Blocking Ubiquitin-Specific Protease 7 Induces Ferroptosis in Gastric Cancer via Targeting Stearoyl-CoA Desaturase

Gastric cancer (GC) presents a formidable global health challenge, and conventional therapies face efficacy limitations. Ubiquitin-specific protease 7 (USP7) plays pivotal roles in GC development, immune response, and chemo-resistance, making it a promising target. Various USP7 inhibitors have shown selectivity and efficacy in preclinical studies. However, the mechanistic role of USP7 has not been fully elucidated, and currently, no USP7 inhibitors have been approved for clinical use. In this study, DHPO is identified as a potent USP7 inhibitor for GC treatment through in silico screening. DHPO demonstrates significant anti-tumor activity in vitro, inhibiting cell viability and clonogenic ability, and preventing tumor migration and invasion. In vivo studies using orthotopic gastric tumor mouse models validate DHPO's efficacy in suppressing tumor growth and metastasis without significant toxicity. Mechanistically, DHPO inhibition triggers ferroptosis, evidenced by mitochondrial alterations, lipid Reactive Oxygen Species (ROS), Malondialdehyde (MDA) accumulation, and iron overload. Further investigations unveil USP7's regulation of Stearoyl-CoA Desaturase (SCD) through deubiquitination, linking USP7 inhibition to SCD degradation and ferroptosis induction. Overall, this study identifies USP7 as a key player in ferroptosis of GC, elucidates DHPO's inhibitory mechanisms, and highlights its potential for GC treatment by inducing ferroptosis through SCD regulation.

Endurance Training Inhibits the JAK2/STAT3 Pathway to Alleviate Sarcopenia

Aging leads to a decrease in muscle function, mass, and strength in skeletal muscle of animals and humans. The transcriptome identified activation of the JAK/STAT pathway, a pathway that is associated with skeletal muscle atrophy, and endurance training has a significant effect on improving sarcopenia; however, the exact mechanism still requires further study. We investigated the effect of endurance training on sarcopenia. Six-month-old male SAMR1 mice were used as a young control group (group C), and the same month-old male SAMP8 mice were divided into an exercise group (group E) and a model group (group M). A 3-month running exercise intervention was performed on group E, and the other two groups were kept normally. Aging caused significant signs of sarcopenia in the SAMP8 mice, and endurance training effectively improved muscle function, muscle mass, and muscle strength in the SAMP8 mice. The expression of JAK2/STAT3 pathway factor was decreased in group E compared with group M, and the expression of SOCS3, the target gene of STAT3, and NR1D1, an atrophy-related factor, was significantly increased. Endurance training significantly improved the phenotypes associated with sarcopenia, and the JAK2/STAT3 pathway is a possible mechanism for the improvement of sarcopenia by endurance training, while NR1D1 may be its potential target. Keywords: Sarcopenia, Endurance training, Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3), Nuclear receptor subfamily 1, group D member 1 (Nr1d1).

Data-mining framework for in-depth quantitative study of influences on low-wind-velocity area from morphological parameters of cuboid-form buildings

Wind environment is important in architectural sustainable design, as existing studies show that it can be considerably influenced by building morphologies. This study aimed to develop a data-mining framework to quantitatively evaluate and compare influences on Low-Wind-Velocity Area (LWVA) of common cuboid-form buildings with typical morphological parameters. The data-mining framework was originally developed by integrating multiple computational methods for rapid in-depth iterative analyses, including the generation of building models using parametric modelling, the big data generation based on hybrid model, and the statistical metric analysis method. The hybrid model was created by combining the CFD model and machine learning model. The accuracy and efficiency of the framework were fully demonstrated through the comprehensive validation and analyses of different models. The data of more than fifty thousand building cases with different morphological parameters and relevant wind conditions were generated and analyzed. Influences on LWVA of morphological parameters of cuboid-form building was comprehensively evaluated, including the visualization of multiple parameters, calculation and comparison of several correlation coefficients. It suggested that the reduction of height and width on the windward side would significantly decrease the LWVA and promote the outdoor ventilation. The change of depth would have relatively limited influence on the LWVA. Multivariate regression model-fit and variance analyses were further implemented, and it was found that there was a relatively significant linear correlation between the LWVA and morphological parameters. The equation of multivariate regression model was provided for extra rapid prediction. The study outcome could contribute to efficient evaluation of LWVA and provide useful information for sustainable design.

A T cell-based SARS-CoV-2 spike protein vaccine provides protection without antibodies

SARS-CoV-2 spike-based vaccines are used to control the COVID-19 pandemic. However, emerging variants have become resistant to antibody neutralization and further mutations may lead to full resistance. We tested whether T cells alone could provide protection without antibodies. We designed a T cell-based vaccine in which SARS-CoV-2 spike sequences were rearranged and attached to ubiquitin. Immunization of mice with the vaccine induced no specific antibodies, but strong specific T cell responses. We challenged mice with SARS-CoV-2 wild-type strain or an Omicron variant after the immunization and monitored survival or viral titers in the lungs. The mice were significantly protected against death and weight loss caused by the SARS-CoV-2 wild-type strain, and the viral titers in the lungs of mice challenged with the SARS-CoV-2 wild-type strain or the Omicron variant were significantly reduced. Importantly, depletion of CD4+ or CD8+ T cells led to significant loss of the protection. Our analyses of spike protein sequences of the variants indicated that fewer than one-third presented by dominant HLA alleles were mutated and that most of the mutated epitopes were in the subunit 1 region. As the subunit 2 region is conservative, the vaccines targeting spike protein are expected to protect against future variants due to the T cell responses.

Associations of pyrethroid exposure with bone mineral density and osteopenia in adults

INTRODUCTION

This study was to investigate the correlations between pyrethroid exposure and bone mineral density (BMD) and osteopenia.

MATERIALS AND METHODS

This cross-sectional study included 1389 participants over 50 years of age drawn from the 2007-2010 and 2013-2014 National Health and Nutrition Examination Survey (NHANES). Three pyrethroid metabolites, 3-phenoxybenzoic acid (3-PBA), trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane-1-carboxylic acid (trans-DCCA), and 4-fluoro-3-phenoxybenzoic acid (4-F-3PBA) were used as indicators of pyrethroid exposure. Low BMD was defined as T-score < - 1.0, including osteopenia. Weighted multivariable linear regression analysis or logistic regression analysis was utilized to evaluate the correlation between pyrethroid exposure and BMD and low BMD. Bayesian kernel machine regression (BKMR) model was utilized to analyze the correlation between pyrethroids mixed exposure and low BMD.

RESULTS

There were 648 (48.41%) patients with low BMD. In individual pyrethroid metabolite analysis, both tertile 2 and tertile 3 of trans-DCCA were negatively related to total femur, femur neck, and total spine BMD [coefficient (β) = - 0.041 to - 0.028; all P < 0.05]. Both tertile 2 and tertile 3 of 4-F-3PBA were negatively related to total femur BMD (P < 0.05). Only tertile 2 [odds ratio (OR) = 1.63; 95% CI = 1.07, 2.48] and tertile 3 (OR = 1.65; 95% CI = 1.10, 2.50) of trans-DCCA was correlated with an increased risk of low BMD. The BKMR analysis indicated that there was a positive tendency between mixed pyrethroids exposure and low BMD.

CONCLUSION

In conclusion, pyrethroids exposure was negatively correlated with BMD levels, and the associations of pyrethroids with BMD and low BMD varied by specific pyrethroids, pyrethroid concentrations, and bone sites.

[The clinical significance of lateral pelvic sentinel lymph node biopsy using indocyanine green fluorescence navigation in laparoscopic lateral pelvic lymph node dissection]

Objectives: This study aims to explore the clinical significance of lateral pelvic sentinel lymph node biopsy (SLNB) using indocyanine green (ICG) fluorescence navigation in laparoscopic lateral pelvic lymph node dissection (LLND) and evaluate the accuracy and feasibility of this technique to predict the status of lateral pelvic lymph nodes (LPLNs). Methods: The clinical and pathological characteristics, surgical outcomes, lymph node findings and perioperative complications of 16 rectal cancer patients who underwent SLNB using ICG fluorescence navigation in laparoscopic LLND in the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College during April 2017 and October 2022 were retrospectively collected and analyzed. The patients did not receive preoperative neoadjuvant radiotherapy and presented with LPLNs but without LPLN enlargement (MRI showed the maximum short axes of the LPLNs were ≥5 mm and <10 mm at first visit). Results: All 16 patients were successfully performed SLNB using ICG fluorescence navigation in laparoscopic LLND. Three patients underwent bilateral LLND and 13 patients underwent unilateral LLND. The lateral pelvic sentinel lymph nodes (SLNs) were clearly fluorescent before dissection in 14 patients and the detection rate of SLNs for these patients was 87.5%. Lateral pelvic SLN metastasis was diagnosed in 2 patients and negative results were found in 12 patients by frozen pathological examinations. Among the 14 patients in whom lateral pelvic SLNs were detected, the dissected lateral pelvic non-SLNs were all negative. All dissected LPLNs were negative in two patients without fluorescent lateral pelvic SLNs. The specificity, sensitivity, negative predictive value, and accuracy was 85.7%, 100%, 100%, and 100%, respectively. Conclusions: This study indicates that lateral pelvic SLNB using ICG fluorescence navigation shows promise as a safe and feasible procedure with good accuracy. This technique may replace preventive LLND for locally advanced lower rectal cancer.

XYA-2: a marine-derived compound targeting apoptosis and multiple signaling pathways in pancreatic cancer

Background

Pancreatic cancer is a highly aggressive and fatal disease with limited treatment options and poor prognosis for patients. This study aimed to investigate the impact of XYA-2 {N-(3,7-dimethyl-2,6-octadienyl)-2-aza-2-deoxychaetoviridin A}, a nitrogenated azaphilon previously reported from a deep-sea-derived fungus on the progression of pancreatic cancer cells.

Methods

The inhibitory effects of XYA-2 on cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion were assessed using various assays. The CCK-8 assay, clone formation assay, flow cytometry assay, wound healing assay, and transwell assay were employed to evaluate cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion, respectively. Moreover, we employed RNA-seq and bioinformatics analyses to uncover the underlying mechanism by which XYA-2 influences pancreatic cancer cells. The revealed mechanism was subsequently validated through qRT-PCR.

Results

Our results demonstrated that XYA-2 dose-dependently inhibited the proliferation of pancreatic cancer cells and induced cell cycle arrest and apoptosis. Additionally, XYA-2 exerted a significant inhibitory effect on the invasion and migration of cancer cells. Moreover, XYA-2 was found to regulate the expression of genes involved in multiple cancer-related pathways based on our RNA-seq and bioinformatics analysis.

Conclusion

These findings highlight the potential of XYA-2 as a promising therapeutic option for the treatment of pancreatic cancer.

An Uncertainty-Guided Deep Learning Method Facilitates Rapid Screening of CYP3A4 Inhibitors

Cytochrome P450 3A4 (CYP3A4), a prominent member of the P450 enzyme superfamily, plays a crucial role in metabolizing various xenobiotics, including over 50% of clinically significant drugs. Evaluating CYP3A4 inhibition before drug approval is essential to avoiding potentially harmful pharmacokinetic drug-drug interactions (DDIs) and adverse drug reactions (ADRs). Despite the development of several CYP inhibitor prediction models, the primary approach for screening CYP inhibitors still relies on experimental methods. This might stem from the limitations of existing models, which only provide deterministic classification outcomes instead of precise inhibition intensity (e.g., IC50) and often suffer from inadequate prediction reliability. To address this challenge, we propose an uncertainty-guided regression model to accurately predict the IC50 values of anti-CYP3A4 activities. First, a comprehensive data set of CYP3A4 inhibitors was compiled, consisting of 27,045 compounds with classification labels, including 4395 compounds with explicit IC50 values. Second, by integrating the predictions of the classification model trained on a larger data set and introducing an evidential uncertainty method to rank prediction confidence, we obtained a high-precision and reliable regression model. Finally, we use the evidential uncertainty values as a trustworthy indicator to perform a virtual screening of an in-house compound set. The in vitro experiment results revealed that this new indicator significantly improved the hit ratio and reduced false positives among the top-ranked compounds. Specifically, among the top 20 compounds ranked with uncertainty, 15 compounds were identified as novel CYP3A4 inhibitors, and three of them exhibited activities less than 1 μM. In summary, our findings highlight the effectiveness of incorporating uncertainty in compound screening, providing a promising strategy for drug discovery and development.

Research progress on antitumor mechanisms and molecular targets of Inula sesquiterpene lactones

The pharmacological effects of natural product therapy have received sigificant attention, among which terpenoids such as sesquiterpene lactones stand out due to their biological activity and pharmacological potential as anti-tumor drugs. Inula sesquiterpene lactones are a kind of sesquiterpene lactones extracted from Inula species. They have many pharmacological activities such as anti-inflammation, anti-asthma, anti-tumor, neuroprotective and anti-allergic. In recent years, more and more studies have proved that they are important candidate drugs for the treatment of a variety of cancers because of its good anti-tumor activity. In this paper, the structure, structure-activity relationship, antitumor activities, mechanisms and targets of Inula sesquiterpene lactones reported in recent years were reviewed in order to provide clues for the development of novel anticancer drugs.

[Study on the correlation between thyroid nodule and metabolic index in physical examination population]

Objective: By analyzing the prevalence and influencing factors of thyroid nodules (TN) among a population undergoing physical examinations in Nantong region, this study aims to provide theoretical basis for early prevention and intervention of TN. Methods: A cross-sectional study was conducted, including 6 950 participants who underwent physical examinations at the Affiliated Hospital of Nantong University from January 2017 to April 2020. All participants underwent high-resolution ultrasound examination of the thyroid, and measurements of height, body mass index (BMI), blood pressure. Fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), uric acid (UA), homocysteine (HCY) and other metabolic indicators were detected. Data analysis was performed using SPSS 26.0 statistical software. The numerical variables with normal distribution were expressed as mean±standard deviation (x¯±s), and the t-test was used for comparison between the two groups. Numerical variables with non-normal distribution were expressed as median (interquartile range), namely M (Q1, Q3). The Mann-Whitney U test was used for comparison between two groups, and the Kruskal-Wallis test was used for comparison between multiple groups. Results: The prevalence of thyroid nodules among the 6 950 participants was 53.97% (3 751/6 950), with a rate of 47.08% (2 218/4 711) in males and 68.47% (1 533/2 239) in females, which was significantly higher in females than in males (χ2=278.575, P<0.001). The prevalence of TN increased with age both overall (χ2=552.145, P<0.001), in males (χ2=304.086, P<0.001), and in females (χ2=202.178, P<0.001). The prevalence of TN was higher in females than in males across different age groups (P<0.05). In the comparison between males in the TN and non-TN groups, significant differences were found in terms of alcohol consumption history, BMI, blood pressure, HCY, and FBG (all P<0.05). In the comparison between females in the TN and non-TN groups, significant differences were found in terms of BMI, blood pressure, HCY, FBG, TC, TG, LDL-C, and UA (all P<0.05). Univariate logistic regression model showed that FBG<6.1 mmol/L (P<0.001) and TC<5.2 mmol/L (P=0.013) were protective factors for TN. Normal UA (P=0.013) was a risk factor for TN. After adjusting for gender, smoking, alcohol consumption, BMI, and blood pressure, multivariate logistic regression analysis revealed that FBG<6.1 mmol/L (OR: 0.713, 95%CI: 0.621-0.817, P<0.001) was a protective factor against TN. Conclusion: The prevalence of TN is relatively high in the Nantong region. Gender, age, blood pressure, BMI, and FBG are important influencing factors for TN. Health screening and management should be strengthened for the physical examination population with abnormal indicators.

GeoDILI: A Robust and Interpretable Model for Drug-Induced Liver Injury Prediction Using Graph Neural Network-Based Molecular Geometric Representation

Drug-induced liver injury (DILI) is a significant cause of drug failure and withdrawal due to liver damage. Accurate prediction of hepatotoxic compounds is crucial for safe drug development. Several DILI prediction models have been published, but they are built on different data sets, making it difficult to compare model performance. Moreover, most existing models are based on molecular fingerprints or descriptors, neglecting molecular geometric properties and lacking interpretability. To address these limitations, we developed GeoDILI, an interpretable graph neural network that uses a molecular geometric representation. First, we utilized a geometry-based pretrained molecular representation and optimized it on the DILI data set to improve predictive performance. Second, we leveraged gradient information to obtain high-precision atomic-level weights and deduce the dominant substructure. We benchmarked GeoDILI against recently published DILI prediction models, as well as popular GNN models and fingerprint-based machine learning models using the same data set, showing superior predictive performance of our proposed model. We applied the interpretable method in the DILI data set and derived seven precise and mechanistically elucidated structural alerts. Overall, GeoDILI provides a promising approach for accurate and interpretable DILI prediction with potential applications in drug discovery and safety assessment. The data and source code are available at GitHub repository (https://github.com/CSU-QJY/GeoDILI).

Causal association of physical activity with low back pain, intervertebral disc degeneration and sciatica: a two-sample mendelian randomization analysis study

Objective: Previous studies are insufficient to confirm a causal association between physical activity (PA) and low back pain (LBP), intervertebral disc degeneration (IDD), and sciatica. The present study used a two-sample Mendelian randomization (MR) analysis method to demonstrate whether or not there was a causal connection. Methods: First, four PA phenotypes were selected [accelerometer-based PA (average acceleration), accelerometer-based PA (acceleration fraction >425 mg), self-reported moderate-to-vigorous PA, and self-reported vigorous PA], setting thresholds for single nucleotide polymorphisms (SNPs) significantly concerned with PA p < 5 × 10-8, linkage disequilibrium (LD) r 2 < 0.01, genetic distance >5,000 kb, and F-value >10. SNPs associated with the outcome and confounding factors were then excluded using the PhenoScanncer database. Finally, after coordinating the genetic instruments from genome-wide association studies (GWAS) effect alleles for exposure and outcomes, multiplicative random effects inverse variance weighting (IVW), MR-Egger, weighted median method (WMM), and weighted mode method were used to assess exposure-outcome causality and perform sensitivity analysis on the estimated results. Results: The current study's IVW findings revealed proof of a causal connection between PA and LBP. While there was a positive causal tie between accelerometer-based PA (acceleration fraction >425 mg) and LBP [OR: 1.818, 95% CI:1.129-2.926, p = 0.012], there was a negative causal link between accelerometer-based PA (average acceleration) and LBP [OR: 0.945, 95% CI: 0.909-0.984, p = 0.005]. However causal relationship between PA and IDD or sciatica was not found. Conclusion: Increasing average PA but needing to avoid high-intensity PA may be an effective means of preventing low back pain. Although PA is not directly causally related to disc degeneration and sciatica, it can act through indirect pathways.

A benzochalcone derivative synchronously induces apoptosis and ferroptosis in pancreatic cancer cells

Background

Pancreatic cancer is a highly aggressive and lethal disease with limited treatment options. In this study, we investigated the potential therapeutic effects of compound KL-6 on pancreatic cancer cells.

Methods

The study involved assessing the inhibitory effects of KL-6 on cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion. Additionally, we examined the action mechanism of KL-6 by RNA-seq and bioinformatic analysis and validated by qRT-PCR and western blot in pancreatic cancer cells.

Results

Our results demonstrated that KL-6 effectively inhibited the growth of pancreatic cancer cells in a dose-dependent manner. It induced G2/M phase cell cycle arrest and apoptosis, disrupting the cell cycle progression and promoting cell death. KL-6 also exhibited inhibitory effects on cell migration and invasion, suggesting its potential to suppress the metastatic properties of pancreatic cancer cells. Furthermore, KL-6 modulated the expression of genes involved in various cancer-related pathways including apoptosis and ferroptosis.

Conclusion

These findings collectively support the potential of KL-6 as a promising therapeutic option for pancreatic cancer treatment. Further research is needed to fully understand the underlying mechanisms and evaluate the clinical efficacy of KL-6 in pancreatic cancer patients.

Glycosylated Delta-receptor-binding domain mucosal vaccine elicits broadly neutralizing antibodies with protection against SARS-CoV-2 challenge

Mucosal COVID-19 vaccines are needed to block SARS-CoV-2 infection at the mucosal site. Intranasal delivery of a glycosylated Delta variant receptor-binding domain (Delta-RBD) mucosal vaccine elicited potent and balanced systemic antibody titers comparable to those induced by the intramuscular injection of the same vaccine or Omicron-S subunit vaccine, as well as high mucosal IgA antibody responses. It elicited broadly neutralizing antibodies against the original SARS-CoV-2 strain, Delta and Omicron BA1/BA2 variants, completely protecting transgenic mice from lethal challenge with a Delta variant, including complete absence of weight loss. Of note, intramuscular priming with the Omicron-S protein followed by intranasal boosting with the Delta-RBD protein improved the vaccine's ability to generate broad-spectrum neutralizing antibodies against recent BA5 and XBB Omicron variants. Overall, this vaccine has the potential to prevent the SARS-CoV-2 infection of the respiratory mucosa, while the i.m. priming and i.n. boosting vaccination strategy may offer protection against known and emerging SARS-CoV-2 variants.

MERS-CoV RBD-mRNA vaccine induces potent and broadly neutralizing antibodies with protection against MERS-CoV infection

Middle East respiratory syndrome coronavirus (MERS-CoV), a highly pathogenic coronavirus in the same Betacoronavirus genus and Coronaviridae family as SARS-CoV-2, continues to post a threat to human health. Mortality remains high; therefore, there is a need to develop effective vaccines to prevent MERS-CoV infection. The receptor-binding domain (RBD) within the MERS-CoV spike (S) protein is a critical vaccine target. The latest mRNA technology has enabled rapid development of much-needed vaccines with high efficiency and scalable manufacturing capacity. Here, we designed a mRNA vaccine encoding the RBD of MERS-CoV S protein (RBD-mRNA) and evaluated its immunogenicity and protective efficacy in a mouse model. The data showed that nucleoside-modified RBD-mRNA, but not RBD-mRNA lacking the nucleoside modification, was stable and elicited broadly and durable neutralizing antibody and cellular immune responses, which neutralized the original strain and multiple MERS-CoV variants. Among all immunization routes tested, the intradermal route was appropriate for this RBD-mRNA to induce strong B-cell responses and the highest neutralizing antibody titers. Importantly, injection of nucleoside-modified RBD-mRNA through the intradermal route protected immunized mice against challenge with MERS-CoV. This protection correlated with serum neutralizing antibody titers. Overall, we have developed an effective MERS-CoV RBD-based mRNA vaccine (with potential for further development) that prevents infection by divergent strains of MERS-CoV.

SMYD2 regulates vascular smooth muscle cell phenotypic switching and intimal hyperplasia via interaction with myocardin

The SET and MYND domain-containing protein 2 (SMYD2) is a histone lysine methyltransferase that has been reported to regulate carcinogenesis and inflammation. However, its role in vascular smooth muscle cell (VSMC) homeostasis and vascular diseases has not been determined. Here, we investigated the role of SMYD2 in VSMC phenotypic modulation and vascular intimal hyperplasia and elucidated the underlying mechanism. We observed that SMYD2 expression was downregulated in injured carotid arteries in mice and phenotypically modulated VSMCs in vitro. Using an SMC-specific SMYD2 knockout mouse model, we found that SMYD2 ablation in VSMCs exacerbated neointima formation after vascular injury in vivo. Conversely, SMYD2 overexpression inhibited VSMC proliferation and migration in vitro and attenuated arterial narrowing in injured vessels in mice. SMYD2 downregulation promoted VSMC phenotypic switching accompanied with enhanced proliferation and migration. Mechanistically, genome-wide transcriptome analysis and loss/gain-of-function studies revealed that SMYD2 up-regulated VSMC contractile gene expression and suppressed VSMC proliferation and migration, in part, by promoting expression and transactivation of the master transcription cofactor myocardin. In addition, myocardin directly interacted with SMYD2, thereby facilitating SMYD2 recruitment to the CArG regions of SMC contractile gene promoters and leading to an open chromatin status around SMC contractile gene promoters via SMYD2-mediated H3K4 methylation. Hence, we conclude that SMYD2 is a novel regulator of VSMC contractile phenotype and intimal hyperplasia via a myocardin-dependent epigenetic regulatory mechanism.

Immunogenic cell death-related classifications guide prognosis and immunotherapy in osteosarcoma

Immunogenic cell death (ICD) is a form of cell death that stimulates the immune system to produce an immune response by releasing tumour-associated antigens and tumour-specific antigens and is considered to play an important role in tumour immunotherapy. In the present study, we identified two ICD-related subtypes in osteosarcoma (OS) by consensus clustering. The ICD-low subtype was associated with favourable clinical outcomes, abundant immune cell infiltration, and high activity of immune response signalling. We also established and validated an ICD-related prognostic model, which could not only be used to predict the overall survival of OS patients but was also found to be closely related to the tumour immune microenvironment of OS patients. Overall, we established a new classification system for OS based on ICD-related genes, which can be used to predict the prognosis of OS patients and to select appropriate immunotherapy drugs.

SMYD2 Regulates Vascular Smooth Muscle Cell Phenotypic Switching and Intimal Hyperplasia via Interaction with Myocardin

The SET and MYND domain-containing protein 2 (SMYD2) is a histone lysine methyltransferase that has been reported to regulate carcinogenesis and inflammation. However, its role in vascular smooth muscle cell (VSMC) homeostasis and vascular diseases has not been determined. Here, we investigated the role of SMYD2 in VSMC phenotypic modulation and vascular intimal hyperplasia and elucidated the underlying mechanism. We observed that SMYD2 expression was downregulated in injured carotid arteries in mice and phenotypically modulated VSMCs in vitro. Using a SMC-specific Smyd2 knockout mouse model, we found that Smyd2 ablation in VSMCs exacerbates neointima formation after vascular injury in vivo. Conversely, Smyd2 overexpression inhibits VSMC proliferation and migration in vitro and attenuates arterial narrowing in injured vessels in mice. Smyd2 downregulation promotes VSMC phenotypic switching accompanied with enhanced proliferation and migration. Mechanistically, genome-wide transcriptome analysis and loss/gain-of-function studies revealed that SMYD2 up-regulates VSMC contractile gene expression and suppresses VSMC proliferation and migration, in part, by promoting expression and transactivation of the master transcription cofactor myocardin. In addition, myocardin directly interacts with SMYD2, thereby facilitating SMYD2 recruitment to the CArG regions of SMC contractile gene promoters and leading to an open chromatin status around SMC contractile gene promoters via SMYD2-mediated H3K4 methylation. Hence, we conclude that SMYD2 is a novel regulator of VSMC contractile phenotype and intimal hyperplasia via a myocardin-dependent epigenetic regulatory mechanism and may be a potential therapeutic target for occlusive vascular diseases.

Robust servo linear quadratic regulator controller based on state compensation and velocity feedforward of the spherical robot: Theory and experimental verification

There are few studies on the lateral motion of spherical robots. In this article, a new algorithm is proposed to solve the problem of low control accuracy of the lateral motion. A single lateral motion model is established, and the optimal solution of the linear quadratic regulator in infinite time domain is obtained. Aiming at the problems of longitudinal velocity and lateral angle coupling and low control precision, state compensation and velocity feedforward are carried out, and an improved robust servo linear quadratic regulator control algorithm is proposed. Experiments show that the proposed lateral control algorithm has strong adaptability and robustness to changing speeds and lateral angles, and the control effect is stable and reliable.

Dual inhibition of MYC and SLC39A10 by a novel natural product STAT3 inhibitor derived from Chaetomium globosum suppresses tumor growth and metastasis in gastric cancer

Gastric cancer remains one of the most common deadly diseases and lacks effective targeted therapies. In the present study, we confirmed that the signal transducer and activator of transcription 3 (STAT3) is highly expressed and associated with a poor prognosis in gastric cancer. We further identified a novel natural product inhibitor of STAT3, termed XYA-2, which interacts specifically with the SH2 domain of STAT3 (K_d= 3.29 μM) and inhibits IL-6-induced STAT3 phosphorylation at Tyr705 and nuclear translocation. XYA-2 inhibited the viability of seven human gastric cancer cell lines with 72-h IC₅₀ values ranging from 0.5 to 0.7 μΜ. XYA-2 at 1 μΜ inhibited the colony formation and migration ability of MGC803 (72.6% and 67.6%, respectively) and MKN28 (78.5% and 96.6%, respectively) cells. In the in vivo studies, intraperitoneal administration of XYA-2 (10 mg/kg/day, 7 days/week) significantly suppressed 59.8% and 88.8% tumor growth in the MKN28-derived xenograft mouse model and MGC803-derived orthotopic mouse model, respectively. Similar results were obtained in a patient-derived xenograft (PDX) mouse model. Moreover, XYA-2 treatment extended the survival of mice bearing PDX tumors. The molecular mechanism studies based on transcriptomics and proteomics analyses indicated that XYA-2 might exert its anticancer activity by synergistically inhibiting the expression of MYC and SLC39A10, two downstream genes of STAT3 in vitro and in vivo. Together, these findings suggested that XYA-2 may be a potent STAT3 inhibitor for treating gastric cancer, and dual inhibition of MYC and SLC39A10 may be an effective therapeutic strategy for STAT3-activated cancer.

Development of a tongue image-based machine learning tool for the diagnosis of gastric cancer: a prospective multicentre clinical cohort study

BACKGROUND

Tongue images (the colour, size and shape of the tongue and the colour, thickness and moisture content of the tongue coating), reflecting the health state of the whole body according to the theory of traditional Chinese medicine (TCM), have been widely used in China for thousands of years. Herein, we investigated the value of tongue images and the tongue coating microbiome in the diagnosis of gastric cancer (GC).

METHODS

From May 2020 to January 2021, we simultaneously collected tongue images and tongue coating samples from 328 patients with GC (all newly diagnosed with GC) and 304 non-gastric cancer (NGC) participants in China, and 16 S rDNA was used to characterize the microbiome of the tongue coating samples. Then, artificial intelligence (AI) deep learning models were established to evaluate the value of tongue images and the tongue coating microbiome in the diagnosis of GC. Considering that tongue imaging is more convenient and economical as a diagnostic tool, we further conducted a prospective multicentre clinical study from May 2020 to March 2022 in China and recruited 937 patients with GC and 1911 participants with NGC from 10 centres across China to further evaluate the role of tongue images in the diagnosis of GC. Moreover, we verified this approach in another independent external validation cohort that included 294 patients with GC and 521 participants with NGC from 7 centres. This study is registered at ClinicalTrials.gov, NCT01090362.

FINDINGS

For the first time, we found that both tongue images and the tongue coating microbiome can be used as tools for the diagnosis of GC, and the area under the curve (AUC) value of the tongue image-based diagnostic model was 0.89. The AUC values of the tongue coating microbiome-based model reached 0.94 using genus data and 0.95 using species data. The results of the prospective multicentre clinical study showed that the AUC values of the three tongue image-based models for GCs reached 0.88-0.92 in the internal verification and 0.83-0.88 in the independent external verification, which were significantly superior to the combination of eight blood biomarkers.

INTERPRETATION

Our results suggest that tongue images can be used as a stable method for GC diagnosis and are significantly superior to conventional blood biomarkers. The three kinds of tongue image-based AI deep learning diagnostic models that we developed can be used to adequately distinguish patients with GC from participants with NGC, even early GC and precancerous lesions, such as atrophic gastritis (AG).

FUNDING

The National Key R&D Program of China (2021YFA0910100), Program of Zhejiang Provincial TCM Sci-tech Plan (2018ZY006), Medical Science and Technology Project of Zhejiang Province (2022KY114, WKJ-ZJ-2104), Zhejiang Provincial Research Center for Upper Gastrointestinal Tract Cancer (JBZX-202006), Natural Science Foundation of Zhejiang Province (HDMY22H160008), Science and Technology Projects of Zhejiang Province (2019C03049), National Natural Science Foundation of China (82074245, 81973634, 82204828), and Chinese Postdoctoral Science Foundation (2022M713203).

Discovery of Isojacareubin as a covalent inhibitor of SARS-CoV-2 main protease using structural and experimental approaches

The ongoing pandemic with the emergence of immune evasion potential and, particularly, the current omicron subvariants intensified the situation further. Although vaccines are available, the immune evasion capabilities of the recent variants demand further efficient therapeutic choices to control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Hence, considering the necessity of the small molecule inhibitor, we target the main protease (3CLpro), which is an appealing target for the development of antiviral drugs against SARS-CoV-2. High-throughput molecular in silico screening of South African natural compounds database reported Isojacareubin and Glabranin as the potential inhibitors for the main protease. The calculated docking scores were reported to be -8.47 and -8.03 kcal/mol, respectively. Moreover, the structural dynamic assessment reported that Isojacareubin in complex with 3CLpro exhibit a more stable dynamic behavior than Glabranin. Inhibition assay indicated that Isojacareubin could inhibit SARS-CoV-2 3CLpro in a time- and dose-dependent manner, with half maximal inhibitory concentration values of 16.00 ± 1.35 μM (60 min incubation). Next, the covalent binding sites of Isojacareubin on SARS-CoV-2 3CLpro was identified by biomass spectrometry, which reported that Isojacareubin can covalently bind to thiols or Cysteine through Michael addition. To evaluate the inactivation potency of Isojacareubin, the inactivation kinetics was further investigated. The inactivation kinetic curves were plotted according to various concentrations with gradient-ascending incubation times. The KI value of Isojacareubin was determined as 30.71 μM, whereas the Kinact value was calculated as 0.054 min-1 . These results suggest that Isojacareubin is a covalent inhibitor of SARS-CoV-2 3CLpro .

Advances in SARS-CoV-2 receptor-binding domain-based COVID-19 vaccines

INTRODUCTION

The Coronavirus Disease 2019 (COVID-19) pandemic has caused devastating human and economic costs. Vaccination is an important step in controlling the pandemic. Severe acute respiratory coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, infects cells by binding a cellular receptor through the receptor-binding domain (RBD) within the S1 subunit of the spike (S) protein. Viral entry and membrane fusion are mediated by the S2 subunit.

AREAS COVERED

SARS-CoV-2 S protein, particularly RBD, serves as an important target for vaccines. Here we review the structure and function of SARS-CoV-2 S protein and its RBD, summarize current COVID-19 vaccines targeting the RBD, and outline potential strategies for improving RBD-based vaccines. Overall, this review provides important information that will facilitate rational design and development of safer and more effective COVID-19 vaccines.

EXPERT OPINION

The S protein of SARS-CoV-2 harbors numerous mutations, mostly in the RBD, resulting in multiple variant strains. Although many COVID-19 vaccines targeting the RBD of original virus strain (and previous variants) can prevent infection of these strains, their ability against recent dominant variants, particularly Omicron and its offspring, is significantly reduced. Collective efforts are needed to develop effective broad-spectrum vaccines to control current and future variants that have pandemic potential.

mRNA vaccines elicit potent neutralization against multiple SARS-CoV-2 omicron subvariants and other variants of concern

SARS-CoV-2 variants of concern (VOCs) have shown resistance to vaccines targeting the original virus strain. An mRNA vaccine encoding the spike protein of Omicron BA1 (BA1-S-mRNA) was designed, and its neutralizing activity, with or without the original receptor-binding domain (RBD)-mRNA, was tested against SARS-CoV-2 VOCs. First-dose of BA1-S-mRNA followed by two-boosts of RBD-mRNA elicited potent neutralizing antibodies (nAbs) against pseudotyped and authentic original SARS-CoV-2; pseudotyped Omicron BA1, BA2, BA2.12.1 and BA5 subvariants, and Alpha, Beta, Gamma and Delta VOCs; authentic Omicron BA1 subvariant and Delta VOC. By contrast, other vaccination strategies, including RBD-mRNA first-dose plus BA1-S-mRNA two-boosts, RBD-mRNA or BA1-S-mRNA three-doses, or their combinations, failed to elicit high nAb titers against all of these viruses. Overall, this vaccination strategy was effective for inducing broadly and potent nAbs against multiple SARS-CoV-2 VOCs, particularly Omicron BA5, and may guide the rational design of next-generation mRNA vaccines with greater efficacy against future variants.

Development and validation of a novel nomogram predicting pseudohypoxia type pheochromocytomas and paragangliomas

PURPOSE

Pseudohypoxia type (PHT) pheochromocytomas and paragangliomas (PPGLs) are more likely to metastasize and have a poor prognosis. However, application of genetic tests has many restrictions. The study aims to establish a novel nomogram for predicting the risk of PHT PPGLs.

METHODS

This retrospective cross-sectional study included 242 patients with pathology confirmed PPGLs in one tertiary care center in China in 2010-2021. Clinical and biochemical characteristics were collected. Next-generation sequencing was performed in all PPGLs patients for detection of mutation. Univariate and multivariable logistic regression analyses were used to select risk factors for constructing the nomogram. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the discrimination of the nomogram and the calibration curve was performed.

RESULTS

Four variables including age ≤ 35 years, hypertension, 24 h urinary output of urinary vanillylmandelic acid (VMA) ≥ 100 umol/24 h and urinary 17-ketosteroide (17 KS) ≤ 50 umol/24 h levels were independently associated with PHT PPGLs in the logistic regression analysis and were included in the nomogram. The nomogram showed a good discrimination performance with AUC of 0.829 [95% confidence interval (CI), 0.767-0.891] in the training set and 0.797 (95%CI, 0.659-0.935) in the validation set, respectively. The calibration curve showed a bias-corrected AUC of 0.809 vs. 0.795, and a Hosmer-Lemeshow (H-L) test yielded a p value of 0.801 vs. 0.885, indicating the nomogram's good ability to distinguish PHT PPGLs from non-PHT PPGLs.

CONCLUSION

Our study has proposed a novel nomogram for individualized prediction of the PHT PPGLs, which may make contributions to guide the patients' personalized management, follow-up, and treatment.

Discovery of benzochalcone derivative as a potential antigastric cancer agent targeting signal transducer and activator of transcription 3 (STAT3)

Gastric cancer remains a significant health burden worldwide. In continuation of our previous study and development of effective small molecules against gastric cancer, a series of benzochalcone analogues involving heterocyclic molecules were synthesised and biologically evaluated in vitro and in vivo. Among them, the quinolin-6-yl substituted derivative KL-6 inhibited the growth of gastric cancer cells (HGC27, MKN28, AZ521, AGS, and MKN1) with a submicromolar to micromolar range of IC₅₀, being the most potent one in this series. Additionally, KL-6 significantly inhibited the colony formation, migration and invasion, and effectively induced apoptosis of MKN1 cells in a concentration-dependent manner. The mechanistic study revealed that KL-6 could concentration-dependently suppress STAT3 phosphorylation, which may partly contribute to its anticancer activity. Furthermore, in vivo antitumour study on the MKN1 orthotopic tumour model showed that KL-6 effectively inhibited tumour growth (TGI of 78%) and metastasis without obvious toxicity. Collectively, compound KL-6 may support the further development of candidates for gastric cancer treatment.

Stem and leaf xylem of angiosperm trees experiences minimal embolism in temperate forests during two consecutive summers with moderate drought

Drought events may increase the likelihood that the plant water transport system becomes interrupted by embolism. Yet our knowledge about the temporal frequency of xylem embolism in the field is frequently lacking, as it requires detailed, long-term measurements. We measured xylem embolism resistance and midday xylem water potentials during the consecutive summers of 2019 and 2020 to estimate maximum levels of embolism in leaf and stem xylem of ten temperate angiosperm tree species. We also studied vessel and pit membrane characteristics based on light and electron microscopy to corroborate potential differences in embolism resistance between leaves and stems. Apart from A. pseudoplatanus and Q. petraea, eight species experienced minimum xylem water potentials that were close to or below those required to initiate embolism. Water potentials corresponding to ca. 12% loss of hydraulic conductivity (PLC) could occur in six species, while considerable levels of embolism around 50% PLC were limited to B. pendula and C. avellana. There was a general agreement in embolism resistance between stems and leaves, with leaves being equally or more resistant than stems. Also, xylem embolism resistance was significantly correlated to intervessel pit membrane thickness (T_PM ) for stems, but not to vessel diameter and total intervessel pit membrane surface area of a vessel. Our data indicate that low amounts of embolism occur in most species during moderate summer drought, and that considerable levels of embolism are uncommon. Moreover, our experimental and T_PM data show that leaf xylem is generally no more vulnerable than stem xylem.

Immune mechanism of low bone mineral density caused by ankylosing spondylitis based on bioinformatics and machine learning

Background and Objective: This study aims to find the key immune genes and mechanisms of low bone mineral density (LBMD) in ankylosing spondylitis (AS) patients.

Methods: AS and LBMD datasets were downloaded from the GEO database, and differential expression gene analysis was performed to obtain DEGs. Immune-related genes (IRGs) were obtained from ImmPort. Overlapping DEGs and IRGs got I-DEGs. Pearson coefficients were used to calculate DEGs and IRGs correlations in the AS and LBMD datasets. Louvain community discovery was used to cluster the co-expression network to get gene modules. The module most related to the immune module was defined as the key module. Metascape was used for enrichment analysis of key modules. Further, I-DEGs with the same trend in AS and LBMD were considered key I-DEGs. Multiple machine learning methods were used to construct diagnostic models based on key I-DEGs. IID database was used to find the context of I-DEGs, especially in the skeletal system. Gene–biological process and gene-pathway networks were constructed based on key I-DEGs. In addition, immune infiltration was analyzed on the AS dataset using the CIBERSORT algorithm.

Results: A total of 19 genes were identified I-DEGs, of which IFNAR1, PIK3CG, PTGER2, TNF, and CCL3 were considered the key I-DEGs. These key I-DEGs had a good relationship with the hub genes of key modules. Multiple machine learning showed that key I-DEGs, as a signature, had an excellent diagnostic performance in both AS and LBMD, and the SVM model had the highest AUC value. Key I-DEGs were closely linked through bridge genes, especially in the skeletal system. Pathway analysis showed that PIK3CG, IFNAR1, CCL3, and TNF participated in NETs formation through pathways such as the MAPK signaling pathway. Immune infiltration analysis showed neutrophils had the most significant differences between case and control groups and a good correlation with key I-DEG.

Conclusion: The key I-DEGs, TNF, CCL3, PIK3CG, PTGER2, and IFNAR1, can be utilized as biomarkers to determine the risk of LBMD in AS patients. They may affect neutrophil infiltration and NETs formation to influence the bone remodeling process in AS.

[The relationship between peripheral blood mitochondrial DNA copy number and incident risk of liver cancer: a case-cohort study]

Objective: To investigate the association between peripheral blood mitochondrial DNA copy number (mtDNAcn) and incident risk of liver cancer. Methods: At the baseline of Dongfeng-Tongji (DFTJ) cohort, 27 009 retirees were recruited from Dongfeng Motor Corporation in 2008. After excluding people without baseline DNA, with current malignant tumor and loss of follow-up, 1 173 participants were randomly selected into a sub-cohort by age-and gender-stratified sampling method at a proportion of 5% among all retirees. A total of 154 incident liver cancer cases identified from the cohort before December 31, 2018 (4 cases had been selected into the sub-cohort) were selected to form the case cohort of liver cancer. For the above 1 323 participants, their baseline levels of mtDNAcn in peripheral blood cells were measured by using quantitative real-time PCR method. The restricted cubic spline analysis was used to fit the shape of the association between baseline mtDNAcn and incident risk of liver cancer. The weighted Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95%CI. Results: In this case-cohort study, the median follow-up time was 10.3 years. The restricted cubic spline analysis indicated that the relationship between peripheral blood mtDNAcn and incident risk of liver cancer followed a U-shaped pattern (P_non-linear<0.05). All case-cohort population were divided into four subgroups by sex-specific quartiles of mtDNAcn levels among sub-cohort participants, when compared to participants in the Q₂ subgroup of mtDNAcn, those in the Q₁ subgroup (HR=2.00,95%CI:1.08-3.70) and Q₄ subgroup (HR=4.11,95%CI:2.32-7.26) both had a significantly elevated risk of liver cancer, while those in the Q₃ subgroup (HR=1.05,95%CI:0.54-2.05) had not. There were no significant multiply interaction effects of aging, gender, tobacco smoking, alcohol drinking and history of chronic hepatitis on the above association (P_interaction>0.05). Conclusion: Both extremely low and high baseline level of mtDNAcn in peripheral blood cells are associated with an increased risk of incident liver cancer, but the underlying mechanisms need to be further clarified.

[The clinical value of multi-target stool fecal immunochemical test-DNA in early screening and diagnosis for colorectal cancer]

Objective: To investigate the clinical diagnostic value of multi-target stool fecal immunochemical test-DNA (FIT-DNA) test in colorectal cancer (CRC) and advanced adenoma (AA). Methods: A total of 235 patients who were undergoing colonoscopy or colorectal cancer surgery in the Cancer Hospital, Chinese Academy of Medical Sciences from April 2021 to January 2022 were prospectively enrolled. There were 141 males and 94 females, with an average age of (55±13) years (22-86). The patients were divided into two groups, including 215 patients who were first diagnosed but not treated (86 cases of CRC, 12 cases of AA, 25 cases of non-advanced adenoma, 8 cases of hyperplastic or other polyps and 84 apparently healthy cases) and 20 patients in the intervention group (2 cases with a history of CRC surgery, 6 cases with a history of endoscopic surgery, 4 non-CRC patients with special diseases and 8 cases with a history of neoadjuvant chemoradiotherapy). Fresh stool samples were collected before intestinal preparation or surgery for FIT-DNA test using the matching kit for sample processing and nucleic acid purification. KRAS mutation and methylation of BMP3 and NDRG4 genes were detected by fluorescence probe method, and FIT method was employed to detect fecal occult blood. Colonoscopy or pathological biopsy results were used as the gold standard. And the screening and diagnostic efficacy of FIT-DNA test for colorectal cancer and advanced adenoma were evaluated by receiver operating curve (ROC). Results: The sensitivity of FIT-DNA test for early colorectal cancer and advanced adenoma was 7/7 and 8/12, respectively. And the negative predictive value was 98.1% (104/106) and 93.7% (104/111), respectively. The overall screening sensitivity for both early colorectal cancer and advanced adenoma was 15/19, and the negative predictive value was 96.3% (104/108). Besides, the area under the curves (AUCs) were 0.982 (95%CI: 0.960-1.000, P<0.05), 0.758 (95%CI: 0.592-0.924, P<0.05) and 0.841 (95%CI: 0.724-0.957, P<0.05), respectively. Moreover, the diagnostic sensitivity of FIT-DNA test was 98.8% (85/86) for colorectal cancer, 8/12 for advanced adenoma, and 94.9% (93/98) for both colorectal cancer and advanced adenoma, with a specificity of 88.9% (104/117). The AUCs were 0.968 (95%CI: 0.937-0.997, P<0.05), 0.758 (95%CI: 0.592-0.924, P<0.05) and 0.942 (95%CI: 0.905-0.979, P<0.05), respectively. After the inclusion of intervention group, the overall diagnostic sensitivity and specificity of FIT-DNA test was 91.6% (98/107) and 89.1% (114/128), respectively. Conclusion: FIT-DNA test has a high early screening and diagnostic efficacy for colorectal cancer.

Design, synthesis, and biological characterization of a potent STAT3 degrader for the treatment of gastric cancer

Gastric cancer is a common malignant tumor that threatens human health, and its occurrence and development mechanism is a complex process involving multiple genes and multiple signals. Signal transducer and activator of transcription 3 (STAT3) has been elucidated as a promising target for developing anticancer drugs in gastric cancer. However, there is no FDA-approved STAT3 inhibitor yet. Herein, we report the design and synthesis of a class of STAT3 degraders based on proteolysis-targeting chimeras (PROTACs). We first synthesized an analog of the STAT3 inhibitor S3I-201 as a ligand, using the cereblon (CRBN)/cullin 4A E3 ligase ligand pomalidomide to synthesize a series of PROTACs. Among them, the SDL-1 achieves the degradation of STAT3 protein in vitro, and exhibits good anti-gastric cancer cell proliferation activity, inhibits invasion and metastasis of MKN1 cell, and induces MKN1 cell apoptosis and arrests cell cycle at the same time. Our study shows that SDL-1 is a potent STAT3 degrader and may serve as a potential anti-gastric cancer drug, providing ideas for further development of drugs for clinical use.

Targeting KRAS mutant cancers: from druggable therapy to drug resistance

Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) is the most frequently mutated oncogene, occurring in a variety of tumor types. Targeting KRAS mutations with drugs is challenging because KRAS is considered undruggable due to the lack of classic drug binding sites. Over the past 40 years, great efforts have been made to explore routes for indirect targeting of KRAS mutant cancers, including KRAS expression, processing, upstream regulators, or downstream effectors. With the advent of KRAS (G12C) inhibitors, KRAS mutations are now druggable. Despite such inhibitors showing remarkable clinical responses, resistance to monotherapy of KRAS inhibitors is eventually developed. Significant progress has been made in understanding the mechanisms of drug resistance to KRAS-mutant inhibitors. Here we review the most recent advances in therapeutic approaches and resistance mechanisms targeting KRAS mutations and discuss opportunities for combination therapy.

Inhibiting STAT3 signaling pathway by natural products for cancer prevention and therapy: In vitro and in vivo activity and mechanisms of action

Signal transducer and activator of transcription 3 (STAT3) plays a critical role in signal transmission from the plasma membrane to the nucleus, regulating the expression of genes involved in essential cell functions and controlling the processes of cell cycle progression and apoptosis. Thus, STAT3 has been elucidated as a promising target for developing anticancer drugs. Many natural products have been reported to inhibit the STAT3 signaling pathway during the past two decades and have exhibited significant anticancer activities in vitro and in vivo. However, there is no FDA-approved STAT3 inhibitor yet. The major mechanisms of these natural product inhibitors of the STAT3 signaling pathway include targeting the upstream regulators of STAT3, directly binding to the STAT3 SH2 domain and inhibiting its activation, inhibiting STAT3 phosphorylation and/or dimerization, and others. In the present review, we have systematically discussed the development of these natural product inhibitors of STAT3 signaling pathway as well as their in vitro and in vivo anticancer activity and mechanisms of action. Outlooks and perspectives on the associated challenges are provided as well.

Indole Diketopiperazine Alkaloids Isolated From the Marine-Derived Fungus Aspergillus chevalieri MCCC M23426

Two new indole diketopiperazines (1–2) obtained from the fermentation culture of a deep-sea-derived fungus Aspergillus chevalieri MCCC M23426, were characterized, together with nine biogenetic related compounds (3–11). The structures of 1–2 were assigned based on NMR, MS, NMR calculation, DP4+ analysis, and ECD calculation. The bioactive assay showed that compounds 1, 5–7 significantly inhibited the growth of Staphylococcus aureus. Meanwhile, compound 8 potently reduced the cell viability of gastric cancer cell MKN1 with an IC₅₀ value of 4.6 μM.

[Advantages of organ protection in colorectal tumor specimen collection through natural orifice specimen extraction surgery]

In recent years, natural orifice specimen extraction surgery (NOSES) has been widely used in surgery of colorectal cancer. The rapid development of NOSES is mainly attributed to its own great advantages and values, including the reduction of surgical trauma, the acceleration of postoperative recovery and the reduction of adverse psychological reactions for patients. These advantages of NOSES are also important embodiment and perfect interpretation of the organ functional protection. Organ functional preservation is a hot topic in surgery today, and it is also an inevitable requirement for minimally invasive surgery. Essentially, NOSES and organ functional preservation are proposed in the same background, and the goals are highly compatible. NOSES is an important practitioner of organ functional preservation, and organ functional preservation is also the vane of the development of the theoretical system of NOSES. These two items complement each other and together constitute the important element in the development of modern minimally invasive surgery. In order to comprehensively discuss the relationship between NOSES and organ functional protection, we elaborate the important role and value of functional protection in NOSES from five key procedures of colorectal surgery, namely surgical approach, extent of resection, lymph node dissection, digestive tract reconstruction and specimen extraction.

Abstract 5072: A novel antibody drug conjugateengineered for chromosome instable gastric cancer

Gastric cancer (GC) ranks the fifth common cancer worldwide. Patients with GC suffer from a low 5-y survival rate due to the lack of effective treatments. Based on the genomic and molecular characteristics of GC, the Cancer Genome Atlas (TCGA) classified GC into four molecular subtypes: microsatellite-instable (MSI), Epstein-Barr virus-positive (EBV), chromosomal-instable (CIN), and genomically stable (GS). CIN tumors usually occur at gastroesophageal junction and normally belong to intestinal type of Lauren classification, which are characterized by DNA anueploidy, abnormal chromosomal copy numbers, and the frequent mutation of gene TP53, leading to chromosomal instability. CIN represents the most prevalent GC subtype (&gt;50%) with a poor prognosis, highlighting a significant and unmet medical need for developing effective CIN-targeted therapeutics. Antibody drug conjugates (ADCs) are a new class of targeted therapeutics, composed of a humanized monoclonal antibody and small molecular cytotoxic drugs via chemical linkers. In this study, we designed and engineered a novel ADC targeting chromosome instable gastric cancer (CINGC). We first explored intercellular adhesion molecule-1 (ICAM1) as a novel molecular target for CINGC by characterizing its overexpression levels in a panel of human GINGC cell lines. ICAM1 is a cell surface transmembrane glycoprotein with functions of regulating cell-cell adhesion, signaling, and transendothelial migration of leukocytes to sites of inflammation. Many malignant tumors including GC were found to aberrantly overexpress ICAM1 on the surfaces of tumor cells. The high overexpression of ICAM1 on CINGC cells was validated by using flow cytometry (FCM) quantitatively and immunofluorescence (IF) staining qualitatively. To correlate it with clinically relevant GC tumor tissues, immunohistochemical (IHC) staining of ICAM1 was then conducted to determine the high expression of tumor tissue compared with para cancer tissue. The antigen-mediated endocytosis of ICAM1 monoclonal antibody was further detected by FCM quantitatively and IF visually. All the results showed that ICAM1 was an promising molecular target for CINGC, therefore, it was selected to engineer CINGC-targeted ADCs. We engineered a panel of ADC formulations with different linkers and cytotoxic payloads. We identified an optimal ADC formulation for CINGC by screening their cytotoxicity against CINGC cells in vitro in comparison with first line chemodrugs including 5-FU and oxaliplatin, which efficacy was validated by measuring its inhibitory activity on tumor growth, progression and metastasis via CINGC xenograft models. In conclusion, a novel ICAM1 ADC was designed and engineered to selectively recognize and ablate CINGC cells in vitro and in vivo. Our engineered new ADC offers the possibility of improving the clinical outcome and life quality of CINGC patients and expanding the scope of clinical use of drugs.

Citation Format: Xinyan Wang, Li Yuan, Xiaoqing Guan, Shili Yao, Bing Zhu, Chun Liu, Tong Yang, Peng Guo, Jiangjiang Qin, Xiangdong Cheng. A novel antibody drug conjugateengineered for chromosome instable gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5072.

Epithelial SMYD5 Exaggerates IBD by Down-regulating Mitochondrial Functions via Post-Translational Control of PGC-1α Stability

BACKGROUND & AIMS

The expression and role of methyltransferase SET and MYND domain-containing protein 5 (SMYD5) in inflammatory bowel disease (IBD) is completely unknown. Here, we investigated the role and underlying mechanism of epithelial SMYD5 in IBD pathogenesis and progression.

METHODS

The expression levels of SMYD5 and the mitochondrial transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) were examined by Western blot, immunofluorescence staining, and immunohistochemistry in intestinal epithelial cells (IECs) and in colon tissues from human IBD patients and colitic mice. Mice with Smyd5 conditional knockout in IECs and littermate controls were subjected to dextran sulfate sodium-induced colitis and the disease severity was assessed. SMYD5-regulated mitochondrial biogenesis was examined by quantitative reverse-transcription polymerase chain reaction and transmission electron microscopy, and the mitochondrial oxygen consumption rate was measured in a Seahorse Analyzer system (Agilent, Santa Clara, CA). SMYD5 and PGC-1α interaction was determined by co-immunoprecipitation assay. PGC-1α degradation and turnover (half-life) were analyzed by cycloheximide chase assay. SMYD5-mediated PGC-1α methylation was assessed via in vitro methylation assay followed by mass spectrometry for identification of methylated lysine residues.

RESULTS

Up-regulated SMYD5 and down-regulated PGC-1α were observed in intestinal epithelia from IBD patients and colitic mice. Smyd5 depletion in IECs protected mice from dextran sulfate sodium-induced colitis. SMYD5 was critically involved in regulating mitochondrial biology such as mitochondrial biogenesis, respiration, and apoptosis. Mechanistically, SMYD5 regulates mitochondrial functions in a PGC-1α-dependent manner. Furthermore, SMYD5 mediates lysine methylation of PGC-1α and subsequently facilitates its ubiquitination and degradation.

CONCLUSIONS

SMYD5 attenuates mitochondrial functions in IECs and promotes IBD progression by enhancing PGC-1α degradation in a methylation-dependent manner. Strategies to decrease SMYD5 expression and/or increase PGC-1α expression in IECs might be a promising therapeutic approach to treat IBD patients.

Characterization of a bioactive meroterpenoid isolated from the marine-derived fungus Talaromyces sp

A new meroterpenoid, taladrimanin A (1), was isolated from a marine-derived fungus Talaromyces sp. HM6-1-1, together with eleven biogenetically related compounds (2-12). A plausible biosynthetic pathway for the meroterpenoids (1-4) was proposed. The planar structure of 1 was assigned by HRESIMS and NMR. Its relative configuration was established by quantum chemical NMR calculation of two possible isomers and analyzed by DP4 + method. Finally, X-ray diffraction unambiguously confirmed the relative configuration and revealed the absolute configuration of compound 1. 2-12 were assigned by comparing their NMR data with those reported in the literature. 1 was the first drimane-type meroterpenoid with a C10 polyketide unit bearing an 8R-configuration. In the bioactive assay, 1 exhibited antitumor activity against gastric cancer cells MGC803 and MKN28; it also inhibited the colony formation and induced apoptosis in MGC803 cells both in a concentration-dependent manner. Additionally, 1 displayed selective antibacterial activity against Staphylococcus aureus 6538P, and low activities towards strains of Vibrio parahaemolyticus and Escherichia coli in this study. KEY POINTS: • Twelve compounds were obtained from Talaromyces sp., including four meroterpenoids, one of which was new. • The new compound taladrimanin A (1) inhibits the growth of gastric cancer cells MGC803 and MKN28 as well as the pathogenic bacteria Staphylococcus aureus 6538P. • The biosynthetic pathway of the meroterpenoids was proposed.

Inhibition of STAT3 Signaling Pathway by Terphenyllin Suppresses Growth and Metastasis of Gastric Cancer

Gastric cancer is a common type of malignant tumor with a relatively poor prognosis and presents a serious threat to global health. Signal Transducer and Activator of Transcription-3 (STAT3) has been strongly implicated in many cancers, and its constitutive activation promotes growth, angiogenesis, inflammation, and immune evasion. Therefore, considerable efforts have been put into developing effective and safe STAT3 inhibitors. In this study, we performed a virtual screening by molecular docking and found that terphenyllin, a marine-derived natural product, directly interacted with STAT3. We further found that terphenyllin inhibited the phosphorylation and activation of STAT3 and decreased the protein levels of STAT3-dependent target genes, including c-Myc and Cyclin D1. Subsequently, we demonstrated that terphenyllin exerted its potent anticancer efficacy against gastric cancer in vitro and in vivo. Terphenyllin concentration-dependently inhibited growth, proliferation, and colony formation and induced cell cycle arrest and apoptosis of gastric cancer cells in vitro. Moreover, terphenyllin treatment suppressed the tumor growth and metastasis in a gastric cancer orthotopic mouse model without notable toxicity in vivo. Taken together, our results indicated that terphenyllin exerts its anticancer activity by inhibiting the STAT3 signaling pathway and may serve as a potent STAT3 inhibitor for gastric cancer treatment.

Targeting E2 ubiquitin-conjugating enzyme UbcH5c by small molecule inhibitor suppresses pancreatic cancer growth and metastasis

BACKGROUND

Pancreatic cancer is one of the most lethal cancers worldwide. The IAPs function as E3 ubiquitin ligases and contribute to pancreatic cancer initiation, progression, and metastasis. Although IAP-targeted therapies have been developed and shown anticancer efficacy in preclinical settings, none of them has been approved yet.

METHODS

Transcriptome data from public datasets were used to analyze the correlation of IAPs and E2s, and the biological function of E2 UbcH5c in pancreatic cancer. A structure-based virtual screen was used to identify UbcH5c inhibitor, and surface plasmon resonance analysis and cellular thermal shift assays were employed to evaluate the binding affinity. The anticancer activities were demonstrated through in vitro and in vivo assays, while the related mechanisms were explored through transcriptomic and proteomic analyses and confirmed by western blot, immunofluorescence, and qRT-PCR.

RESULTS

UbcH5c is positively correlated with the expression of IAPs in pancreatic cancer. We further found that UbcH5c is overexpressed and associated with a poor prognosis in pancreatic cancer. We identified a small-molecule UbcH5c inhibitor, termed DHPO, which directly bound to UbcH5c protein. DHPO inhibited cell viability and colony formation, induced apoptosis, and suppressed migration and invasion of pancreatic cancer cells in vitro. The compound inhibited UbcH5c-mediated IκBα degradation and NF-κB activation, which is critical for its anticancer activity. Furthermore, DHPO suppressed the tumor growth and metastasis in two orthotopic pancreatic tumor mouse models.

CONCLUSIONS

These results indicated that inhibiting UbcH5c is a novel and effective strategy for treating pancreatic cancer and DHPO represents a new class of UbcH5c inhibitor and may be further developed as an anti-pancreatic cancer therapeutic agent.