Diverse mechanisms of somatic structural variations in human cancer genomes.

Identification of somatic rearrangements in cancer genomes has accelerated through analysis of high-throughput sequencing data. However, characterization of complex structural alterations and their underlying mechanisms remains inadequate. Here, applying an algorithm to predict structural variations from short reads, we report a comprehensive catalog of somatic structural variations and the mechanisms generating them, using high-coverage whole-genome sequencing data from 140 patients across ten tumor types. We characterize the relative contributions of different types of rearrangements and their mutational mechanisms, find that ~20% of the somatic deletions are complex deletions formed by replication errors, and describe the differences between the mutational mechanisms in somatic and germline alterations. Importantly, we provide detailed reconstructions of the events responsible for loss of CDKN2A/B and gain of EGFR in glioblastoma, revealing that these alterations can result from multiple mechanisms even in a single genome and that both DNA double-strand breaks and replication errors drive somatic rearrangements.

The combination of breast cancer PDO and mini-PDX platform for drug screening and individualized treatment.

The majority of advanced breast cancers exhibit strong aggressiveness, heterogeneity, and drug resistance, and currently, the lack of effective treatment strategies is one of the main challenges that cancer research must face. Therefore, developing a feasible preclinical model to explore tailored treatments for refractory breast cancer is urgently needed. We established organoid biobanks from 17 patients with breast cancer and characterized them by immunohistochemistry (IHC) and next generation sequencing (NGS). In addition, we in the first combination of patient-derived organoids (PDOs) with mini-patient-derived xenografts (Mini-PDXs) for the rapid and precise screening of drug sensitivity. We confirmed that breast cancer organoids are a high-fidelity three-dimension (3D) model in vitro that recapitulates the original tumour's histological and genetic features. In addition, for a heavily pretreated patient with advanced drug-resistant breast cancer, we combined PDO and Mini-PDX models to identify potentially effective combinations of therapeutic agents for this patient who were alpelisib + fulvestrant. In the drug sensitivity experiment of organoids, we observed changes in the PI3K/AKT/mTOR signalling axis and oestrogen receptor (ER) protein expression levels, which further verified the reliability of the screening results. Our study demonstrates that the PDO combined with mini-PDX model offers a rapid and precise drug screening platform that holds promise for personalized medicine, improving patient outcomes and addressing the urgent need for effective therapies in advanced breast cancer.

Epigenetic silencing of LDHB promotes hepatocellular carcinoma by remodeling the tumor microenvironment.

Lactate dehydrogenase B (LDHB) reversibly catalyzes the conversion of pyruvate to lactate or lactate to pyruvate and expressed in various malignancies. However, the role of LDHB in modulating immune responses against hepatocellular carcinoma (HCC) remains largely unknown. Here, we found that down-regulation of lactate dehydrogenase B (LDHB) was coupled with the promoter hypermethylation and knocking down the DNA methyltransferase 3A (DNMT 3A) restored LDHB expression levels in HCC cell lines. Bioinformatics analysis of the HCC cohort from The Cancer Genome Atlas revealed a significant positive correlation between LDHB expression and immune regulatory signaling pathways and immune cell infiltrations. Moreover, immune checkpoint inhibitors (ICIs) have shown considerable promise for HCC treatment and patients with higher LDHB expression responded better to ICIs. Finally, we found that overexpression of LDHB suppressed HCC growth in immunocompetent but not in immunodeficient mice, suggesting that the host immune system was involved in the LDHB-medicated tumor suppression. Our findings indicate that DNMT3A-mediated epigenetic silencing of LDHB may contribute to HCC progression through remodeling the tumor immune microenvironment, and LDHB may become a potential prognostic biomarker and therapeutic target for HCC immunotherapy.

USP29 activation mediated by FUBP1 promotes AURKB stability and oncogenic functions in gastric cancer.

BACKGROUND: Gastric cancer is a highly prevalent cancer type and the underlying molecular mechanisms are not fully understood. Ubiquitin-specific peptidase (USP) 29 has been suggested to regulate cell fate in several types of cancer, but its potential role in gastric carcinogenesis remains unclear. METHODS: The expression of USP29 in normal and gastric cancer tissues was analyzed by bioinformatics analysis, immunohistochemistry and immunoblot. Gene overexpression, CRISPR-Cas9 technology, RNAi, and Usp29 knockout mice were used to investigate the roles of USP29 in cell culture, xenograft, and benzo[a]pyrene (BaP)-induced gastric carcinogenesis models. We then delineated the underlying mechanisms using mass spectrometry, co-immunoprecipitation (Co-IP), immunoblot, ubiquitination assay, chromatin immunoprecipitation (ChIP), quantitative real-time PCR (qRT-PCR), and luciferase assays. RESULTS: In this study, we found that USP29 expression was significantly upregulated in gastric cancers and associated with poor patient survival. Ectopic expression of USP29 promoted, while depletion suppressed the tumor growth in vitro and in vivo mouse model. Mechanistically, transcription factor far upstream element binding protein 1 (FUBP1) directly activates USP29 gene transcription, which then interacts with and stabilizes aurora kinase B (AURKB) by suppressing K48-linked polyubiquitination, constituting a FUBP1-USP29-AURKB regulatory axis that medicates the oncogenic role of USP29. Importantly, systemic knockout of Usp29 in mice not only significantly decreased the BaP-induced carcinogenesis but also suppressed the Aurkb level in forestomach tissues. CONCLUSIONS: These findings uncovered a novel FUBP1-USP29-AURKB regulatory axis that may play important roles in gastric carcinogenesis and tumor progression, and suggested that USP29 may become a promising drug target for cancer therapy.

Metabolomic alterations in the plasma of patients with various clinical manifestations of COVID-19.

BACKGROUND: The metabolomic profiles of individuals with different clinical manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have not been clearly characterized. METHODS: We performed metabolomics analysis of 166 individuals, including 62 healthy controls, 16 individuals with asymptomatic SARS-CoV-2 infection, and 88 patients with moderate (n = 42) and severe (n = 46) symptomatic 2019 coronavirus disease (COVID-19; 17 with short-term and 34 with long-term nucleic-acid test positivity). By examining differential expression, we identified candidate metabolites associated with different SARS-CoV-2 infection presentations. Functional and machine learning analyses were performed to explore the metabolites' functions and verify their candidacy as biomarkers. RESULTS: A total of 417 metabolites were detected. We discovered 70 differentially expressed metabolites that may help differentiate asymptomatic infections from healthy controls and COVID-19 patients with different disease severity. Cyclamic acid and N-Acetylneuraminic Acid were identified to distinguish symptomatic infected patients and asymptomatic infected patients. Shikimic Acid, Glycyrrhetinic acid and 3-Hydroxybutyrate can supply significant insights for distinguishing short-term and long-term nucleic-acid test positivity. CONCLUSION: Metabolomic profiling may highlight novel biomarkers for the identification of individuals with asymptomatic SARS-CoV-2 infection and further our understanding of the molecular pathogenesis of COVID-19.

Clinical study on conversion therapy of hepatocellular carcinoma - summary and comparison of clinical data from a single center of consecutive four years.

AIM: The purpose of this study was to interpret real-world clinical data to analyze the surgical safety and survival outcomes of patients with initial unresectable hepatocellular carcinoma (uHCC) after conversion therapy. METHODS: A retrospective analysis was performed on 2984 hepatocellular carcinoma (HCC) patients hospitalized in Shandong Cancer Hospital Affiliated to Shandong First Medical University from June 1st, 2019 to June 1st, 2023. Clinicopathological features, response to systemic and/or loco-regional treatments, surgical resection rate after conversion therapy, surgical safety, and postoperative recurrence were analyzed. RESULTS: A total of 38 patients were successfully converted to obtain surgical resection. 35 patients underwent radical resection. A high objective response rate (ORR) (52.6% under RECIST v1.1 and 78.9% under mRECIST criteria) was observed in patients under conversion therapy, and the disease control rate (DCR) was 100%. Pathologic complete response (pCR) was 42.9%. Treatment-related adverse events (TRAEs) of any grade were observed in 37 patients (97.4%). Safety of conversion or direct surgery continues to improve. The median follow-up time was 19.3 months. The 1-year Disease-free survival (DFS) rate of patients with direct surgery and patients with conversion surgery were 91.4% and 86.8%, respectively. CONCLUSIONS: With conversion therapy, a small percentage (1.81%) of uHCC patients are likely to be converted to radical resection. Local combined systemic therapy is a relatively safe and effective conversion therapy, and the safety of surgery is gradually improved after successful conversion. Preliminary follow-up data showed satisfactory survival benefits for patients undergoing conversion surgery. TRIAL REGISTRATION: This was a retrospective study and it did not interfere with treatment decisions.

Microbial organic fertilizer prepared by co-composting of Trichoderma dregs mitigates dissemination of resistance, virulence genes, and bacterial pathogens in soil and rhizosphere.

The use of manure, mycelium dregs and other waste as organic fertilizer is the main source of antibiotic resistance genes (ARGs) and pathogens in farmland. Composting of waste may effectively remove ARGs and pathogens. However, the profiles and drivers of changes in metal resistance genes (MRGs), biocide resistance genes (BRGs), and virulence genes (VGs) in soil-crop rhizosphere systems after compost application remain largely unknown. Here, we prepared two kinds of microbial organic fertilizers (MOF) by using Trichoderma dregs (TDs) and organic fertilizer mixing method (MOF1) and TDs co-composting method (MOF2). The effects of different types and doses of MOF on resistance genes, VGs and pathogens in soil-rhizosphere system and their potential mechanisms were studied. The results showed that co-composting of TDs promoted the decomposition of organic carbon and decreased the absolute abundance of ARGs and mobile genetic elements (MGEs) by 53.4-65.0%. MOF1 application significantly increased the abundance and diversity of soil ARGs, BRGs, and VGs, while low and medium doses of MOF2 significantly decreased their abundance and diversity in soil and rhizosphere. Patterns of positive co-occurrence between MGEs and VGs/MRGs/BRGs/ARGs were observed through statistical analysis and gene arrangements. ARGs/MRGs reductions in MOF2 soil were directly driven by weakened horizontal gene transfer triggered by MGEs. Furthermore, MOF2 reduced soil BRGs/VGs levels by shifting bacterial communities (e.g., reduced bacterial host) or improving soil property. Our study provided new insights into the rational use of waste to minimize the spread of resistomes and VGs in soil.

Integrated transcriptome and metabolome analysis revealed that HaMYB1 modulates anthocyanin accumulation to deepen sunflower flower color.

KEY MESSAGE: HanMYB1 was found to play positive roles in the modulation of anthocyanins metabolism based on the integrative analysis of different color cultivars and the related molecular genetic analyses. As a high value ornamental and edible crop with various colors, sunflowers (Helianthus annuus L.) provide an ideal system to understand the formation of flower color. Anthocyanins are major pigments in higher plants, which is associated with development of flower colors and ability of oxidation resistance. Here, we performed an integrative analysis of the transcriptome and flavonoid metabolome in five sunflower cultivars with different flower colors. According to differentially expressed genes and differentially accumulated flavonoids, these cultivars could be grouped into yellow and red. The results showed that more anthocyanins were accumulated in the red group flowers, especially the chrysanthemin. Some anthocyanins biosynthesis-related genes like UFGT (UDP-glycose flavonoid glycosyltransferase) also expressed more in the red group flowers. A MYB transcriptional factor, HanMYB1, was found to play vital positive roles in the modulation of anthocyanins metabolism by the integrative analysis. Overexpressed HanMYB1 in tobacco could deepen the flower color, increase the accumulation of anthocyanins and directly active the express of UFGT genes. Our findings indicated that the MYB transcriptional factors provide new insight into the dynamic regulation of the anthocyanin biosynthesis in facilitating sunflower color formation and anthocyanin accumulation.

Transcriptome analysis reveals how cadmium promotes root development and accumulates in Apocynum venetum, a promising plant for greening cadmium-contaminated soil.

Cadmium (Cd) contamination poses a substantial threat the environment, necessitating effective remediation strategies. Phytoremediation emerges as a cost-efficient and eco-friendly approach for reducing Cd levels in the soil. In this study, the suitability of A. venetum for ameliorating Cd-contaminated soils was evaluated. Mild Cd stress promoted seedling and root growth, with the root being identified as the primary tissue for Cd accumulation. The Cd content of roots ranged from 0.35 to 0.55 mg/g under treatment with 10-50 µM CdCl2·2.5 H2O, and the bioaccumulation factor ranged from 28.78 to 84.43. Transcriptome sequencing revealed 20,292 unigenes, and 7507 nonredundant differentially expressed genes (DEGs) were identified across five comparison groups. DEGs belonging to the "MAPK signaling pathway-plant," "monoterpenoid biosynthesis," and "flavonoid biosynthesis pathway" exhibited higher expression levels in roots compared to stems and leaves. In addition, cytokinin-related DEGs, ROS scavenger genes, such as P450, glutathione-S-transferase (GST), and superoxide dismutase (SOD), and the cell wall biosynthesis-related genes, CSLG and D-GRL, were also upregulated in the root tissue, suggesting that Cd promotes root development. Conversely, certain ABC transporter genes, (e.g, NRAMP5), and some vacuolar iron transporters, predominantly expressed in the roots, displayed a strong correlation with Cd content, revealing the mechanism underlying the compartmentalized storage of Cd in the roots. KEGG enrichment analysis of DEGs showed that the pathways associated with the biosynthesis of flavonoids, lignin, and some terpenoids were significantly enriched in the roots under Cd stress, underscoring the pivotal role of these pathways in Cd detoxification. Our study suggests A. venetum as a potential Cd-contaminated phytoremediation plant and provides insights into the molecular-level mechanisms of root development promotion and accumulation mechanism in response to Cd stress.

Ensifer sp. GMS14 enhances soybean salt tolerance for potential application in saline soil reclamation.

Rhizosphere microbiomes play an important role in enhancing plant salt tolerance and are also commonly employed as bio-inoculants in soil remediation processes. Cultivated soybean (Glycine max) is one of the major oilseed crops with moderate salt tolerance. However, the response of rhizosphere microbes me to salt stress in soybean, as well as their potential application in saline soil reclamation, has been rarely reported. In this study, we first investigated the microbial communities of salt-treated and non-salt-treated soybean by 16S rRNA gene amplicon sequencing. Then, the potential mechanism of rhizosphere microbes in enhancing the salt tolerance of soybean was explored based on physiological analyses and transcriptomic sequencing. Our results suggested that Ensifer and Novosphingobium were biomarkers in salt-stressed soybean. One corresponding strain, Ensifer sp. GMS14, showed remarkable growth promoting characteristics. Pot experiments showed that GMS14 significantly improved the growth performance of soybean in saline soils. Strain GMS14 alleviated sodium ions (Na+) toxicity by maintaining low a Na+/K+ ratio and promoted nitrogen (N) and phosphorus (P) uptake by soybean in nutrient-deficient saline soils. Transcriptome analyses indicated that GMS14 improved plant salt tolerance mainly by ameliorating salt stress-mediated oxidative stress. Interestingly, GMS14 was evidenced to specifically suppress hydrogen peroxide (H2O2) production to maintain reactive oxygen species (ROS) homeostasis in plants under salt stress. Field experiments with GMS14 applications showed its great potential in saline soil reclamation, as evidenced by the increased biomass and nodulation capacity of GMS14-inoculated soybean. Overall, our findings provided valuable insights into the mechanisms underlying plant-microbes interactions, and highlighted the importance of microorganisms recruited by salt-stressed plant in the saline soil reclamation.

Recombinant outer membrane vesicles delivering eukaryotic expression plasmid of cytokines act as enhanced adjuvants against Helicobacter pylori infection in mice.

The widespread prevalence of Helicobacter pylori (H. pylori) infection remains a great challenge to human health. The existing vaccines are not ideal for preventing H. pylori infection; thus, exploring highly effective adjuvants may improve the immunoprotective efficacy of H. pylori vaccines. In a previous study, we found that the outer membrane vesicles (OMVs), a type of nanoscale particle spontaneously produced by Gram-negative bacteria, could act as adjuvants to boost the immune responses to vaccine antigens. In this study, we explored the potential application of OMVs as delivery vectors for adjuvant development. We constructed recombinant OMVs containing eukaryotic expression plasmid of cytokines, including interleukin 17A or interferon-γ, and evaluated their function as adjuvants in combination with inactivated whole-cell vaccine (WCV) or UreB as vaccine antigens. Our results showed that recombinant OMVs as adjuvants could induce stronger humoral and mucosal immune responses in mice than wild-type H. pylori OMVs and the cholera toxin (CT) adjuvant. Additionally, the recombinant OMVs significantly promoted Th1/Th2/Th17-type immune responses. Furthermore, the recombinant OMV adjuvant induced more potent clearance of H. pylori than CT and wild-type OMVs. Our findings suggest that the recombinant OMVs coupled with cytokines may become potent adjuvants for the development of novel and effective vaccines against H. pylori infection.

Anlotinib Combined With Toripalimab as First-Line Therapy for Unresectable Hepatocellular Carcinoma: A Prospective, Multicenter, Phase II Study.

BACKGROUND: For patients with unresectable hepatocellular carcinoma (HCC), the first-line therapeutic options are still relatively limited, and treatment outcomes remain poor. We aimed to assess the efficacy and safety of anlotinib combined with toripalimab as first-line therapy for unresectable HCC. METHODS: In this single-arm, multicenter, phase II study (ALTER-H-003), patients with advanced HCC without previous systemic anticancer therapy were recruited. Eligible patients were given anlotinib (12 mg on days 1-14) combined with toripalimab (240 mg on day 1) in a 3-week cycle. The primary endpoint was the objective response rate (ORR) by immune-related Response Evaluation Criteria in Solid Tumours (irRECIST)/RECIST v1.1 and modified RECIST (mRECIST). Secondary endpoints included disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Between January 2020 and Jul 2021, 31 eligible patients were treated and included in the full analysis set. At data cutoff (January 10, 2023), the ORR was 29.0% (95% CI: 12.1%-46.0%) by irRECIST/RECIST v1.1, and 32.3% (95% CI: 14.8%-49.7%) by mRECIST criteria, respectively. Confirmed DCR and median DoR by irRECIST/RECIST v1.1 and mRECIST criteria were 77.4 % (95% CI: 61.8%-93.0%) and not reached (range: 3.0-22.5+ months), respectively. Median PFS was 11.0 months (95% CI: 3.4-18.5 months) and median OS was 18.2 months (95% CI: 15.8-20.5 months). Of the 31 patients assessed for adverse events (AEs), the most common grade ≥ 3 treatment-related AEs were hand-foot syndrome (9.7%, 3/31), hypertension (9.7%, 3/31), arthralgia (9.7%, 3/31), abnormal liver function (6.5%, 2/31), and decreased neutrophil counts (6.5%, 2/31). CONCLUSIONS: Anlotinib combined with toripalimab showed promising efficacy and manageable safety in Chinese patients with unresectable HCC in the first-line setting. This combination therapy may offer a potential new therapeutic approach for patients with unresectable HCC.

Real-world practice of conversion surgery for unresectable hepatocellular carcinoma - a single center data of 26 consecutive patients.

AIM: To understand the proportion of uHCC (unresectable hepatocellular carcinoma) patients who achieve successful conversion resection in a high-volume setting with state of the art treatment options. METHODS: We retrospectively reviewed all HCC patients hospitalized to our center from June 1st, 2019 to June 1st, 2022. Conversion rate, clinicopathological features, response to systemic and/or loco-regional therapy and surgical outcomes were analyzed. RESULTS: A total of 1,904 HCC patients were identified, with 1672 patients receiving anti-HCC treatment. 328 patients were considered up-front resectable. Of the remaining 1344 uHCC patients, 311 received loco-regional treatment, 224 received systemic treatment, and the remainder (809) received combination systemic plus loco-regional treatment. Following treatment, one patient from the systemic group and 25 patients from the combination group were considered to have resectable disease. A high objective response rate (ORR) was observed in these converted patients (42.3% under RECIST v1.1 and 76.9% under mRECIST criteria). The disease control rate (DCR) reached 100%. 23 patients underwent curative hepatectomy. Major post-operative morbidity was equivalent in the both groups (P=0.76). Pathologic complete response (pCR) was 39.1%. During conversion treatment, grade 3 or higher treatment-related adverse events (TRAEs) were observed in 50% of patients. The median follow-up time was 12.9 months (range, 3.9~40.6) from index diagnosis and 11.4 months (range, 0.9~26.9) from resection. Three patients experienced disease recurrence following conversion surgery. CONCLUSIONS: By intensive treatment, a small sub-group of uHCC patients (2%) may potentially be converted to curative resection. Loco-regional combined with systemic modality was relative safe and effective in the conversion therapy. Short-term outcomes are encouraging, but long-term follow-up in a larger patient population are required to fully understand the utility of this approach.

Effect of planting salt-tolerant legumes on coastal saline soil nutrient availability and microbial communities.

Soil salinization is a serious global environmental problem affecting sustainable development of agriculture. Legumes are excellent candidates for the phytoremediation of saline soils; however, how soil microbes mediate the amelioration of coastal saline ecosystems is unknown. In this study, two salt-tolerant legumes, Glycine soja and Sesbania cannabina were planted in coastal saline soil for three years. Soil nutrient availability and microbiota structure (including bacteria, fungi, and diazotrophs) were compared between the phytoremediated soils and control soil (barren land). Planting legumes reduced soil salinity, and increased total carbon, total nitrogen, and NO3--N contents. Among the soil microbiota, some nitrogen-fixing bacteria (e.g., Azotobacter) were enriched in legumes, which were probably responsible for soil nitrogen accumulation. The complexity of the bacterial, fungal, and diazotrophic networks increased significantly from the control to the phytoremediated soils, suggesting that the soil microbial community formed closer ecological interactions during remediation. Furthermore, the dominant microbial functions were chemoheterotrophy (24.75%) and aerobic chemoheterotrophy (21.97%) involved in the carbon cycle, followed by nitrification (13.68%) and aerobic ammonia oxidation (13.34%) involved in the nitrogen cycle. Overall, our findings suggested that G. soja and S. cannabina legumes were suitable for ameliorating saline soils as they decreased soil salinity and increased soil nutrient content, with microorganisms especially nitrogen-fixing bacteria, playing an important role in this remediation process.

Comprehensive Molecular Characterization of Adenocarcinoma of the Gastroesophageal Junction Between Esophageal and Gastric Adenocarcinomas.

OBJECTIVE: To investigate the molecular characteristics of AGEJ compared with EAC and gastric adenocarcinoma. SUMMARY OF BACKGROUND DATA: Classification of AGEJ based on differential molecular characteristics between EAC and gastric adenocarcinoma has been long-standing controversy but rarely conducted due to anatomical ambiguity and epidemiologic difference. METHODS: The molecular classification model with Bayesian compound covariate predictor was developed based on differential mRNA expression of EAC (N = 78) and GCFB (N = 102) from the Cancer Genome Atlas (TCGA) cohort. AGEJ/cardia (N = 48) in TCGA cohort and AGEJ/upper third GC (N = 46 pairs) in Seoul National University cohort were classified into the EAC-like or GCFB-like groups whose genomic, transcriptomic, and proteomic characteristics were compared. RESULTS: AGEJ in both cohorts was similarly classified as EAC-like (31.2%) or GCFB-like (68.8%) based on the 400-gene classifier. The GCFB-like group showed significantly activated phosphoinositide 3-kinase-AKT signaling with decreased expression of ERBB2. The EAC-like group presented significantly different alternative splicing including the skipped exon of RPS24, a significantly higher copy number amplification including ERBB2 amplification, and increased protein expression of ERBB2 and EGFR compared with GCFB-like group. High-throughput 3D drug test using independent cell lines revealed that the EAC-like group showed a significantly better response to lapatinib than the GCFB-like group (P = 0.015). CONCLUSIONS: AGEJ was the combined entity of the EAC-like and GCFB-like groups with consistently different molecular characteristics in both Seoul National University and TCGA cohorts. The EAC-like group with a high Bayesian compound covariate predictor score could be effectively targeted by dual inhibition of ERBB2 and EGFR.

c-MYC-USP49-BAG2 axis promotes proliferation and chemoresistance of colorectal cancer cells in vitro.

Deubiquitinases (DUBs) play critical roles in tumorigenesis and are emerging as potential therapeutic targets. However, it remains less clear which DUBs may play important roles and represent a realistic vulnerability for a particular type of tumor. Here we revealed that Ubiquitin Specific Peptidase 49 (USP49) is transcriptionally activated by c-MYC in colorectal cancer (CRC), and CRC patients with elevated USP49 levels exhibited significantly shorter survival. Knockdown of USP49 markedly inhibited CRC cell proliferation, colony formation, and chemotherapy resistance in vitro. Investigation of mechanisms unravels that USP49 deubiquitinates and stabilizes Bcl-2-Associated Athanogene 2 (BAG2), a well-known protein that antagonizes apoptosis and enables adaptive response of CRC cells. This study identified a novel mechanism by which USP49 promotes CRC cell survival by stabilizing BAG2 through the c-MYC-USP49-BAG2 axis, indicating that USP49 may become a potential therapeutic target for CRC.

Identification of TCR repertoires in asymptomatic COVID-19 patients by single-cell T-cell receptor sequencing.

The T cell-mediated immune responses associated with asymptomatic infection (AS) of SARS-CoV-2 remain largely unknown. The diversity of T-cell receptor (TCR) repertoire is essential for generating effective immunity against viral infections in T cell response. Here, we performed the single-cell TCR sequencing of the PBMC samples from five AS subjects, 33 symptomatic COVID-19 patients and eleven healthy controls to investigate the size and the diversity of TCR repertoire. We subsequently analyzed the TCR repertoire diversity, the V and J gene segment deference, and the dominant combination of αß VJ gene pairing among these three study groups. Notably, we revealed significant TCR preference in the AS group, including the skewed usage of TRAV1-2-J33-TRBV6-4-J2-2 and TRAV1-2-J33-TRBV6-1-J2-3. Our findings may shed new light on understanding the immunopathogenesis of COVID-19 and help identify optimal TCRs for development of novel therapeutic strategies against SARS-CoV-2 infection.

The emerging role of deubiquitylating enzymes as therapeutic targets in cancer metabolism.

Cancer cells must rewire cellular metabolism to satisfy the unbridled proliferation, and metabolic reprogramming provides not only the advantage for cancer cell proliferation but also new targets for cancer treatment. However, the plasticity of the metabolic pathways makes them very difficult to target. Deubiquitylating enzymes (DUBs) are proteases that cleave ubiquitin from the substrate proteins and process ubiquitin precursors. While the molecular mechanisms are not fully understood, many DUBs have been shown to be involved in tumorigenesis and progression via controlling the dysregulated cancer metabolism, and consequently recognized as potential drug targets for cancer treatment. In this article, we summarized the significant progress in understanding the key roles of DUBs in cancer cell metabolic rewiring and the opportunities for the application of DUBs inhibitors in cancer treatment, intending to provide potential implications for both research purpose and clinical applications.

Metabolomic and regular analysis reveal phytotoxic mechanisms of sterigmatocystin in Amaranthus retroflexus L.

Sterigmatocystin (STE) is a common hepatotoxic and nephrotoxic contaminant in cereals, however, its phytotoxicity and mechanisms are poorly understood. Here, the phytotoxic mechanisms of STE were investigated via the metabolomics of Amaranthus retroflexus L. A total of 140 and 113 differential metabolites were detected in the leaves and stems, respectively, among which amino acids, lipids, and phenolic compounds were significantly perturbed. Valine, leucine, isoleucine, and lysine biosynthesis were affected by STE. These metabolic responses revealed that STE might be toxic to plants by altering the plasma membrane and inducing oxidative damage, which was verified by measuring the relative electrical conductivity and quantification of reactive oxygen species. The elevated amino acids, as well as the decreased of D-sedoheptuiose-7-phosphate indicated increased proteolysis and carbohydrate metabolism restriction. Furthermore, the IAA level also decreased. This study provides a better understanding of the impacts of STE on the public health, environment and food security.

A novel treatment strategy for lapatinib resistance in a subset of HER2-amplified gastric cancer.

BACKGROUND: Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Human epidermal growth factor receptor 2 (HER2) amplification occurs in approximately 13-23% of all GC cases and patients with HER2 overexpression exhibit a poor prognosis. Lapatinib, a dual EGFR/HER2 tyrosine kinase inhibitor, is an effective agent to treat HER2-amplified breast cancer but it failed in gastric cancer (GC) clinical trials. However, the molecular mechanism of lapatinib resistance in HER2-amplified GC is not well studied. METHODS: We employed an unbiased, genome-scale screening with pooled CRISPR library on HER2-amplified GC cell lines to identify genes that are associated with resistance to lapatinib. To validate the candidate genes, we applied in vitro and in vivo pharmacological tests to confirm the function of the target genes. RESULTS: We found that loss of function of CSK or PTEN conferred lapatinib resistance in HER2-amplified GC cell lines NCI-N87 and OE19, respectively. Moreover, PI3K and MAPK signaling was significantly increased in CSK or PTEN null cells. Furthermore, in vitro and in vivo pharmacological study has shown that lapatinib resistance by the loss of function of CSK or PTEN, could be overcome by lapatinib combined with the PI3K inhibitor copanlisib and MEK inhibitor trametinib. CONCLUSIONS: Our study suggests that loss-of-function mutations of CSK and PTEN cause lapatinib resistance by re-activating MAPK and PI3K pathways, and further proved these two pathways are druggable targets. Inhibiting the two pathways synergistically are effective to overcome lapatinib resistance in HER2-amplified GC. This study provides insights for understanding the resistant mechanism of HER2 targeted therapy and novel strategies that may ultimately overcome resistance or limited efficacy of lapatinib treatment for subset of HER2 amplified GC.