DGPRI, a new liver fibrosis assessment index, predicts recurrence of AFP-negative hepatocellular carcinoma after hepatic resection: a single-center retrospective study

Although patients with alpha-fetoprotein-negative hepatocellular carcinoma (AFPNHCC) have a favorable prognosis, a high risk of postoperative recurrence remains. We developed and validated a novel liver fibrosis assessment index, the direct bilirubin-gamma-glutamyl transpeptidase-to-platelet ratio (DGPRI). DGPRI was calculated for each of the 378 patients with AFPNHCC who underwent hepatic resection. The patients were divided into high- and low-score groups using the optimal cutoff value. The Lasso-Cox method was used to identify the characteristics of postoperative recurrence, followed by multivariate Cox regression analysis to determine the independent risk factors associated with recurrence. A nomogram model incorporating the DGPRI was developed and validated. High DGPRI was identified as an independent risk factor (hazard ratio = 2.086) for postoperative recurrence in patients with AFPNHCC. DGPRI exhibited better predictive ability for recurrence 1-5 years after surgery than direct bilirubin and the gamma-glutamyl transpeptidase-to-platelet ratio. The DGPRI-nomogram model demonstrated good predictive ability, with a C-index of 0.674 (95% CI 0.621-0.727). The calibration curves and clinical decision analysis demonstrated its clinical utility. The DGPRI nomogram model performed better than the TNM and BCLC staging systems for predicting recurrence-free survival. DGPRI is a novel and effective predictor of postoperative recurrence in patients with AFPNHCC and provides a superior assessment of preoperative liver fibrosis.

Local hyperthermia mediated by gold nanoparticle-integrated silicone-covered stent: feasibility and tissue response in a rat esophageal model

BACKGROUND

To assess the feasibility and tissue response of using a gold nanoparticle (AuNP)-integrated silicone-covered self-expandable metal stent (SEMS) for local hyperthermia in a rat esophageal model.

METHODS

The study involved 42 Sprague-Dawley rats. Initially, 6 animals were subjected to near-infrared (NIR) laser irradiation (power output from 0.2 to 2.4 W) to assess the in vitro heating characteristics of the AuNP-integrated SEMS immediately after its placement. The surface temperature of the stented esophagus was then measured using an infrared thermal camera before euthanizing the animals. Subsequently, the remaining 36 animals were randomly divided into 4 groups of 9 each. Groups A and B received AuNP-integrated SEMS, while groups C and D received conventional SEMS. On day 14, groups A and C underwent NIR laser irradiation at a power output of 1.6 W for 2 min. By days 15 (3 animals per group) or 28 (6 animals per group), all groups were euthanized for gross, histological, and immunohistochemical analysis.

RESULTS

Under NIR laser irradiation, the surface temperature of the stented esophagus quickly increased to a steady-state level. The surface temperature of the stented esophagus increased proportionally with power outputs, being 47.3 ± 1.4 °C (mean ± standard deviation) at 1.6 W. Only group A attained full circumferential heating through all layers, from the epithelium to the muscularis propria, demonstrating marked apoptosis in these layers without noticeable necroptosis.

CONCLUSIONS

Local hyperthermia using the AuNP-integrated silicone-covered SEMS was feasible and induced cell death through apoptosis in a rat esophageal model.

RELEVANCE STATEMENT

A gold nanoparticle-integrated silicone-covered self-expanding metal stent has been developed to mediate local hyperthermia. This approach holds potential for irreversibly damaging cancer cells, improving the sensitivity of cancer cells to therapies, and triggering systemic anticancer immune responses.

KEY POINTS

• A gold nanoparticle-integrated silicone-covered self-expanding metal stent was placed in the rat esophagus. • Upon near-infrared laser irradiation, this stent quickly increased the temperature of the stented esophagus. • Local hyperthermia using this stent was feasible and resulted in cell death through apoptosis.

Construction and Validation of a Novel Nomogram Predicting Recurrence in Alpha-Fetoprotein-Negative Hepatocellular Carcinoma Post-Surgery Using an Innovative Liver Function-Nutrition-Inflammation-Immune (LFNII) Score: A Bicentric Investigation

Purpose

We developed a nomogram based on the liver function, nutrition, inflammation, and immunity (LFNII) score to predict recurrence-free survival (RFS) post-resection in patients with hepatocellular carcinoma (HCC) exhibiting alpha-fetoprotein (AFP) negativity (AFP ≤20 ng/mL).

Patients and Methods

Clinical data of 661 patients diagnosed with alpha-fetoprotein-negative hepatocellular carcinoma (AFP-NHCC) who underwent surgical resection at two medical centers between 2012 and 2021 were collected. A total of 462 and 199 patients served as the training and validation sets, respectively. Pre-operative blood markers were collected and analyzed for LFNII. The LFNII score was formulated using the least absolute shrinkage and selection operator Cox regression model. A nomogram model was developed using the training set to incorporate other relevant clinicopathological indicators and predict postoperative recurrence. Model discrimination was assessed using the receiver operating characteristic curve, calibration was evaluated using a calibration curve, and clinical applicability was assessed using clinical decision curve analysis. A comparison with liver cancer staging was performed using the nomogram model. Finally, a cohort study was conducted to validate our findings.

Results

We derived the LFNII scores from nine indicators. Elevated LFNII scores correlated with unfavorable clinicopathological features. The LFNII score area under the curve revealed superior predictive efficacy at 1-, 2-, and 5-year RFS intervals, with values of 0.675, 0.658, and 0.633, respectively. Multivariate Cox analysis revealed that a high LFNII score independently increased RFS risk in patients with AFP-NHCC. The C-index of the LFNII-nomogram model was 0.686 (95% confidence interval [CI], 0.651-0.721). The nomogram model's clinical application value surpassed that of standard HCC staging systems.

Conclusion

The LFNII score-derived nomogram effectively predicted the RFS of patients with AFP-NHCC after curative resection.

Targeting DNA Damage and Repair Machinery via Delivering WEE1 Inhibitor and Platinum (IV) Prodrugs to Stimulate STING Pathway for Maximizing Chemo-Immunotherapy in Bladder Cancer

Both cisplatin-based chemotherapy and immune checkpoint blockers (ICBs)-based immunotherapy are the first-line treatments for patients with advanced bladder cancer. Cancer cells can develop resistance to cisplatin through extensive DNA repair, while a low response rate to ICBs is mostly due to the presence of an immunosuppressive microenvironment and low PD-L1 expression. Herein, a glutathione (GSH)-responsive nanoparticle (NP2) loaded with cisplatin prodrug (Pt (IV)) and WEE1 inhibitor (MK1775) is designed. NP2 can be triggered by GSH in cancer cells, and the released MK1775 can inhibit the activity of WEE1 protein, which ultimately increases DNA damage by cisplatin. Genome-wide RNA sequencing first reveals that NP2 can inhibit DNA repair machinery by interfering with the cell cycle and significantly activate the stimulator of interferon genes pathway. Tumor growth is significantly inhibited by NP2 in vivo. As innate and adaptive immune responses are stimulated, the immunosuppressive microenvironment is modified, and the "immune cold tumor" is transformed into an "immune hot tumor". In addition, NP2 can upregulate PD-L1 expression in tumor cells, thereby increasing the response rate of PD-L1 monoclonal antibody (αPD-L1) and eliciting long-term immune responses in both primary and metastatic tumors.

Semiconducting Polymers for Cancer Immunotherapy

As a monumental breakthrough in cancer treatment, immunotherapy has attracted tremendous attention in recent years. However, one challenge faced by immunotherapy is the low response rate and the immune-related adverse events (irAEs). Therefore, it is important to explore new therapeutic strategies and platforms for boosting therapeutic benefits and decreasing the side effects of immunotherapy. In recent years, semiconducting polymer (SP), a category of organic materials with π-conjugated aromatic backbone, has been attracting considerable attention because of their outstanding characteristics such as excellent photophysical features, good biosafety, adjustable chemical flexibility, easy fabrication, and high stability. With these distinct advantages, SP is extensively explored for bioimaging and photo- or ultrasound-activated tumor therapy. Here, the recent advancements in SP-based nanomedicines are summarized for enhanced tumor immunotherapy. According to the photophysical properties of SPs, the cancer immunotherapies enabled by SPs with the photothermal, photodynamic, or sonodynamic functions are highlighted in detail, with a particular focus on the construction of combination immunotherapy and activatable nanoplatforms to maximize the benefits of cancer immunotherapy. Herein, new guidance and comprehensive insights are provided for the design of SPs with desired photophysical properties to realize maximized effectiveness of required biomedical applications.

Neoantigen-Based Nanovaccine In Combination with Immune Checkpoint Inhibitors Abolish Postsurgical Tumor Recurrence and Metastasis

The notorious limitation of conventional surgical excision of primary tumor is the omission of residual and occult tumor cells, which often progress to recurrence and metastasis, leading to clinical treatment failure. The therapeutic vaccine is emerging as a promising candidate for dealing with the issue of postsurgical tumor residuals or nascent metastasis. Here, a flexible and modularized nanovaccine scaffold based on the SpyCatcher003-decorated shell (S) domain of norovirus (Nov) is employed to support the presentation of varied tumor neoantigens fused with SpyTag003. The prepared tumor neoantigen-based nanovaccines (Neo-NVs) are able to efficiently target to lymph nodes and engage with DCs in LNs, triggering strong antigen-specific T-cell immunity and significantly inhibiting the growth of established orthotopic 4T1 breast tumor in mice. Further, the combination of Neo-NVs and anti-PD-1 monoclonal antibody (mAb) produces significant inhibition on postsurgical tumor recurrence and metastasis and induces a long-lasting immune memory. In conclusion, the study provides a simple and reliable strategy for rapid preparing personalized neoantigens-based cancer vaccines and engaging checkpoint treatment to restore the capability of tumor immune surveillance and clearance in surgical patients.

Anti-Biofilm Activity of Cocultimycin A against Candida albicans

Candida albicans (C. albicans), the most common fungal pathogen, has the ability to form a biofilm, leading to enhanced virulence and antibiotic resistance. Cocultimycin A, a novel antifungal antibiotic isolated from the co-culture of two marine fungi, exhibited a potent inhibitory effect on planktonic C. albicans cells. This study aimed to evaluate the anti-biofilm activity of cocultimycin A against C. albicans and explore its underlying mechanism. Crystal violet staining showed that cocultimycin A remarkably inhibited biofilm formation in a dose-dependent manner and disrupted mature biofilms at higher concentrations. However, the metabolic activity of mature biofilms treated with lower concentrations of cocultimycin A significantly decreased when using the XTT reduction method. Cocultimycin A could inhibit yeast-to-hypha transition and mycelium formation of C. albicans colonies, which was observed through the use of a light microscope. Scanning electron microscopy revealed that biofilms treated with cocultimycin A were disrupted, yeast cells increased, and hypha cells decreased and significantly shortened. The adhesive ability of C. albicans cells treated with cocultimycin A to the medium and HOEC cells significantly decreased. Through the use of a qRT-PCR assay, the expression of multiple genes related to adhesion, hyphal formation and cell membrane changes in relation to biofilm cells treated with cocultimycin A. All these results suggested that cocultimycin A may be considered a potential novel molecule for treating and preventing biofilm-related C. albicans infections.

ADAR1 links R-loop homeostasis to ATR activation in replication stress response

Unscheduled R-loops are a major source of replication stress and DNA damage. R-loop-induced replication defects are sensed and suppressed by ATR kinase, whereas it is not known whether R-loop itself is actively involved in ATR activation and, if so, how this is achieved. Here, we report that the nuclear form of RNA-editing enzyme ADAR1 promotes ATR activation and resolves genome-wide R-loops, a process that requires its double-stranded RNA-binding domains. Mechanistically, ADAR1 interacts with TOPBP1 and facilitates its loading on perturbed replication forks by enhancing the association of TOPBP1 with RAD9 of the 9-1-1 complex. When replication is inhibited, DNA-RNA hybrid competes with TOPBP1 for ADAR1 binding to promote the translocation of ADAR1 from damaged fork to accumulate at R-loop region. There, ADAR1 recruits RNA helicases DHX9 and DDX21 to unwind R-loops, simultaneously allowing TOPBP1 to stimulate ATR more efficiently. Collectively, we propose that the tempo-spatially regulated assembly of ADAR1-nucleated protein complexes link R-loop clearance and ATR activation, while R-loops crosstalk with blocked replication forks by transposing ADAR1 to finetune ATR activity and safeguard the genome.

Comparing the clinical value of baseline [68 Ga]Ga-FAPI-04 PET/CT and [18F]F-FDG PET/CT in pancreatic ductal adenocarcinoma: additional prognostic value of the distal pancreatitis

PURPOSE

Anatomical and molecular staging strategies are needed for the personalized treatment of localized pancreatic ductal adenocarcinoma (PDAC). This study evaluated the performance of [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT on the disease staging and prognostic value of patients with localized PDAC on contrast-enhanced (CE)-CT images.

METHODS

Patients with suspected localized PDAC on CE-CT were recruited for static [68 Ga]Ga-FAPI-04 and 18[F]F-FDG and PET/CT, and select patients underwent simultaneous 60-min dynamic 68 Ga-FAPI-04 PET/CT. The diagnostic and staging performances of the static PET/CT results were evaluated by delineating regions of interest in the primary tumor, whole pancreas, and distal pancreas in both types of scans and then evaluating correlations between the PET/CT findings and clinicopathological characteristics. Furthermore, Kaplan-Meier and hazard ratio (log-rank) methods were used to evaluate the prognostic value of the combined dynamic [68 Ga]Ga-FAPI-04 and static [18F]F-FDG PET/CT method.

RESULTS

We included 49 patients with histologically confirmed PDAC adenocarcinomas; 32 underwent 60-min dynamic [68 Ga]Ga-FAPI-04 PET/CT imaging simultaneously. The static [68 Ga]Ga-FAPI-04 method had significantly higher accuracy and uptake values than the static [18F]F-FDG method for primary PDAC lesions, metastatic lymph nodes, and distal metastases. Furthermore, 18.4% and 10.2% of the patients' stages changed after using the [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT methodologies, respectively, compared to the CE-CT-designated stage. The Ki values obtained from dynamic [68 Ga]Ga-FAPI-04 PET/CT did not differ between PDAC and distal obstructive pancreatitis lesions. Pathologically enlarged tumor size, poor differentiation, and perineural invasion were associated with increased [68 Ga]Ga-FAPI-04 uptake but not with [18F]F-FDG uptake. The preoperative prognostic performance of [68 Ga]Ga-FAPI-04 was better than that of [18F]F-FDG. Interestingly, combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG uptake results in the whole pancreas could further stratify patients based on their postoperative prognosis.

CONCLUSION

6[68 Ga]Ga-FAPI-04 PET/CT was more sensitive and accurate than [18F]F-FDG PET/CT for tumor, node, and metastasis staging of PDAC identified on CE-CT. Additionally, [68 Ga]Ga-FAPI-04 uptake was significantly associated with pathologically aggressive tumor features. Combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT findings improved the prognostic value, potentially providing a non-invasive guide for clinical management. Finally, increased fibroblast activity in PDAC-induced obstructive pancreatitis may be associated with poor patient survival rates.

Cuproptosis Induced by ROS Responsive Nanoparticles with Elesclomol and Copper Combined with αPD-L1 for Enhanced Cancer Immunotherapy

Cuproptosis is a new cell death that depends on copper (Cu) ionophores to transport Cu into cancer cells, which induces cell death. However, existing Cu ionophores are small molecules with a short blood half-life making it hard to transport enough Cu into cancer cells. Herein, a reactive oxygen species (ROS)-sensitive polymer (PHPM) is designed, which is used to co-encapsulate elesclomol (ES) and Cu to form nanoparticles (NP@ESCu). After entering cancer cells, ES and Cu, triggered by excessive intracellular ROS, are readily released. ES and Cu work in a concerted way to not only kill cancer cells by cuproptosis, but also induce immune responses. In vitro, the ability of NP@ESCu to efficiently transport Cu and induce cuproptosis is investigated. In addition, the change in the transcriptomes of cancer cells treated with NP@ESCu is explored by RNA-Seq. In vivo, NP@ESCu is found to induce cuproptosis in the mice model with subcutaneous bladder cancer, reprograming the tumor microenvironment. Additionally, NP@ESCu is further combined with anti-programmed cell death protein ligand-1 antibody (αPD-L1). This study provides the first report of combining nanomedicine that can induce cuproptosis with αPD-L1 for enhanced cancer therapy, thereby providing a novel strategy for future cancer therapy.

Systemic Analyses of Cuproptosis-Related lncRNAs in Pancreatic Adenocarcinoma, with a Focus on the Molecular Mechanism of LINC00853

Pancreatic cancer (PC) is a deadly malignant digestive tumor with poor prognoses and a lack of effective treatment options. Cuproptosis, a recently identified copper-dependent programmed cell death type, has been implicated in multiple cancers. Long non-coding RNAs (lncRNAs) are also linked to the progression of PC. However, the role and prognostic values of cuproptosis-related lncRNAs in pancreatic adenocarcinoma (PAAD) remain unclear. In this study, we systemically analyzed the differential expressions and prognostic values of 672 cuproptosis-related lncRNAs in PAAD. Based on this, a prognostic signature including four lncRNAs (LINC00853, AC099850.3, AC010719.1, and AC006504.7) was constructed and was able to divide PAAD patients into high- and low-risk groups with significantly different prognoses. Next, we focused on lncRNA LINC00853. The differential expressions of LINC00853 between normal tissue and PAAD samples were validated by qRT-PCR. LINC00853 was knocked down by siRNA in PC cell lines BxPC-3 and PANC-1 and the oncogenic role of LINC00853 was validated by CCK8, colony formation, and EdU assays. Subsequently, LINC00853 knockdown cells were subjected to tumor xenograft tests and exhibited decreased tumor growth in nude mice. Mechanistically, knockdown of LINC00853 significantly reduced cellular glycolysis and enhanced cellular mitochondrial respiration levels in PC cells. Moreover, knockdown of LINC00853 decreased the protein level of a glycolytic kinase PFKFB3. Finally, glycolysis tests and functional tests using LINC00853 and HA-PFKFB3 indicated that the effects of LINC00853 on glycolysis and cell proliferation were mediated by PFKFB3. In conclusion, our systemic analyses have highlighted the important roles of cuproptosis-related lncRNAs in PAAD while the prognostic signature based on them showed excellent performance in PAAD patients and is expected to provide clinical guidance for individualized treatment. In addition, our findings provide a novel mechanism by which the LINC00853-PFKFB3 axis critically regulates aerobic glycolysis and cell proliferation in PC cells.

Mic60 is essential to maintain mitochondrial integrity and to prevent encephalomyopathy

Mitochondrial encephalomyopathies (ME) are frequently associated with mutations of mitochondrial DNA, but the pathogenesis of a subset of ME (sME) remains elusive. Here we report that haploinsufficiency of a mitochondrial inner membrane protein, Mic60, causes progressive neurological abnormalities with insulted mitochondrial structure and neuronal loss in mice. In addition, haploinsufficiency of Mic60 reduces mitochondrial membrane potential and cellular ATP production, increases reactive oxygen species, and alters mitochondrial oxidative phosphorylation complexes in neurons in an age-dependent manner. Moreover, haploinsufficiency of Mic60 compromises brain glucose intake and oxygen consumption in mice, resembling human ME syndrome. We further discover that MIC60 protein expression declined significantly in human sME, implying that insufficient MIC60 may contribute for pathogenesis of human ME. Notably, systemic administration of antioxidant N-acetylcysteine largely reverses mitochondrial dysfunctions and metabolic disorders in haplo-insufficient Mic60 mice, also restores neurological abnormal symptom. These results reveal Mic60 is required in the maintenance of mitochondrial integrity and function, and likely a potential therapeutics target for mitochondrial encephalomyopathies.

Identification of a Small Molecule That Inhibits the Interaction of LPS Transporters LptA and LptC

The need for novel antibiotics has become imperative with the increasing prevalence of antibiotic resistance in Gram-negative bacteria in clinics. Acting as a permeability barrier, lipopolysaccharide (LPS) protects Gram-negative bacteria against drugs. LPS is synthesized in cells and transported to the outer membrane (OM) via seven lipopolysaccharide transport (Lpt) proteins (LptA-LptG). Of these seven Lpt proteins, LptC interacts with LptA to transfer LPS from the inner membrane (IM) to the OM, and assembly is aided by LptD/LptE. This interaction among the Lpt proteins is important for the biosynthesis of LPS; therefore, the Lpt proteins, which are significant in the assembly process of LPS, can be a potential target for new antibiotics. In this study, a yeast two-hybrid (Y2H) system was used to screen compounds that could block LPS transport by inhibiting LptA/LptC interaction, which finally disrupts the biosynthesis of the OM. We selected the compound IMB-0042 for this study. Our results suggest that IMB-0042 disrupts LptA/LptC interaction by binding to both LptA and LptC. Escherichia coli cells, when treated with IMB-0042, showed filament morphology, impaired OM integrity, and an accumulation of LPS in the periplasm. IMB-0042 inhibited the growth of Gram-negative bacteria and showed synergistic sensitization to other antibiotics, with low cytotoxicity. Thus, we successfully identified a potential antibacterial agent by using a Y2H system, which blocks the transport of LPS by targeting LptA/LptC interaction in Escherichia coli.

Construction of the cervical cancer common terminology for promoting semantic interoperability and utilization of Chinese clinical data

BACKGROUND

We aimed to build a common terminology in the domain of cervical cancer, named Cervical Cancer Common Terminology (CCCT), that will facilitate clinical data exchange, ensure quality of data and support large scale data analysis.

METHODS

The standard concepts and relations of CCCT were collected from ICD-10-CM Chinese Version, ICD-9-PC Chinese Version, officially issued commonly used Chinese clinical terms, Chinese guidelines for diagnosis and treatment of cervical cancer and Chinese medical book Lin Qiaozhi Gynecologic Oncology. 2062 cervical cancer electronic medical records (EMRs) from 16 hospitals, belong to different regions and hospital tiers, were collected for terminology enrichment and building common terms and relations. Concepts hierarchies, terms and relationships were built using Protégé. The performance of natural language processing results was evaluated by average precision, recall, and F1-score. The usability of CCCT were evaluated by terminology coverage.

RESULTS

A total of 880 standard concepts, 1182 common terms, 16 relations and 6 attributes were defined in CCCT, which organized in 6 levels and 11 classes. Initial evaluation of the natural language processing results demonstrated average precision, recall, and F1-score percentages of 96%, 72.6%, and 88.5%. The average terminology coverage for three classes of terms, clinical manifestation, treatment, and pathology, were 87.22%, 92.63%, and 89.85%, respectively. Flexible Chinese expressions exist between regions, traditions, cultures, and language habits within the country, linguistic variations in different settings and diverse translation of introduced western language terms are the main reasons of uncovered terms.

CONCLUSIONS

Our study demonstrated the initial results of CCCT construction. This study is an ongoing work, with the update of medical knowledge, more standard clinical concepts will be added in, and with more EMRs to be collected and analyzed, the term coverage will be continuing improved. In the future, CCCT will effectively support clinical data analysis in large scale.

Effective control of large deletions after double-strand breaks by homology-directed repair and dsODN insertion

BACKGROUND

After repairing double-strand breaks (DSBs) caused by CRISPR-Cas9 cleavage, genomic damage, such as large deletions, may have pathogenic consequences.

RESULTS

We show that large deletions are ubiquitous but are dependent on editing sites and cell types. Human primary T cells display more significant deletions than hematopoietic stem and progenitor cells (HSPCs), whereas we observe low levels in induced pluripotent stem cells (iPSCs). We find that the homology-directed repair (HDR) with single-stranded oligodeoxynucleotides (ssODNs) carrying short homology reduces the deletion damage by almost half, while adeno-associated virus (AAV) donors with long homology reduce large deletions by approximately 80%. In the absence of HDR, the insertion of a short double-stranded ODN by NHEJ reduces deletion indexes by about 60%.

CONCLUSIONS

Timely bridging of broken ends by HDR and NHEJ vastly decreases the unintended consequences of dsDNA cleavage. These strategies can be harnessed in gene editing applications to attenuate unintended outcomes.

RBD-Modified Bacterial Vesicles Elicited Potential Protective Immunity against SARS-CoV-2

The disease caused by SARS-CoV-2 infection threatens human health. In this study, we used high-pressure homogenization technology not only to efficiently drive the bacterial membrane to produce artificial vesicles but also to force the fusion protein ClyA-receptor binding domain (RBD) to pass through gaps in the bacterial membrane to increase the contact between ClyA-RBD and the membrane. Therefore, the load of ClyA-RBD on the membrane is substantially increased. Using this technology, we constructed a "ring-like" bacterial biomimetic vesicle (BBV) loaded with polymerized RBD (RBD-BBV). RBD-BBVs injected subcutaneously can accumulate in lymph nodes, promote antigen uptake and processing, and elicit SARS-CoV-2-specific humoral and cellular immune responses in mice. In conclusion, we evaluated the potential of this novel bacterial vesicle as a vaccine delivery system and provided a new idea for the development of SARS-CoV-2 vaccines.

ADP-ribosyltransferase PARP11 suppresses Zika virus in synergy with PARP12

BACKGROUND

Zika virus (ZIKV) infection and ZIKV epidemic have been continuously spreading silently throughout the world and its associated microcephaly and other serious congenital neurological complications poses a significant global threat to public health. Type I interferon response to ZIKV infection in host cells suppresses viral replication by inducing the expression of interferon-stimulated genes (ISGs).

METHODS

The study aims to demonstrate the anti-ZIKV mechanism of PARP11. PARP11 knock out and overexpressing A549 cell lines were constructed to evaluate the anti-ZIKV function of PARP11. PARP11-/-, PARP12-/- and PARP11-/-PARP12-/- HEK293T cell lines were constructed to explain the synergistic effect of PARP11 and PARP12 on NS1 and NS3 protein degradation. Western blotting, immunofluorescence and immunoprecipitation assay were performed to illustrate the interaction between PARP11 and PARP12.

RESULTS

Both mRNA and protein levels of PARP11 were induced in WT but not IFNAR1-/- cells in response to IFNα or IFNβ stimulation and ZIKV infection. ZIKV replication was suppressed in cells expressed PARP11 but was enhanced in PARP11-/- cells. PARP11 suppressed ZIKV independently on itself PARP enzyme activity. PARP11 interacted with PARP12 and promoted PARP12-mediated ZIKV NS1 and NS3 protein degradation.

CONCLUSION

We identified ADP-ribosyltransferase PARP11 as an anti-ZIKV ISG and found that it cooperated with PARP12 to enhance ZIKV NS1 and NS3 protein degradation. Our findings have broadened the understanding of the anti-viral function of ADP-ribosyltransferase family members, and provided potential therapeutic targets against viral ZIKV infection.

Ginsenoside Re protects against chronic restraint stress-induced cognitive deficits through regulation of NLRP3 and Nrf2 pathways in mice

Exposure to chronic stress negatively affects the development of cognition, characterized by learning and memory decline. Ginsenoside Re (GRe), an active compound derived from Panax ginseng, exhibited neuroprotective activity in various neurological diseases. In this study, the protective effect of GRe on chronic restraint stress (CRS)-induced memory deficit was investigated. The mice were experienced 35 days of the CRS induction. The GRe was administered daily orally (10, 20, or 40 mg/kg) during the next 3 weeks stress session and the behavior test period. The CRS-induced memory impairment mice were subjected to behavioral tasks, such as the Y-maze, novel objects recognition, and step-through passive avoidance tests. Nissl staining was used to examine the neuron numbers. The levels of antioxidant enzymes, malondialdehyde, and proinflammatory factor were determined by kits and ELISA assays. The expressions of brain-derived neurotrophic factor (BDNF), NOD-like receptor protein 3 (NLRP3), nuclear factor erythroid-2 related factor 2 (Nrf2) and synapse-associated proteins (synaptophysin, SYP, and postsynaptic density 95, PSD95) were measured by Western blotting. Behavioral assessments indicated that GRe could ameliorate the cognitive impairment of CRS-induced mice, as indicated by increased responses in Y-maze (p < .05), novel objects recognition (p < .01), and step-through passive avoidance tests (p < .01). In addition, GRe treatment significantly decreased the neuronal loss in CRS mice in histological examination. Moreover, chronic GRe treatment significantly ameliorated the down-regulated the expressions of BDNF, Nrf2, heme oxygenase (HO)-1, SYP, and PSD95, as well as up-regulated NLRP3, the adaptor protein ASC, and Caspase-1 protein expression in the hippocampus of CRS-treated mice. Taken together, these findings suggest that GRe has a potential therapeutic effect on memory impairment in C57BL/6J mice exposed to CRS paradigm.

Serum IgE in the clinical features and disease outcomes of IgG4-related disease: a large retrospective cohort study

OBJECTIVE

The aim of this study was to investigate the role of serum IgE levels in the clinical features and outcomes of IgG4-related disease (IgG4-RD).

METHODS

We retrospectively enrolled 459 newly diagnosed IgG4-RD patients with serum IgE examined at baseline from 2012 to 2019 and compared the clinical features between group A (serum IgE level ≤ 60 KU/L) and group B (serum IgE level > 60 KU/L). Subsequently, 312 patients who had been followed up for ≥ 1 year were further selected to evaluate the correlation between serum IgE level and disease outcome.

RESULTS

At baseline, the serum IgE level was positively correlated with the serum IgG4 level (r = 0.1779, P = 0.0001), eosinophil count (r = 0.3004, P < 0.0001), and serum IgG level (r = 0.2189, P < 0.0001) in IgG4-RD patients. Compared with group A, group B had more patients with allergic diseases (P = 0.004), more organ involvement (P = 0.003), and higher IgG4-RD responder index scores (P = 0.002). During follow-up, group A patients had a higher remission induction rate than group B patients (88.4% vs. 73.6%, P = 0.035), while group B patients had a higher relapse rate than group A patients (29.0% vs. 16.2%, P = 0.039). Multivariate analysis found that a serum IgE level > 125 KU/L at baseline was a risk factor for disease relapse (hazard ratio [HR], 1.894 [95% confidence interval (CI) 1.022-3.508]; P = 0.042). Cox regression analysis showed that elevation of the eosinophil count was a risk factor for relapse in both group A and group B patients (HR, 8.504 [95% CI 1.071-42.511]; P = 0.009; and HR, 2.078 [95% CI 1.277-3.380]; P = 0.003, respectively), and the involvement of the lacrimal gland (HR, 1.756 [95% CI 1.108-2.782]; P = 0.017), submandibular gland (HR, 1.654 [95% CI 1.037-2.639]; P = 0.035), and kidney (HR, 3.413 [95% CI 1.076-10.831]; P = 0.037) were also risk factors for relapse in group B patients.

CONCLUSION

IgG4-RD patients with high serum IgE levels at baseline were more likely to have higher disease activity, and baseline high IgE levels were associated with disease relapse.

Dammarane sapogenins attenuates stress-induced anxiety-like behaviors by upregulating ERK/CREB/BDNF pathways

Dammarane sapogenins (DS), an extract derived from ginseng by alkaline hydrolysis of total ginsenosides, possesses high pharmacological activity and higher bioavailability than ginsenosides. The present study was designed to investigate the anxiolytic-like effects of DS in a mouse model of chronic social defeat stress (CSDS). DS (40 and 80 mg/kg) significantly ameliorated social avoidance and anxiety-like behavior in four test models of CSDS, showing increased time in the interaction zone in the social interaction test and in the center of the field in the open field test, an increased percentage of entries and open arm time in the elevated plus maze, and reduced latency to eat in the novelty-suppressed feeding test. Biochemical analyses showed that DS significantly reduced serum corticosterone levels and increased brain concentration of neurotransmitter 5-HT and noradrenaline in CSDS mice. Treatment with DS significantly upregulated BDNF (brain-derived neurotrophic factor), p-CREB/CREB and p-ERK1/2/ERK1/2 protein expression in the hippocampus and prefrontal cortex of CSDS mice. Collectively, these results suggest that DS exerts anxiolytic-like effects in CSDS model mice and the action is mediated, at least in part, by modulating the HPA (hypothalamic-pituitary-adrenal) axis and monoamine neurotransmitter levels, and via ERK/CREB/BDNF signaling pathway.

Advances in the understanding of poor graft function following allogeneic hematopoietic stem-cell transplantation

Poor graft function (PGF) following allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is a life-threatening complication and is characterized by bilineage or trilineage blood cell deficiency and hypoplastic marrow with full chimerism. With the rapid development of allo-HSCT, especially haploidentical-HSCT, PGF has become a growing concern. The most common risk factors illustrated by recent studies include low dose of infused CD34+ cells, donor-specific antibody, cytomegalovirus infection, graft versus host disease (GVHD), iron overload and splenomegaly, among others. Because of the poor prognosis of PGF, it is crucial to uncover the underlying mechanism, which remains elusive. Recent studies have suggested that the bone marrow microenvironment may play an important role in the pathogenesis of PGF. Deficiency and dysfunction of endothelial cells and mesenchymal stem cells, elevated reactive oxygen species (ROS) levels, and immune abnormalities are believed to contribute to PGF. In this review, we also discuss recent clinical trials that evaluate the safety and efficacy of new strategies in patients with PGF. CD34+-selected stem-cell boost (SCB) is effective with an acceptable incidence of GVHD, despite the need for a second donation. Alternative strategies including the applications of mesenchymal stem cells, N-acetyl-l-cysteine (NAC), and eltrombopag have shown favorable outcomes, but further large-scale studies are needed due to the small sample sizes of the recent clinical trials.

A HSV1 mutant leads to an attenuated phenotype and induces immunity with a protective effect

Herpes simplex virus type 1 (HSV1) is a complicated structural agent with a sophisticated transcription process and a high infection rate. A vaccine against HSV1 is urgently needed. As multiple viral-encoded proteins, including structural and nonstructural proteins, contribute to immune response stimulation, an attenuated or deficient HSV1 vaccine may be relatively reliable. Advances in genomic modification technologies provide reliable means of constructing various HSV vaccine candidates. Based on our previous work, an M6 mutant with mutations in the UL7, UL41, LAT, Us3, Us11 and Us12 genes was established. The mutant exhibited low proliferation in cells and an attenuated phenotype in an animal model. Furthermore, in mice and rhesus monkeys, the mutant can induce remarkable serum neutralizing antibody titers and T cell activation and protect against HSV1 challenge by impeding viral replication, dissemination and pathogenesis.

Competition between PAF1 and MLL1/COMPASS confers the opposing function of LEDGF/p75 in HIV latency and proviral reactivation

Transcriptional status determines the HIV replicative state in infected patients. However, the transcriptional mechanisms for proviral replication control remain unclear. In this study, we show that, apart from its function in HIV integration, LEDGF/p75 differentially regulates HIV transcription in latency and proviral reactivation. During latency, LEDGF/p75 suppresses proviral transcription via promoter-proximal pausing of RNA polymerase II (Pol II) by recruiting PAF1 complex to the provirus. Following latency reversal, MLL1 complex competitively displaces PAF1 from the provirus through casein kinase II (CKII)-dependent association with LEDGF/p75. Depleting or pharmacologically inhibiting CKII prevents PAF1 dissociation and abrogates the recruitment of both MLL1 and Super Elongation Complex (SEC) to the provirus, thereby impairing transcriptional reactivation for latency reversal. These findings, therefore, provide a mechanistic understanding of how LEDGF/p75 coordinates its distinct regulatory functions at different stages of the post-integrated HIV life cycles. Targeting these mechanisms may have a therapeutic potential to eradicate HIV infection.

Development and validation of a sensitive LC-MS/MS method for the quantitation of IMB-YH-4py5-2H, an antituberculosis candidate, and its application to the pharmacokinetic study

(E)-N,N-dimethyl-4-oxo-4-(4-(pyridin-4-yl)phenyl)but-2-enamide hydrochloride (IMB-YH-4py5-2H) is a novel Protein Kinase B (PknB) inhibitor with potent activity against Mycobacterium tuberculosis strains. In the present study, a sensitive and specific liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine IMB-YH-4py5-2H in rat plasma. Sample pretreatment was achieved by liquid-liquid extraction with ethyl acetate, and separation was performed on an XTerra MS C₁₈ column (2.1×50 mm, 3.5 μm) with gradient elution (methanol and 0.1% formic acid) at a flow rate of 0.3 mL/min. Detection was performed in multiple reaction monitoring (MRM) mode. Linear calibration curves were obtained over a concentration range of 1−100 ng/mL. The intra-day and inter-day precisions were lower than 8.46%, and the accuracies ranged from -8.71% to 12.36% at all quality control levels. The extraction recoveries were approximately 70%, and the matrix effects were negligible. All quality control samples were stable under different storage conditions. The validated method was successfully applied to a preclinical pharmacokinetic study in Sprague-Dawley rats. IMB-YH-4py5-2H demonstrated improved pharmacokinetic properties (higher exposure level) compared with its leading compound. IMB-YH-4py5-2H was also distributed throughout the lung pronouncedly, especially inside alveolar macrophages, indicating its effectiveness against lower respiratory infections.

A CRISPR-Assisted Nonhomologous End-Joining Strategy for Efficient Genome Editing in Mycobacterium tuberculosis

New tools for genetic manipulation of Mycobacterium tuberculosis are needed for the development of new drug regimens and vaccines aimed at curing tuberculosis infections. Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) systems generate a highly specific double-strand break at the target site that can be repaired via nonhomologous end joining (NHEJ), resulting in the desired genome alteration. In this study, we first improved the NHEJ repair pathway and developed a CRISPR-Cas-mediated genome-editing method that allowed us to generate markerless deletion in Mycobacterium smegmatis, Mycobacterium marinum, and M. tuberculosis Then, we demonstrated that this system could efficiently achieve simultaneous generation of double mutations and large-scale genetic mutations in M. tuberculosis Finally, we showed that the strategy we developed can also be used to facilitate genome editing in Escherichia coli IMPORTANCE The global health impact of M. tuberculosis necessitates the development of new genetic tools for its manipulation, to facilitate the identification and characterization of novel drug targets and vaccine candidates. Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) genome editing has proven to be a powerful genetic tool in various organisms; to date, however, attempts to use this approach in M. tuberculosis have failed. Here, we describe a genome-editing tool based on CRISPR cleavage and the nonhomologous end-joining (NHEJ) repair pathway that can efficiently generate deletion mutants in M. tuberculosis More importantly, this system can generate simultaneous double mutations and large-scale genetic mutations in this species. We anticipate that this CRISPR-NHEJ-assisted genome-editing system will be broadly useful for research on mycobacteria, vaccine development, and drug target profiling.

Swim Bladder as a Novel Biomaterial for Cardiovascular Materials with Anti-Calcification Properties

Calcification is a major cause of cardiovascular materials failure and deterioration, which leads to the restriction of their wide application. To develop new materials with anti-calcification capability is an urgent clinical requirement. Herein, a natural material derived from swim bladders as one promising candidate is introduced, which is prepared by decellularization and glutaraldehyde (GA) crosslinking. Data show that the swim bladder is mainly composed of collagen I, glycosaminoglycan (GAG), and elastin, especially rich in elastin, in accordance with higher elastic modulus in comparison to bovine pericardium. Moreover, the calcification of this material is proved dramatically lower than that of bovine pericardium by in vitro calcification assessments and in vivo assay using a rat subcutaneous implantation model. Meanwhile, good cytocompatibility, hemocompatibility, and enzymatic stability are demonstrated by in vitro assays. Further, a small diameter vascular graft using this material is successfully developed by rolling method and in situ implantation assay using a rat abdominal artery replacement model shows great performances in the aspect of higher patency and lower calcification. Taken together, these superior properties of swim bladder-derived material in anti-calcification, proper mechanical strength and stability, and excellent hemocompatibility and cytocompatibility endow it a great candidate as cardiovascular biomaterials.

High-Throughput Screening Identifies Mixed-Lineage Kinase 3 as a Key Host Regulatory Factor in Zika Virus Infection

The Zika virus (ZIKV) life cycle involves multiple steps and requires interactions with host factors. However, the inability to systematically identify host regulatory factors for ZIKV has hampered antiviral development and our understanding of pathogenicity. Here, using a bioactive compound library with 2,659 small molecules, we applied a high-throughput and imaging-based screen to identify host factors that modulate ZIKV infection. The screen yielded hundreds of hits that markedly inhibited or potentiated ZIKV infection in SNB-19 glioblastoma cells. Among the hits, URMC-099, a mixed-lineage kinase 3 (MLK3) inhibitor, significantly facilitated ZIKV replication in both SNB-19 cells and the neonatal mouse brain. Using gene silencing and overexpression, we further confirmed that MLK3 was a host restriction factor against ZIKV. Mechanistically, MLK3 negatively regulated ZIKV replication through induction of the inflammatory cytokines interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha (TNF-α), and monocyte chemoattractant protein 1 (MCP-1) but did not modulate host interferon-related pathways. Importantly, ZIKV activated the MLK3/MKK7/Jun N-terminal protein kinase (JNK) pathway in both SNB-19 cells and neonatal mouse brain. Together, these findings reveal a critical role for MLK3 in regulating ZIKV infection and facilitate the development of anti-ZIKV therapeutics by providing a number of screening hits.IMPORTANCE Zika fever, an infectious disease caused by the Zika virus (ZIKV), normally results in mild symptoms. Severe infection can cause Guillain-Barré syndrome in adults and birth defects, including microcephaly, in newborns. Although ZIKV was first identified in Uganda in 1947 in rhesus monkeys, a widespread epidemic of ZIKV infection in South and Central America in 2015 and 2016 raised major concerns. To date, there is no vaccine or specific medicine for ZIKV. The significance of our research is the systematic discovery of small molecule candidates that modulate ZIKV infection, which will allow the development of antiviral therapeutics. In addition, we identified MLK3, a key mediator of host signaling pathways that can be activated during ZIKV infection and limits virus replication by inducing multiple inflammatory cytokines. These findings broaden our understanding of ZIKV pathogenesis.

Gut microbiota promote the inflammatory response in the pathogenesis of systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease whose onset and progression are affected by genetic and environmental factors. The purpose of this study is to identify the influence of gut microbiota in the pathogenesis of SLE, and to investigate the mechanism involved.

METHODS

Fecal microbiota from C57/BL6 mice and SLE prone mice were examined using next-generation sequencing (NGS). Germ free mice were given fecal microbiota transplantation (FMT), and their gut microbiome and gene expression in recipients' colons were examined by NGS. The anti-double stranded DNA (anti-dsDNA) antibodies in recipients were determined using an enzyme-linked immunosorbent assay (ELISA). The immune cell profiles of mice were analyzed by flow cytometry at the 3rd week after FMT, and the expression of genes associated with SLE after FMT was determined using quantitative real-time PCR (qRT-PCR).

RESULTS

The fecal microbiota of SLE mice had lower community richness and diversity than healthy mice. Fecal microbiota of recipient mice were similar to their donors. Fecal microbiome from SLE mice could lead to a significant increase of anti-dsDNA antibodies and promote the immune response in recipient mice. Our results also indicated that fecal microbiome from SLE mice resulted in significant changes in the distribution of immune cells and upregulated expression of certain lupus susceptibility genes.

CONCLUSIONS

SLE is associated with alterations of gut microbiota. Fecal microbiome from SLE mice can induce the production of anti-dsDNA antibodies in germ free mice and stimulate the inflammatory response, and alter the expression of SLE susceptibility genes in these mice.

Microdialysis combined with liquid chromatography-tandem mass spectrometry for the quantitation of gemifloxacin and its application to a muscle penetration study in healthy and MRSA-infected rats

Pharmacological efficacy is based on the drug concentration in target tissues, which usually cannot be represented by the plasma concentration. The purpose of this study was to compare the pharmacokinetic characteristics of gemifloxacin in plasma and skeletal muscle and evaluate its tissue penetration in both healthy and MRSA (methicillin-resistant Staphylococcus aureus)-infected rats. A microdialysis (MD) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine free gemifloxacin concentrations in rat plasma and skeletal muscle simultaneously. The in vivo recoveries of MD were 23.21% ± 3.42% for skeletal muscle and 20.62% ± 3.19% for plasma, and were concentration independent. We provided evidence that the method developed here meets FDA requirements. Additionally, this method was successfully applied to the determination of free gemifloxacin in rats. Muscle and blood dialysates were collected after an 18 mg/kg intravenous bolus dose. The mean areas under the concentration-time curves (AUCs) from 0 to 9 h for skeletal muscle and plasma were 3641.50 ± 915.65 h*ng/mL and 7068.32 ± 1964.19 h*ng/mL in MRSA-infected rats and 3774.72 ± 700.36 h*ng/mL and 6927.49 ± 1714.86 h*ng/mL in healthy rats, respectively. There was no significant difference (P>0.05) in gemifloxacin exposure between healthy rats and MRSA-infected rats for plasma or muscle. The low ratio of AUC0-9 muscle to AUC0-9 plasma suggested lower drug exposure in skeletal muscle than in plasma for both healthy and MRSA-infected rats. Our study suggested that the administration of gemifloxacin according to drug levels in plasma to treat local infection is unreasonable and might result in an inadequate dose regimen.

Combination regimens with PD-1/PD-L1 immune checkpoint inhibitors for gastrointestinal malignancies

Gastrointestinal (GI) malignant neoplasms have a high global incidence and treatment prospects for patients with advanced GI tumors are dismal. PD-1/PD-L1 inhibitors emerged as a frontline treatment for several types of cancer. However, the shortcomings of PD-1/PD-L1 inhibitors have been observed, including low objective response rates and acquired tumor resistance, especially in patients receiving PD-1/PD-L1 inhibitors as a single treatment. Accumulating evidence from clinical trials increasingly suggests that combined immunotherapies enhance therapeutic responses in patients with malignances, especially for GI tumors which have a complex matrix, and significant molecular and immunological differences. Preclinical and clinical studies suggest there are advantages to combined immunological regimens, which represents the next logical step in this field, although further research is necessary. This literature review explores the current limitations of monotherapies, before critically discussing the rationale behind combination regimens. Then, we provide a summary of the clinical applications for gastrointestinal cancers.

Preparation and Evaluation of Liposomes Co-Loaded with Doxorubicin, Phospholipase D Inhibitor 5-Fluoro-2-Indolyl Deschlorohalopemide (FIPI) and D-Alpha Tocopheryl Acid Succinate (α-TOS) for Anti-Metastasis

Tumor metastasis has become a key obstacle to cancer treatment, which causes high mortality. Nowadays, it involves multiple complex pathways, and conventional treatments are not effective due to fewer targets. The aims of the present study were to construct a novel liposome delivery system co-loading a specific PLD inhibitor 5-fluoro-2-indolyldes-chlorohalopemide (FIPI) in combination with antitumor drug doxorubicin (DOX) and functional excipient D-alpha tocopheryl acid succinate (α-TOS) for anti-metastasis. In this study, the liposomes containing three components (DFT-Lip) with different physicochemical properties were successfully prepared by film dispersion method combined with pH-gradient method. Physicochemical parameters such as particles size, potential, encapsulation efficiency, stability, and release profiles were investigated. In vitro and in vivo anti-metastasis effectiveness against highly metastatic breast cancer MDA-MB-231 cell line was evaluated. The liposomes showed uniform particle size (approximately 119 nm), high drug encapsulation efficiency (> 90%), slow release characteristics and stability. In vitro anti-tumor cell metastasis study demonstrated DFT-Lip could greatly inhibit motility, migration and invasion of MDA-MB-231 cells compared to other liposomes, predicting a synergistic anti-tumor metastasis effect between FIPI with α-TOS in liposomes. In vivo anti-metastasis study showed that DFT-Lip prevented the initiation and the progression of metastasis of high metastatic breast cancer. These results suggested that the liposomes containing DOX, FIPI, and α-TOS might be a promising strategy for metastatic tumor therapy in clinics.

Chrysoxanthones A⁻C, Three New Xanthone⁻Chromanone Heterdimers from Sponge-Associated Penicillium chrysogenum HLS111 Treated with Histone Deacetylase Inhibitor

By treating with histone-deacetylase inhibitor valproate sodium, three new heterdimeric tetrahydroxanthone⁻chromanone lactones chrysoxanthones A⁻C (1⁻3), along with 17 known compounds were isolated from a sponge-associated Penicillium chrysogenum HLS111. The planar structures of chrysoxanthones A⁻C were elucidated by means of spectroscopic analyses, including MS, 1D, and 2D NMR. Their absolute configurations were established by electronic circular dichroism (ECD) calculations. Chrysoxanthones A⁻C exhibited moderate antibacterial activities against Bacillus subtilis with minimum inhibitory concentration (MIC) values of 5⁻10 μg/mL.

Mutant TP53 G245C and R273H promote cellular malignancy in esophageal squamous cell carcinoma

BACKGROUND

TP53 gene mutations occur in more than 50% of human cancers and the vast majority of these mutations in human cancers are missense mutations, which broadly occur in DNA binding domain (DBD) (Amino acids 102-292) and mainly reside in six "hotspot" residues. TP53 G245C and R273H point mutations are two of the most frequent mutations in tumors and have been verified in several different cancers. In the previous study of the whole genome sequencing (WGS), we found some mutations of TP53 DBD in esophageal squamous cell carcinoma (ESCC) clinical samples. We focused on two high-frequent mutations TP53 p.G245C and TP53 p.R273H and investigated their oncogenic roles in ESCC cell lines, p53-defective cell lines H1299 and HCT116 p53-/-.

RESULTS

MTS and colony formation assays showed that mutant TP53 G245C and R273H increased cell vitality and proliferation. Flow cytometry results revealed inhibition of ultraviolet radiation (UV)- and ionizing radiation (IR)- induced apoptosis and disruption of TP53-mediated cell cycle arrest after UV, IR and Nocodazole treatment. Transwell assays indicated that mutant TP53 G245C and R273H enhanced cell migration and invasion abilities. Moreover, western blot revealed that they were able to suppress the expression of TP53 downstream genes in the process of apoptosis and cell cycle arrest induced by UV, which suggests that these two mutations can influence apoptosis and growth arrest might be due, at least in part, to down-regulate the expression of P21, GADD45α and PARP.

CONCLUSIONS

These results indicate that mutant TP53 G245C and R273H can lead to more aggressive phenotypes and enhance cancer cell malignancy, which further uncover TP53 function in carcinogenesis and might be useful in clinical diagnosis and therapy of TP53 mutant cancers.

RNA m6A methylation participates in regulation of postnatal development of the mouse cerebellum

BACKGROUND

N6-methyladenosine (m6A) is an important epitranscriptomic mark with high abundance in the brain. Recently, it has been found to be involved in the regulation of memory formation and mammalian cortical neurogenesis. However, while it is now established that m6A methylation occurs in a spatially restricted manner, its functions in specific brain regions still await elucidation.

RESULTS

We identify widespread and dynamic RNA m6A methylation in the developing mouse cerebellum and further uncover distinct features of continuous and temporal-specific m6A methylation across the four postnatal developmental processes. Temporal-specific m6A peaks from P7 to P60 exhibit remarkable changes in their distribution patterns along the mRNA transcripts. We also show spatiotemporal-specific expression of m6A writers METTL3, METTL14, and WTAP and erasers ALKBH5 and FTO in the mouse cerebellum. Ectopic expression of METTL3 mediated by lentivirus infection leads to disorganized structure of both Purkinje and glial cells. In addition, under hypobaric hypoxia exposure, Alkbh5-deletion causes abnormal cell proliferation and differentiation in the cerebellum through disturbing the balance of RNA m6A methylation in different cell fate determination genes. Notably, nuclear export of the hypermethylated RNAs is enhanced in the cerebellum of Alkbh5-deficient mice exposed to hypobaric hypoxia.

CONCLUSIONS

Together, our findings provide strong evidence that RNA m6A methylation is controlled in a precise spatiotemporal manner and participates in the regulation of postnatal development of the mouse cerebellum.

Broad and diverse mechanisms used by deubiquitinase family members in regulating the type I interferon signaling pathway during antiviral responses

The innate immune response conferred by type I interferons is essential for host defense against viral infection but needs to be tightly controlled to avoid immunopathology. We performed a systematic functional screening by CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) knockout and overexpression to investigate the roles of the deubiquitinating enzyme (DUB) family in regulating antiviral immunity. We demonstrated that the expression of a large fraction of DUBs underwent complex temporal alteration, suggesting a dynamic program of feedback regulation. Moreover, we identified previously unrecognized roles of a subset of DUBs, including USP5, USP14, USP22, USP48, USP52, COPS5, and BRCC3, in inhibiting antiviral immunity at various levels. We explored an unexpected mechanism where multiple DUBs, such as USP5 and USP22, form diverse signalosomes with E3 ligases or DUBs to alter the substrates' ubiquitination state instead of directly cleaving the ubiquitin chains on substrates via their protease activity. Altogether, our study has revealed a panoramic view of the broad and dynamic involvement of DUB family proteins in regulating antiviral responses.

Novel Mutations in PLOD2 Cause Rare Bruck Syndrome

Bruck syndrome is a rare autosomal recessive form of osteogenesis imperfecta (OI), which is mainly characterized by joint contractures and recurrent fragility fractures. Mutations in FKBP10 and PLOD2 were identified as the underlying genetic defects of Bruck syndrome. Here we investigated the phenotypes and the pathogenic mutations of three unrelated Chinese patients with Bruck syndrome. Clinical fractures, bone mineral density (BMD), bone turnover biomarkers, and skeletal images were evaluated in detail. The pathogenic mutations were identified by targeted next-generation sequencing and subsequently confirmed by Sanger sequencing and cosegregation analysis. We also evaluated the effects of zoledronic acid on bone fracture incidence and BMD of the patients. Three patients had congenital joint contractures, recurrent fragility fractures, camptodactyly, clubfoot, scoliosis, but without dentinogenesis imperfecta and hearing loss. Five novel heterozygous mutations were detected in PLOD2, including three heterozygous missense mutations (c.1138C>T, p.Arg380Cys; c.1153T>C, p.Cys385Arg; and c.1982G>A, p.Gly661Asp), one heterozygous nonsense mutation (c.2038C>T, p.Arg680X), and one heterozygous splice-site mutation (c.503-2A>G). Their parents were all heterozygous carriers of these mutations in PLOD2. No clear genotype-phenotype correlations were found in these patients with PLOD2 mutations. Z-score of BMD was significantly increased, but scoliosis progressed and new bone fractures occurred during the treatment of zoledronic acid. Our findings expanded the spectrum of gene mutations of Bruck syndrome.