Centurial deposition records of polychlorinated biphenyls and organochlorine pesticides in sediment cores from a plateau deep-water lake of China: Significance of anthropogenic impacts, transformation signals and ecological risks revealed by full congener analysis

Lake Fuxian, the largest deep freshwater lake in China, has been suffering from increasing ecological and environmental issues along with the rapid urbanization and industrialization in the past 40 years. To better understand the historical pollution of persistent organic pollutants (POPs) in Lake Fuxian, comprehensive analyses of 209 polychlorinated biphenyl (PCB) congeners and 20 organochlorine pesticides (OCPs) were conducted in two intact sediment cores (Core V1 and Core V2). The total mass concentrations of PCBs ranged from 7.60 to 31.47 ng/g (dry weight basis) and 5.55 to 28.90 ng/g during the period of 1908-2019 in Core V1 and 1924-2019 in Core V2, respectively. PCBs exhibited a consecutive increasing trend from 1940s to 2019 in Core V1. The temporal trend of PCBs in Core V2 basically matched to the history of PCB usage and prohibition in China (increasing from 1940s to mid-1960s, a remarkable drop in mid-1970s, and then increasing until 2019). Moreover, low-chlorinated PCBs were dominant among PCB homologues. Mono-CBs, di-CBs, tri-CBs and tetra-CBs accounted for 86.71 %-98.57 % in sediment segments. The PCB sources included unintentional emission and atmospheric deposition, as well as biological transformation. The total mass concentrations of OCPs ranged from 0.74 to 3.82 ng/g in Core V1 and 0.35 to 2.23 ng/g in Core V2, respectively. Similar trend was observed in the two sediment cores with peaks in the early 1990s. The predominant OCPs were γ-hexachlorohexane (γ-HCHs), dieldrin and p,p'-DDD. The ecological risks posed by PCBs and p-p'-DDD in Lake Fuxian were relatively low. In contrast, dieldrin might pose a potential threat to exposed organisms and apparently adverse ecological effects were caused by γ-HCH. This study will provide important baseline information on historical POPs contamination of Lake Fuxian.

Mechanism of organic phosphorus transformation and its impact on the primary production in a deep oligotrophic plateau lake during stratification

Global warming is leading to extended stratification in deep lakes, which may exacerbate phosphorus (P) limitation in the upper waters. Conversion of labile dissolved organic P (DOP) is a possible adaptive strategy to maintain primary production. To test this, the spatiotemporal distributions of various soluble P fractions and phosphomonesterase (PME)/phosphodiesterase (PDE) activities were investigated in Lake Fuxian during the stratification period and the transition capacity of organic P and its impact on primary productivity were evaluated. The results indicated that the DOP concentration (mean 0.20 ± 0.05 μmol L-1) was significantly higher than that of dissolved inorganic P (DIP) (mean 0.08 ± 0.03 μmol L-1) in the epilimnion and metalimnion, which were predominantly composed of orthophosphate monoester (monoester-P) and orthophosphate diesters (diester-P). The low ratio of diester-P / monoester-P and high activities of PME and PDE indicate DOP mineralization in the epilimnion and metalimnion. We detected a DIP threshold of approximately 0.19 μmol L-1, corresponding to the highest total PME activity in the lake. Meta-analysis further demonstrated that DIP thresholds of PME activities were prevalent in oligotrophic (0.19 μmol L-1) and mesotrophic (0.74 μmol L-1) inland waters. In contrast to the phosphate-sensitive phosphatase PME, dissolved PDE was expressed independent of phosphate availability and its activity invariably correlated with chlorophyll a, suggesting the involvement of phytoplankton in DOP utilization. This study provides important field evidence for the DOP transformation processes and the strategy for maintaining primary productivity in P-deficient scenarios, which contributes to the understanding of P cycles and the mechanisms of system adaptation to future long-term P limitations in stratified waters.

ADPS: Asymmetric Distillation Postsegmentation for Image Anomaly Detection

Knowledge distillation-based anomaly detection (KDAD) methods rely on the teacher-student paradigm to detect and segment anomalous regions by contrasting the unique features extracted by both networks. However, existing KDAD methods suffer from two main limitations: 1) the student network can effortlessly replicate the teacher network's representations and 2) the features of the teacher network serve solely as a "reference standard" and are not fully leveraged. Toward this end, we depart from the established paradigm and instead propose an innovative approach called asymmetric distillation postsegmentation (ADPS). Our ADPS employs an asymmetric distillation paradigm that takes distinct forms of the same image as the input of the teacher-student networks, driving the student network to learn discriminating representations for anomalous regions. Meanwhile, a customized Weight Mask Block (WMB) is proposed to generate a coarse anomaly localization mask that transfers the distilled knowledge acquired from the asymmetric paradigm to the teacher network. Equipped with WMB, the proposed postsegmentation module (PSM) can effectively detect and segment abnormal regions with fine structures and clear boundaries. Experimental results demonstrate that the proposed ADPS outperforms the state-of-the-art methods in detecting and segmenting anomalies. Surprisingly, ADPS significantly improves average precision (AP) metric by 9% and 20% on the MVTec anomaly detection (AD) and KolektorSDD2 datasets, respectively.

"Cell Disk" DNA Storage System Capable of Random Reading and Rewriting

DNA has emerged as an appealing material for information storage due to its great storage density and durability. Random reading and rewriting are essential tasks for practical large-scale data storage. However, they are currently difficult to implement simultaneously in a single DNA-based storage system, strongly limiting their practicability. Here, a "Cell Disk" storage system is presented, achieving high-density in vivo DNA data storage that enables both random reading and rewriting. In this system, each yeast cell is used as a chamber to store information, similar to a "disk block" but with the ability to self-replicate. Specifically, each genome of yeast cell has a customized CRISPR/Cas9-based "lock-and-key" module inserted, which allows selective retrieval, erasure, or rewriting of the targeted cell "block" from a pool of cells ("disk"). Additionally, a codec algorithm with lossless compression ability is developed to improve the information density of each cell "block". As a proof of concept, target-specific reading and rewriting of the compressed data from a mimic cell "disk" comprising up to 105 "blocks" are demonstrated and achieve high specificity and reliability. The "Cell Disk" system described here concurrently supports random reading and rewriting, and it should have great scalability for practical data storage use.

Diffusion kinetic processes and release risks of trace metals in plateau lacustrine sediments

The ecological risk posed by trace metals in the plateau lacustrine sediments of China has attracted worldwide attentions. A better understanding of the kinetic diffusion processes and bioavailability of these metals in plateau lakes is needed. Using the diffusive gradient in thin films (DGT) and Rhizon, concentrations of Mn, Mo, Ni, Cr, and Co in the sediments, labile fractions, and interstitial water of Lake Fuxian were comprehensively analyzed. According to the DGT-induced fluxes in sediments (DIFS) model, fully sustained and unsustained resupplies are possible ways in which metals are released from solids to the solution. Moreover, the resupply characteristics of metals varied at different depths in the sediments and at different sites in the lake. Based on the DIFS model, the effective concentrations (CE) of the trace metals were calculated and all except Cr showed good linear relationships with the DGT-labile concentrations, indicating that the CE values were valuable for predicting metal bioavailability. According to the CE values, the metal contamination released from the sediments was relatively low based on the Monte Carlo simulation. This study provides a comprehensive solution for studying the environmental behavior and potential ecological risks of toxic metals in sedimentary environment.

Methane ebullition fluxes and temperature sensitivity in a shallow lake

Inland waters are important sources of atmospheric methane (CH4), with a major contribution from the CH4 ebullition pathway. However, there is still a lack of CH4 ebullition flux (eFCH4) and their temperature sensitivity (Q10) in shallow lakes, which might lead to large uncertainties in CH4 emission response from aquatic to climate and environmental change. Herein, the magnitude and regulatory of two CH4 pathways (ebullition and diffusion) were studied in subtropical Lake Chaohu, China, using the real-time portable greenhouse gas (GHG) analyzer-floating chamber method at 18 sites over four seasons. eFCH4 (12.06 ± 4.10 nmol m-2 s-1) was the dominant contributing pathway (73.0 %) to the two CH4 emission pathways in Lake Chaohu. The whole-lake mass balance calculation demonstrated that 56.6 % of the CH4 emitted from the sediment escaped through the ebullition pathway. eFCH4 was significantly higher in the western (WL: 16.54 ± 22.22 nmol m-2 s-1) and eastern lake zones (EL: 11.89 ± 15.43 nmol m-2 s-1) than in the middle lake zone (ML: 8.86 ± 13.78 nmol m-2 s-1; p < 0.05) and were significantly higher in the nearshore lake zone (NL: 15.94 ± 19.58 nmol m-2 s-1) than in the pelagic lake zone (PL: 6.64 ± 12.37 nmol m-2 s-1; p < 0.05). eFCH4 was significantly higher in summer (32.12 ± 13.82 nmol m-2 s-1) than in other seasons (p < 0.05). eFCH4 had a strong temperature dependence. Sediment total organic carbon (STOC) is an important ecosystem level Q10 driver of eFCH4. The meta-analysis also verified that across ecosystems the ecosystem-level Q10 of eFCH4 was significantly positively correlated with STOC and latitude (p < 0.05). This study suggests that eFCH4 will become increasingly crucial in shallow lake ecosystems as climate change and human activities increase. The potential increase in ebullition fluxes in high-latitude lakes is of great importance.

The dual roles of dissimilatory iron reduction in the carbon cycle: The "iron mesh" effect can increase inorganic carbon sequestration

Dissimilatory iron reduction (DIR) can drive the release of organic carbon (OC) as carbon dioxide (CO2 ) by mediating electron transfer between organic compounds and microbes. However, DIR is also crucial for carbon sequestration, which can affect inorganic-carbon redistribution via iron abiotic-phase transformation. The formation conditions of modern carbonate-bearing iron minerals (ICFe ) and their potential as a CO2 sink are still unclear. A natural environment with modern ICFe , such as karst lake sediment, could be a good analog to explore the regulation of microbial iron reduction and sequential mineral formation. We find that high porosity is conducive to electron transport and dissimilatory iron-reducing bacteria activity, which can increase the iron reduction rate. The iron-rich environment with high calcium and OC can form a large sediment pore structure to support rapid DIR, which is conducive to the formation and growth of ICFe . Our results further demonstrate that the minimum DIR threshold suitable for ICFe formation is 6.65 μmol g-1  dw day-1 . DIR is the dominant pathway (average 66.93%) of organic anaerobic mineralization, and the abiotic-phase transformation of Fe2+ reduces CO2 emissions by ~41.79%. Our findings indicate that as part of the carbon cycle, DIR not only drives mineralization reactions but also traps carbon, increasing the stability of carbon sinks. Considering the wide geographic distribution of DIR and ICFe , our findings suggest that the "iron mesh" effect may become an increasingly important vector of carbon sequestration.

Microcystis blooms caused the decreasing richness of and interactions between free-living microbial functional genes in Lake Taihu, China

Microcystis blooms have a marked effect on microbial taxonomical diversity in eutrophic lakes, but their influence on the composition of microbial functional genes is still unclear. In this study, the free-living microbial functional genes (FMFG) composition was investigated in the period before Microcystis blooms (March) and during Microcystis blooms (July) using a comprehensive functional gene array (GeoChip 5.0). The composition and richness of FMFG in the water column was significantly different between these two periods. The FMFG in March was enriched in the functional categories of nitrogen, sulfur, and phosphorus cycling, whereas the FMFG in July was enriched in carbon cycling, organic remediation, and metal homeostasis. Molecular ecological network analysis further demonstrated fewer functional gene interactions and reduced complexity in July than in March. Module hubs of the March network were mediated by functional genes associated with carbon, nitrogen, sulfur, and phosphorus, whereas those in July by a metal homeostasis functional gene. We also observed stronger deterministic processes in the FMFG assembly in July than in March. Collectively, this study demonstrated that Microcystis blooms induced significant changes in FMFG composition and metabolic potential, and abundance-information, which can support the understanding and management of biogeochemical cycling in eutrophic lake ecosystems.

Methylomonadaceae was the active and dominant methanotroph in Tibet lake sediments

Methane (CH4), an important greenhouse gas, significantly impacts the local and global climate. Our study focused on the composition and activity of methanotrophs residing in the lakes on the Tibetan Plateau, a hotspot for climate change research. Based on the field survey, the family Methylomonadaceae had a much higher relative abundance in freshwater lakes than in brackish and saline lakes, accounting for ~92% of total aerobic methanotrophs. Using the microcosm sediment incubation with 13CH4 followed by high throughput sequencing and metagenomic analysis, we further demonstrated that the family Methylomonadaceae was actively oxidizing CH4. Moreover, various methylotrophs, such as the genera Methylotenera and Methylophilus, were detected in the 13C-labeled DNAs, which suggested their participation in CH4-carbon sequential assimilation. The presence of CH4 metabolism, such as the tetrahydromethanopterin and the ribulose monophosphate pathways, was identified in the metagenome-assembled genomes of the family Methylomonadaceae. Furthermore, they had the potential to adapt to oxygen-deficient conditions and utilize multiple electron acceptors, such as metal oxides (Fe3+), nitrate, and nitrite, for survival in the Tibet lakes. Our findings highlighted the predominance of Methylomonadaceae and the associated microbes as active CH4 consumers, potentially regulating the CH4 emissions in the Tibet freshwater lakes. These insights contributed to understanding the plateau carbon cycle and emphasized the significance of methanotrophs in mitigating climate change.

Rationale and Design of a Phase II Trial of Combined Serplulimab and Chemotherapy in Patients with Histologically Transformed Small Cell Lung Cancer: a Prospective, Single-arm and Multicentre Study

AIMS

Transformed small cell lung cancer (T-SCLC) is a highly aggressive clinical disease with a notably poor prognosis. It most often arises from epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) following treatment. To date, no standard treatment has been established for T-SCLC. Platinum-etoposide was the most commonly used regimen, but progression-free survival remains unsatisfactory. Therefore, there is an urgent unmet need to develop novel and effective strategies for this population. Our study, a multicentre, open-label, single-arm phase II clinical trial (NCT05957510), aims to evaluate the efficacy and safety of serplulimab plus chemotherapy in untreated T-SCLC patients after histological transformation.

MATERIALS AND METHODS

In total, 36 eligible participants experiencing SCLC transformation from EGFR-mutant NSCLC will be enrolled to receive combination therapy of serplulimab, etoposide and carboplatin for four to six cycles, followed by maintenance therapy with serplulimab for up to 2 years. The primary endpoint is progression-free survival; secondary endpoints include objective response rate, overall survival and safety.

RESULTS

Enrolment started in July 2023 and is ongoing, with an estimated completion date of December 2025.

CONCLUSIONS

This study aims to provide valuable insights into the efficacy and safety of combining serplulimab with chemotherapy for treating patients with T-SCLC originating from EGFR-mutant NSCLC.

Phosphorus-driven regime shift from heterotrophic to autotrophic diazotrophs in a deep alpine lake

Biological nitrogen fixation plays a critical role in maintaining primary production, particularly in systematic nitrogen deficiency. However, little is known about the dynamics within diazotrophic community facing ongoing nutrient enrichment in freshwater lakes. Here, a consecutive five-year investigation on diazotrophic community was conducted in Lake Fuxian, an oligotrophic deep alpine lake on the trajectory to eutrophic state. Results showed a regime shift from heterotrophic to autotrophic diazotrophs induced by total phosphorus (TP) enrichment. Specifically, heterotrophic diazotrophs dominated the diazotrophic community when TP was lower than 21.8 μg/L, whereas heterotrophic diazotrophs or diazotrophic Cyanobacteria randomly dominated when TP ranged between 21.8 μg/L and 28.8 μg/L. When TP was higher than 28.8 μg/L, diazotrophic Cyanobacteria accounted for 60.4%-97.7% of the total N2-fixers, indicating diazotrophic biodiversity significantly declined under TP enrichment scenario. Moreover, the dominance of diazotrophic Cyanobacteria further facilitated phytoplankton growth, which strengthened positive feedback between phytoplankton and phosphorus under nitrogen deficiency conditions. This is the first report on the threshold-like state responses of freshwater diazotrophs to environmental drivers. Our study expands the knowledge of the diazotrophic dynamics in freshwater ecosystems and contributes quantitative evidence of ecological thresholds for future environmental policymaking.

Nuclear isoform of RAPH1 interacts with FOXQ1 to promote aggressiveness and radioresistance in breast cancer

Radioresistance limits the efficacy of radiotherapy against breast cancer, especially the most lethal subtype of breast cancer, triple-negative breast cancer (TNBC). Epithelial-to-mesenchymal transition (EMT) is closely related to tumor radioresistance. In this work, we attempted to identify the key EMT-related transcription factor(s) that can induce radioresistance in breast cancer cells. A set of 44 EMT transcription factors were analyzed in parental and radioresistant TNBC cell lines. The function of FOXQ1, a differentially expressed transcription factor, was determined in TNBC radioresistance. FOXQ1-interacting proteins were identified by co-immunoprecipitation and mass spectrometry. Compared with parental cells, FOXQ1 was significantly upregulated in radioresistant TNBC cells. Silencing of FOXQ1 increased the radiosensitiviy of radioresistant TNBC cells both in vitro and in vivo. FOXQ1 associated with a nuclear isoform of RAPH1 (named RAPH1-i3) in radioresistant TNBC cells. Overexpression of RAPH1-i3 enhanced TNBC cell proliferation and migration, and most interestingly, induced radioresistance in parental TNBC cells when co-expressed with FOXQ1. Similar findings were observed in estrogen receptor-positive breast cancer cell lines that had co-expression of RAPH1-i3 and FOXQ1. Mechanistically, co-expression of RAPH1-i3 and FOXQ1 activated STAT3 signaling and increased the expression of CCND1, MCL1, Bcl-XL, and MMP2. Depletion of RAPH1-i3 impaired the radioresistance of radioresistant TNBC cells. Additionally, RAPH1-i3 upregulation was associated with advanced tumor stage and reduced disease-free survival in TNBC patients. These results collectively show that RAPH1-i3 interacts with FOXQ1 to promote breast cancer progression and radioresistance. RAPH1-i3 and FOXQ1 represent therapeutic targets for the treatment of breast cancer including TNBC.

Correlation between pre-treatment serum total blood bilirubin and unconjugated bilirubin and prognosis in patients with colorectal cancer

BACKGROUND

Epidemiological studies have found that unconjugated bilirubin (UCB) levels are positively correlated with the incidence of colorectal cancer (CRC). Therefore, bilirubin may also play an important role in the prognosis of CRC.

AIM

To investigate the predictive value of total bilirubin (TBIL) and UCB in the prognosis of patients with CRC.

METHODS

A total of 142 CRC patients were selected as the research subjects in Jingxian Hospital, from October 2014 to May 2021. General and tumour-related clinical data at admission and the overall survival at 3 years after surgery were collected. The optimal cut-off values of TBIL and UCB were determined by receiver operating characteristic curve analysis. Univariate and multivariate Cox regression were used to analyse the effect of bilirubin level on the survival of CRC patients. The Kaplan-Meier method was used to assess the survival time.

RESULTS

The 3-year overall survival rate of CRC patients was significantly higher in the high TBIL (> 13.45 μmol/L) group than in the low TBIL (≤ 13.45 μmol/L) group (76.4% vs 37.1%; P < 0.05). The 3-year overall survival rate of CRC patients in the high UCB (> 10.75 μmol/L) group was significantly higher than that in the low UCB (≤ 10.75 μmol/L) group (83.3% vs 34.2%; P < 0.05). Multivariate Cox regression analysis showed that higher TBIL levels were an independent predictor of better prognosis in CRC patients (hazard ratio = 0.360, 95% confidence interval: 0.159-0.812, P = 0.014).

CONCLUSION

TBIL levels can be used as a prognostic indicator for CRC patients.

Genomics of Yoonia sp. Isolates (Family Roseobacteraceae) from Lake Zhangnai on the Tibetan Plateau

Understanding the genomic differentiation between marine and non-marine aquatic microbes remains a compelling question in ecology. While previous research has identified several lacustrine lineages within the predominantly marine Roseobacteraceae family, limited genomic data have constrained our understanding of their ecological adaptation mechanisms. In this study, we isolated four novel Yoonia strains from a brackish lake on the Tibetan Plateau. These strains have diverged from their marine counterparts within the same genus, indicating a recent habitat transition event from marine to non-marine environments. Metabolic comparisons and ancestral genomic reconstructions in a phylogenetic framework reveal metabolic shifts in salinity adaptation, compound transport, aromatics degradation, DNA repair, and restriction systems. These findings not only corroborate the metabolic changes commonly observed in other non-marine Roseobacters but also unveil unique adaptations, likely reflecting the localized metabolic changes in responses to Tibetan Plateau environments. Collectively, our study expands the known genomic diversity of non-marine Roseobacteraceae lineages and enhances our understanding of microbial adaptations to lacustrine ecosystems.

Treatment strategies and drug resistance mechanisms in adenocarcinoma of different organs

Adenocarcinoma is a common type of malignant tumor, originating from glandular epithelial cells in various organs, such as pancreas, breast, lung, stomach, colon, rectus, and prostate. For patients who lose the opportunity for radical surgery, medication is available to provide potential clinical benefits. However, drug resistance is a big obstacle to obtain desired clinical prognosis. In this review, we provide a summary of treatment strategies and drug resistance mechanisms in adenocarcinoma of different organs, including pancreatic cancer, gastric adenocarcinoma, colorectal adenocarcinoma, lung adenocarcinoma, and prostate cancer. Although the underlying molecular mechanisms involved in drug resistance of adenocarcinoma vary from one organ to the other, there are several targets that are universal for drug resistance in adenocarcinoma, and targeting these molecules could potentially reverse drug resistance in the treatment of adenocarcinomas.

Design method of an ultra-thin two-dimensional geometrical waveguide near-eye display based on forward-ray-tracing and maximum FOV analysis

A two-dimensional geometrical waveguide enables ultra-thin augmented reality (AR) near-eye display (NED) with wide field of view (FOV) and large exit-pupil diameter (EPD). A conventional design method can efficiently design waveguides that meet the requirements, but is unable to fully utilize the potential display performance of the waveguide. A forward-ray-tracing waveguide design method with maximum FOV analysis is proposed, enabling two-dimensional geometrical waveguides to achieve their maximum FOV while maintaining minimum dimensions. Finally, the designed stray-light-suppressed waveguide NED has a thickness of 1.7 mm, a FOV of 50.00°H × 29.92°V, and an eye-box of 12 mm × 12 mm at an eye-relief of 18 mm.

An Innovative Regimen Basing on HFRT/SBRT and RC48-ADC Coactivation for Salvage Therapy in Patients with HER2-Expressing Advanced Solid Tumors

PURPOSE/OBJECTIVE(S)

It is now widely accepted that radiotherapy, especially hypofractionated radiation therapy (HFRT) or stereotactic radiotherapy (SBRT), can modulate tumor phenotypes, enhance antigen presentation and provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). The PRaG therapy is an innovative iRT, when combined with HFRT/SBRT, PD-1/L1 inhibitor and GM-CSF to activate the immune response and modulate the tumor microenvironment to exert the desired in abscopal effect. Previous studies have demonstrated encouraging efficacy of the PRaG regimen in the treatment of advanced refractory tumors. RC48-ADC is a promising anti-HER2 antibody-drug conjugate with inducing immunogenic cell death and widespread release of cancer cell antigens, synergize with immunotherapy by promoting effector T-cell activation. The aim of this study is to explore efficacy and safety of RC48-ADC combined with radiotherapy, PD-1/L1 inhibitor sequential GM-CSF and IL-2(PRaG3.0 regimen) for treatment of HER2-expressing advanced solid tumors.

MATERIALS/METHODS

Participants with advanced, confirmed HER2-expressing (IHC3+, 2+ or 1+) solid tumors that had progressed after standard treatment, or intolerance were enrolled. In a PRaG3.0 regimen cycle, those received RC48-ADC (2.0 mg/kg d1, every 3 weeks), then HFRT (2-3 doses of 5-8 Gy) was delivered for one metastatic lesion every other day, followed by GM-CSF (200 μg d3-7), sequential IL-2(2million IU d8-12), and PD-1/L1 inhibitor was dosing within one week after completion of HFRT. After RC48-ADC combined with PD-1/L1 inhibitor sequential GM-CSF and IL-2 for at least 6 cycles, then maintenance with PD-1/L1 inhibitor was administered until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR). This trial is registered with ClinicalTrials.gov, number NCT05115500.

RESULTS

With the cutoff date of 31 December 2022, a total of 30 patients (n = 6 for gynecological cancer, n = 5 for pancreatic cancer, n = 19 for other cancers) were enrolled, in which 21 patients completed at least 1 tumor assessment. The objective response rate (ORR) was 42.9%, and the disease control rate was 71.4% by RECIST1.1. The ORR was 66.7% in gynecological cancer, 25.3% in pancreatic cancer, and 36.4% in other cancers. Median progression-free survival (PFS) for all patients was 7.0 months (95% CI: 3.4, 10.7). The most common treatment-related adverse events (TRAEs) included fatigue, fever, alopecia and anorexia. Grade ≥3 TRAEs occurred in two patients (6.7%).

CONCLUSION

These preliminary results show that of PRaG3.0 regimen has a manageable safety profile and encouraging antitumor activity in heavily pretreated patients with HER2- expressing cancers. Ultimately the regimen achieved the accurate integration of RT, immunotherapy and targeted therapy.

Impact of PRaG Therapy on Immune Microenvironment of Bilateral Subcutaneous Tumor Model of Colon Cancer

PURPOSE/OBJECTIVE(S)

Immune microenvironment is closely related to the efficacy of PD-1 inhibitors. The immune microenvironment contains a variety of immune cells, including effector T cells (cytotoxic CD8+T cells and effector CD4+T cells), dendritic cells (DC), and Myeloid-derived suppressor cells (MDSCs). The antitumor effects of PRaG therapy have been confirmed in bilateral subcutaneous transplantation tumor model of colon cancer. But the impact of PRaG therapy on immune microenvironment of such model is unclear. Therefore, the study continued to reveal the changes of immune microenvironment in mice.

MATERIALS/METHODS

80 male Balb/c mice aged 6-8 weeks were divided into five groups: control group, PD-1 inhibitor group, radiation group, radiation + PD-1 inhibitor group, and radiation + PD-1 inhibitor +GM-CSF (PRaG therapy) group. Bilateral subcutaneous tumor model of colon cancer in mice was constructed. 3×105 CT26.WT cells were inoculated subcutaneously in the right thigh root, and then the left thigh root 3 days later. Right subcutaneous tumor was selected for radiotherapy of 8 Gy×3. GM-CSF (100ng, i.p.) was given on the 1st day and PD-1 inhibitor (0.25mg/kg, i.p.) was given on the 2nd day after radiotherapy with one cycle every 3 days. On day 15, the spleen, left inguinal lymph node and left subcutaneous tumor of mice were collected. The proportion of immune cells was detected by flow cytometry.

RESULTS

Compared with other groups, PRaG therapy decreased the proportion of cDC1 in left inguinal lymph node, increased the proportion of cDC2 in left subcutaneous tumor and left inguinal lymph node. Moreover, PRaG therapy increased the proportion of CD8+ effector memory T cells and CD226+CD8+T cells in left inguinal lymph nodes. Finally, PRaG therapy increased the proportion of CD4+, CD8+ central memory T cells and CD69+CD8+T cells and reduced the proportion of M-MDSCs in spleen.

CONCLUSION

PRaG therapy can improve the immune microenvironment of spleen, unirradiated tumors and inguinal draining lymph nodes of bilateral subcutaneous tumor model of colon cancer in mice.

A Prospective Clinical Trial of Radiotherapy Combined with PD-1 Inhibitors and GM-CSF, Sequentially Followed by IL-2 (PRaG 2.0) Regimen in Advanced Refractory Solid Tumors

PURPOSE/OBJECTIVE(S)

Radiotherapy could stimulate the immune response and might synergize with PD-1/PD-L1 inhibitors in the clinical treatment of malignancies. Our previous PRaG trial also demonstrated that SBRT/HFRT in combination with PD-1 inhibitors and granulocyte macrophage-colony stimulating factor (GM-CSF) could improve clinical response in patients with advanced refractory solid tumors (ChiCTR1900026175). To further improve the efficacy of immunotherapy combined with radiotherapy, we conducted the PRaG 2.0 trial (ClinicalTrials.gov: NCT04892498) and optimized the PRaG regimen by adding interleukin-2 (IL-2). Preliminary results of PRaG 2.0 had been reported in the 64th ASTRO. Now we report an updated result.

MATERIALS/METHODS

The PRaG 2.0 regimen was administered to patients with advanced refractory solid tumors who lacked or were unable to tolerate standard-of-care treatments. A treatment cycle consisted of SBRT or HFRT (5 or 8 Gy×2-3f) delivered for one metastatic lesion, PD-1 inhibitor dosing within one week after completion of radiotherapy, GM-CSF 200μg subcutaneous (SC) injection once daily for 7 days, and then sequentially followed by IL-2 2million IU SC once daily for 7 days. PRaG 2.0 regimen was repeated every 21 days for at least 2 cycles until no appropriate lesions for irradiation or reached the tolerance dose of normal tissues. Patients who could not continue radiotherapy and had not yet developed progression disease (PD) allowed PD-1 inhibitors to be continued as maintenance therapy until PD or unacceptable toxicity but no more than one year. The primary endpoint was Progression-Free Survival (PFS).

RESULTS

As of 31st October 2022, 51 patients were enrolled in the study, and 42 completed at least one tumor assessment. The median Progression-Free Survival (PFS) was 5.8 months, and the median overall survival (OS) was 13.5 months. The objective response rate (ORR) was 21.4%, and the disease control rate (DCR) was 61.9% according to RECIST version 1.1. Lower plasma levels of Interleukin (IL)-6 and IL-17 at baseline were found to be associated with improved PFS. Treatment-related adverse events (TRAE) occurred in 34 of 42 (78.6%) patients, Grade ≥ 3 TRAEs occurred in 4 patients (9.5%). TRAEs leading to discontinuation of all study treatments occurred in three patients (7.1%).

CONCLUSION

The PRaG 2.0 trial demonstrates that PD-1 inhibitors in combination with SBRT/HFRT, GM-CSF, and IL-2 could be a potential treatment regimen for patients with advanced refractory solid tumors, with an acceptable benefit/risk profile.

Impact of PRaG Therapy on Peripheral Immune Cells of Subcutaneous Tumor Peritoneal Metastasis Model of Colon Cancer

PURPOSE/OBJECTIVE(S)

Immune cells in peripheral blood may be closely related to the efficacy of immune checkpoint inhibitors. T cells originally present in tumors may have limited antitumor effects, and T cells that respond to immune checkpoint inhibitors may be derived from peripheral blood. Therefore, in this study, subcutaneous tumor peritoneal metastasis model of colon cancer was constructed to reveal the changes of T cells and their subsets (CD4+T cells, CD8+T cells, CD226+T cells), MDSCs and their subsets (G-MDSCs, M-MDSCs) in peripheral blood of mice after PRaG therapy.

MATERIALS/METHODS

A total of 90 male Balb/c mice aged 6-8 weeks were divided into five groups: control group, PD-1 inhibitor group, radiation group, radiation + PD-1 inhibitor group, and radiation + PD-1 inhibitor +GM-CSF (PRaG therapy) group. The subcutaneous tumor peritoneal metastasis model of colon cancer was constructed. 3×105 CT26.WT cells was inoculated subcutaneously at the right thigh root, and 5 days later, 1×105 CT26.WT cells was inoculated on the left side at the junction of the anterior superior iliac spine and the midabdominal line. The subcutaneous tumor was selected for radiotherapy of 8 Gy×3. GM-CSF (100ng, i.p.) was given on the 1st day and PD-1 inhibitor (0.25mg/kg, i.p.) was given on the 2nd day after radiotherapy with one cycle every 3 days. On day 22, the peripheral blood of mice was collected. The proportion of immune cells was detected by flow cytometry.

RESULTS

Compared with other groups, PRaG therapy decreased the proportion of CD4+T cells and increased the proportion of CD8+T cells. Moreover, PRaG therapy increased the proportion of CD226+CD4+T cells and CD226+CD8+T cells. Finally, PRaG therapy increased the proportion of M-MDSCs and decreased the proportion of G-MDSCs.

CONCLUSION

PRaG therapy can improve the immune microenvironment of peripheral blood of subcutaneous tumor peritoneal metastasis model of colon cancer in mice.

Combining Vis-NIR and NIR Spectral Imaging Techniques with Data Fusion for Rapid and Nondestructive Multi-Quality Detection of Cherry Tomatoes

Firmness, soluble solid content (SSC) and titratable acidity (TA) are characteristic substances for evaluating the quality of cherry tomatoes. In this paper, a hyper spectral imaging (HSI) system using visible/near-infrared (Vis-NIR) and near-infrared (NIR) was proposed to detect the key qualities of cherry tomatoes. The effects of individual spectral information and fused spectral information in the detection of different qualities were compared for firmness, SSC and TA of cherry tomatoes. Data layer fusion combined with multiple machine learning methods including principal component regression (PCR), partial least squares regression (PLSR), support vector regression (SVR) and back propagation neural network (BP) is used for model training. The results show that for firmness, SSC and TA, the determination coefficient R2 of the multi-quality prediction model established by Vis-NIR spectra is higher than that of NIR spectra. The R2 of the best model obtained by SSC and TA fusion band is greater than 0.9, and that of the best model obtained by the firmness fusion band is greater than 0.85. It is better to use the spectral bands after information fusion for nondestructive quality detection of cherry tomatoes. This study shows that hyperspectral imaging technology can be used for the nondestructive detection of multiple qualities of cherry tomatoes, and the method based on the fusion of two spectra has a better prediction effect for the rapid detection of multiple qualities of cherry tomatoes compared with a single spectrum. This study can provide certain technical support for the rapid nondestructive detection of multiple qualities in other melons and fruits.

Identification of Brassica rapa BrEBF1 homologs and their characterization in cold signaling

EIN3-binding F-box 1 (EBF1) is involved in cold tolerance in Arabidopsis; however, its exact roles in cold signaling in Brassica rapa remain uncertain. Herein, we demonstrated that EBF1 homologs are highly conserved in Brassica species, but their copy numbers are diverse, with some motifs being species specific. Cold treatment activated the expression of EBF1 homologs BrEBF1 and BrEBF2 in B. rapa; however, their expression schemas were diverse in different cold-resistant varieties of the plant. Subcellular localization analysis revealed that BrEBF1 is a nuclear-localized F-box protein, and cold treatment did not alter its localization but induced its degradation. BrEBF1 overexpression enhanced cold tolerance, reduced cold-induced ROS accumulation, and enhanced MPK3 and MPK6 kinase activity in Arabidopsis. Our study revealed that BrEBF1 positively regulates cold tolerance in B. rapa and that BrEBF1-regulated cold tolerance is associated with ROS scavenging and MPK3 and MPK6 kinase activity through the C-repeat binding factor pathway.

Sunlight irradiation promotes both the chemodiversity of terrestrial DOM and the biodiversity of bacterial community in a subalpine lake

Alpine lake habitats are evolving into subalpine lakes under the scenario of climate change, where the vegetation are promoted due to increasing temperature and precipitation. The abundant terrestrial dissolved organic matter (TDOM) leached from watershed soil into subalpine lakes would undergo strong photochemical reaction due to the high altitude, with the potential to alter DOM composition and affect the bacterial communities. To reveal the transformation of TDOM by both photochemical and microbial processes in a typical subalpine lake, Lake Tiancai (located 200 m below the tree line) was chosen. TDOM was extracted from the surrounding soil of Lake Tiancai and then subjected to the photo/micro-processing for 107 days. The transformation of TDOM was analyzed by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and fluorescence spectroscopy, and the shift of bacterial communities was analyzed using 16s rRNA gene sequencing technology. Dissolved organic carbon and light-absorbing components (a₃₅₀) decay accounted for approximately 40% and 80% of the original, respectively, in the sunlight process, but both less than 20% in the microbial process for 107 days. The photochemical process promoted the chemodiversity as there were ∼7000 molecules after sunlight irradiation, compared to ∼3000 molecules in the original TDOM. Light promoted the production of highly unsaturated molecules and aliphatics, which were significantly associated with Bacteroidota, suggesting that light may influence bacterial communities by regulating the DOM molecules. Carboxylic-rich alicyclic molecules were generated in both photochemical and biological processes, suggesting TDOM was converted to a stable pool over time. Our finding on the transformation of terrestrial DOM and the alternation of bacterial community under the simultaneously photochemical and microbial processes will help to reveal the response of the carbon cycle and lake system structure to climate change for high-altitude lakes.

Unexpected enrichment of antibiotic resistance genes and organic remediation genes in high-altitude lakes at Eastern Tibetan Plateau

Elevation has a strong effect on aquatic microbiome. However, we know little about the effects of elevation on functional genes, especially antibiotic resistance genes (ARGs) and organic remediation genes (ORGs) in freshwater ecosystems. In this study, we analyzed five classes of functional genes including ARGs, metal resistance genes (MRGs), ORGs, bacteriophages, and virulence genes between two high-altitude lakes (HALs) and two low-altitude lakes (LALs) in Mountain Siguniang at Eastern Tibetan Plateau by means of GeoChip 5.0. No differences (Student's t-test, p > 0.05) of gene richness including ARGs, MRGs, ORGs, bacteriophages, and virulence genes in HALs and LALs were found. The abundance of most ARGs and ORGs was higher in HALs than in LALs. For MRGs, the abundance of macro metal resistance genes of potassium, calcium, and aluminum was higher in HALs than in LALs (Student's t-test, p < 0.05; all Cohen's d > 0.8). The abundance of some heavy metal resistance genes of lead and mercury was lower in HALs than in LALs (Student's t-test, p < 0.05; all Cohen's d < -0.8). The composition of these functional genes in HALs differed significantly from in LALs. The functional gene network in HALs was also more complex than that in LALs. We speculate that enrichment of ARGs and ORGs in HALs is related to different microbial communities, exogenous ARGs, and enriched persistent organic pollutants through long-range atmospheric transport driven by the Indian monsoon. This study highlights the unexpected enrichment of ARGs, MRGs, and ORGs in remote lakes at high elevations.

Hydrogenotrophic pathway dominates methanogenesis along the river-estuary continuum of the Yangtze River

Rivers are considered as an important source of methane (CH₄) to the atmosphere, but our understanding for the methanogenic pathway in rivers and its linkage with CH₄ emission is very limited. Here, we investigated the diffusive flux of CH₄ and its stable carbon isotope signature (δ¹³C-CH₄) along the river-estuary continuum of the Yangtze River. The diffusive CH₄ flux was estimated to 27.9 ± 11.4 μmol/m²/d and 36.5 ± 24.4 μmol/m²/d in wet season and dry season, respectively. The δ¹³C-CH₄ values were generally lower than -60‰, with the fractionation factor (α_c) higher than 1.055 and the isotope separation factor (ε_c) ranged from 55 to 100. In situ microbial composition showed that hydrogenotrophic methanogens accounts for over 70% of the total reads. Moreover, the incubation test showed that the headspace CH₄ concentration by adding CO₂/H₂ to the sediment was orders of magnitude higher than that by adding trimethylamine and sodium acetate. These results jointly verified the river-estuary continuum is a minor CH₄ source and dominated by hydrogenotrophic pathway. Based on the methanogenic pathway here and previous reported data in the same region, the historical variation of diffusive CH₄ flux was calculated and results showed that CH₄ emission has reduced 82.5% since the construction of Three Gorges Dam (TGD). Our study verified the dominant methanogenic pathway in river ecosystems and clarified the effect and mechanism of dam construction on riverine CH₄ emission.

Iron oxides act as an alternative electron acceptor for aerobic methanotrophs in anoxic lake sediments

Conventional aerobic CH₄-oxidizing bacteria (MOB) are frequently detected in anoxic environments, but their survival strategy and ecological contribution are still enigmatic. Here we explore the role of MOB in enrichment cultures under O₂ gradients and an iron-rich lake sediment in situ by combining microbiological and geochemical techniques. We found that enriched MOB consortium used ferric oxides as alternative electron acceptors for oxidizing CH₄ with the help of riboflavin when O₂ was unavailable. Within the MOB consortium, MOB transformed CH₄ to low molecular weight organic matter such as acetate for consortium bacteria as a carbon source, while the latter secrete riboflavin to facilitate extracellular electron transfer (EET). Iron reduction coupled to CH₄ oxidation mediated by the MOB consortium was also demonstrated in situ, reducing 40.3% of the CH₄ emission in the studied lake sediment. Our study indicates how MOBs survive under anoxia and expands the knowledge of this previously overlooked CH₄ sink in iron-rich sediments.

Evaluating potential ecological risks of emerging toxic elements in lacustrine sediments: A case study in Lake Fuxian, China

The fragile ecosystems of plateau lakes are in face of ecological risks from emerging toxic elements. Beryllium (Be) and thallium (Tl) have been considered priority control metals in recent years owing to their persistence, toxicity, and bioaccumulation. However, the toxic factors of Be and Tl are scarce and ecological risks of them in the aquatic environment were seldom investigated. Hence, this study developed a framework for calculating the potential ecological risk index (PERI) of Be and Tl in aquatic systems and used it to assess the ecological risks of Be and Tl in Lake Fuxian, a plateau lake in China. The toxicity factors of Be and Tl were calculated to be 40 and 5, respectively. In sediments of Lake Fuxian, the concentrations of Be and Tl were between 2.18 and 4.04 mg/kg and 0.72-0.94 mg/kg, respectively. The spatial distribution indicated that Be was more abundant in the eastern and southern regions, and Tl had higher concentrations near the northern and southern banks, consistent with the distribution of anthropogenic activities. The background values were calculated as 3.38 mg/kg and 0.89 mg/kg for Be and Tl, respectively. In comparison with Be, Tl was more enriched in Lake Fuxian. The increasing Tl enrichment has been attributed to anthropogenic activities (e.g., coal burning and non-ferrous metal production), especially since the 1980s. Generally, Be and Tl contamination has decreased over the past several decades, from moderate to low, since the 1980s. The ecological risk of Tl was low, whereas Be might have caused low to moderate ecological risks. In the future, the obtained toxic factors of Be and Tl in this study can be adopted in assessing the ecological risks of them in sediments. Moreover, the framework can be employed for the ecological risk assessment of other newly emerging toxic elements in the aquatic environment.

Natural products in digestive tract tumors metabolism: Functional and application prospects

Digestive tract diseases are presently the hotspot of clinical diagnosis and treatment, and the incidence of digestive tract tumor is increasing annually. Surgery remains the main therapeutic schedule for digestive tract tumor. Though benefits were brought by neoadjuvant chemotherapy, a part of patients lose the chance of surgery because of late detection or inappropriate intervention. Therefore, the treatment of inoperable patients has become an urgent need. At the same time, tumor metabolism is an extremely complex and diverse process. Natural products are confirmed effective to inhibit the development of tumors in vitro and in vitro. There are many kinds of natural products and their functions remain not clear. However, some natural products such as polyphenols have been proven to have definite anti-cancer effects, and some terpenoids have definite anti-inflammatory, anti-ulcer, anti-tumor, and other effects. Therefore, the anti-tumor characteristics of natural products should arouse our high attention. Although there are many obstacles to study the activities of natural products in tumor, including the difficulty in detection or distinguishing each component due to their low levels in tumor tissue, etc., the emergence of highly sensitive and locatable spatial metabolomics make the research and application of natural products a big step forward. In this review, natural products such as phenols, terpenoids and biotinoids were summarized to further discuss the development and therapeutic properties of natural metabolites on digestive tract tumors.

Transformation of algal-dissolved organic matter via sunlight-induced photochemical and microbial processes: interactions between two processes

Algal-dissolved organic matter (ADOM) is an important fraction of dissolved organic carbon (DOC) in eutrophic water. Although ADOM is known to be readily transformed by microbes, the role of sunlight-induced photochemical process and the interactions between two processes on ADOM transformation remains unclear. In this study, three types of treatments for ADOM, including photochemical process under natural solar light (L treatment), microbial process (M treatment), and the simultaneous photochemical plus microbial process (L&M), were performed for 18 days. Our results showed that M treatment was more effective for the loss of DOC, chromophoric DOM (CDOM) at short wavelengths (a₂₅₄ and a₂₈₀), than L treatment, while L treatment was more effective for the transformation of a₃₅₀ and the fluorescent components of the ubiquitous humic-like component and the tryptophan-like component. Comparison in the decay kinetics of DOC and CDOM in the three treatments showed that the simultaneous photochemical and biological processes exhibited an inhibitory effect on DOC decay rate but not the percentage of labile DOC fraction. Higher relative abundance of protein-like substances was found after L&M treatment, while the relative abundance of humic-like substance and aromaticity increased after M treatment, and the low molecular-weight compounds were produced after L treatment. Our results emphasized the importance of photochemistry in processing ADOM to mediate the chemodiversity in natural water.

Co-occurrence pattern of bacteria and fungi on the leaves of invasive aquatic plant Alternanthera philoxeroides

The microbes that are attached to aquatic plants play critical roles in nutrient cycles and the maintenance of water quality. However, their community compositions, biodiversity, and functions have not been well explored for the invasive plants in inland waters. Here, the co-occurrence patterns between bacteria and fungi on the leaves of Alternanthera philoxeroides and their potential ecological interactions were studied during the growing seasons. Along with significant variations in the alpha diversity of attached microbes over time, shifts in their community composition were significantly associated with the dynamics of plant stoichiometry, substrate composition and extracellular enzyme activity. Deterministic processes (heterogenous selection) play predominant role in community assembly of the attached bacteria, while stochasticity (undominant process) was the major driver for the attached fungi assembly. Compared to free-living microbial network, attached microbial network was structurally simple but highly modular. The attached microbes had more intra-phylum links (primarily within the phyla Actinomycetota, Alphaproteobacteria, Bacillota and Basidiomycota) and distinct co-exclusion patterns between bacteria and fungi in the modules. In summary, the study of microbial community composition, biodiversity, community assembly processes and species interactions in the phyllosphere will be helpful in understanding the impact of biological invasion on the aquatic biodiversity and ecosystem function.

The selection of copiotrophs may complicate biodiversity-ecosystem functioning relationships in microbial dilution-to-extinction experiments

The relationships between biodiversity-ecosystem functioning (BEF) for microbial communities are poorly understood despite the important roles of microbes acting in natural ecosystems. Dilution-to-extinction (DTE), a method to manipulate microbial diversity, helps to fill the knowledge gap of microbial BEF relationships and has recently become more popular with the development of high-throughput sequencing techniques. However, the pattern of community assembly processes in DTE experiments is less explored and blocks our further understanding of BEF relationships in DTE studies. Here, a microcosm study and a meta-analysis of DTE studies were carried out to explore the dominant community assembly processes and their potential effect on exploring BEF relationships. While stochastic processes were dominant at low dilution levels due to the high number of rare species, the deterministic processes became stronger at a higher dilution level because the microbial copiotrophs were selected during the regrowth phase and rare species were lost. From the view of microbial functional performances, specialized functions, commonly carried by rare species, are more likely to be impaired in DTE experiments while the broad functions seem to be less impacted due to the good performance of copiotrophs. Our study indicated that shifts in the prokaryotic community and its assembly processes induced by dilutions result in more complex BEF relationships in DTE experiments. Specialized microbial functions could be better used for defining BEF. Our findings may be helpful for future studies to design, explore, and interpret microbial BEF relationships using DTE.

Distinct responses of soil methanotrophy in hummocks and hollows to simulated glacier meltwater and temperature rise in Tibetan glacier foreland

Glacier foreland soils are known to be essential methane (CH₄) consumers. However, global warming and increased glacier meltwater have turned some foreland meadows into swamp meadows. The potential impact of this change on the function of foreland soils in methane consumption remains unclear. Therefore, we collected Tibetan glacier foreland soils in the non-melting season from typical microtopography in swamp meadows (hummock and hollow). Three soil moisture conditions (moist, saturated, and submerged) were set by adding glacier runoff water. Soil samples were then incubated in the laboratory for two weeks at 10 °C and 20 °C. About 5 % of ¹³CH₄/¹²CH₄ was added to the incubation bottles, and daily methane concentrations were measured. DNA stable isotope probing (DNA-SIP) and high-throughput sequencing were combined to target the active methanotroph populations. The results showed that type Ia methanotrophs, including Crenothrix, Methylobacter, and an unclassified Methylomonadaceae cluster, actively oxidized methane at 10 °C and 20 °C. There were distinct responses of methanotrophs to soil moisture rises in hummock and hollow soils, resulting in different methane oxidation potentials. In both hummock and hollow soils, the methane oxidation potential was positively correlated with temperature. Furthermore, saturated hummock soils exhibited the highest methane oxidation potential and methanotroph populations, while submerged hollow soils had the lowest. This suggests that the in-situ hummock soils, generally saturated with water, are more essential than in-situ hollows, typically submerged in water, for alleviating the global warming potential of swamp meadows in the Tibetan glacier foreland during the growing season.

Postglacial adaptations enabled colonization and quasi-clonal dispersal of ammonia-oxidizing archaea in modern European large lakes

Ammonia-oxidizing archaea (AOA) play a key role in the aquatic nitrogen cycle. Their genetic diversity is viewed as the outcome of evolutionary processes that shaped ancestral transition from terrestrial to marine habitats. However, current genome-wide insights into AOA evolution rarely consider brackish and freshwater representatives or provide their divergence timeline in lacustrine systems. An unbiased global assessment of lacustrine AOA diversity is critical for understanding their origins, dispersal mechanisms, and ecosystem roles. Here, we leveraged continental-scale metagenomics to document that AOA species diversity in freshwater systems is remarkably low compared to marine environments. We show that the uncultured freshwater AOA, "Candidatus Nitrosopumilus limneticus," is ubiquitous and genotypically static in various large European lakes where it evolved 13 million years ago. We find that extensive proteome remodeling was a key innovation for freshwater colonization of AOA. These findings reveal the genetic diversity and adaptive mechanisms of a keystone species that has survived clonally in lakes for millennia.

Kinetics study and recycling strategies in different stages of full-component pyrolysis of spent LiNixCoyMnzO2 lithium-ion batteries

Full-component pyrolysis has been proven to be a prospective method for the disposal of organic matters and the cathode material reduction of spent LiNi_xCo_yMn_zO₂ (NCM) lithium-ion batteries (LIBs). However, the kinetics of the full-component pyrolysis of spent NCM LIBs is still unclear. This work represents the first attempt to study the kinetics of different stages of full-component pyrolysis of NCM LIBs based on isoconversional method to guide the recycling of spent LIBs. Pyrolysis process was divided into four stages in accordance to the main weight loss temperature ranges and the classical Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa kinetics models were employed to calculate the activation energy (E) in each stage. The main physicochemical reactions were clarified though in situ analysis, and the average E in the four stages was determined: (I) The volatilization of electrolytes occurred in the temperature range of 100-200 °C with the E of 98.6 kJ/mol. (II) The decomposition of organic matters and the preliminary reduction of cathode material transpired in the temperature range of 400-500 °C with the E of 227.2 kJ/mol. (III) The further reduction of NiO and CoO occurred from 650 to 800 °C with the E of 258.8 kJ/mol. (Ⅳ) The reduction of MnO took place from 850 to 1000 °C with the E of 334.9 kJ/mol. The recycling strategies based on full-component pyrolysis of spent NCM LIBs was accordingly proposed. During pyrolysis, the cathode material was gradually reduced and the pyrolytic products can be controlled through temperature regulation.

Proposal to reclassify Aquiflexum aquatile into a novel genus as Cognataquiflexum aquatile gen. nov., comb. nov., and description of Cognataquiflexum nitidum sp. nov. and Cognataquiflexum rubidum sp. nov., isolated from freshwater lakes on the Tibetan Plateau

Thousands of lakes harbouring different characteristics (pH, salinity, temperature) are located on the Tibetan Plateau, and the mining of microbial resources inhabited in these lakes has great value. Two Gram-stain-negative, aerobic, rod-shaped, non-motile strains (LQ15W^T and AIY15W^T) were isolated from freshwater lakes on the Tibetan Plateau. Comparisons based on the 16S rRNA gene sequences showed that both strains LQ15W^T and AIY15W^T share 16S rRNA gene sequence similarities 98.4 % with Aquiflexum aquatile Z0201^T, but only about 95.0 % with Aquiflexum balticum DSM 16537^T. The 16S rRNA gene sequence similarity between strains LQ15W^T and AIY15W^T was 98.9 %. The phylogenetic tree reconstructed based on 16S rRNA gene sequences also showed that strains LQ15W^T and AIY15W^T take A. aquatile Z0201^T as their closest neighbour and these three strains form a tight cluster. In the phylogenomic tree, the genus Aquiflexum was splited into two clusters by Mariniradius saccharolyticus. Strains LQ15W^T, AIY15W^T and A. aquatile Z0201^T still formed a close cluster, and A. balticum DSM 16537^T and Aquiflexum lacus CUG 91378^T formed another cluster. The calculated OrthoANIu, average amino acid identity and digital DNA-DNA hybridization values among strains LQ15W^T, AIY15W^T, A. aquatile Z0201^T, A. balticum DSM 16537^T and A. lacus CUG 91378^T were less than 91.0, 92.9 and 42.1 %, respectively. The major respiratory quinones of both strains LQ15W^T and AIY15W^T were MK-7 (32 %) and MK-8 (68 %), and their major fatty acids were iso-C_15 : 0, C_18 : 1  ω9c, summed feature 3 and summed feature 9. The predominant polar lipids of both strains were phosphatidylethanolamine, unidentified aminophospholipids, unidentified phospholipids and lipids. Strain AIY15W^T also contained phosphatidylglycerol and unidentified glycolipid. Considering the distinct phylogenetic relationships and chemotaxonomic characteristics between strains A. aquatile Z0201^T and A. balticum DSM 16537^T, it is proposed to reclassify A. aquatile into a novel genus Cognataquiflexum gen. nov. as Cognataquiflexum aquatile comb. nov., and strains LQ15W^T and AIY15W^T should represent two independent novel species of the genus Cognataquiflexum, for which the names Cognataquiflexum nitidum sp. nov. (type strain: LQ15W^T=CICC 24711^T=JCM 34222^T) and Cognataquiflexum rubidum sp. nov. (type strain: AIY15W^T=CICC 24708^T=JCM 34612^T) are proposed.

Blockade of the immunosuppressive KIR2DL5/PVR pathway elicits potent human NK cell-mediated antitumor immunity

Cancer immunotherapy targeting the TIGIT/PVR pathway is currently facing challenges. KIR2DL5, a member of the human killer cell, immunoglobulin-like receptor (KIR) family, has recently been identified as another binding partner for PVR. The biology and therapeutic potential of the KIR2DL5/PVR pathway are largely unknown. Here we report that KIR2DL5 was predominantly expressed on human NK cells with mature phenotype and cytolytic function and that it bound to PVR without competition with the other 3 known PVR receptors. The interaction between KIR2DL5 on NK cells and PVR on target cells induced inhibitory synapse formation, whereas new monoclonal antibodies blocking the KIR2DL5-PVR interaction robustly augmented the NK cytotoxicity against PVR+ human tumors. Mechanistically, both intracellular ITIM and ITSM of KIR2DL5 underwent tyrosine phosphorylation after engagement, which was essential for KIR2DL5-mediated NK suppression by recruiting SHP-1 and/or SHP-2. Subsequently, ITIM/SHP-1/SHP-2 and ITSM/SHP-1 downregulated the downstream Vav1/ERK1/2/p90RSK/NF-κB signaling. KIR2DL5+ immune cells infiltrated in various types of PVR+ human cancers. Markedly, the KIR2DL5 blockade reduced tumor growth and improved overall survival across multiple NK cell-based humanized tumor models. Thus, our results revealed functional mechanisms of KIR2DL5-mediated NK cell immune evasion, demonstrated blockade of the KIR2DL5/PVR axis as a therapy for human cancers, and provided an underlying mechanism for the clinical failure of anti-TIGIT therapies.

Disentangling the assembly mechanisms of bacterial communities in a transition zone between the alpine steppe and alpine meadow ecosystems on the Tibetan Plateau

Alpine meadows and alpine steppes are two major grassland types distributed on the Tibetan Plateau. Due in large part to the differences in hydrothermal and nutrient conditions following the thawing of lakeshore permafrost, alpine meadows and alpine steppes which are characterized by disparate above- and below-ground biomass, could emerge together in the grassland transition zone between meadows and steppes of the Tibetan Plateau. Bacterial communities are essential components of alpine grassland ecosystems and respond rapidly to environmental changes. Despite their ecological significance, it remains poorly elucidated whether and how the assembly patterns of bacterial communities differed between alpine meadows and alpine steppes. Here, to disentangle the assembly mechanisms of bacterial communities from alpine meadows and alpine steppes, we collected samples from three diverse habitats (i.e., sediments, rhizosphere soils and bulk soils) in both alpine meadow and steppe ecosystems on the Tibetan Plateau. Our results indicated that in both meadows and steppes, rhizosphere bacterial communities exhibited higher alpha-diversity but lower beta-diversity compared to the bacterial communities in sediments and bulk soils. However, the close relationships of bacterial communities between different habitats weakened from meadows to steppes. Null model analysis indicated that the importance of environmental selection shaping bacterial community assemblages in all habitats decreased from meadows to steppes, whereas the role of dispersal limitation showed an opposite pattern. Moreover, pH was the primary driver of phylogenetic turnover of bacterial communities in the steppes across all habitats, whereas the dominant drivers of phylogenetic turnover of bacterial communities in meadows varied with habitat types. Overall, our findings provide novel insights into understanding the differences in microbial communities between meadows and steppes in the grassland transition zone on the Tibetan Plateau.

Circulating tumor DNA integrating tissue clonality detects minimal residual disease in resectable non-small-cell lung cancer

BACKGROUND

Circulating tumor DNA (ctDNA) has been proven as a marker for detecting minimal residual diseases following systemic therapies in mid-to-late-stage non-small-cell lung cancers (NSCLCs) by multiple studies. However, fewer studies cast light on ctDNA-based MRD monitoring in early-to-mid-stage NSCLCs that received surgical resection as the standard of care.

METHODS

We prospectively recruited 128 patients with stage I-III NSCLCs who received curative surgical resections in our Lung Cancer Tempo-spatial Heterogeneity prospective cohort. Plasma samples were collected before the surgery, 7 days after the surgery, and every 3 months thereafter. Targeted sequencing was performed on a total of 628 plasma samples and 645 matched tumor samples using a panel covering 425 cancer-associated genes. Tissue clonal phylogeny of each patient was reconstructed and used to guide ctDNA detection.

RESULTS

The results demonstrated that ctDNA was more frequently detected in patients with higher stage diseases pre- and postsurgery. Positive ctDNA detection at as early as 7 days postsurgery identified high-risk patients with recurrence (HR = 3.90, P < 0.001). Our results also show that longitudinal ctDNA monitoring of at least two postsurgical time points indicated a significantly higher risk (HR = 7.59, P < 0.001), preceding radiographic relapse in 73.5% of patients by a median of 145 days. Further, clonal ctDNA mutations indicated a high-level specificity, and subclonal mutations informed the origin of tumor recurrence.

CONCLUSIONS

Longitudinal ctDNA surveillance integrating clonality information may stratify high-risk patients with disease recurrence and infer the evolutionary origin of ctDNA mutations.

ZNF33A Promotes Tumor Progression and BET Inhibitor Resistance in Triple-Negative Breast Cancer

Overexpression of ZNF33A (Krüppel-type zinc finger 33A) promotes carcinogenesis in several malignant tumors. However, the biochemical role and clinical importance of ZNF33A in triple-negative breast cancer (TNBC) still need to be explored. In this study, overexpression of ZNF33A in TNBC patient tissues and cell lines led to a worse prognosis. ZNF33A promoted cell growth and facilitated the resistance of cancer cells to inhibitors of bromodomain and extraterminal domain (BET) in TNBC. ZNF33A also promoted the induction of c-Myc, the primary player for the resistance to BET inhibitors in TNBC. In conclusion, ZNF33A may be a tumor growth-promoting factor associated with TNBC prognosis, and ZNF33A repression may sensitize TNBC cells to BET inhibitors.