Proteomic analysis of toxic effects of short-term cadmium exposure on goat livers.

Food safety is closely related to environmental pollution. It is worth noting that the long-term accumulation of Cd, a toxic heavy metal, in animals may pose a threat to human health through food chain. Previous studies have found that Cd exposure may cause liver metabolic disorders of black goats, but the mechanism of its impact on liver proteome of goats has not been widely studied. Therefore, in this study, ten male goats (Nubian black goat × native black goat) were exposed to Cd via drinking water containing CdCl2 (20 mg Cd·kg - 1·BW) for 30 days (five male goats per group). Blood physiology and liver antioxidant indices in black goats were determined and differentially expressed proteins (DEPs) in the livers of Cd-exposed goats were profiled by using TMT-labelled proteomics. It was found that plasma Hb and RBC levels as well as PCV values were decreased, liver SOD, GSH-Px, T-AOC and CAT levels were decreased, and MDA level was increased in Cd-treated goats, and 630 DEPs (up 326, down 304) in the livers of Cd-treated goats. Proteomics analysis revealed that Cd exposure affected glutathione metabolism and drug metabolism-cytochrome P450. We identified GP×2, GSTM3, and TBXAS1 as potential protein markers of early Cd toxicity in goats. This study provided theoretical basis for early diagnosis of Cd poisoning in goats.

A Mechanical Immune Checkpoint Inhibitor Stiffens Tumor Cells to Potentiate Antitumor Immunity.

Tumor progression is associated with tumor-cell softening. Improving the stiffness of the tumor cells can make them more vulnerable to lymphocyte-mediated attack. Tumor cell membranes typically exhibit higher cholesterol levels than normal cells, making tumor cells soft. Herein, we demonstrate a mechanical immune checkpoint inhibitor (MICI) formulated by cyclodextrin (CD) lipids and fusogenic lipids. Through fusing CD lipids into the tumor cell membrane using a fusogenic liposome formulation, the cholesterol in the plasma membrane is reduced due to the specific host-guest interactions between CD lipid and cholesterol. As a result, tumor cells are stiffened, and the activation of lymphocytes (including NK and cytotoxic effector T cells) is improved when contacting the stiffened tumor cells, characterized by robust degranulation and effector cytokine production. Notably, this treatment has negligible influence on the infiltration and proliferation of lymphocytes in tumor tissues, confirming that the enhanced antitumor efficacy should result from activating a specific number of lymphocytes caused by direct regulation of the tumor cell stiffness. The combination of MICIs and clinical immunotherapies enhances the lymphocyte-mediated antitumor effects in two tumor mouse models, including breast cancer and melanoma. Our research also reveals an unappreciated mechanical dimension to lymphocyte activation.

Genomic Amplification of TBC1D31 Promotes Hepatocellular Carcinoma Through Reducing the Rab22A-Mediated Endolysosomal Trafficking and Degradation of EGFR.

Hepatocellular carcinomas (HCCs) are characterized by a vast spectrum of somatic copy number alterations (CNAs); however, their functional relevance is largely unknown. By performing a genome-wide survey on prognosis-associated focal CNAs in 814 HCC patients by an integrative computational framework based on transcriptomic data, genomic amplification is identified at 8q24.13 as a promising candidate. Further evidence is provided that the 8q24.13 amplification-driven overexpression of Rab GTPase activating protein TBC1D31 exacerbates HCC growth and metastasis both in vitro and in vivo through activating Epidermal growth factor receptor (EGFR) signaling. Mechanistically, TBC1D31 acts as a Rab GTPase activating protein to catalyze GTP hydrolysis for Rab22A and then reduces the Rab22A-mediated endolysosomal trafficking and degradation of EGFR. Notably, overexpression of TBC1D31 markedly increases the resistance of HCC cells to lenvatinib, whereas inhibition of the TBC1D31-EGFR axis can reverse this resistance phenotype. This study highlights that TBC1D31 at 8q24.13 is a new critical oncogene, uncovers a novel mechanism of EGFR activation in HCC, and proposes the potential strategies for treating HCC patients with TBC1D31 amplification or overexpression.

A novel risk scoring system predicts overall survival of hepatocellular carcinoma using cox proportional hazards machine learning method.

BACKGROUND: Robust and practical prognosis prediction models for hepatocellular carcinoma (HCC) patients play crucial roles in personalized precision medicine. MATERIAL AND METHODS: We recruited two independent HCC cohorts (discovery cohort and validation cohort), totally consisting of 222 HCC patients undergone surgical resection. We quantified the expressions of immune-related proteins (CD8, CD68, CD163, PD-1 and PD-L1) in paired HCC tissues and non-tumor liver tissues from these HCC patients using immunohistochemistry (mIHC) assays. We constructed the HCC prognosis prediction model using five different machine learning methods based on the patients in the discovery cohort, such as Cox proportional hazards (CoxPH). RESULTS: We identified 19 features that were associated with overall survival of HCC patients in the discovery cohort (p < 0.1), such as immune-related features CD68+ and CD8+ cell infiltration. We constructed five HCC prognosis prediction models using five different machine learning methods. Among the five different machine learning models, the CoxPH model achieved the best performance (area under the curve [AUC], 0.839; C-index, 0.779). According to the risk score from CoxPH model, we divided HCC patients into high-risk group/low-risk group. In both discovery cohort and validation cohort, the patients in low-risk group showed longer overall survival compared with those in high-risk group (p = 1.8 × 10-7 and 3.4 × 10-5, respectively). Moreover, our novel scoring system efficiently predicted the 6, 12, and 18 months survival rate of HCC patients with AUC >0.75 in both discovery cohort and validation cohort. In addition, we found that the scoring system could also distinguish the patients with high/low risks of relapse in both discovery cohort and validation cohort (p = 0.00015 and 0.00012). CONCLUSION: The novel CoxPH-based risk scoring model on clinical, laboratory-testing and immune-related features showed high prediction efficiencies for overall survival and recurrence of HCCs undergone surgical resection. Our results may be helpful to optimize clinical follow-up or therapeutic interventions.

NRDE2 deficiency impairs homologous recombination repair and sensitizes hepatocellular carcinoma to PARP inhibitors.

To identify novel susceptibility genes for hepatocellular carcinoma (HCC), we performed a rare-variant association study in Chinese populations consisting of 2,750 cases and 4,153 controls. We identified four HCC-associated genes, including NRDE2, RANBP17, RTEL1, and STEAP3. Using NRDE2 (index rs199890497 [p.N377I], p = 1.19 × 10-9) as an exemplary candidate, we demonstrated that it promotes homologous recombination (HR) repair and suppresses HCC. Mechanistically, NRDE2 binds to the subunits of casein kinase 2 (CK2) and facilitates the assembly and activity of the CK2 holoenzyme. This NRDE2-mediated enhancement of CK2 activity increases the phosphorylation of MDC1 and then facilitates the HR repair. These functions are eliminated almost completely by the NRDE2-p.N377I variant, which sensitizes the HCC cells to poly(ADP-ribose) polymerase (PARP) inhibitors, especially when combined with chemotherapy. Collectively, our findings highlight the relevance of the rare variants to genetic susceptibility to HCC, which would be helpful for the precise treatment of this malignancy.

MARCH5 promotes aerobic glycolysis to facilitate ovarian cancer progression via ubiquitinating MPC1.

MARCH5 is a ring-finger E3 ubiquitin ligase located in the outer membrane of mitochondria. A previous study has reported that MARCH5 was up-regulated and contributed to the migration and invasion of OC cells by serving as a competing endogenous RNA. However, as a mitochondrial localized E3 ubiquitin ligase, the function of MARCH5 in mitochondrial-associated metabolism reprogramming in human cancers remains largely unexplored, including OC. We first assessed the glycolysis effect of MARCH5 in OC both in vitro and in vivo. Then we analyzed the effect of MARCH5 knockdown or overexpression on respiratory activity by evaluating oxygen consumption rate, activities of OXPHOS complexes and production of ATP in OC cells with MARCH5. Co-immunoprecipitation, western-blot, and in vitro and vivo experiments were performed to investigate the molecular mechanisms underlying MARCH5-enhanced aerobic glycolysis s in OC. In this study, we demonstrate that the abnormal upregulation of MARCH5 is accompanied by significantly increased aerobic glycolysis in OC. Mechanistically, MARCH5 promotes aerobic glycolysis via ubiquitinating and degrading mitochondrial pyruvate carrier 1 (MPC1), which mediates the transport of cytosolic pyruvate into mitochondria by localizing on mitochondria outer membrane. In line with this, MPC1 expression is significantly decreased and its downregulation is closely correlated with unfavorable survival. Furthermore, in vitro and in vivo assays revealed that MARCH5 upregulation-enhanced aerobic glycolysis played a critical role in the proliferation and metastasis of OC cells. Taken together, we identify a MARCH5-regulated aerobic glycolysis mechanism by degradation of MPC1, and provide a rationale for therapeutic targeting of aerobic glycolysis via MARCH5-MPC1 axis inhibition.

Glycyrrhiza Extract and Curcumin Alleviates the Toxicity of Cadmium via Improving the Antioxidant and Immune Functions of Black Goats.

To investigate the mitigative effects of glycyrrhiza extract (GE) and curcumin (CUR) on the antioxidant and immune functions of the Guizhou black goat exposed to cadmium (Cd), 50 healthy Guizhou black goats (11.08 ± 0.22 kg, male, six months old) were used in a 60-day trial and were randomly assigned to five groups with 10 replicates per group, one goat per replicate. All goats were fed a basal diet, with drinking water and additives varying slightly between groups. Control group: tap water (0.56 µg·L-1 Cd); Cd group: drinking water containing Cd (20 mg Cd·kg-1·body weight, CdCl2·2.5H2O); GE group: drinking water containing Cd, at days 31 to 60, the basic diet had added 500 mg·kg-1 GE; CUR group: drinking water containing Cd, at days 31 to 60, the basic diet had added 500 mg·kg-1 CUR; combined group: drinking water containing Cd, at days 31 to 60, the basic diet had added 500 mg·kg-1 GE and CUR. Compared with the Cd group, GE and CUR significantly increased the levels of hemoglobin and red blood cell count in the blood, and the activities of serum antioxidant enzyme activity and immune function in the Guizhou black goat (p < 0.05). The treatment effect in the combined group was better than that in the GE and CUR groups. The results showed that GE and CUR improved the antioxidant and immune functions of the serum and livers of the Guizhou black goat and alleviated the toxicity damage of Cd contamination. This research has positive implications for both livestock management and human health.

Metal-Phenolic Network with Pd Nanoparticle Nodes Synergizes Oxidase-Like and Photothermal Properties to Eradicate Oral Polymicrobial Biofilm-Associated Infections.

Designing an effective treatment strategy to combat oral diseases caused by complex polymicrobial biofilms remains a great challenge. Herein, a series of metal-phenolic network with Pd nanoparticle nodes using polyphenols as stabilizers and reducing agents is constructed. Among them, sulfonated lignin-Pd (SLS-Pd) with ultrafine size palladium nanoparticles and broadband near infrared absorption exhibit excellent oxidase-like activity and stable photothermal effect. In vitro experiments demonstrate that the superoxide radical generated by SLS-Pd oxidase-like activity exhibits selective antibacterial effects, while its photothermal effect induced hyperthermia exhibits potent antifungal properties. This difference is further elucidated by RNA-sequencing analysis and all-atom simulation. Moreover, the SLS-Pd-mediated synergistic antimicrobial system exhibits remarkable efficacy in combating various biofilms and polymicrobial biofilms. By establishing a root canal model and an oropharyngeal candidiasis model, the feasibility of the synergistic antimicrobial system in treating oral biofilm-related infections is further validated. This system provides a promising therapeutic approach for polymicrobial biofilm-associated infections in the oral cavity.

A single site ruthenium catalyst for robust soot oxidation without platinum or palladium.

The quest for efficient non-Pt/Pd catalysts has proved to be a formidable challenge for auto-exhaust purification. Herein, we present an approach to construct a robust catalyst by embedding single-atom Ru sites onto the surface of CeO2 through a gas bubbling-assisted membrane deposition method. The formed single-atom Ru sites, which occupy surface lattice sites of CeO2, can improve activation efficiency for NO and O2. Remarkably, the Ru1/CeO2 catalyst exhibits exceptional catalytic performance and stability during auto-exhaust carbon particle oxidation (soot), rivaling commercial Pt-based catalysts. The turnover frequency (0.218 h-1) is a nine-fold increase relative to the Ru nanoparticle catalyst. We further show that the strong interfacial charge transfer within the atomically dispersed Ru active site greatly enhances the rate-determining step of NO oxidation, resulting in a substantial reduction of the apparent activation energy during soot oxidation. The single-atom Ru catalyst represents a step toward reducing dependence on Pt/Pd-based catalysts.

CDK4/6i enhances the antitumor effect of PD1 antibody by promoting TLS formation in ovarian cancer.

Ovarian cancer is insensitive to immunotherapy and has a high mortality rate. CDK4/6 inhibitors (CDK4/6i) regulate the tumor microenvironment and play an antitumor role. Our previous research demonstrated that lymphocyte aggregation (tertiary lymphoid structures, TLSs) was observed after CDK4/6i treatment. This may explain the synergistic action of CDK4/6i with the anti-PD1 antibody. However, the key mechanism by which CDK4/6i promotes TLS formation has not been elucidated. We examine the link between TLS and prognosis. Animal models and high-throughput sequencing were used to explore the potential mechanism by which CDK4/6i promotes TLS formation. Our results showed the presence of TLSs was associated with a favorable prognosis for ovarian cancer. CDK4/6i promoted TLS formation and enhanced the immunotherapeutic effect of the anti-PD1 antibody. The potential mechanism of CDK4/6i affecting the formation of TLS may be through modulating SCD1 and its regulatory molecules ATF3 and CCL4. Our findings provide a theoretical basis for the application of CDK4/6i in ovarian cancer.

RNA N6-methyladenosine modification-based biomarkers for absorbed ionizing radiation dose estimation.

Radiation triage and biological dosimetry are critical for the medical management of massive potentially exposed individuals following radiological accidents. Here, we performed a genome-wide screening of radiation-responding mRNAs, whose N6-methyladenosine (m6A) levels showed significant alteration after acute irradiation. The m6A levels of three genes, Ncoa4, Ate1 and Fgf22, in peripheral blood mononuclear cells (PBMCs) of mice showed excellent dose-response relationships and could serve as biomarkers of radiation exposure. Especially, the RNA m6A of Ncoa4 maintained a high level as long as 28 days after irradiation. We demonstrated its responsive specificity to radiation, conservation across the mice, monkeys and humans, and the dose-response relationship in PBMCs from cancer patients receiving radiation therapy. Finally, NOCA4 m6A-based biodosimetric models were constructed for estimating absorbed radiation doses in mice or humans. Collectively, this study demonstrated the potential feasibility of RNA m6A in radiation accidents management and clinical applications.

Cadmium Exposure Affects Serum Metabolites and Proteins in the Male Guizhou Black Goat.

Food safety and environmental pollution are the hotspots of general concern globally. Notably, long-term accumulation of trace toxic heavy metals, such as cadmium (Cd), in animals may endanger human health via the food chain. The mechanism of Cd toxicity in the goat, a popular farmed animal, has not been extensively investigated to date. Therefore, in this study, ten male goats (Nubian black goat × native black goat) were exposed to Cd via drinking water containing CdCl2 (20 mg Cd·kg-1·BW) for 30 days (five male goats per group). In this study, we used an integrated approach combining proteomics and metabolomics to profile proteins and metabolites in the serum of Cd-exposed goats. It was found that Cd exposure impacted the levels of 30 serum metabolites and 108 proteins. The combined proteomic and metabolomic analysis revealed that Cd exposure affected arginine and proline metabolism, beta-alanine metabolism, and glutathione metabolism. Further, antioxidant capacity in the serum of goats exposed to Cd was reduced. We identified CKM and spermidine as potential protein and metabolic markers, respectively, of early Cd toxicity in the goat. This study details approaches for the early diagnosis and prevention of Cd-poisoned goats.

Two-Tailed Dynamic Covalent Amphiphile Combats Bacterial Biofilms.

Drug combination provides an efficient pathway to combat drug resistance in bacteria and bacterial biofilms. However, the facile methodology to construct the drug combinations and their applications in nanocomposites is still lacking. Here the two-tailed antimicrobial amphiphiles (T2 A2 ) composed of nitric oxide (NO)-donor (diethylenetriamine NONOate, DN) and various natural aldehydes are reported. T2 A2 self-assemble into nanoparticles due to their amphiphilic nature, with remarkably low critical aggregation concentration. The representative cinnamaldehyde (Cin)-derived T2 A2 (Cin-T2 A2 ) assemblies demonstrate excellent bactericidal efficacy, notably higher than free Cin and free DN. Cin-T2 A2 assemblies kill multidrug-resistant staphylococci and eradicate their biofilms via multiple mechanisms, as proved by mechanism studies, molecular dynamics simulations, proteomics, and metabolomics. Furthermore, Cin-T2 A2 assemblies rapidly eradicate bacteria and alleviate inflammation in the subsequent murine infection models. Together, the Cin-T2 A2 assemblies may provide an efficient, non-antibiotic alternative in combating the ever-increasing threat of drug-resistant bacteria and their biofilms.

miR-424-3p promotes metastasis of hepatocellular carcinoma via targeting the SRF-STAT1/2 axis.

Although emerging evidence has established the roles of miRNAs in hepatocellular carcinoma (HCC), the global functional implication of miRNAs in this malignancy remains largely uncharacterized. Here, we aim to systematically identify novel miRNAs involved in HCC and clarify the function and mechanism of specific novel candidate miRNA(s) in this malignancy. Through an integrative omics approach, we identified ten HCC-associated functional modules and a collection of candidate miRNAs. Among them, we demonstrated that miR-424-3p, exhibiting strong associations with extracellular matrix (ECM), promotes HCC cells migration and invasion in vitro and facilitates HCC metastasis in vivo. We further demonstrated that SRF is a direct functional target of miR-424-3p, and is required for the oncogenic activity of miR-424-3p. Finally, we found that miR-424-3p reduces the interferon pathway by attenuating the transactivation of SRF on STAT1/2 and IRF9 genes, which in turn enhances the matrix metalloproteinases (MMPs)-mediated ECM remodeling. This study provides comprehensive functional relevance of miRNAs in HCC by an integrative omics analysis, and further clarifies that miR-424-3p in ECM functional module plays an oncogenic role via reducing the SRF-STAT1/2 axis in this malignancy.

Dynamic covalent nano-networks comprising antibiotics and polyphenols orchestrate bacterial drug resistance reversal and inflammation alleviation.

New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms. This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks (aDCNs) composing antibiotics bearing multiple primary amines, polyphenols, and a cross-linker acylphenylboronic acid. Mechanistically, the iminoboronate bond drives the formation of aDCNs, facilitates their stability, and renders them highly responsive to stimuli, such as low pH and high H2O2 levels. Besides, the representative A1B1C1 networks, composed of polymyxin B1(A1), 2-formylphenylboronic acid (B1), and quercetin (C1), inhibit biofilm formation of drug-resistant Escherichia coli, eliminate the mature biofilms, alleviate macrophage inflammation, and minimize the side effects of free polymyxins. Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model. The facile synthesis, excellent antimicrobial performance, and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.

Lipid Prodrug Nanoassemblies via Dynamic Covalent Boronates.

Prodrug nanoassemblies combine the advantages of prodrug and nanomedicines, offering great potential in targeting the lesion sites and specific on-demand drug release, maximizing the therapeutic performance while minimizing their side effects. However, there is still lacking a facile pathway to prepare the lipid prodrug nanoassemblies (LPNAs). Herein, we report the LPNAs via the dynamic covalent boronate between catechol and boronic acid. The resulting LPNAs possess properties like drug loading in a dynamic covalent manner, charge reversal in an acidic microenvironment, and specific drug release at an acidic and/or oxidative microenvironment. Our methodology enables the encapsulation and delivery of three model drugs: ciprofloxacin, bortezomib, and miconazole. Moreover, the LPNAs are often more efficient in eradicating pathogens or cancer cells than their free counterparts, both in vitro and in vivo. Together, our LPNAs with intriguing properties may boost the development of drug delivery and facilitate their clinical applications.

Effects of Cadmium on Liver Function and Its Metabolomics Profile in the Guizhou Black Goat.

Cadmium (Cd) is a toxic heavy metal, which will lead to ecosystem contamination, threatening the life of grazing animals. Goats are an important grazing animal biomarker to evaluate Cd toxicity, but the effect of short-term and high-concentration Cd toxicity on goat liver function and its latent mechanism is still unclear. A total of ten male Guizhou black goats were randomly divided into two groups: CON group, sterilized tap water (no CdCl2), and Cd group (20 mg Cd·kg-1·BW, CdCl2⋅2.5H2O). The test lasted for 30 days. In this study, we found that Cd poisoning in drinking water affected significantly the distribution of Cd in the goat offal and tissues, and damaged the goat's immune function of the liver. With a metabolomics approach, 59 metabolites were identified. Metabolomics analysis suggested that Cd affected lipid and amino acid metabolism of the goat liver. Collectively, our results confirmed the effect of Cd on liver function and liver metabolism, and provided insights on the molecular basis for early warnings of Cd poisoning in goats.

Synergistic Effect of Pt and Dual Ni/Co Cations in Hydrotalcite-Derived Pt/Ni1.5Co0.5AlO Catalysts for Promoting Soot Combustion.

In this article, the catalysts of hydrotalcite-derived Ni1.5Co0.5AlO nanosheet-supported highly dispersed Pt nanoparticles (Ptn/Ni1.5Co0.5AlO, where n% is the weigh percentage of the Pt element in the catalysts) were elaborately fabricated by the gas-bubble-assisted membrane--reduction method. The specific porous structure formed by the stack of hydrotalcite-derived Ni1.5Co0.5AlO nanosheets can increase the transfer mass efficiency of the reactants (O2, NO, and soot) and the strong Pt-Ni1.5Co0.5AlO interaction can weaken the Ni/Co-O bond for promoting the mobility of lattice oxygen and the formation of surface-oxygen vacancies. The Ptn/Ni1.5Co0.5AlO catalysts exhibited excellent catalytic activity and stability during diesel soot combustion under the loose contact mode between soot particles and catalysts. Among all the catalysts, the Pt2/Ni1.5Co0.5AlO catalyst showed the highest catalytic activities for soot combustion (T50 = 350 °C, TOF = 6.63 × 10-3 s-1). Based on the characterization results, the catalytic mechanism for soot combustion is proposed: the synergistic effect of Pt and dual Ni/Co cations in the Pt/Ni1.5Co0.5AlO catalysts can promote the vital step of catalyzing NO oxidation to NO2 in the NO-assisted soot oxidation mechanism. This insight into the synergistic effect of Pt and dual Ni/Co cations for soot combustion provides new strategies for reducing the amounts of noble metals in high-efficient catalysts.

Molybdenum fertilizer improved antioxidant capacity of Chinese Merino sheep under compound contamination.

To investigate the response of different levels of molybdenum (Mo) fertilizer to Chinese Merino sheep (Junken Type) grazing on natural heavy metal-contaminated meadows, this study was carried out in the Bayanbulak Grassland lying in the northwest of Xinjiang Uygur Autonomous Region, China. A total of 24-hm2 polluted meadows were fenced and were randomly divided into four groups (3 replication/group and 2 hm2/replication) applied 0-kg Mo, 1-kg Mo, 2-kg Mo, and 3-kg Mo (ammonium molybdate tetrahydrate) per hectare for the CON group, group I, group II, and group III, respectively. Seventy-two healthy 1-year-old Chinese Merino sheep (45.56 ± 2.35 kg) were randomly assigned to the tested pastures for 90 days. Compared with the CON group, the Mo content from fertilized groups and the Se content from group II and group III in serums and livers were significantly increased (P < 0.05), and the Cu content from fertilized groups in serums and livers was significantly decreased (P < 0.05). The levels of blood Hb and RBC, and the activities of serum SOD, CAT, GSH-Px, and Cp in group III, were significantly higher (P < 0.05) than those in the CON group, group I, and group II. Serum MDA content in group III was significantly lower (P < 0.05) than that in the other three groups. In summary, Mo fertilization improved the antioxidant capacity of grazing sheep and also reduced the toxic damage to Chinese Merino sheep grazing on natural grasslands contaminated by heavy metals, but Mo poisoning caused by excessive fertilization should be prevented.

The A-to-I editing of KPC1 promotes intrahepatic cholangiocarcinoma by attenuating proteasomal processing of NF-κB1 p105 to p50.

BACKGROUND: Aberrant RNA editing of adenosine-to-inosine (A-to-I) has been linked to multiple human cancers, but its role in intrahepatic cholangiocarcinoma (iCCA) remains unknown. We conducted an exome-wide investigation to search for dysregulated RNA editing that drive iCCA pathogenesis. METHODS: An integrative whole-exome and transcriptome sequencing analysis was performed to elucidate the RNA editing landscape in iCCAs. Putative RNA editing sites were validated by Sanger sequencing. In vitro and in vivo experiments were used to assess the effects of an exemplary target gene Kip1 ubiquitination-promoting complex 1 (KPC1) and its editing on iCCA cells growth and metastasis. Crosstalk between KPC1 RNA editing and NF-κB signaling was analyzed by molecular methods. RESULTS: Through integrative omics analyses, we revealed an adenosine deaminases acting on RNA 1A (ADAR1)-mediated over-editing pattern in iCCAs. ADAR1 is frequently amplified and overexpressed in iCCAs and plays oncogenic roles. Notably, we identified a novel ADAR1-mediated A-to-I editing of KPC1 transcript, which results in substitution of methionine with valine at residue 8 (p.M8V). KPC1 p.M8V editing confers loss-of-function phenotypes through blunting the tumor-suppressive role of wild-type KPC1. Mechanistically, KPC1 p.M8V weakens the affinity of KPC1 to its substrate NF-κB1 p105, thereby reducing the ubiquitinating and proteasomal processing of p105 to p50, which in turn enhances the activity of oncogenic NF-κB signaling. CONCLUSIONS: Our findings established that amplification-driven ADAR1 overexpression results in overediting of KPC1 p.M8V in iCCAs, leading to progression via activation of the NF-κB signaling pathway, and suggested ADAR1-KPC1-NF-κB axis as a potential therapeutic target for iCCA.