Galectin-3 induces pathogenic immunosuppressive macrophages through interaction with TREM2 in lung cancer.

BACKGROUND: High infiltration of tumor-associated macrophages (TAMs) is associated with tumor promotion and immunosuppression. The triggering receptor expressed on myeloid cells 2 (TREM2) is emerged as a key immunosuppressive regulator for TAMs, however, how TREM2-expressing TAMs are recruited and what ligands TREM2 interacts with to mediate immunosuppression is unknown. METHODS: Flow cytometry and single-cell RNA sequencing were used to analyze TREM2 expression. Mechanistically, mass spectrometry and immunoprecipitation were employed to identify proteins binding to TREM2. Phagocytosis and co-culture experiments were used to explore the in vitro functions of galectin3-TREM2 pair. Establishment of TREM2f/f-Lyz2-cre mice to validate the role of TREM2 signaling pathway in lung carcinogenesis. GB1107 were further supplemented to validate the therapeutic effect of Galectin3 based on TREM2 signaling regulation. RESULTS: This study identified that abundant TREM2+ macrophages were recruited at the intra-tumor site through the CCL2-CCR2 chemotactic axis. Galectin-3 impaired TREM2-mediated phagocytosis and promoted the conversion of TREM2+ macrophages to immunosuppressive TAMs with attenuated antigen presentation and co-stimulatory functions both in vitro both in vivo, and galectin-3 is a potential ligand for TREM2. Genetic and pharmacological blockade of TREM2 and galectin-3 significantly inhibited lung cancer progression in subcutaneous and orthotopic cancer models by remodeling the tumor immune microenvironment. CONCLUSION: Our findings revealed a previously unknown association between galectin-3 and TREM2 in TAMs of lung cancer, and suggested simultaneous inhibition of galectin3 and TREM2 as potent therapeutic approach for lung cancer therapy.

Advances in drug delivery-based therapeutic strategies for renal fibrosis treatment.

Renal fibrosis is the result of all chronic kidney diseases and is becoming a major global health hazard. Currently, traditional treatments for renal fibrosis are difficult to meet clinical needs due to shortcomings such as poor efficacy or highly toxic side effects. Therefore, therapeutic strategies that target the kidneys are needed to overcome these shortcomings. Drug delivery can be attained by improving drug stability and addressing controlled release and targeted delivery of drugs in the delivery category. By combining drug delivery technology with nanosystems, controlled drug release and biodistribution can be achieved, enhancing therapeutic efficacy and reducing toxic cross-wise effects. This review discusses nanomaterial drug delivery strategies reported in recent years. Firstly, the present review describes the mechanisms of renal fibrosis and anti-renal fibrosis drug delivery. Secondly, different nanomaterial drug delivery strategies for the treatment of renal injury and fibrosis are highlighted. Finally, the limitations of these strategies are also discussed. Investigating various anti-renal fibrosis drug delivery strategies reveals the characteristics and therapeutic effects of various novel nanosystem-derived drug delivery approaches. This will serve as a reference for future research on drug delivery strategies for renal fibrosis treatment.

Identification of Molecular Subtype and Prognostic Signature for Prostate Adenocarcinoma based on Neutrophil Extracellular Traps.

Background: Prostate adenocarcinoma (PRAD) is one of the most common cancers in male. Increasing evidences pointed out that Neutrophil Extracellular Traps (NETs) play an important role in tumor angiogenesis, tumor metastasis and drug resistance. However, limited systematic studies regarding the role of NETs in PRAD have been performed. Identification of biomarkers based on NETs might facilitate risk stratification which help optimizing the clinical strategies. Methods: NETs-related genes with differential expressions were identified between PRAD and adjacent normal tissues in TCGA-PRAD dataset. Consensus cluster analysis was performed to determine the PRAD subtypes based on the different-expressed NETs-related genes. The difference of pathway enrichment, infiltrating immune cell and genomic mutation were also evaluated between subtypes. LASSO cox regression analysis was conducted to construct a NETs-related prognostic signature. Result: We identified 19 NETs related genes with differential expressions between PRAD and adjacent normal tissue in TCGA-PRAD dataset. Two significant subtypes were identified based on these 19 genes by consensus cluster analysis, namely subtype 1 and subtype 2. Significant differences in prognosis, immune infiltration and tumor mutation burden were observed in subtypes. LASSO Cox regression analysis identified a NETs-associated prognostic signature including 13 genes, and this signature had a good performance in predicting the progression-free survival of PRAD patients. Further integrated analysis indicated that MMP9 mostly expressed in Mono/Macrophage cells might play a role in regulating NETs formation via neutrophil activation in PRAD. Conclusion: To sum up, the current study identified two NETs-related molecular subtypes and based on which constructed a prognostic signature for PRAD.

RNA modifications in cellular metabolism: implications for metabolism-targeted therapy and immunotherapy.

Cellular metabolism is an intricate network satisfying bioenergetic and biosynthesis requirements of cells. Relevant studies have been constantly making inroads in our understanding of pathophysiology, and inspiring development of therapeutics. As a crucial component of epigenetics at post-transcription level, RNA modification significantly determines RNA fates, further affecting various biological processes and cellular phenotypes. To be noted, immunometabolism defines the metabolic alterations occur on immune cells in different stages and immunological contexts. In this review, we characterize the distribution features, modifying mechanisms and biological functions of 8 RNA modifications, including N6-methyladenosine (m6A), N6,2'-O-dimethyladenosine (m6Am), N1-methyladenosine (m1A), 5-methylcytosine (m5C), N4-acetylcytosine (ac4C), N7-methylguanosine (m7G), Pseudouridine (Ψ), adenosine-to-inosine (A-to-I) editing, which are relatively the most studied types. Then regulatory roles of these RNA modification on metabolism in diverse health and disease contexts are comprehensively described, categorized as glucose, lipid, amino acid, and mitochondrial metabolism. And we highlight the regulation of RNA modifications on immunometabolism, further influencing immune responses. Above all, we provide a thorough discussion about clinical implications of RNA modification in metabolism-targeted therapy and immunotherapy, progression of RNA modification-targeted agents, and its potential in RNA-targeted therapeutics. Eventually, we give legitimate perspectives for future researches in this field from methodological requirements, mechanistic insights, to therapeutic applications.

m6A Modification Promotes EMT and Metastasis of Castration-Resistant Prostate Cancer by Upregulating NFIB.

The widespread use of androgen receptor (AR) signaling inhibitors has led to an increased incidence of AR-negative castration-resistant prostate cancer (CRPC), limiting effective treatment and patient survival. A more comprehensive understanding of the molecular mechanisms supporting AR-negative CRPC could reveal therapeutic vulnerabilities to improve treatment. This study showed that the transcription factor nuclear factor I/B (NFIB) was upregulated in patient with AR-negative CRPC tumors and cell lines and was positively associated with an epithelial-to-mesenchymal transition (EMT) phenotype. Loss of NFIB inhibited EMT and reduced migration of CRPC cells. NFIB directly bound to gene promoters and regulated the transcription of EMT-related factors E-cadherin (CDH1) and vimentin (VIM), independent of other typical EMT-related transcriptional factors. In vivo data further supported the positive role of NFIB in the metastasis of AR-negative CRPC cells. Moreover, N6-methyladenosine (m6A) modification induced NFIB upregulation in AR-negative CRPC. Mechanistically, the m6A levels of mRNA, including NFIB and its E3 ubiquitin ligase TRIM8, were increased in AR-negative CRPC cells. Elevated m6A methylation of NFIB mRNA recruited YTHDF2 to increase mRNA stability and protein expression. Inversely, the m6A modification of TRIM8 mRNA, induced by ALKBH5 downregulation, decreased its translation and expression, which further promoted NFIB protein stability. Overall, this study reveals that upregulation of NFIB, mediated by m6A modification, triggers EMT and metastasis in AR-negative CRPC. Targeting the m6A/NFIB axis is a potential prevention and treatment strategy for AR-negative CRPC metastasis. SIGNIFICANCE: NFIB upregulation mediated by increased m6A levels in AR-negative castration-resistant prostate cancer regulates transcription of EMT-related factors to promote metastasis, providing a potential therapeutic target to improve prostate cancer treatment.

Isothermal Amplification-Based Detection of Single-Base RNA N6-Methyladenosine.

N6-methyladenosine (m6A) has recently gained much attention due to its diverse biological functions. Currently, the commonly used detection methods for locus-specific m6A marks are complicated to operate, it is difficult to quantify the methylation level, and they have high false-positive levels. Here, we report a new method for locus-specific m6A detection based on the methylate-sensitive endonuclease activity of MazF and the simultaneous amplification and testing (SAT) method, termed "m6A-MazF-SAT". Mechanically, MazF fails to cleave the A (m6A) CA motif; therefore, the undigested template can be SAT-amplified using specific probes targeting the upstream and downstream of sites of interest. Fluorescent signals of SAT amplification can be detected by real-time PCR, and therefore, they achieve the detection of m6A existence. After the condition optimization, m6A-MazF-SAT can significantly, accurately, and rapidly detect the m6A-modified sites in mRNA, rRNA, and lncRNA at the fmol level, as well as 10% m6A at the fmol level. In addition, m6A-MazF-SAT can quantify the abundance of target m6A in biological samples and can be used for the inhibitor selection of m6A-related enzymes. Together, we offer a new approach to detect locus-specific m6A both qualitatively and quantitatively; it is easy to operate, results can be obtained rapidly, and it has low false-positive levels and high repeatability.

Target delivery of a PD-1-TREM2 scFv by CAR-T cells enhances anti-tumor efficacy in colorectal cancer.

BACKGROUND: Chimeric antigen receptor (CAR) -T cell therapy is an efficient therapeutic strategy for specific hematologic malignancies. However, positive outcomes of this novel therapy in treating solid tumors are curtailed by the immunosuppressive tumor microenvironment (TME), wherein signaling of the checkpoint programmed death-1 (PD-1)/PD-L1 directly inhibits T-cell responses. Although checkpoint-targeted immunotherapy succeeds in increasing the number of T cells produced to control tumor growth, the desired effect is mitigated by the action of myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) in the TME. Previous studies have confirmed that targeting triggering-receptor-expressed on myeloid cells 2 (TREM2) on TAMs and MDSCs enhances the outcomes of anti-PD-1 immunotherapy. METHODS: We constructed carcinoembryonic antigen (CEA)-specific CAR-T cells for colorectal cancer (CRC)-specific antigens with an autocrine PD-1-TREM2 single-chain variable fragment (scFv) to target the PD-1/PD-L1 pathway, MDSCs and TAMs. RESULTS: We found that the PD-1-TREM2-targeting scFv inhibited the activation of the PD-1/PD-L1 pathway. In addition, these secreted scFvs blocked the binding of ligands to TREM2 receptors present on MDSCs and TAMs, reduced the proportion of MDSCs and TAMs, and enhanced T-cell effector function, thereby mitigating immune resistance in the TME. PD-1-TREM2 scFv-secreting CAR-T cells resulted in highly effective elimination of tumors compared to that achieved with PD-1 scFv-secreting CAR-T therapy in a subcutaneous CRC mouse model. Moreover, the PD-1-TREM2 scFv secreted by CAR-T cells remained localized within tumors and exhibited an extended half-life. CONCLUSIONS: Together, these results indicate that PD-1-TREM2 scFv-secreting CAR-T cells have strong potential as an effective therapy for CRC.

Sequential Targeting Hybrid Nanovesicles Composed of Chimeric Antigen Receptor T-Cell-Derived Exosomes and Liposomes for Enhanced Cancer Immunochemotherapy.

Paclitaxel (PTX)-based chemotherapy remains the main approach to treating lung cancer but systemic toxicity limits its use. As chimeric antigen receptor-T (CAR-T) cell-derived exosomes contain tumor-targeted CARs and cytotoxic granules (granzyme B and perforin), they are considered potential delivery vehicles for PTX. However, the low drug-loading capacity and hepatotropic properties of exosomes are obstacles to their application to extrahepatic cancer. Here, a hybrid nanovesicle named Lip-CExo@PTX was designed for immunochemotherapy of lung cancer by fusing exosomes derived from bispecific CAR-T cells targeting both mesothelin (MSLN) and programmed death ligand-1 (PD-L1) with lung-targeted liposomes. Due to the lung-targeting ability of the liposomes, over 95% of intravenously administered Lip-CExo@PTX accumulated in lung tissue. In addition, with the help of the anti-MSLN single-chain variable fragment (scFv), the PTX and cytotoxic granules inside Lip-CExo@PTX were further delivered into MSLN-positive tumors. Notably, the anti-PD-L1 scFv on Lip-CExo@PTX blocked PD-L1 on the tumors to avoid T cell exhaustion and promoted PTX-induced immunogenic cell death. Furthermore, Lip-CExo@PTX prolonged the survival time of tumor-bearing mice in a CT-26 metastatic lung cancer model. Therefore, Lip-CExo@PTX may deliver PTX to tumor cells through sequential targeted delivery and enhance the antitumor effects, providing a promising strategy for immunochemotherapy of lung cancer.

METTL16 promotes glycolytic metabolism reprogramming and colorectal cancer progression.

BACKGROUND: Glycolysis is the key hallmark of cancer and maintains malignant tumor initiation and progression. The role of N6-methyladenosine (m6A) modification in glycolysis is largely unknown. This study explored the biological function of m6A methyltransferase METTL16 in glycolytic metabolism and revealed a new mechanism for the progression of Colorectal cancer (CRC). METHODS: The expression and prognostic value of METTL16 was evaluated using bioinformatics and immunohistochemistry (IHC) assays. The biological functions of METTL16 in CRC progression was analyzed in vivo and in vitro. Glycolytic metabolism assays were used to verify the biological function of METTL16 and Suppressor of glucose by autophagy (SOGA1). The protein/RNA stability, RNA immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP) and RNA pull-down assays were used to explore the potential molecular mechanisms. RESULTS: SOGA1 is a direct downstream target of METTL16 and involved in METTL16 mediated glycolysis and CRC progression. METTL16 significantly enhances SOGA1 expression and mRNA stability via binding the "reader" protein insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1). Subsequently, SOGA1 promotes AMP-activated protein kinase (AMPK) complex ubiquitination, inhibits its expression and phosphorylation, thus upregulates pyruvate dehydrogenase kinase 4 (PDK4), a crucial protein controlling glucose metabolism. Moreover, Yin Yang 1 (YY1) can transcriptionally inhibit the expression of METTL16 in CRC cells by directly binding to its promoter. Clinical data showed that METTL16 expression is positively correlated to SOGA1 and PDK4, and is associated with poor prognosis of CRC patients. CONCLUSIONS: Our findings suggest that METTL16/SOGA1/PDK4 axis might be promising therapeutic targets for CRC.

Inhalable CAR-T cell-derived exosomes as paclitaxel carriers for treating lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a worldwide health threat with high annual morbidity and mortality. Chemotherapeutic drugs such as paclitaxel (PTX) have been widely applied clinically. However, systemic toxicity due to the non-specific circulation of PTX often leads to multi-organ damage, including to the liver and kidney. Thus, it is necessary to develop a novel strategy to enhance the targeted antitumor effects of PTX. METHODS: Here, we engineered exosomes derived from T cells expressing the chimeric antigen receptor (CAR-Exos), which targeted mesothelin (MSLN)-expressing Lewis lung cancer (MSLN-LLC) through the anti-MSLN single-chain variable fragment (scFv) of CAR-Exos. PTX was encapsulated into CAR-Exos (PTX@CAR-Exos) and administered via inhalation to an orthotopic lung cancer mouse model. RESULTS: Inhaled PTX@CAR-Exos accumulated within the tumor area, reduced tumor size, and prolonged survival with little toxicity. In addition, PTX@CAR-Exos reprogrammed the tumor microenvironment and reversed the immunosuppression, which was attributed to infiltrating CD8+ T cells and elevated IFN-γ and TNF-α levels. CONCLUSIONS: Our study provides a nanovesicle-based delivery platform to promote the efficacy of chemotherapeutic drugs with fewer side effects. This novel strategy may ameliorate the present obstacles to the clinical treatment of lung cancer.

Analysis of Risk Factors for Early Progression of Prostate Cancer After Initial Endocrine Therapy.

Background: Prolonged androgen deprivation therapy (ADT) in patients with prostate cancer can eventually lead to the development of castration-resistant prostate cancer (CRPC). Once CRPC occurs, the patient's prognosis will be inferior. However, the risk factors for progression to CRPC in a short period of time are unclear. Methods: We retrospectively analyzed prostate cancer patients who received their first ADT between January 1, 2015 and January 1, 2021. The main statistical methods used were a logistic regression model and Kaplan-Meier survival analysis. Results: Among 159 prostate cancer patients initially treated with ADT, 90 were screened for inclusion. Patients who progressed to CRPC after ADT were included in group B and others were included in group A. Group B was divided into group B1 and B2 according to whether CRPC progressed within 18 months. Multi-factor logistic regression analysis showed that the time to PSA nadir (TTN) (p = 0.031) and serum lactate dehydrogenase (LDH) (p = 0.013) were significantly different between Group A and B. TTN (p < 0.001), LDH (p = 0.001) and platelet to lymphocyte ratio (PLR) (p = 0.005) were significantly different between Group B1 and B2. Kaplan-Meier survival analysis and log-rank tests showed that TTN, LDH, and PLR statistically differed in CRPC patients' progression-free survival. The ROC curve showed the AUC value of TTN combined with PLR and LDH increased to 0.958 (95% CI 0.911-0.997, p < 0.001). The Chi-square test showed that the expression of p63 in group A was higher than that in groups B1 (p = 0.002) and B2 (p = 0.001). Conclusion: Lower TTN, higher LDH and PLR were associated with early CRPC occurrence after ADT in hormone-sensitive prostate cancer patients. p63 expression was associated with favorable prognosis in prostate cancer patients.

Rolling circle extension-assisted loop-mediated isothermal amplification (Rol-LAMP) method for locus-specific and visible detection of RNA N6-methyladenosine.

N6-methyladenosine (m6A) is the most prevalent RNA modification in eukaryotic mRNAs. Currently available detection methods for locus-specific m6A marks rely on RT-qPCR, radioactive methods, or high-throughput sequencing. Here, we develop a non-qPCR, ultrasensitive, isothermal, and naked-eye visible method for m6A detection based on rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP), named m6A-Rol-LAMP, to verify putative m6A sites in transcripts obtained from the high-throughput data. When padlock probes hybridize to the potential m6A sites on targets, they are converted to circular form by DNA ligase in the absence of m6A modification, while m6A modification hinders the sealing of padlock probes. Subsequently, Bst DNA polymerase-mediated RCA and LAMP allow the amplification of the circular padlock probe to achieve the locus-specific detection of m6A. Following optimization and validation, m6A-Rol-LAMP can ultra-sensitively and quantitatively determine the existence of m6A modification on a specific target site as low as 100 amol under isothermal conditions. Detections of m6A can be performed on rRNA, mRNA, lincRNA, lncRNA and pre-miRNA from biological samples with naked-eye observations after dye incubation. Together, we provide a powerful tool for locus-specific detection of m6A, which can simply, quickly, sensitively, specifically, and visually determine putative m6A modification on RNA.

COVID-19 Metabolomic-Guided Amino Acid Therapy Protects from Inflammation and Disease Sequelae.

The outbreak of coronavirus disease 2019 (COVID-19) has caused a worldwide pandemic since 2019. A metabolic disorder is a contributing factor to deaths from COVID-19. However, the underlying mechanism of metabolic dysfunction in COVID-19 patients and the potential interventions are not elucidated. Here targeted plasma metabolomic is performed, and the metabolite profiles among healthy controls, and asymptomatic, moderate, and severe COVID-19 patients are compared. Among the altered metabolites, arachidonic acid and linolenic acid pathway metabolites are profoundly up-regulated in COVID-19 patients. Arginine biosynthesis, alanine, aspartate, and glutamate metabolism pathways are significantly disturbed in asymptomatic patients. In the comparison of metabolite variances among the groups, higher levels of l-citrulline and l-glutamine are found in asymptomatic carriers and moderate or severe patients at the remission stage. Furthermore, l-citrulline and l-glutamine combination therapy is demonstrated to effectively protect mice from coronavirus infection and endotoxin-induced sepsis, and is observed to efficiently prevent the occurrence of pulmonary fibrosis and central nervous system damage. Collectively, the data reveal the metabolite profile of asymptomatic COVID-19 patients and propose a potential strategy for COVID-19 treatment.

Epigenetic and post-translational modifications in autophagy: biological functions and therapeutic targets.

Autophagy is a conserved lysosomal degradation pathway where cellular components are dynamically degraded and re-processed to maintain physical homeostasis. However, the physiological effect of autophagy appears to be multifaced. On the one hand, autophagy functions as a cytoprotective mechanism, protecting against multiple diseases, especially tumor, cardiovascular disorders, and neurodegenerative and infectious disease. Conversely, autophagy may also play a detrimental role via pro-survival effects on cancer cells or cell-killing effects on normal body cells. During disorder onset and progression, the expression levels of autophagy-related regulators and proteins encoded by autophagy-related genes (ATGs) are abnormally regulated, giving rise to imbalanced autophagy flux. However, the detailed mechanisms and molecular events of this process are quite complex. Epigenetic, including DNA methylation, histone modifications and miRNAs, and post-translational modifications, including ubiquitination, phosphorylation and acetylation, precisely manipulate gene expression and protein function, and are strongly correlated with the occurrence and development of multiple diseases. There is substantial evidence that autophagy-relevant regulators and machineries are subjected to epigenetic and post-translational modulation, resulting in alterations in autophagy levels, which subsequently induces disease or affects the therapeutic effectiveness to agents. In this review, we focus on the regulatory mechanisms mediated by epigenetic and post-translational modifications in disease-related autophagy to unveil potential therapeutic targets. In addition, the effect of autophagy on the therapeutic effectiveness of epigenetic drugs or drugs targeting post-translational modification have also been discussed, providing insights into the combination with autophagy activators or inhibitors in the treatment of clinical diseases.

Functionalized biomimetic nanoparticles combining programmed death-1/programmed death-ligand 1 blockade with photothermal ablation for enhanced colorectal cancer immunotherapy.

Immune checkpoint blockade therapy targeting programmed death-1 (PD-1) or its major ligand programmed death-ligand 1 (PD-L1) has achieved remarkable success in the treatment of several tumors, including colorectal cancer. However, the efficacy of PD-1/PD-L1 inhibitors is limited in some colorectal cancers within the immunosuppressive tumor microenvironment (such as when there is a lack of immune cell infiltration). Herein, anti-PD-L1 functionalized biomimetic polydopamine-modified gold nanostar nanoparticles (PDA/GNS@aPD-L1 NPs) were developed for synergistic anti-tumor treatment by combining PD-1/PD-L1 blockade with photothermal ablation. PDA/GNS@aPD-L1 NPs were prepared by encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane isolated from anti-PD-L1 single-chain variable fragment (scFv) over-expressing cells. In addition to disrupting PD-1/PD-L1 immunosuppressive signals, the anti-PD-L1 scFv on the membrane of PDA/GNS@aPD-L1 NPs was conducive to the accumulation of PDA-GNS at tumor sites. Importantly, the tumor photothermal ablation induced by PDA-GNS could reverse the immunosuppressive tumor microenvironment, thereby further improving the efficiency of PD-1/PD-L1 blockade therapy. In this study, the synthetized PDA/GNS@aPD-L1 NPs exhibited good biocompatibility, efficient photothermal conversion ability, and enhanced tumor-targeting ability. In vivo studies revealed that a PDA/GNS@aPD-L1 NP-based therapeutic strategy significantly inhibited tumor growth, and prolonged overall survival by further promoting the maturation of dendritic cells (DCs), increasing the infiltration of CD8+T cells, and decreasing the number of immunosuppressive cells (such as regulatory T cells and myeloid-derived suppressive cells). Collectively, the developed PDA/GNS@aPD-L1 NP-based therapeutic strategy combines PD-1/PD-L1 blockade with photothermal ablation, which could remodel the tumor microenvironment for effective clinical colorectal cancer therapy. STATEMENT OF SIGNIFICANCE: Immunosuppressive tumor microenvironment is the main challenge facing programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) blockade therapy. By encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane over-expressing anti-PD-L1 single-chain variable fragment, we constructed anti-PD-L1 functionalized biomimetic nanoparticles (PDA/GNS@aPD-L1 NPs). By specific binding to the PD-L1 present on tumor cells, PDA/GNS@aPD-L1 NPs could disrupt PD-1/PD-L1 immunosuppression signaling, and effectively deliver PDA-GNS targeting to tumor sites. Additionally, PDA-GNS-mediated local photothermal ablation of tumors promoted the release of tumor-associated antigens and thus activated anti-tumor immune responses. Meanwhile, hyperthermia facilitates immune cell infiltration by increasing tumor vascular permeability. Therefore, PDA/GNS@aPD-L1 NPs could sensitize tumors to PD-1/PD-L1 blockade therapy by remodeling the immunosuppressive tumor microenvironment, which provides a new strategy for tumor treatment.

ALKBH5-Mediated m6A Demethylation of GLUT4 mRNA Promotes Glycolysis and Resistance to HER2-Targeted Therapy in Breast Cancer.

Resistance to HER2-targeted therapy represents a significant challenge for the successful treatment of patients with breast cancer with HER2-positive tumors. Through a global mass spectrometry-based proteomics approach, we discovered that the expression of the N6-methyladenosine (m6A) demethylase ALKBH5 was significantly upregulated in HER2-targeted therapy-resistant breast cancer cells. Elevated expression of ALKBH5 was sufficient to confer resistance to HER2-targeted therapy, and specific knockdown of ALKBH5 rescued the efficacy of trastuzumab and lapatinib in resistant breast cancer cells. Mechanistically, ALKBH5 promoted m6A demethylation of GLUT4 mRNA and increased GLUT4 mRNA stability in a YTHDF2-dependent manner, resulting in enhanced glycolysis in resistant breast cancer cells. In breast cancer tissues obtained from patients with poor response to HER2-targeted therapy, increased expression of ALKBH5 or GLUT4 was observed and was significantly associated with poor prognosis in the patients. Moreover, suppression of GLUT4 via genetic knockdown or pharmacologic targeting with a specific inhibitor profoundly restored the response of resistant breast cancer cells to trastuzumab and lapatinib, both in vitro and in vivo. In conclusion, ALKBH5-mediated m6A demethylation of GLUT4 mRNA promotes resistance to HER2-targeted therapy, and targeting the ALKBH5/GLUT4 axis has therapeutic potential for treating patients with breast cancer refractory to HER2-targeted therapies. SIGNIFICANCE: GLUT4 upregulation by ALKBH5-mediated m6A demethylation induces glycolysis and resistance to HER2-targeted therapy and represents a potential therapeutic target for treating HER2-positive breast cancer.

The role, mechanism, and application of RNA methyltransferase METTL14 in gastrointestinal cancer.

Gastrointestinal cancer is the most common human malignancy characterized by high lethality and poor prognosis. Emerging evidences indicate that N6-methyladenosine (m6A), the most abundant post-transcriptional modification in eukaryotes, exerts important roles in regulating mRNA metabolism including stability, decay, splicing, transport, and translation. As the key component of the m6A methyltransferase complex, methyltransferase-like 14 (METTL14) catalyzes m6A methylation on mRNA or non-coding RNA to regulate gene expression and cell phenotypes. Dysregulation of METTL14 was deemed to be involved in various aspects of gastrointestinal cancer, such as tumorigenesis, progression, chemoresistance, and metastasis. Plenty of findings have opened up new avenues for exploring the therapeutic potential of gastrointestinal cancer targeting METTL14. In this review, we systematically summarize the recent advances regarding the biological functions of METTL14 in gastrointestinal cancer, discuss its potential clinical applications and propose the research forecast.

Clinical Course and Factors Associated with Viral RNA Shedding and Radiologic Resolution in Patients with COVID-19: a Retrospective Study.

BACKGROUND: The outbreak of SARS-CoV-2 lead to a worldwide pandemic which poses substantial challenges to public health. METHODS: We enrolled 102 consecutive recovered patients with laboratory-confirmed SARS-CoV-2 infection. Epidemiological and demographic characteristics, temporal dynamic profiles of laboratory tests and findings on chest CT radiography, and clinical outcomes were collected and analyzed. RESULTS: Independent risk factors for prolonged fever, viral RNA shedding or radiologic recovery included age of more than 44 years, female gender, having symptoms of cough and fever, a delay from the symptom onset to hospitalization of more than 3 days, a lower CD4 count of less than 500/µL on admission, and severe or critical illness in hospitalization. The estimated median time from symptom onset was 6.4 (5.5 - 7.4) days to peak viral load, 9.1 (7.9 - 10.4) days to afebrile, 8 (6.7 - 9.4) days to worst radiologic finding, 12.7 (11.2 - 14.3) days to viral RNA negativity, and 26.7 (23.8 - 29.9) days to radiologic resolution. This study included the entire cross-section of patients seen in our clinical practice and reflected the real-world situation. CONCLUSIONS: These findings provide the rationale for strategies of active symptom monitoring, timing of quarantine and antiviral interventions, and duration of radiologic follow-up in patients with COVID-19.

SARS-CoV-2 spike spurs intestinal inflammation via VEGF production in enterocytes.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can cause gastrointestinal (GI) symptoms that often correlate with the severity of COVID-19. Here, we explored the pathogenesis underlying the intestinal inflammation in COVID-19. Plasma VEGF level was particularly elevated in patients with GI symptoms and significantly correlated with intestinal edema and disease progression. Through an animal model mimicking intestinal inflammation upon stimulation with SARS-CoV-2 spike protein, we further revealed that VEGF was over-produced in the duodenum prior to its ascent in the circulation. Mechanistically, SARS-CoV-2 spike promoted VEGF production through activating the Ras-Raf-MEK-ERK signaling in enterocytes, but not in endothelium, and inducing permeability and inflammation. Blockage of the ERK/VEGF axis was able to rescue vascular permeability and alleviate intestinal inflammation in vivo. These findings provide a mechanistic explanation and therapeutic targets for the GI symptoms of COVID-19.