USP8-governed GPX4 homeostasis orchestrates ferroptosis and cancer immunotherapy.

Ferroptosis is an iron-dependent type of regulated cell death resulting from extensive lipid peroxidation and plays a critical role in various physiological and pathological processes. However, the regulatory mechanisms for ferroptosis sensitivity remain incompletely understood. Here, we report that homozygous deletion of Usp8 (ubiquitin-specific protease 8) in intestinal epithelial cells (IECs) leads to architectural changes in the colonic epithelium and shortens mouse lifespan accompanied by increased IEC death and signs of lipid peroxidation. However, mice with heterozygous deletion of Usp8 in IECs display normal phenotype and become resistant to azoxymethane/dextran sodium sulfate-induced colorectal tumorigenesis. Mechanistically, USP8 interacts with and deubiquitinates glutathione peroxidase 4 (GPX4), leading to GPX4 stabilization. Thus, USP8 inhibition destabilizes GPX4 and sensitizes cancer cells to ferroptosis in vitro. Notably, USP8 inhibition in combination with ferroptosis inducers retards tumor growth and enhances CD8+ T cell infiltration, which potentiates tumor response to anti-PD-1 immunotherapy in vivo. These findings uncover that USP8 counteracts ferroptosis by stabilizing GPX4 and highlight targeting USP8 as a potential therapeutic strategy to boost ferroptosis for enhancing cancer immunotherapy.

Construction of Tetrahymena strains with highly active arsenic methyltransferase genes for arsenic detoxification in aquatic environments.

Biomethylation is an effective means of arsenic detoxification by organisms living in aquatic environments. Ciliated protozoa (including Tetrahymena species) play an important role in the biochemical cycles of aquatic ecosystems and have a potential application in arsenic biotransformation. This study compared arsenic tolerance, accumulation, methylation, and efflux in 11 Tetrahymena species. Nineteen arsenite (As(III)) S-adenosylmethionine (SAM) methyltransferase (arsM) genes, of which 12 are new discoveries, were identified, and protein sequences were studied. We then constructed recombinant cell lines based on the Tetrahymena thermophila (T. thermophila) wild-type SB210 strain and expressed each of the 19 arsM genes under the control of the metal-responsive the MTT1 promoter. In the presence of Cd2+ and As(V), expression of the arsM genes in the recombinant cell lines was much higher than in the donor species. Evaluation of the recombinant cell line identified one with ultra-high arsenic methylation enzyme activity, significantly higher arsenic methylation capacity and much faster methylation rate than other reported arsenic methylated organisms, which methylated 89% of arsenic within 6.5 h. It also had an excellent capacity for the arsenic detoxification of lake water containing As(V), 56% of arsenic was methylated at 250 µg/L As(V) in 48 h. This study has made a significant contribution to our knowledge on arsenic metabolism in protozoa and demonstrates the great potential to use Tetrahymena species in the arsenic biotransformation of aquatic environments.

Transthoracic single-port-assisted laparoscopic gastrectomy versus laparoscopic transhiatal approach for Siewert type II adenocarcinoma of the esophagogastric junction: a single-center retrospective study.

BACKGROUND: The surgical approach for patients with Siewert type II AEG remains controversial. Several studies have described a new laparoscopic radical resection approach of Siewert type II AEG through the left diaphragm. However, the technical safety and feasibility of the new surgical approach compared with the transhiatal approach have not yet been tested. STUDY DESIGN: We retrospectively reviewed patients with AEG who underwent TSLG and LTH operations in the Guangdong Provincial Hospital of Chinese Medicine between January 2017 and April 2021. Histologically confirmed AEG and D2 lymphadenectomy with curative R0 patients were included, and patients with Siewert I/III AEG or distant metastasis were excluded. Blood loss, the amount of harvested lymph node, and complications related to surgery were evaluated. RESULTS: A total of 99 patients with Siewert type II AEG were analyzed, 44 in the TSLG group and 55 in the LTH group. There was no difference in clinicopathological features between the two groups. The more harvested lymph node (23.33 ± 11.41 vs. 32.18 ± 12.85, p < 0.01), lower mediastinal lymph node (1.07 ± 2.08 vs. 3.25 ± 3.31, p < 0.01), and longer proximal margin length (3.08 ± 1.19 vs. 4.47 ± 0.95 cm, p < 0.01) were observed in the TSLG group. The rate of cure (R0 gastrectomy) in the TSLG group was higher than that in the LTH group (100% vs. 89.09%, p = 0.03). CONCLUSION: The TSLG approach is associated with improved surgical views, simplified lymphatic dissection in the inferior mediastinum, and more reliable margins. TSLG surgery may be an effective addition to LTH surgery, particularly when lower mediastinal lymph node metastases are suspected.

Comprehensive assessment of immune context and immunotherapy response via noninvasive imaging in gastric cancer.

BACKGROUNDThe tumor immune microenvironment can provide prognostic and therapeutic information. We aimed to develop noninvasive imaging biomarkers from computed tomography (CT) for comprehensive evaluation of immune context and investigate their associations with prognosis and immunotherapy response in gastric cancer (GC).METHODSThis study involved 2,600 patients with GC from 9 independent cohorts. We developed and validated 2 CT imaging biomarkers (lymphoid radiomics score [LRS] and myeloid radiomics score [MRS]) for evaluating the IHC-derived lymphoid and myeloid immune context respectively, and integrated them into a combined imaging biomarker [LRS/MRS: low(-) or high(+)] with 4 radiomics immune subtypes: 1 (-/-), 2 (+/-), 3 (-/+), and 4 (+/+). We further evaluated the imaging biomarkers' predictive values on prognosis and immunotherapy response.RESULTSThe developed imaging biomarkers (LRS and MRS) had a high accuracy in predicting lymphoid (AUC range: 0.765-0.773) and myeloid (AUC range: 0.736-0.750) immune context. Further, similar to the IHC-derived immune context, 2 imaging biomarkers (HR range: 0.240-0.761 for LRS; 1.301-4.012 for MRS) and the combined biomarker were independent predictors for disease-free and overall survival in the training and all validation cohorts (all P < 0.05). Additionally, patients with high LRS or low MRS may benefit more from immunotherapy (P < 0.001). Further, a highly heterogeneous outcome on objective response ​rate was observed in 4 imaging subtypes: 1 (-/-) with 27.3%, 2 (+/-) with 53.3%, 3 (-/+) with 10.2%, and 4 (+/+) with 30.0% (P < 0.0001).CONCLUSIONThe noninvasive imaging biomarkers could accurately evaluate the immune context and provide information regarding prognosis and immunotherapy for GC.

Entorhinohippocampal cholecystokinin modulates spatial learning by facilitating neuroplasticity of hippocampal CA3-CA1 synapses.

The hippocampus is broadly impacted by neuromodulations. However, how neuropeptides shape the function of the hippocampus and the related spatial learning and memory remains unclear. Here, we discover the crucial role of cholecystokinin (CCK) in heterosynaptic neuromodulation from the medial entorhinal cortex (MEC) to the hippocampus. Systematic knockout of the CCK gene impairs CA3-CA1 LTP and space-related performance. The MEC provides most of the CCK-positive neurons projecting to the hippocampal region, which potentiates CA3-CA1 long-term plasticity heterosynaptically in a frequency- and NMDA receptor (NMDAR)-dependent manner. Selective inhibition of MEC CCKergic neurons or downregulation of their CCK mRNA levels also impairs CA3-CA1 LTP formation and animals' performance in the water maze. This excitatory extrahippocampal projection releases CCK upon high-frequency excitation and is active during animal exploration. Our results reveal the critical role of entorhinal CCKergic projections in bridging intra- and extrahippocampal circuitry at electrophysiological and behavioral levels.

CRISPR/Cas-Based Techniques for Live-Cell Imaging and Bioanalysis.

CRISPR/Cas systems have found widespread applications in gene editing due to their high accuracy, high programmability, ease of use, and affordability. Benefiting from the cleavage properties (trans- or cis-) of Cas enzymes, the scope of CRISPR/Cas systems has expanded beyond gene editing and they have been utilized in various fields, particularly in live-cell imaging and bioanalysis. In this review, we summarize some fundamental working mechanisms and concepts of the CRISPR/Cas systems, describe the recent advances and design principles of CRISPR/Cas mediated techniques employed in live-cell imaging and bioanalysis, highlight the main applications in the imaging and biosensing of a wide range of molecular targets, and discuss the challenges and prospects of CRISPR/Cas systems in live-cell imaging and biosensing. By illustrating the imaging and bio-sensing processes, we hope this review will guide the best use of the CRISPR/Cas in imaging and quantifying biological and clinical elements and inspire new ideas for better tool design in live-cell imaging and bioanalysis.

Targeting METTL3 reprograms the tumor microenvironment to improve cancer immunotherapy.

The tumor microenvironment (TME) is a heterogeneous ecosystem containing cancer cells, immune cells, stromal cells, cytokines, and chemokines which together govern tumor progression and response to immunotherapies. Methyltransferase-like 3 (METTL3), a core catalytic subunit for RNA N6-methyladenosine (m6A) modification, plays a crucial role in regulating various physiological and pathological processes. Whether and how METTL3 regulates the TME and anti-tumor immunity in non-small-cell lung cancer (NSCLC) remain poorly understood. Here, we report that METTL3 elevates expression of pro-tumorigenic chemokines including CXCL1, CXCL5, and CCL20, and destabilizes PD-L1 mRNA in an m6A-dependent manner, thereby shaping a non-inflamed TME. Thus, inhibiting METTL3 reprograms a more inflamed TME that renders anti-PD-1 therapy more effective in several murine lung tumor models. Clinically, NSCLC patients who exhibit low-METTL3 expression have a better prognosis when receiving anti-PD-1 therapy. Collectively, our study highlights targeting METTL3 as a promising strategy to improve immunotherapy in NSCLC patients.

Biology-guided deep learning predicts prognosis and cancer immunotherapy response.

Substantial progress has been made in using deep learning for cancer detection and diagnosis in medical images. Yet, there is limited success on prediction of treatment response and outcomes, which has important implications for personalized treatment strategies. A significant hurdle for clinical translation of current data-driven deep learning models is lack of interpretability, often attributable to a disconnect from the underlying pathobiology. Here, we present a biology-guided deep learning approach that enables simultaneous prediction of the tumor immune and stromal microenvironment status as well as treatment outcomes from medical images. We validate the model for predicting prognosis of gastric cancer and the benefit from adjuvant chemotherapy in a multi-center international study. Further, the model predicts response to immune checkpoint inhibitors and complements clinically approved biomarkers. Importantly, our model identifies a subset of mismatch repair-deficient tumors that are non-responsive to immunotherapy and may inform the selection of patients for combination treatments.

Asymptotic Stability of Delayed Boolean Networks With Random Data Dropouts.

In real networks, communication constraints often prevent the full exchange of information between nodes, which is inevitable. This brief investigates the problem of time delay and randomly missing data in Boolean networks (BNs). A Bernoulli random variable is assigned to each node to characterize the probability of data packet dropout. Time delay and missing data are modeled by independent random variables. A novel data-sending rule that incorporates both communication constraints is proposed. An augmented system, comprising current states, delayed information, and successfully transmitted data, is established for theoretical analysis. Using the semitensor product (STP), the necessary and sufficient condition for asymptotic stability of delayed BNs with random data dropouts is derived. The convergence rate is also obtained.

Non-invasive tumor microenvironment evaluation and treatment response prediction in gastric cancer using deep learning radiomics.

The tumor microenvironment (TME) plays a critical role in disease progression and is a key determinant of therapeutic response in cancer patients. Here, we propose a noninvasive approach to predict the TME status from radiological images by combining radiomics and deep learning analyses. Using multi-institution cohorts of 2,686 patients with gastric cancer, we show that the radiological model accurately predicted the TME status and is an independent prognostic factor beyond clinicopathologic variables. The model further predicts the benefit from adjuvant chemotherapy for patients with localized disease. In patients treated with checkpoint blockade immunotherapy, the model predicts clinical response and further improves predictive accuracy when combined with existing biomarkers. Our approach enables noninvasive assessment of the TME, which opens the door for longitudinal monitoring and tracking response to cancer therapy. Given the routine use of radiologic imaging in oncology, our approach can be extended to many other solid tumor types.

Fibroblast-specific knockout of METTL1 attenuates myocardial infarction-induced cardiac fibrosis.

Cardiac fibrosis, a common pathology in inherited and acquired heart diseases, necessitates the identification of diagnostic and therapeutic targets. Methyltransferase Like 1 (METTL1), an enzyme responsible for RNA modification by methylating guanosine to form m7G, is an emerging area of research in understanding cellular processes and disease pathogenesis. Dysregulation of m7G modification has been implicated in various diseases. However, the role of METTL1 in cardiac fibrosis remains unclear. This study aimed to investigate the role of METTL1 in myocardial infarction-induced heart failure and cardiac fibrosis. Our findings demonstrate that elevated METTL1-mediated RNA m7G methylation is observed in cardiac fibrosis tissues and TGF-ß1-induced cardiac fibroblast proliferation and myofibroblast transformation. Furthermore, fibroblast-specific knockout of METTL1 attenuated myocardial infarction-induced heart failure and cardiac fibrosis. Additionally, METTL1 knockout decreased m7G methylated fibrotic genes and impaired their translation efficiency. These results suggest a novel pro-fibrosis role of METTL1-mediated RNA m7G methylation, highlighting its potential as a therapeutic target in cardiac fibrosis.

Cancer immunotherapy response prediction from multi-modal clinical and image data using semi-supervised deep learning.

BACKGROUND AND PURPOSE: Immunotherapy is a standard treatment for many tumor types. However, only a small proportion of patients derive clinical benefit and reliable predictive biomarkers of immunotherapy response are lacking. Although deep learning has made substantial progress in improving cancer detection and diagnosis, there is limited success on the prediction of treatment response. Here, we aim to predict immunotherapy response of gastric cancer patients using routinely available clinical and image data. MATERIALS AND METHODS: We present a multi-modal deep learning radiomics approach to predict immunotherapy response using both clinical data and computed tomography images. The model was trained using 168 advanced gastric cancer patients treated with immunotherapy. To overcome limitations of small training data, we leverage an additional dataset of 2,029 patients who did not receive immunotherapy in a semi-supervised framework to learn intrinsic imaging phenotypes of the disease. We evaluated model performance in two independent cohorts of 81 patients treated with immunotherapy. RESULTS: The deep learning model achieved area under receiver operating characteristics curve (AUC) of 0.791 (95% CI 0.633-0.950) and 0.812 (95% CI 0.669-0.956) for predicting immunotherapy response in the internal and external validation cohorts. When combined with PD-L1 expression, the integrative model further improved the AUC by 4-7% in absolute terms. CONCLUSION: The deep learning model achieved promising performance for predicting immunotherapy response from routine clinical and image data. The proposed multi-modal approach is general and can incorporate other relevant information to further improve prediction of immunotherapy response.

Pharmacologic inhibition of IL11/STAT3 signaling increases MHC-I expression and T cell infiltration.

BACKGROUND: Recent studies have discovered an emerging role of IL11 in various colitis-associated cancers, suggesting that IL11 mainly promotes tumor cell survival and proliferation in regulating tumorigenesis. Herein we aimed to reveal a novel function of IL-11 through STAT3 signaling in regulating tumor immune evasion. METHODS: AOM/DSS model in Il11-/- and Apcmin/+/Il11-/- mice were used to detect tumor growth and CD8+ T infiltration. STAT1/3 phosphorylation and MHC-I, CXCL9, H2-K1 and H2-D1 expression were detected in MC38 cells and intestine organoids treated with/without recombinant IL11 to explore effect of IL11/STAT3 signaling, with IL11 mutein used to competitively inhibit IL11 and rescue inhibited STAT1 activation. Correlation between IL11 and CD8+ T infiltration was analyzed using TIMER2.0 website. IL11 expression and survival prognosis was analyzed in clinical data of patient cohort from Nanfang Hospital. RESULTS: IL11 is highly expressed in CRC and indicates unfavorable prognosis. IL11 knockout increased CD8+ T cell infiltration and reduced intestinal and colon formation. Tumors were significantly suppressed while MHC-I and CXCL9 expression for CD8+ T infiltration were remarkably increased in the tumor tissues of Apcmin/+/Il11-/- mice or Il11-/- mice induced by AOM/DSS. IL11/STAT3 signaling downregulated MHC-I and CXCL9 by inhibiting IFNγ-induced STAT1 phosphorylation. IL11 mutein competitively inhibit IL11 to upregulate CXCL9 and MHC-I in tumor and attenuated tumor growth. CONCLUSIONS: This study ascribes for a new immunomodulatory role for IL11 during tumor development that is amenable to anti-cytokine based therapy of colon cancer.

Initial analytical theory of plasma disruption and experimental evidence.

It is a great physical challenge to achieve controlled nuclear fusion in magnetic confinement tokamak and solve energy shortage problem for decades. In tokamak plasma, large-scale plasma instability called disruption will halt power production of reactor and damage key components. Prediction and prevention of plasma disruption is extremely urgent and important. However, there is no analytical theory can elucidate plasma disruption physical mechanism yet. Here we show an analytical theory of tokamak plasma disruption based on nonextensive geodesic acoustic mode theory, which can give the physical mechanism of disruption. The proposed theory has not only been confirmed by experimental data of disruption on T-10 device, but also can explain many related phenomena around plasma disruption, filling the gap in physical mechanism of tokamak plasma disruption.

ERK and USP5 govern PD-1 homeostasis via deubiquitination to modulate tumor immunotherapy.

The programmed cell death protein 1 (PD-1) is an inhibitory receptor on T cells and plays an important role in promoting cancer immune evasion. While ubiquitin E3 ligases regulating PD-1 stability have been reported, deubiquitinases governing PD-1 homeostasis to modulate tumor immunotherapy remain unknown. Here, we identify the ubiquitin-specific protease 5 (USP5) as a bona fide deubiquitinase for PD-1. Mechanistically, USP5 interacts with PD-1, leading to deubiquitination and stabilization of PD-1. Moreover, extracellular signal-regulated kinase (ERK) phosphorylates PD-1 at Thr234 and promotes PD-1 interaction with USP5. Conditional knockout of Usp5 in T cells increases the production of effector cytokines and retards tumor growth in mice. USP5 inhibition in combination with Trametinib or anti-CTLA-4 has an additive effect on suppressing tumor growth in mice. Together, this study describes a molecular mechanism of ERK/USP5-mediated regulation of PD-1 and identifies potential combinatorial therapeutic strategies for enhancing anti-tumor efficacy.

Metformin Collaborates with PINK1/Mfn2 Overexpression to Prevent Cardiac Injury by Improving Mitochondrial Function.

Both mitochondrial quality control and energy metabolism are critical in maintaining the physiological function of cardiomyocytes. When damaged mitochondria fail to be repaired, cardiomyocytes initiate a process referred to as mitophagy to clear defective mitochondria, and studies have shown that PTEN-induced putative kinase 1 (PINK1) plays an important role in this process. In addition, previous studies indicated that peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) is a transcriptional coactivator that promotes mitochondrial energy metabolism, and mitofusin 2 (Mfn2) promotes mitochondrial fusion, which is beneficial for cardiomyocytes. Thus, an integration strategy involving mitochondrial biogenesis and mitophagy might contribute to improved cardiomyocyte function. We studied the function of PINK1 in mitophagy in isoproterenol (Iso)-induced cardiomyocyte injury and transverse aortic constriction (TAC)-induced myocardial hypertrophy. Adenovirus vectors were used to induce PINK1/Mfn2 protein overexpression. Cardiomyocytes treated with isoproterenol (Iso) expressed high levels of PINK1 and low levels of Mfn2, and the changes were time dependent. PINK1 overexpression promoted mitophagy, attenuated the Iso-induced reduction in MMP, and reduced ROS production and the apoptotic rate. Cardiac-specific overexpression of PINK1 improved cardiac function, attenuated pressure overload-induced cardiac hypertrophy and fibrosis, and facilitated myocardial mitophagy in TAC mice. Moreover, metformin treatment and PINK1/Mfn2 overexpression reduced mitochondrial dysfunction by inhibiting ROS generation leading to an increase in both ATP production and mitochondrial membrane potential in Iso-induced cardiomyocyte injury. Our findings indicate that a combination strategy may help ameliorate myocardial injury by improving mitochondrial quality.

Angiotensin II-induced calcium overload affects mitochondrial functions in cardiac hypertrophy by targeting the USP2/MFN2 axis.

Ubiquitination, a common type of post-translational modification, is known to affect various diseases, including cardiac hypertrophy. Ubiquitin-specific peptidase 2 (USP2) plays a crucial role in regulating cell functions, but its role in cardiac functions remains elusive. The present study aims to investigate the mechanism of USP2 in cardiac hypertrophy. Animal and cell models of cardiac hypertrophy were established using Angiotensin II (Ang II) induction. Our experiments revealed that Ang II induced USP2 downregulation in the in vitro and in vivo models. USP2 overexpression suppressed the degree of cardiac hypertrophy (decreased ANP, BNP, and ß-MHC mRNA levels, cell surface area, and ratio of protein/DNA), calcium overload (decreased Ca2+ concentration and t-CaMKⅡ and p-CaMKⅡ, and increased SERCA2), and mitochondrial dysfunction (decreased MDA and ROS and increased MFN1, ATP, MMP, and complex Ⅰ and II) both in vitro and in vivo. Mechanically, USP2 interacted with MFN2 and improved the protein level of MFN2 through deubiquitination. Rescue experiments confirmed that MFN2 downregulation neutralized the protective role of USP2 overexpression in cardiac hypertrophy. Overall, our findings suggested that USP2 overexpression mediated deubiquitination to upregulate MFN2, thus alleviating calcium overload-induced mitochondrial dysfunction and cardiac hypertrophy.

Hand-sewn esophagojejunostomy in transthoracic single-port assisted laparoscopic esophagogastrectomy for Siewert type II adenocarcinoma of the esophagogastric junction with esophageal invasion > 3 cm.

BACKGROUND: An optimal method for digestive tract reconstruction (DTR) in laparoscopic radical resection of Siewert type II adenocarcinoma of esophagogastric junction (AEG) has not yet been standardized. The aim of this study was to evaluate the safety and feasibility of a hand-sewn esophagojejunostomy (EJ) technique during transthoracic single-port assisted laparoscopic esophagogastrectomy (TSLE) for Siewert type II AEG with esophageal invasion > 3 cm. METHODS: The perioperative clinical data and short-term outcomes for patients who underwent TSLE using hand-sewn EJ for Siewert type II AEG with esophageal invasion > 3 cm between March 2019 and April 2022 have been retrospectively reviewed. RESULTS: A total of 25 patients were eligible. All 25 patients were successfully operated. None was converted to open surgery or mortality. 84.00% of patients were male and 16.00% were female. The mean age, body mass index (BMI), and the American Society of Anesthesiologists (ASA) score were 67.88 ± 8.10 years, 21.30 ± 2.80 kg/m2, and 2.08, respectively. The average incorporated operative and hand-sewn EJ procedural times were 274.92 ± 57.46 and 23.36 ± 3.00 min, respectively. The length of extracorporeal esophageal involvement and proximal margin was 3.31 ± 0.26 cm and 3.12 ± 0.12 cm, respectively. The average time for the first oral feeding and hospital stay were 6 (3-14) and 7 (3-18) days, respectively. Two patients (8.00%) developed postoperative grade IIIa complications according to the Clavien-Dindo classification, including 1 case of pleural effusion and 1 case of anastomotic leakage, both of whom were cured by puncture drainage. CONCLUSION: Hand-sewn EJ in TSLE is safe and feasible for Siewert type II AEG. This method can ensure safe proximal margins and could be a good option with an advanced endoscopic suture technique for type II tumor with esophageal invasion > 3 cm.