Pharmacological inhibition of BAP1 recruits HERC2 to competitively dissociate BRCA1-BARD1, suppresses DNA repair and sensitizes CRC to radiotherapy.

Radiotherapy is widely used in the management of advanced colorectal cancer (CRC). However, the clinical efficacy is limited by the safe irradiated dose. Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation. The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination (HR) DSB repair, and its functions may be affected by HERC2 or BAP1. Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes; however, the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn't been defined. Through activity-based profiling, we identified PT33 as an active entity for HR repair suppression. Subsequently, we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen. Mechanistically, pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction, interrupting HR repair. Consequently, PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo. Overall, these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.

Caged Luciferase Inhibitor-Based Bioluminescence Switching Strategy Enables Efficient Detection of Serum APN Activity and the Identification of Its Roles in Metastasis of Non-Small Cell Lung Cancer.

Bioluminogenic probes emerged as powerful tools for imaging and analysis of various bioanalyses, but traditional approaches would be limited to the low sensitivity during determine the low activity of protease in clinical specimens. Herein, we proposed a caged luciferase inhibitor-based bioluminescence-switching strategy (CLIBS) by using a cleavable luciferase inhibitor to modulate the activity of luciferase reporter to amplify the detective signals, which led to the enhancement of detection sensitivity, and enabled the determination of circulating Aminopeptidase N (APN) activity in thousands of times diluted serum. By applying the CLIBS to serum samples in non-small cell lung cancer (NSCLC) patients from two clinical cohorts, we revealed that, for the first time, higher circulating APN activities but not its concentration, were associated with more NSCLC metastasis or higher metastasis stages by subsequent clinical analysis, and can serve as an independent factor for forecasting NSCLC patients' risk of metastasis.

A rice-chicory rotation pattern ensures safe grain production and phytoremediation of cadmium-contaminated paddy fields: A four-year field experiment in southern China.

Cadmium (Cd) contamination in paddy systems is a serious problem, and a strategy must be devised that ensures safe grain production and rapid remediation of soil Cd contamination. To investigate the remediation potential of crop rotation and its effect on Cd accumulation in rice, a four-year (seven-season) rice-chicory rotation field trial was conducted on a moderately acidic Cd-contaminated paddy soil. Rice was planted in summers, followed by straw removal, and chicory, a Cd-enrichment plant, was planted during winter fallows. Rotation effects were compared with those with rice only (control). Rice yields between the rotation and control were not significantly different, whereas Cd concentrations in rice tissues decreased in the rotation. Cd concentration in brown rice of the low-Cd variety decreased to less than 0.2 mg/kg (national food safety standard) from the third season onward, whereas in the high-Cd variety, it decreased from 0.43 mg/kg in the first season to 0.24 mg/kg in the fourth season. The highest Cd concentration in chicory aboveground parts was 24.47 mg/kg, with an enrichment factor of 27.81. Chicory had high regenerative capacity and was repeatedly harvested for biomass in multiple mowings, with average aboveground biomass over 2000 kg/ha in a single mowing. Theoretical phytoextraction efficiency (TPE) of one rice season with straw removal was 0.84%-2.44%, whereas the highest TPE of one chicory season reached 8.07%. The seven seasons of rice-chicory rotation extracted up to 407 g/ha Cd from soil with a TPE exceeding 20%. Therefore, rice-chicory rotation and straw removal can effectively reduce Cd accumulation in subsequent rice crops, without interrupting production and simultaneously rapidly remediating Cd-contaminated soil. Thus, the production potential of light to moderately Cd-contaminated paddy fields can be realized with crop rotation.

NONO regulates multiple cytokine production in sepsis via the ERK1/2 signaling pathway.

The massive release of pro-inflammatory cytokines is a crucial step in triggering the inflammatory cascade in sepsis. Exploring the key molecules regulating the expression and release of multiple cytokines has important value for revealing the mechanism of the cytokine storm in sepsis. This study aimed to investigate the role of multifunctional nuclear protein non-POU domain containing octamer-binding protein (NONO) in the sepsis cytokine storm and to elucidate the underlying mechanism. We found that NONO expression in tissues and cells of sepsis mice was significantly upregulated. Downregulation of NONO expression inhibited the mRNA expression of multiple cytokines, including IL-6, IL-1ß, MCP-1, MIP-1α, and MIP-1ß in inflammatory cells from mice and human leukemic monocyte-THP1 cells challenged with lipopolysaccharide (LPS), and significantly decreased the level of these cytokines and TNF-α in the supernatant of THP1 cells challenged by LPS. Nono knockout also reduced the levels of TNF-α, IL-6, MIP-1α, and MIP-1ß in serum, alleviated hepatocyte edema, and improved the survival rate of sepsis mice. Reduced NONO expression decreased the phospho-ERK1/2 level in inflammatory cells from sepsis mice or THP1 cells challenged by LPS. Phospho-ERK1/2 inhibitor decreased the mRNA expression and concentration of cytokines in the culture supernatant of LPS-induced THP1 cells, similar to the effect of NONO knockdown. After LPS challenge, the levels of phospho-ERK1/2 and NONO were increased, with obvious colocalization in the nucleus and vesicular-like organelles in macrophages. NONO knockdown decreased nuclear translocation of phospho-ERK1/2 in LPS-challenged THP1 cells. These results suggest that NONO is a potentially critical molecule involved in multiple cytokine production in sepsis. Upregulated NONO in sepsis may promote the expression and release of multiple cytokines to participate in a sepsis cytokine storm by promoting ERK1/2 phosphorylation.

Blockade of USP14 potentiates type I interferon signaling and radiation-induced antitumor immunity via preventing IRF3 deubiquitination.

PURPOSE: The adaptive immune responses induced by radiotherapy has been demonstrated to largely rely on STING-dependent type I interferons (IFNs) production. However, irradiated tumor cells often fail to induce dendritic cells (DCs) to produce type I IFNs. Hence, we aim to uncover the limitation of STING-mediated innate immune sensing following radiation, and identify efficient reagents capable to rescue the failure of type I IFNs induction for facilitating radiotherapy. METHODS: A targeted cell-based phenotypic screening was performed to search for active molecules that could elevate the production of type I IFNs. USP14 knockout or inhibition was assayed for IFN production and the activation of STING signaling in vitro. The mechanisms of USP14 were investigated by western blot and co-immunoprecipitation in vitro. Additionally, combinational treatments with PT33 and radiation in vivo and in vitro models were performed to evaluate type I IFNs responses to radiation. RESULTS: PT33 was identified as an enhancer of STING agonist elicited type I IFNs production to generate an elevated and durable STING activation profile in vitro. Mechanistically, USP14 inhibition or deletion impairs the deubiquitylation of K63-linked IRF3. Furthermore, blockade of USP14 with PT33 enhances DC sensing of irradiated-tumor cells in vitro, and synergizes with radiation to promote systemic antitumor immunity in vivo. CONCLUSION: Our findings reveal that USP14 is one of the major IFN production suppressors and impairs the activation of IRF3 by removing the K63-linked ubiquitination of IRF3. Therefore, blockage of USP14 results in the gain of STING signaling activation and radiation-induced adaptive immune responses.

Stabilization of DEPTOR sensitizes hypopharyngeal cancer to radiotherapy via targeting degradation.

The use of radiotherapy for hypopharyngeal cancer (HC) treatment is increasing, and it is currently the primary treatment option for this cancer. However, radioresistance occurs in a proportion of patients. Here, we found that radiation increased proteasomal gene expression and that proteasome assembly was dependent on the induction of transcription factor NRF1 in HC. Through screening assays, we identified a mechanism by which proteasome-mediated degradation of DEP domain-containing mTOR-interacting protein (DEPTOR) contributes to the elevation of mTORC1 signaling after radiation. Therefore, after treatment with proteasome inhibitors (PIs), stabilization of DEPTOR inhibited mTORC1 signaling elevated by radiation and ultimately sensitized HC to radiotherapy. Mechanically, PIs not only interrupted the deubiquitination and degradation of DEPTOR but also suppressed the ubiquitination of DEPTOR mediated by ß-TrCP. Clinically, the high levels of DEPTOR in HC cells were associated with sensitivity to radiotherapy and favorable prognosis. Stabilizing DEPTOR through targeting proteasome-mediated degradation is a potential strategy for sensitizing HC to radiotherapy.

Nicotiana tabacum as a dead-end trap for adult Diaphorina citri: A potential biological tactic for protecting citrus orchards.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a key vector of the causal agents of Huanglongbing (HLB), a devastating disease affecting citrus almost worldwide. Nicotiana tabacum L. is an important commercial crop in China. Field observations suggested that D. citri adults die on N. tabacum leaves when grown nearby citrus orchards. In this study, the preference for and survivorship of D. citri adults on N. tabacum and their feeding behavior were investigated. The results showed that D. citri adults were attracted to N. tabacum and to the green leaf volatiles (GLVs) (Z)-3-hexenol and (E)-2-hexenol. The survival of D. citri adults on N. tabacum was less than 30 h, which was shorter than that for adults without food (35 h) and on a suitable host Murraya exotica L. (29 days). Electrical penetration graph (EPG) recordings revealed that the pathway phase of D. citri on N. tabacum leaves consisted of four waveforms-the non-probing phase (NP), the pathway phase (PP, including intercellular probing of activity in the phloem (C) and phloem penetration (D)), phloem salivation (E1), and phloem ingestion (E2). Diaphorina citri only secreted saliva and ingested sap from phloem on N. tabacum leaves and spent the longest duration in phloem sap ingestion (E2). Moreover, L-nicotine, an important defense compound against insects in N. tabacum plants, was highly toxic to D. citri. These results suggested that N. tabacum plants could help to sustainably control the spread of D. citri and HLB when growing in and around citrus orchards.

Design and Discovery of Natural Cyclopeptide Skeleton Based Programmed Death Ligand 1 Inhibitor as Immune Modulator for Cancer Therapy.

Blockade of immune checkpoint PD-1/PD-L1 facilitates the rescue of immune escapes of tumor cells. Though various monoclonal antibodies have been approved for clinical therapy, the development of small molecular inhibitors lags behind antibodies partially owing to the challenges of protein-protein interaction (PPI) blocker design. In this work, we adopted the skeleton of natural cyclopeptidic antibiotics gramicidin S as the start point for PD-1/PD-L1 inhibitor exploring and discovered a series of novel cyclopeptides that could interfere with the PPI of PD-1/PD-L1 based on several rounds of structural design and optimization. The representative active cyclopeptide 66 can bind two PD-L1 and efficiently block the PD-1/PD-L1 interaction, recruit the immune cells to the tumor cells, enhance their killing against tumor cells by promoting the release of granzyme B and perforin, and display significant CD8+ T cell-dependent tumor suppression activity in vivo.

Glioblastoma precision therapy: From the bench to the clinic.

Glioblastoma (GBM) is the most common malignancy of the central nervous system, and most patients with GBM die of the disease despite standard treatment. By clarifying the molecular abnormalities that drive the malignant phenotype of GBM, various drugs that specifically target tumor cells and the tumor microenvironment have been developed. These drugs, including drugs targeting growth factor receptors and their downstream signaling pathways, angiogenesis, aberrant metabolism, epigenetic deregulation, and aberrant immune microenvironments, have been investigated in preclinical or clinical trials. However, these drugs that significantly inhibited the growth of GBM in the preclinical stage have not produced survival benefits in patients with GBM. One reason for their failure is the lack of a definite driver gene to select patients most likely to benefit. Another reason is the inadequate pharmacokinetic properties of the drugs owing of the blood-brain barrier. In the present review, we discuss progress in the development of target therapeutic strategies. Furthermore, we discuss the development of nanomaterials that act as local drug delivery systems to penetrate the blood-brain barrier for managing GBM.

Double Rolling Circle Amplification Generates Physically Cross-Linked DNA Network for Stem Cell Fishing.

Stem cells have been widely studied in cell biology and utilized in cell-based therapies, and fishing stem cells from marrow is highly challenging due to the ultralow content. Herein, a physically cross-linked DNA network-based cell fishing strategy is reported, achieving efficient capture, 3D envelop, and enzyme-triggered release of bone marrow mesenchymal stem cells (BMSCs). DNA network is constructed via a double rolling circle amplification method and through the intertwining and self-assembly of two strands of ultralong DNA chains. DNA-chain-1 containing aptamer sequences ensures specific anchor with BMSCs from marrow. Hybridization between DNA-chain-1 and DNA-chain-2 enables the cross-link of cell-anchored DNA chains to form a 3D network, thus realizing cell envelop and separation. DNA network creates a favorable microenvironment for 3D cell culture, and remarkably the physically cross-linked DNA network shows no damage to cells. DNA network is digested by nuclease, realizing the deconstruction from DNA network to fragments, and achieving enzyme-triggered cell release; after release, the activity of cells is well maintained. The strategy provides a powerful and effective method for fishing stem cells from tens of thousands of nontarget cells.

Enhanced immobilization of arsenic and cadmium in a paddy soil by combined applications of woody peat and Fe(NO3)3: Possible mechanisms and environmental implications.

Organic matter (OM) plays an important role in the mobility of heavy metal(loid)s. Peat containing abundant OM can be used as an organic fertilizer improving physical and chemical properties of soil. Previous studies indicated that the immobilization of heavy metal(loid)s by peat is affected by the presence of metal oxides and/or hydroxides and that Fe-enriched peat is very effective in immobilizing metal(loid)s. Accordingly, we hypothesize that simultaneous application of peat and Fe-containing compounds may pronouncedly immobilize heavy metal(loid)s. In this study, the effects of the combined applications of woody peat and Fe(NO3)3 on As and Cd mobilities and accumulations in rice during the whole growth period were investigated by a pot experiment. The combined applications of woody peat and Fe(NO3)3 significantly decreased As(III) and Cd in porewater due to pH increases induced by applications of Fe(NO3)3, and these decreases were enhanced with increasing Fe(NO3)3. In addition, simultaneous application of peat and Fe(NO3)3 significantly decreased mobile portions of As and Cd but significantly increased their immobile portions. Increasing Fe(NO3)3 increased the amount of As immobilized by poorly crystalline Fe oxides. The formation of Fe plaques and production of poorly crystalline Fe oxides were enhanced by Fe(NO3)3 addition, which also contributed to the immobilization of As and Cd in soil. Overall, the combined applications of woody peat and Fe(NO3)3 provided a strategy for simultaneously immobilizing As and Cd in soils and further alleviating their accumulations from soil to rice plants. In paddy soil, the frequent occurrence of iron redox activity due to the alternating wetting and drying cycles provided favorable conditions for interactions between Fe and OM, and this process and its associated metal(loid) immobilization may be more important than we thought and need further study.

The diversity and abundance of As(III) oxidizers on root iron plaque is critical for arsenic bioavailability to rice.

Iron plaque is a strong adsorbent on rice roots, acting as a barrier to prevent metal uptake by rice. However, the role of root iron plaque microbes in governing metal redox cycling and metal bioavailability is unknown. In this study, the microbial community structure on the iron plaque of rice roots from an arsenic-contaminated paddy soil was explored using high-throughput next-generation sequencing. The microbial composition and diversity of the root iron plaque were significantly different from those of the bulk and rhizosphere soils. Using the aoxB gene as an identifying marker, we determined that the arsenite-oxidizing microbiota on the iron plaque was dominated by Acidovorax and Hydrogenophaga-affiliated bacteria. More importantly, the abundance of arsenite-oxidizing bacteria (AsOB) on the root iron plaque was significantly negatively correlated with the arsenic concentration in the rice root, straw and grain, indicating that the microbes on the iron plaque, particularly the AsOB, were actively catalyzing arsenic transformation and greatly influencing metal uptake by rice. This exploratory research represents a preliminary examination of the microbial community structure of the root iron plaque formed under arsenic pollution and emphasizes the importance of the root iron plaque environment in arsenic biogeochemical cycling compared with the soil-rhizosphere biotope.

Anaerobic transformation of DDT related to iron(III) reduction and microbial community structure in paddy soils.

We studied the mechanisms of microbial transformation in functional bacteria on 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in two different field soils, Haiyan (HY) and Chenghai (CH). The results showed that microbial activities had a steady dechlorination effect on DDT and its metabolites (DDx). Adding lactate or glucose as carbon sources increased the amount of Desulfuromonas, Sedimentibacter, and Clostridium bacteria, which led to an increase in adsorbed Fe(II) and resulted in increased DDT transformation rates. The electron shuttle of anthraquinone-2,6-disulfonic disodium salt resulted in an increase in the negative potential of soil by mediating the electron transfer from the bacteria to the DDT. Moreover, the DDT-degrading bacteria in the CH soil were more abundant than those in the HY soil, which led to higher DDT transformation rates in the CH soil. The most stable compound of DDx was 1,1-dichloro-2,2-bis(p-chloro-phenyl)ethane, which also was the major dechlorination metabolite of DDT, and 1-chloro-2,2-bis-(p-chlorophenyl)ethane and 4,4'-dichlorobenzo-phenone were found to be the terminal metabolites in the anaerobic soils.