Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Reactor neutrino experiments play a crucial role in advancing our knowledge of neutrinos. In this Letter, the evolution of the flux and spectrum as a function of the reactor isotopic content is reported in terms of the inverse-beta-decay yield at Daya Bay with 1958 days of data and improved systematic uncertainties. These measurements are compared with two signature model predictions: the Huber-Mueller model based on the conversion method and the SM2018 model based on the summation method. The measured average flux and spectrum, as well as the flux evolution with the ^{239}Pu isotopic fraction, are inconsistent with the predictions of the Huber-Mueller model. In contrast, the SM2018 model is shown to agree with the average flux and its evolution but fails to describe the energy spectrum. Altering the predicted inverse-beta-decay spectrum from ^{239}Pu fission does not improve the agreement with the measurement for either model. The models can be brought into better agreement with the measurements if either the predicted spectrum due to ^{235}U fission is changed or the predicted ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu spectra are changed in equal measure.

The Dawn of a New Era: Targeting the "Undruggables" with Antibody-Based Therapeutics

The high selectivity and affinity of antibodies toward their antigens have made them a highly valuable tool in disease therapy, diagnosis, and basic research. A plethora of chemical and genetic approaches have been devised to make antibodies accessible to more "undruggable" targets and equipped with new functions of illustrating or regulating biological processes more precisely. In this Review, in addition to introducing how naked antibodies and various antibody conjugates (such as antibody-drug conjugates, antibody-oligonucleotide conjugates, antibody-enzyme conjugates, etc.) work in therapeutic applications, special attention has been paid to how chemistry tools have helped to optimize the therapeutic outcome (i.e., with enhanced efficacy and reduced side effects) or facilitate the multifunctionalization of antibodies, with a focus on emerging fields such as targeted protein degradation, real-time live-cell imaging, catalytic labeling or decaging with spatiotemporal control as well as the engagement of antibodies inside cells. With advances in modern chemistry and biotechnology, well-designed antibodies and their derivatives via size miniaturization or multifunctionalization together with efficient delivery systems have emerged, which have gradually improved our understanding of important biological processes and paved the way to pursue novel targets for potential treatments of various diseases.

A comparative investigation of catalytic mechanism and domain between catechol-O-methyltransferase isoforms by isomeric shikonin and alkannin

The differences in catalytic mechanism and domain between the soluble (S-COMT) and membrane-bound catechol-O-methyltransferase (MB-COMT) are poorly documented due to the unavailable crystal structure of MB-COMT. Considering the enzymatic nature of S-COMT and MB-COMT, the challenge could be solvable by probing the interactions between the enzymes with the ligands with minor differences in structures. Herein, isomeric shikonin and alkannin bearing a R/S -OH group in side chain at the C2 position were used for domain profiling of COMTs. Human and rat liver-derived COMTs showed the differences in inhibitory response (human's IC₅₀ and K_i values for S-COMT < rat's, 5.80-19.56 vs. 19.56-37.47 μM; human's IC₅₀ and K_i values for MB-COMT > rat's) and mechanism (uncompetition vs. noncompetition) towards the two isomers. The inhibition of the two isomers against human and rat S-COMTs was stronger than those for MB-COMTs (S-COMT's IC₅₀ and K_i values < MB-COMT's, 5.80-37.47 vs. 40.01-111.8 μM). Additionally, the inhibition response of alkannin was higher than those of shikonin in no matter human and rat COMTs. Molecular docking stimulation was used for analysis. The inhibitory effects observed in in vitro and in silico tests were confirmed in vivo. These findings would facilitate further COMT-associated basic and applied research.

Activation of xanthine oxidase by 1,4-naphthoquinones: A novel potential research topic for diet management and risk assessment

Oral intake of 1,4-naphthoquinones could be a potential risk factor for hyperuricemia and gout via activation of xanthine oxidase (XO). Herein, 1,4-naphthoquinones derived from food and food-borne pollutants were selected to investigate the structure and activity relationship (SAR) and the relative mechanism for activating XO in liver S9 fractions from humans (HLS9) and rats (RLS9). The SAR analysis showed that introduction of electron-donating substituents on the benzene ring or electron-withdrawing substituents on the quinone ring improved the XO-activating effect of 1,4-naphthoquinones. Different activation potential and kinetics behaviors were observed for activating XO by 1,4-naphthoquinones in HLS9/RLS9. Molecular docking simulation and density functional theory calculations showed a good correlation between -LogEC₅₀ and docking free energy or HOMO-LUMO energy gap. The risk of exposure to the 1,4-naphthoquinones was evaluated and discussed. Our findings are helpful to guide diet management in clinic and avoid adverse events attributable to exposure to food-derived 1,4-naphthoquinones.

Precision Measurement of Reactor Antineutrino Oscillation at Kilometer-Scale Baselines by Daya Bay

We present a new determination of the smallest neutrino mixing angle θ_{13} and the mass-squared difference Δm_{32}^{2} using a final sample of 5.55×10^{6} inverse beta-decay (IBD) candidates with the final-state neutron captured on gadolinium. This sample is selected from the complete dataset obtained by the Daya Bay reactor neutrino experiment in 3158 days of operation. Compared to the previous Daya Bay results, selection of IBD candidates has been optimized, energy calibration refined, and treatment of backgrounds further improved. The resulting oscillation parameters are sin^{2}2θ_{13}=0.0851±0.0024, Δm_{32}^{2}=(2.466±0.060)×10^{-3}  eV^{2} for the normal mass ordering or Δm_{32}^{2}=-(2.571±0.060)×10^{-3}  eV^{2} for the inverted mass ordering.

Studies on the interaction of five triazole fungicides with human renal transporters in cells

The widespread use of triazole fungicides in agricultural production poses a potential risk to human health. This study investigates the interaction of five triazole fungicides, i.e., tebuconazole, triticonazole, hexaconazole, penconazole, and uniconazole with human renal transporters, including OAT1, OAT3, OCT2, OCTN1, OCTN2, MATE1, MATE2-K, MRP2, MDR1, and BCRP, using transgenic cell models. For uptake transporters, triticonazole was the substrate of OAT1 and OAT3 and the inhibitor of OCT2. Tebuconazole and penconazole inhibited OCTN2 (100 μM), while tebuconazole, triticonazole, hexaconazole, penconazole, and uniconazole inhibited MATE1 (100 μM). Tebuconazole and hexaconazole inhibited MATE2-K (100 μM). All five triazole fungicides were not substrates or strong inhibitors of MRP2, MDR1, and BCRP efflux transporters. Penconazole inhibited OCT2 with IC₅₀ = 1.12 μM. Penconazole and uniconazole inhibited MATE1 with IC₅₀ = 0.94 μM and 0.87 μM. Tebuconazole and hexaconazole inhibited MATE2-K with IC₅₀ = 0.96 μM and 1.04 μM, indicating that triazole fungicides may inhibit renal drug transporter activity at low concentrations. Triticonazole was transported by OAT1 and OAT3, and the K_m values of triticonazole were 5.81 ± 1.75 and 47.35 ± 14.27, respectively. Tebuconazole and uniconazole were transported by OAT3, and the K_m values of tebuconazole and uniconazole were 30.28 ± 7.18 and 87.61 ± 31.70, respectively, which may induce nephrotoxicity.

Impaired ascending aortic elasticity in fetuses with tetralogy of Fallot

OBJECTIVES

Aortic wall stiffness has been reported in infants with tetralogy of Fallot (ToF) and may contribute to long-term aortic dilation even after corrective repair surgery. However, little is known about aortic elasticity in fetuses with ToF and the association with neonatal aortic dilation. The objectives of this study were to assess measures of elasticity of the ascending aorta (AAo) in fetuses with ToF and explore the association with neonatal aortic annular dilation in this population.

METHODS

Seventy-six singleton fetuses with ToF and 76 control fetuses of singleton low-risk pregnancies were enroled into this prospective study. Fetal measures of AAo elasticity, including mean longitudinal strain (MLS), global circumferential strain (GCS) and fractional area change (FAC), were assessed by velocity vector imaging. The z-score of the aortic valve (AV) diameter at the level of the annulus, as a measure of aortic annular dilation, was determined in newborns. Logistic regression analysis was used to investigate the association between fetal measures of AAo elasticity and neonatal aortic annular dilation (defined as an AV annular z-score > 2) in cases with ToF identified prenatally.

RESULTS

Median MLS, GCS and FAC in fetuses with ToF were lower than those in normal fetuses (7.52% vs 12.15% for MLS, 22.05% vs 29.73% for GCS and 34.2% vs 48.3% for FAC, all P < 0.001). Aortic annular dilation was present in 53/76 (69.7%) newborns with ToF. After adjustment for gestational age at fetal echocardiography and birth weight, fetal MLS, GCS and FAC were independently associated with aortic annular dilation neonatally, with odds ratios of 0.66, 0.78 and 0.82, respectively (P < 0.05). The best cut-off values of these prenatal measures of AAo elasticity for predicting neonatal aortic annular dilation in fetuses with ToF were 9.02% for MLS, 23.56% for GCS and 37.2% for FAC (P < 0.001), with areas under the receiver-operating-characteristics curves of 0.94, 0.91 and 0.93, respectively.

CONCLUSION

Measures of AAo elasticity are decreased in fetuses with ToF. Impaired AAo elasticity in the fetal period is associated with aortic annular dilation postnatally. Additional research is needed to evaluate the relationship between the AAo elasticity injury pattern and degeneration of AAo elasticity under stress as well as the long-term outcome in this population. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

A review of ten years of experience using dexamethasone intravitreal implants (Ozurdex) for uveitis

Uveitis is a type of ocular inflammatory disease caused by various etiologies, for which corticosteroids are the main treatment. Dexamethasone Intravitreal implant (DEX-I) has been widely used in the treatment of uveitis across the world. Then, new indications and complications appeared. This review aims to summarize the use of DEX-I in uveitis in the past 10 years. We summarized the clinical data (baseline characteristics, efficacy and safety) and discussed controversies by retrospectively analyzing the articles and cases published in PubMed and Web of Science using the terms "Ozurdex", OR "intravitreal dexamethasone implant", AND "uveitis" from 2010 to 2022. DEX-I is effective in reducing edema, improving inflammation and improving vision when treating various conditions of uveitis including infectious, no-infectious, pediatric uveitis, and surgery-related applications. The efficacy of DEX-I as a monotherapy is related to the following: etiology and course of disease, treatment of systemic diseases, patients' toleration after multiple injections, economic situation, etc. In addition, intravitreal corticosteroids implantation may replace systemic therapy in some patients. In terms of safety, the incidence of high intraocular pressure is about 20.52%, and the incidence of cataract is about 15.51%. DEX-I can effectively treat non-infectious uveitis and some infectious uveitis such as suspected tuberculosis, and its safety is controllable. Further studies are necessary to evaluate the effect of monotherapy and to expand more indications.

A duplex-specific nuclease (DSN) and catalytic hairpin assembly (CHA)-mediated dual amplification method for miR-146b detection

A novel method for detecting miRNA has been developed using a combination of duplex-specific nuclease signal amplification (DSNSA) and a catalytic hairpin assembly (CHA). In this work, a biotinylated trigger release (BTR) probe with a biotin group at the 3'-end and a CHA reaction sequence trigger as an initiator (catalyst I) at the 5'-end was designed to hybridize target miRNA. The DSN enzyme was introduced to initiate the DSNSA. The miRNA was released to consume more BTR probes and amplify the signals. Subsequently, streptavidin-coated magnetic beads (SA-MBs) were added to the DSNSA reaction solution to remove excess BTR probes that did not hybridize with miRNA, which would then separate BTR probes and catalyst-I, to ensure detection with high selectivity and sensitivity. The catalyst-I remaining in the solution could trigger the CHA reaction to enable signal amplification in the second step. The developed method exhibits a sensitive detection limit and excellent selectivity in identifying a high sequence homology among family members.

MiR-183-5p promotes renal cell carcinoma metastasis by targeting TET1

Ten-eleven translocation 1 (TET1) is a member of the DNA demethylase family that regulates the methylation level of the genome. Dysregulation of TET1 in renal cell carcinoma (RCC) may be associated with RCC progression, but the mechanism of TET1 down-regulation in RCC is not yet known. MiR-183-5p is up-regulated in various tumor tissues and acts as an oncogene. We used Transwell and wound healing assays to test cell invasion and migration. To investigate DNA methylation, we used dot blot, which indicates TET1 enzyme activity. We verified the binding of miR-183-5p and TET1 3'-UTR (untranslated region) using dual-luciferase reporter assay. Our study demonstrated, for the first time, that miR-183-5p can directly repress TET1 expression in RCC. We observed a significant decrease in TET1 expression in RCC specimens, as reported in the literature, and a significant decrease in the concentration of 5hmC in RCC. By aligning the microRNA with a database and using the luciferase reporter gene method, we found that miR-183-5p can inhibit luciferase activity by binding to 453-459 bp of TET1 3'-UTR, leading to inhibition of TET1 expression. Furthermore, down-regulation of TET1 inhibited miR-200c expression and promoted RCC cell invasion and migration. Our findings suggest that in RCC, increased expression of miR-183-5p inhibits the expression of TET1, which in turn inhibits the expression of miR-200c and E-cadherin, both of which are associated with cell adhesion. This leads to the promotion of cell invasion and migration.

State-of-the-art Application of Artificial Intelligence to Transporter-centered Functional and Pharmaceutical Research

Protein transporters not only have essential functions in regulating the transport of endogenous substrates and remote communication between organs and organisms, but they also play a vital role in drug absorption, distribution, and excretion and are recognized as major determinants of drug safety and efficacy. Understanding transporter function is important for drug development and clarifying disease mechanisms. However, the experimental-based functional research on transporters has been challenged and hinged by the expensive cost of time and resources. With the increasing volume of relevant omics datasets and the rapid evolution of artificial intelligence (AI) techniques, next-generation AI is becoming increasingly prevalent in the functional and pharmaceutical research of transporters. Thus, a comprehensive discussion on the state-of-the-art application of AI in three cutting-edge directions was provided in this review, which included (a) transporter classification and function annotation, (b) structure discovery of membrane transporters, and (c) drug-transporter interaction prediction. This study provides a panoramic view of AI algorithms and tools applied to the field of transporters. It is expected to guide a better understanding and utilization of AI techniques for in-depth studies of transporter-centered functional and pharmaceutical research.

Potential use of a dried saliva spot (DSS) in therapeutic drug monitoring and disease diagnosis

In recent years, scientific researchers have increasingly become interested in noninvasive sampling methods for therapeutic drug monitoring and disease diagnosis. As a result, dried saliva spot (DSS), which is a sampling technique for collecting dried saliva samples, has been widely used as an alternative matrix to serum for the detection of target molecules. Coupling the DSS method with a highly sensitive detection instrument improves the efficiency of the preparation and analysis of biological samples. Furthermore, dried blood spots, dried plasma spots, and dried matrix spots, which are similar to those of the DSS method, are discussed. Compared with alternative biological fluids used in dried spot methods, including serum, tears, urine, and plasma, saliva has the advantage of convenience in terms of sample collection from children or persons with disabilities. This review aims to provide integral strategies and guidelines for dried spot methods to analyze biological samples by illustrating several dried spot methods. Herein, we summarize recent advancements in DSS methods from June 2014 to March 2021 and discuss the advantages and disadvantages of the key aspects of this method, including sample preparation and method validation. Finally, we outline the challenges and prospects of such methods in practical applications.

DrugMAP: molecular atlas and pharma-information of all drugs

The efficacy and safety of drugs are widely known to be determined by their interactions with multiple molecules of pharmacological importance, and it is therefore essential to systematically depict the molecular atlas and pharma-information of studied drugs. However, our understanding of such information is neither comprehensive nor precise, which necessitates the construction of a new database providing a network containing a large number of drugs and their interacting molecules. Here, a new database describing the molecular atlas and pharma-information of drugs (DrugMAP) was therefore constructed. It provides a comprehensive list of interacting molecules for >30 000 drugs/drug candidates, gives the differential expression patterns for >5000 interacting molecules among different disease sites, ADME (absorption, distribution, metabolism and excretion)-relevant organs and physiological tissues, and weaves a comprehensive and precise network containing >200 000 interactions among drugs and molecules. With the great efforts made to clarify the complex mechanism underlying drug pharmacokinetics and pharmacodynamics and rapidly emerging interests in artificial intelligence (AI)-based network analyses, DrugMAP is expected to become an indispensable supplement to existing databases to facilitate drug discovery. It is now fully and freely accessible at: https://idrblab.org/drugmap/.

Sensitive Imaging of Cellular RNA via Cascaded Proximity-Induced Fluorogenic Reactions

Owing to its important biological functions, RNA has become a promising molecular biomarker of various diseases. With a dynamic change in its expression level and a relatively low amount within the complicated biological matrix, signal amplification detection based on DNA probes has been put forward, which is helpful for early diagnosis and prognostic prediction. However, conventional methods are confined to cell lysates or dead cells and are not only time-consuming in sample preparation but also inaccessible to the spatial-temporal information of target RNAs. To achieve live-cell imaging of specific RNAs, both the detection sensitivity and intracellular delivery issues should be addressed. Herein, a new cascaded fluorogenic system based on the combination of hybridization chain reactions (HCRs) and proximity-induced bioorthogonal chemistry is developed, in which a bioorthogonal reaction pair (a tetrazine-quenched dye and its complementary dienophile) is brought into spatial proximity upon target RNA triggering the HCR to turn on and amplify the fluorescence in one step, sensitively indicating the cellular distribution of RNA with minimal false positive results caused by unspecific degradation. Facilitated by a biodegradable carrier based on black phosphorus with high loading capacity and excellent biocompatibility, the resulting imaging platform allows wash-free tracking of target RNAs inside living cells.

Association between maternal oxygenation and brain growth in fetuses with left-sided cardiac obstructive lesions

OBJECTIVE

Impaired brain growth has been observed in fetuses with left-sided obstructive lesions (LSOL). Maternal oxygenation (MO) can alter fetal cerebral oxygenation and vascular reactivity. Our aim was to observe whether brain growth improves during MO in fetuses with LSOL.

METHODS

Forty-six fetuses with LSOL and 23 control fetuses were enrolled in this prospective longitudinal study. Fetuses with LSOL were subgrouped into those with MO (LSOL-MO, n = 23) and those without MO (LSOL-nMO, n = 23). Fetal head circumference (HC) and total intracranial volume (TIV) were evaluated serially at 4-week intervals. Brain biometry and growth were analyzed using linear mixed models adjusted for gestational age and sex. Spearman's correlation coefficients were calculated to identify baseline characteristics predictive of brain growth in the LSOL-MO group.

RESULTS

Duration of MO therapy had significant interaction effects on cerebral biometry in fetuses with LSOL. TIV increased more rapidly after 8 weeks of oxygen exposure and HC was larger after 16 weeks of oxygen exposure in the LSOL-MO group compared with the LSOL-nMO group (P &lt; 0.001). The change in TIV at the final time- point relative to the initial timepoint in the LSOL-MO group correlated negatively with the baseline pulsatility index of the middle cerebral artery (r = -0.58, P = 0.003) and baseline myocardial performance index of the left ventricle (r = -0.68, P &lt; 0.001).

CONCLUSIONS

TIV and HC increased faster in fetuses with LSOL which had MO compared with those that did not. Lower cerebral vascular resistance and preserved left heart function at baseline may predict greater cerebral biometric growth during MO. Additional research, including larger serial studies, is needed to confirm these preliminary findings and evaluate the clinical application of MO in this population. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Deep Underground Laboratory Measurement of ^{13}C(α,n)^{16}O in the Gamow Windows of the s and i Processes

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

Integrate thermostabilized fusion protein apocytochrome b562RIL and N-glycosylation mutations: A novel approach to heterologous expression of human UDP-glucuronosyltransferase (UGT) 2B7

Human UDP-glucuronosyltransferase (UGT) 2B7 is a crucial phase II metabolic enzyme that transfers glucuronic acid from UDP-glucuronic acid (UDPGA) to endobiotic and xenobiotic substrates. Biophysical and biochemical investigations of UGT2B7 are hampered by the challenge of the integral membrane protein purification. This study focused on the expression and purification of recombinant UGT2B7 by optimizing the insertion sites for the thermostabilized fusion protein apocytochrome b₅₆₂RIL (BRIL) and various mutations to improve the protein yields and homogeneity. Preparation of the recombinant proteins with high purity accelerated the measurement of pharmacokinetic parameters of UGT2B7. The dissociation constants (K_D) of two classical substrates (zidovudine and androsterone) and two inhibitors (schisanhenol and hesperetin) of UGT2B7 were determined using the surface plasmon resonance spectroscopy (SPR) for the first time. Using negative-staining transmission electron microscopy (TEM), UGT2B7 protein particles were characterized, which could be useful for further exploring its three-dimensional structure. The methods described in this study could be broadly applied to other UGTs and are expected to provide the basis for the exploration of metabolic enzyme kinetics, the mechanisms of drug metabolisms and drug interactions, changes in pharmacokinetics, and pharmacodynamics studies in vitro.

First Measurement of High-Energy Reactor Antineutrinos at Daya Bay

This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{β} isotopes in commercial reactors.

Charge and Spin Order Dichotomy in NdNiO_{2} Driven by the Capping Layer

Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, with similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic and magnetic excitations and charge density correlations in Nd_{1-x}Sr_{x}NiO_{2} thin films with and without an SrTiO_{3} capping layer. We observe dispersing magnons only in the capped samples, progressively dampened at higher doping. We detect an elastic resonant scattering peak in the uncapped x=0 compound at wave vector (∼⅓,0), remindful of the charge order signal in hole doped cuprates. The peak weakens at x=0.05 and disappears in the superconducting x=0.20 film. The role of the capping on the electronic reconstruction far from the interface remains to be understood.

RT-LAMP assay combining multi-fluorescent probes for SARS-CoV-2 RNA detection and variant differentiation

Simple and accurate testing tools for SARS-CoV-2 viral RNA detection are essential for the prevention of the spread of the virus and timely governmental actions. Herein, we present a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the simultaneous detection of ORF1ab and N gene fragments of SARS-CoV-2 in one pot. Using two primer sets and two molecular beacon (MB) probes respectively labelled with different fluorophore, positive results were obtained with a limit of detection of 20 and 2 copies/μL for ORF1ab and N gene fragments, respectively. Moreover, the RT-LAMP based assay was applied to detect single-site differences in S genes using two one-step displacement (OSD) probes targeting wild-type and mutant (P681R mutation was chosen as model) genes. Through that, the wild type strain and P681R mutant variant were well distinguished from each other, and a preliminary observation was also made on other mutations at this site such as P681H. The proposed method has high sensitivity for quantification and high specificity for mutation differentiation. In addition, it does not require accurate sophisticated thermal cycler instrumentation and can be used in clinical settings in resource-limited regions.

Blockade LAT1 Mediates Methionine Metabolism to Overcome Oxaliplatin Resistance under Hypoxia in Renal Cell Carcinoma

Simple Summary

The transformation and mechanism of methionine metabolism of renal cell carcinoma (RCC) under a hypoxic microenvironment is not well understood as yet. This study illustrated that the reprogramming of methionine metabolism and the subsequent glutathione (GSH) synthesis were mediated by amino acid transporter 1 (LAT1). Correspondingly, we proposed a combination strategy of LAT1 inhibitor JPH203 and oxaliplatin, which presented an enhanced therapeutic efficacy for RCC both in vivo and in vitro.

Abstract

Hypoxic microenvironment and metabolic dysregulation of tumor impairs the therapeutic efficacy of chemotherapeutic drugs, resulting in drug resistance and tumor metastasis, which has always been a challenge for the treatment of solid tumors, including renal cell carcinoma (RCC). Herein, starting from the evaluation of methionine metabolism in RCC cells, we demonstrated that the increased methionine accumulation in RCC cells was mediated by L-type amino acid transporter 1 (LAT1) under hypoxia. Glutathione (GSH), as a methionine metabolite, would attenuate the therapeutic efficacy of oxaliplatin through chemical chelation. Reducing methionine uptake by LAT1 inhibitor JPH203 significantly enhanced the sensitivity of RCC cells to oxaliplatin by reducing GSH production in vitro and in vivo. Therefore, we proposed an effective and stable therapeutic strategy based on the combination of oxaliplatin and LAT1 inhibitor, which is expected to solve the resistance of RCC to platinum-based drugs under hypoxia to a certain extent, providing a meaningful insight into the development of new therapeutic strategies and RCC treatment

Oncopeptide MBOP Encoded by LINC01234 Promotes Colorectal Cancer through MAPK Signaling Pathway

Colorectal cancer (CRC) ranks third in incidence rate and second in mortality rate of malignancy worldwide, and the diagnosis and therapeutics of it remain to be further studied. With the emergence of noncoding RNAs (ncRNAs) and potential peptides derived from ncRNAs across various biological processes, we here aimed to identify a ncRNA-derived peptide possible for revealing the oncogenesis of CRC. Through combined predictive analysis of the coding potential of a batch of long noncoding RNAs (lncRNAs), the existence of an 85 amino-acid-peptide, named MEK1-binding oncopeptide (MBOP) and encoded from LINC01234 was confirmed. Mass spectrometry and Western blot assays indicated the overexpression of MBOP in CRC tissues and cell lines compared to adjacent noncancerous tissues and the normal colonic epithelial cell line. In vivo and in vitro migration and proliferation assays defined MBOP as an oncogenic peptide. Immunoprecipitation trials showed that MEK1 was the key interacting protein of MBOP, and MBOP promoted the MEK1/pERK/MMP2/MMP9 axis in CRC. Two E3-ligase enzymes MAEA and RMND5A mediated the ubiquitin-protease-system-related degradation of MBOP. This study indicates that MBOP might be a candidate prognostic indicator and a potential target for clinical therapy of CRC.