with the KAT8 inhibitor MG149 decreased YEATS4 acetylation, reduced cell viability, and sensitized BC cells to cisplatin treatment. The findings reveal a critical role of the KAT8/YEATS4 axis in both tumor growth and cisplatin sensitivity in BC cells, potentially generating a novel therapeutic strategy for BC patients.

Genome and transcriptome analysis of Enterococcus faecium from intestinal colonization and Enterococcus faecium from urinary tract infection.

Introduction: Enterococcus faecium is a common pathogen responsible for urinary tract infections (UTIs) and often establishes extensive colonization within the intestinal tract. Our aim was to assess the genomic and transcriptomic differences between colonized E. faecium without UTI (only-colonization) and colonized E. faecium causing UTI (endogenous infections). Method: We investigated the correlation between fecal isolates from the same patient and UTI-causing isolates using PFGE and WGS, and classified fecal isolates into two groups: those that solely colonized and those associated with endogenous urinary tract infections. We characterized the genomes of colonization-only and endogenously infected isolates by Scoary GWAS, and the transcriptomes of the isolates at 3 h urine exposure to assess pathogen-related changes. Result: Based on PFGE and WGS, eight isolates of endogenously infected E. faecium and nine isolates of only-colonized E. faecium were characterized and carbon and nitrogen regulated metabolisms such as genes encoding the phosphotransferase (PTS) system were enriched in endogenously infected E. faecium. Transcriptome analysis revealed significant differences in gene expression in the PTS system, lysine synthesis, galactose metabolism and citrate import between endogenously infected and only-colonized E. faecium isolates, highlighting the important role of certain carbon regulatory genes in the colonization and survival of endogenously infected E. faecium. Conclusion: In only-colonized and endogenously infected isolates, we observed differential expression patterns of genes related to carbon metabolism and amino acids, suggesting that metabolic diversity is a strategy for isolates leading to endogenous infection.

Augmenting L3MBTL2-induced condensates suppresses tumor growth in osteosarcoma.

Osteosarcoma is a highly aggressive cancer and lacks effective therapeutic targets. We found that L3MBTL2 acts as a tumor suppressor by transcriptionally repressing IFIT2 in osteosarcoma. L3MBTL2 recruits the components of Polycomb repressive complex 1.6 to form condensates via both Pho-binding pockets and polybasic regions within carboxyl-terminal intrinsically disordered regions; the L3MBTL2-induced condensates are required for its tumor suppression. Multi-monoubiquitination of L3MBTL2 by UBE2O results in its proteasomal degradation, and the UBE2O/L3MBTL2 axis was crucial for osteosarcoma growth. There is a reverse correlation between L3MBTL2 and UBE2O in osteosarcoma tissues, and higher UBE2O and lower L3MBTL2 are associated with poorer prognosis in osteosarcoma. Pharmacological blockage of UBE2O by arsenic trioxide can enhance L3MBTL2-induced condensates and consequently suppress osteosarcoma growth. Our findings unveil a crucial biological function of L3MBTL2-induced condensates in mediating tumor suppression, proposing the UBE2O-L3MBTL2 axis as a potential cancer therapeutic target in osteosarcoma.

NFYC-37 promotes tumor growth by activating the mevalonate pathway in bladder cancer.

Dysregulation of transcription is a hallmark of cancer, including bladder cancer (BLCA). CRISPR-Cas9 screening using a lentivirus library with single guide RNAs (sgRNAs) targeting human transcription factors and chromatin modifiers is used to reveal genes critical for the proliferation and survival of BLCA cells. As a result, the nuclear transcription factor Y subunit gamma (NFYC)-37, but not NFYC-50, is observed to promote cell proliferation and tumor growth in BLCA. Mechanistically, NFYC-37 interacts with CBP and SREBP2 to activate mevalonate pathway transcription, promoting cholesterol biosynthesis. However, NFYC-50 recruits more of the arginine methyltransferase CARM1 than NFYC-37 to methylate CBP, which prevents the CBP-SREBP2 interaction and subsequently inhibits the mevalonate pathway. Importantly, statins targeting the mevalonate pathway can suppress NFYC-37-induced cell proliferation and tumor growth, indicating the need for conducting a clinical trial with statins for treating patients with BLCA and high NFYC-37 levels, as most patients with BLCA have high NFYC-37 levels.

Genomic Epidemiology and Antimicrobial Resistance Profiles of Clostridioides difficile from Multi-Hospitals in a City in Eastern China.

Background: Clostridioides difficile is an important pathogen causing approximately 20-30% of the cases-with antibiotic-associated diarrhea and 90% of those with Pseudomembranous enteritis. However, limited surveillance of C. difficile infections (CDI) in China is done at present, especially in terms of multi-hospital epidemiological reports. Methods: Between June 2020 and November 2020, we conducted a prospective study addressing antimicrobial susceptibility profiles and genomic epidemiology of C. difficile strains isolated from inpatients with diarrhea in seven tertiary hospitals in the same city. Results: In total, 177 strains of toxin-producing C. difficile were isolated, and the dominant toxin gene profiles were tcdA+tcdB+ (84.2%, 149/177) and tcdA-tcdB+ (15.8%, 28/177). Furthermore, 130 isolates were successfully analyzed for antimicrobial susceptibility phenotype in which the rates of resistance to clindamycin, erythromycin, levofloxacin, and moxifloxacin were higher than to other antibiotics. All strains were susceptible to metronidazole and vancomycin. Fluoroquinolone-associated mutations (such as gyrA) were the most frequently found ones in the analyzed genomes. Moreover, 24 different sequence types (STs) were identified in the 130 isolates, and the most prevalent types were ST3 (26.2%, 34/130) followed by ST54 (16.9%, 22/130) and ST2 (10%, 13/130). The so-called highly virulent strain ribotyping 027 (B1/NAP1/ST1) was not identified. In addition, we also compared single nucleotide polymorphisms (SNPs) among the isolates and carried out genomic epidemiological studies on the isolates. We found that ST3 and ST54 could cause transmission in both intra- and inter-hospital settings. Conclusion: Although it is the so-called hypervirulent epidemic strain, ribotyping 027 (ST1), was not detected. ST3 and ST54 can be transmitted through different hospitals. Therefore, it is necessary to conduct further molecular epidemiological monitoring of C. difficile and screening of patients admitted to key departments.

Disrupting the phase separation of KAT8-IRF1 diminishes PD-L1 expression and promotes antitumor immunity.

Immunotherapies targeting the PD-1/PD-L1 axis have become first-line treatments in multiple cancers. However, only a limited subset of individuals achieves durable benefits because of the elusive mechanisms regulating PD-1/PD-L1. Here, we report that in cells exposed to interferon-γ (IFNγ), KAT8 undergoes phase separation with induced IRF1 and forms biomolecular condensates to upregulate PD-L1. Multivalency from both the specific and promiscuous interactions between IRF1 and KAT8 is required for condensate formation. KAT8-IRF1 condensation promotes IRF1 K78 acetylation and binding to the CD247 (PD-L1) promoter and further enriches the transcription apparatus to promote transcription of PD-L1 mRNA. Based on the mechanism of KAT8-IRF1 condensate formation, we identified the 2142-R8 blocking peptide, which disrupts KAT8-IRF1 condensate formation and consequently inhibits PD-L1 expression and enhances antitumor immunity in vitro and in vivo. Our findings reveal a key role of KAT8-IRF1 condensates in PD-L1 regulation and provide a competitive peptide to enhance antitumor immune responses.

Retrospective Study of the Epidemiology of Clostridioides difficile Infection in the Neurosurgery Department of a Tertiary Hospital in China.

Background: Although the epidemiology of Clostridioides difficile is important, few studies examining transmission of C. difficile have been reported, especially in wards with low detection rates, such as neurosurgery departments. Purpose: This retrospective study investigated the epidemiology of C. difficile infection in a neurosurgery department over a 24-month period, particularly examining the transmission of C. difficile using whole-genome sequencing (WGS). Methods: Clostridioides difficile strains were isolated and identified from fecal samples of neurosurgical patients. Toxigenic strains were typed using multilocus sequence typing, PCR ribotyping and using capillary gel electrophoresis. WGS was used to characterize C. difficile ST-37/RT017 isolates, and comparative genomic analyses were performed to compare genomic differences between all ST-37 strains from other wards. The susceptibility to 8 antimicrobial agents was examined using the E-test. Results: Comparative genomic analyses revealed that isolates obtained from neurosurgical patients clustered into two lineages. Only strains s11052403 and s10090304, respectively, isolated from a patient on the 8th floor of the neurosurgery ward and a patient on the 9th floor, were highly similar, exhibiting differences of only two single-nucleotide polymorphisms. All C. difficile ST-37/RT017 strains isolated from neurosurgical patients were resistant to multiple classes of antibiotics. Conclusion: There is an urgent need to raise awareness of C. difficile infection, and epidemiologic surveillance is required to detect clustering and transmission of C. difficile cases in China. Strict disinfection of the environment is essential to reduce transmission of C. difficile and achieve effective infection control in the hospital setting.

Knockdown of ZBTB11 impedes R-loop elimination and increases the sensitivity to cisplatin by inhibiting DDX1 transcription in bladder cancer.

INTRODUCTION: Bladder cancer (BC) is one of the most common malignant cancers, with poor prognosis and high incidence. Cisplatin is the standard chemotherapy for muscle invasive bladder cancer; however, chemotherapy resistance remains a major challenge. Moreover, oncogenic signalling and the specific mechanisms underlying cisplatin resistance in BC remain largely unclear METHODS: In this study, RT-PCR, Western blot, immunofluorescence, and immunohistochemistry were used to measure gene and protein expression. Colony formation assay and flow cytometry were performed to evaluate the proliferation of BC cells. Gene set enrichment analysis was performed to identify the function in which ZBTB11 was involved. Luciferase and chromatin immunoprecipitation experiments were performed to determine the transcriptional regulation mechanism of ZBTB11. The effects of ZBTB11 on the malignant phenotypes of BC cells were examined in vitro and in vivo RESULTS: The results showed that ZBTB11 was remarkably upregulated in BC tissues, which was associated with poor prognosis in patients with BC. Furthermore, we found that knockdown of ZBTB11 remarkably inhibited the proliferation and tumorigenesis of BC cells by inducing apoptosis. Mechanistically, the knockdown of ZBTB11 transcriptionally inhibited DDX1 to suppress R-loop clearance, resulting in DNA damage in BC cells. Importantly, the ZBTB11/DDX1 axis is required for the chemotherapy resistance of BC cells to cisplatin CONCLUSION: Our findings not only reveal an underlying mechanism by which the ZBTB11/DDX1 axis promotes the tumorigenesis of BC but also provide a potential target for a combination strategy of cisplatin-based chemotherapy for BC.

Akkermansia muciniphila Ameliorates Clostridioides difficile Infection in Mice by Modulating the Intestinal Microbiome and Metabolites.

Clostridioides difficile is a common cause of nosocomial infection. Antibiotic-induced dysbiosis in the intestinal microbiota is a core cause of C. difficile infection (CDI). Akkermansia muciniphila plays an active role in maintaining gastrointestinal balance and might offer the protective effects on CDI as probiotics. Here, we investigated the effects and mechanisms of A. muciniphila on CDI. C57BL/6 mice (n = 29) were administered A. muciniphila Muc T (3 × 109 CFUs, 0.2 mL) or phosphate-buffered saline (PBS) by oral gavage for 2 weeks. Mice were pretreated with an antibiotic cocktail and subsequently challenged with the C. difficile strain VPI 10463. A. muciniphila treatment prevented weight loss in mice and reduced the histological injury of the colon. And it also alleviated inflammation and improved the barrier function of the intestine. The administration effects of A. muciniphila may be associated with an increase in short-chain fatty acid production and the maintenance of bile acids' steady-state. Our results provide evidence that administration of A. muciniphila to CDI mice, with an imbalance in the microbial community structure, lead to a decrease in abundance of members of the Enterobacteriaceae and Enterococcaceae. In short, A. muciniphila shows a potential anti-CDI role by modulating gut microbiota and the metabolome.

CREB1 contributes colorectal cancer cell plasticity by regulating lncRNA CCAT1 and NF-κB pathways.

The CREB1 gene encodes an exceptionally pleiotropic transcription factor that frequently dysregulated in human cancers. CREB1 can regulate tumor cell status of proliferation and/or migration; however, the molecular basis for this switch involvement in cell plasticity has not fully been understood yet. Here, we first show that knocking out CREB1 triggers a remarkable effect of epithelial-mesenchymal transition (EMT) and leads to the occurrence of inhibited proliferation and enhanced motility in HCT116 colorectal cancer cells. By monitoring 45 cellular signaling pathway activities, we find that multiple growth-related pathways decline significantly while inflammatory pathways including NF-κB are largely upregulated in comparing between the CREB1 wild-type and knocked out cells. Mechanistically, cells with CREB1 knocked out show downregulation of MYC as a result of impaired CREB1-dependent transcription of the oncogenic lncRNA CCAT1. Interestingly, the unbalanced competition between the coactivator CBP/p300 for CREB1 and p65 leads to the activation of the NF-κB pathway in cells with CREB1 disrupted, which induces an obvious EMT phenotype of the cancer cells. Taken together, these studies identify previously unknown mechanisms of CREB1 in CRC cell plasticity via regulating lncRNA CCAT1 and NF-κB pathways, providing a critical insight into a combined strategy for CREB1-targeted tumor therapies.

Molecular characterization and antibiotic resistance of Clostridioides difficile in patients with inflammatory bowel disease from two hospitals in China.

OBJECTIVES: Patients with inflammatory bowel disease (IBD) are susceptible to Clostridioides difficile infection (CDI), resulting in poor outcomes and recurrence; therefore, the molecular characterization of C. difficile in IBD patients in China needs further investigation. METHODS: C. difficile strains were isolated and identified from faecal samples of adult and paediatric IBD patients. Toxigenic strains were typed using multilocus sequence typing and whole genomic sequencing (WGS) to construct the phylogenetic tree. Susceptibility to 10 antimicrobials was evaluated using the Etest. RESULTS: Among the 838 IBD patients, 82 toxigenic C. difficile were identified, which comprised 46 from adults and 36 children. A total of 90.2% (74/82) of the isolates were positive for both toxin A and toxin B genes (A+B+), whereas the remaining 9.8% were negative for toxin A gene but positive for toxin B gene (A-B+). These toxigenic strains were susceptible to metronidazole and vancomycin, but highly resistant to clindamycin, erythromycin, and fluoroquinolones. All moxifloxacin-resistant isolates had mutations resulting in an amino acid substitution in gryA (T82I). The dominant types were ST-35 (20.7%), ST-2 (17.1%), ST-54 (13.4%), and ST-3 (13.4%) in all patients. CONCLUSION: The incidence and molecular epidemiology of C. difficile infection in adult IBD patients resembled CDI in the general inpatient population. A higher antibiotic resistance rate was identified among the C. difficile isolates obtained from paediatric IBD patients than from adult patients, and a few STs accounted for most multidrug-resistant strains. However, the molecular genetic features of the same ST type between these two groups remains highly correlated.

Downregulation of HINFP induces senescence-associated secretory phenotype to promote metastasis in a non-cell-autonomous manner in bladder cancer.

Transcription dysregulation is a salient characteristic of bladder cancer (BC), but no appropriate therapeutic target for it has been established. Here, we found that heterogeneous downregulation of histone H4 transcription factor (HINFP) was associated with senescence in BC tissues and that lower HINFP expression could predict an unfavorable outcome in BC patients. Knockout of HINFP transcriptionally inhibited H1F0 and H1FX to trigger DNA damage, consequently inducing cell senescence to repress the proliferation and growth of BC cells. However, the senescence-associated secretory phenotype, characterized by increases in MMP1/3, enhances the invasion and metastasis of non-senescent BC cells. Histone deacetylase inhibitors (HDACis) could efficiently eliminate the senescent cells induced by HINFP knockout to suppress the invasion and metastasis of BC cells. Our study suggests that HDACis, widely used in multiple cancer types in a clinical context, may also benefit BC patients with metastases induced by cell senescence.

Disordered Intestinal Microbial Communities During Clostridioides difficile Colonization and Subsequent Infection of Hepatic Cirrhosis Patients in a Tertiary Care Hospital in China.

Patients with hepatic cirrhosis are more susceptible to Clostridioides difficile infection (CDI) and colonization with Clostridioides difficile (C. difficile). Asymptomatic C. difficile colonization is thought to predispose to subsequent CDI. However, the dynamic gut microbiota changes remain unclear. In this study, we used 16S rRNA gene sequencing to longitudinally monitor alterations in the intestinal microbiota of 22 hepatic cirrhosis patients with toxigenic C. difficile colonization at admission (pre-CDI) and developed CDI during hospitalization, subdivided into pre-CDI and CDI. 21 hospitalized cirrhotic patients without C. difficile colonization served as controls (HC). Compared with HC, pre-CDI and CDI samples had significantly decreased microbial richness and diversity, a significantly higher relative abundance of opportunistic pathogen Enterococcus, and a lower relative abundance of beneficial symbionts, such as Faecalibacterium, Dorea, and Roseburia. Three biomarkers showed high accuracy for distinguishing pre-CDI samples from HC with an area under the curve (AUC) up to 0.81. In conclusion, our study explored the changes of the gut microbiome before and after CDI. The gut microbial richness as well as diversity in CDI patients were notably reduced, relative to controls. Imbalance of the intestinal flora may be related to the risk for development of CDI. Identifying key members of the gut microbiota and illustrating their roles and mechanisms of action in CDI development are important avenues for future research.

Expression and prognostic significance of NKD2 in ovarian cancer.

PURPOSE: Naked2 (NKD2) is a negative regulator of Wnt signaling pathway and associates with transforming growth factor secretion. The role of NKD2 in ovarian cancer is unknown. PATIENTS AND METHODS: Gene expression profiles were measured and compared in nine patients by RNA sequencing. NKD2 expressions in ovarian cancer were measured by reverse transcription polymerase chain reaction and western blot. Tissue slides of 79 patients were stained and scored for NKD2 expression. In vitro experiments were conducted to explore the role of NKD2 in ovarian cancer. The prognostic role of NKD2 was evaluated by survival analysis. RESULTS: NKD2 was upregulated in patients with better survival by mRNA and protein expression. Patients were classified as NKD2-high group (n = 30) and NKD2-low group (n = 49) according to immunohistochemical score. High NKD2 was correlated with lower recurrence rate (P = 0.002) and higher percentage of platinum-sensitive recurrence (P = 0.006). Median progression-free survival was significantly longer for NKD2-high patients than NKD2-low patients (49.1 vs.14.1 months, P < 0.001). Accordingly, there was a significantly difference in terms of overall survival time between two groups (hazard ratio: 3.04; 95% confidence interval: 1.58-5.85, P < 0.001). Multivariate regression suggested that NKD2 was independently prognostic factors in terms of progression-free survival (hazard ratio: 2.91; 95% confidence interval: 1.61-5.27, P < 0.001) and overall survival (hazard ratio: 3.6; 95% confidence interval: 1.80-7.21, P < 0.001). In vitro studies further demonstrated that NKD2 suppressed ovarian cancer cell proliferation, colony formation and cell migration. CONCLUSION: NKD2 is a novel prognostic marker and could suppress tumor progression in ovarian cancer.

Inhibition of ferroptosis by up-regulating Nrf2 delayed the progression of diabetic nephropathy.

Diabetic nephropathy (DN) is now considered the leading cause of end-stage renal disease. In diabetes, the accumulation of reactive oxygen species (ROS) and iron overload are important determinants that promote the occurrence of DN. However, the underlying mechanism of how they cause diabetic kidney damage remains unclear. Ferroptosis, characterized by iron-dependent lipid peroxidation, provided us with a new idea to explore the progression of DN. Iron overload, reduced antioxidant capability, massive ROS and lipid peroxidation were detected in the kidneys of streptozotocin-induced DBA/2J diabetic mice and high-glucose cultured human renal proximal tubular (HK-2) cells, which were the symbolic changes of ferroptosis. Furthermore, the characteristic mitochondrial morphological changes of ferroptosis were observed in high glucose cultured cells. Additional treatment of Ferrostatin-1 (Fer-1) in DN models significantly rescued these changes and alleviated the renal pathological injuries in diabetic mice. Besides, the decreased NFE2-related factor 2 (Nrf2) was observed in DN models. The specific knockdown of Nrf2 increased the sensitivity of cells to ferroptosis in the high glucose condition. In Nrf2 knockdown cells, up-regulating Nrf2 by treating with fenofibrate improved the situation of ferroptosis, which was verified in RSL-3 induced cells. Moreover, the ferroptosis-related changes were inhibited by increasing Nrf2 in fenofibrate treated diabetic mice, which delayed the progression of DN. Collectively, we demonstrated that ferroptosis was involved in the development of DN, and up-regulating Nrf2 by treating with fenofibrate inhibited diabetes-related ferroptosis, delaying the progression of DN. Our research revealed the development mechanism of DN from a new perspective, and provide a new approach delaying the progression of DN.

Systematic screening for potential therapeutic targets in osteosarcoma through a kinome-wide CRISPR-Cas9 library.

Objective: Osteosarcoma is the most common primary malignant bone tumor. However, the survival of patients with osteosarcoma has remained unchanged during the past 30 years, owing to a lack of efficient therapeutic targets. Methods: We constructed a kinome-targeting CRISPR-Cas9 library containing 507 kinases and 100 nontargeting controls and screened the potential kinase targets in osteosarcoma. The CRISPR screening sequencing data were analyzed with the Model-based Analysis of Genome-wide CRISPR/Cas9 Knockout (MAGeCK) Python package. The functional data were applied in the 143B cell line through lenti-CRISPR-mediated gene knockout. The clinical significance of kinases in the survival of patients with osteosarcoma was analyzed in the R2: Genomics Analysis and Visualization Platform. Results: We identified 53 potential kinase targets in osteosarcoma. Among these targets, we analyzed 3 kinases, TRRAP, PKMYT1, and TP53RK, to validate their oncogenic functions in osteosarcoma. PKMYT1 and TP53RK showed higher expression in osteosarcoma than in normal bone tissue, whereas TRRAP showed no significant difference. High expression of all 3 kinases was associated with relatively poor prognosis in patients with osteosarcoma. Conclusions: Our results not only offer potential therapeutic kinase targets in osteosarcoma but also provide a paradigm for functional genetic screening by using a CRISPR-Cas9 library, including target design, library construction, screening workflow, data analysis, and functional validation. This method may also be useful in potentially accelerating drug discovery for other cancer types.

SUMOylation stabilizes hSSB1 and enhances the recruitment of NBS1 to DNA damage sites.

Human single-stranded DNA-binding protein 1 (hSSB1) is required for the efficient recruitment of the MRN complex to DNA double-strand breaks and is essential for the maintenance of genome integrity. However, the mechanism by which hSSB1 recruits NBS1 remains elusive. Here, we determined that hSSB1 undergoes SUMOylation at both K79 and K94 under normal conditions and that this modification is dramatically enhanced in response to DNA damage. SUMOylation of hSSB1, which is specifically fine-tuned by PIAS2α, and SENP2, not only stabilizes the protein but also enhances the recruitment of NBS1 to DNA damage sites. Cells with defective hSSB1 SUMOylation are sensitive to ionizing radiation, and global inhibition of SUMOylation by either knocking out UBC9 or adding SUMOylation inhibitors significantly enhances the sensitivity of cancer cells to etoposide. Our findings reveal that SUMOylation, as a novel posttranslational modification of hSSB1, is critical for the functions of this protein, indicating that the use of SUMOylation inhibitors (e.g., 2-D08 and ML-792) may be a new strategy that would benefit cancer patients being treated with chemo- or radiotherapy.

A bio-inspired injectable hydrogel as a cell platform for real-time glycaemic regulation.

Frequent subcutaneous insulin injection and islet transplantation are promising therapeutic options for type 1 diabetes mellitus. However, poor patient compliance, insufficient appropriate islet ß cell donors and body immune rejection limit their clinical applications. The design of a platform capable of encapsulating insulin-secreting cells and achieving real-time blood glucose regulation, is a so far unmet need. Herein, inspired by the natural processes of regulating blood glucose in pancreatic islet ß cells, we developed a poly(N-isopropylacrylamide-co-dextran-maleic acid-co-3-acrylamidophenylboronic acid) (P(AAPBA-Dex-NIPAM)) hydrogel as a cell platform with glucose responsiveness and thermo-responsiveness for the therapy of diabetes. This platform showed good biocompatibility against insulin-secreting cells and presented glucose-dependent insulin release behaviour. The bioinspired P(AAPBA6-Dex-NIPAM64) hydrogel had a positive effect on real-time glycaemic regulation, as observed by intraperitoneal glucose tolerance tests. The non-fasting blood glucose of diabetic rats was restored to a normal level during the period of treatment. Additionally, the inflammatory response did not occur after administration of the platform. Collectively, we expected that the bio-mimetic platform combined with an insulin-secreting capability could be a new diabetic treatment strategy.

miR-372 and miR-373 enhance the stemness of colorectal cancer cells by repressing differentiation signaling pathways.

miR-372/373, a cluster of stem cell-specific microRNAs transactivated by the Wnt pathway, has been reported to be dysregulated in various cancers, particularly colorectal cancer (CRC); however, the unique role of these microRNAs in cancer remains to be discovered. In the present study, we characterized the upregulation in expression of miR-372/373 in CRC tissues from The Cancer Genome Atlas data, and then showed that overexpression of miR-372/373 enhanced the stemness of CRC cells by enriching the CD26/CD24-positive cell population and promoting self-renewal, chemotherapy resistance and the invasive potential of CRC cells. To clarify the mechanism underlying microRNA-induced stemness, we profiled 45 cell signaling pathways in CRC cells overexpressing miR-372/373 and found that stemness-related pathways, such as Nanog and Hedgehog, were upregulated. Instead, differentiation-related pathways, such as NFκB, MAPK/Erk and VDR, were markedly repressed by miR-372/373. Numerous new targets of miR-372/373 were identified, including SPOP, VDR and SETD7, all of which are factors important for cell differentiation. Furthermore, in contrast to the increase in miR-372/373 expression in CRC tissues, the expression levels of SPOP and VDR mRNA were significantly downregulated in these tissues, indicative of the poor differentiation status of CRC. Taken together, our findings suggest that miR-372/373 enhance CRC cell stemness by repressing the expression of differentiation genes. These results provide new insights for understanding the function and mechanisms of stem cell-specific microRNAs in the development of metastasis and drug resistance in CRC.

Wnt/ß-catenin pathway transactivates microRNA-150 that promotes EMT of colorectal cancer cells by suppressing CREB signaling.

A hallmark of aberrant activation of the Wnt/ß-catenin signaling pathway has been observed in most colorectal cancers (CRC), but little is known about the role of non-coding RNAs regulated by this pathway. Here, we found that miR-150 was the most significantly upregulated microRNA responsive to elevated of Wnt/ß-catenin signaling activity in both HCT116 and HEK293T cells. Mechanistically, the ß-catenin/LEF1 complex binds to the conserved TCF/LEF1-binding element in the miR-150 promoter and thereby transactivates its expression. Enforced expression of miR-150 in HCT116 cell line transformed cells into a spindle shape with higher migration and invasion activity. miR-150 markedly suppressed the CREB signaling pathway by targeting its core transcription factors CREB1 and EP300. Knockdown of CREB1 or EP300 and knockout of CREB1 by CRISPR/Cas9 phenocopied the epithelial-mesenchymal transition (EMT) observed in HCT116 cells in response to miR-150 overexpression. In summary, our data indicate that miR-150 is a novel Wnt effector that may significantly enhance EMT of CRC cells by targeting the CREB signaling pathway.