Enhancing m6A modification in the motor cortex facilitates corticospinal tract remodeling after spinal cord injury.

JOURNAL/nrgr/04.03/01300535-202506000-00026/figure1/v/2024-08-05T133530Z/r/image-tiff Spinal cord injury typically causes corticospinal tract disruption. Although the disrupted corticospinal tract can self-regenerate to a certain degree, the underlying mechanism of this process is still unclear. N6-methyladenosine (m6A) modifications are the most common form of epigenetic regulation at the RNA level and play an essential role in biological processes. However, whether m6A modifications participate in corticospinal tract regeneration after spinal cord injury remains unknown. We found that expression of methyltransferase 14 protein (METTL14) in the locomotor cortex was high after spinal cord injury and accompanied by elevated m6A levels. Knockdown of Mettl14 in the locomotor cortex was not favorable for corticospinal tract regeneration and neurological recovery after spinal cord injury. Through bioinformatics analysis and methylated RNA immunoprecipitation-quantitative polymerase chain reaction, we found that METTL14 regulated Trib2 expression in an m6A-regulated manner, thereby activating the mitogen-activated protein kinase pathway and promoting corticospinal tract regeneration. Finally, we administered syringin, a stabilizer of METTL14, using molecular docking. Results confirmed that syringin can promote corticospinal tract regeneration and facilitate neurological recovery by stabilizing METTL14. Findings from this study reveal that m6A modification is involved in the regulation of corticospinal tract regeneration after spinal cord injury.

OsPUB75-OsHDA716 mediates deactivation and degradation of OsbZIP46 to negatively regulate drought tolerance in rice.

Histone deacetylases (HDACs) play crucial roles in plant stress responses via modification of histone as well as non-histone proteins; however, how HDAC-mediated deacetylation of non-histone substrates affects protein functions remains elusive. Here, we report that the Reduced Potassium Dependency3/Histone Deacetylase1 (RPD3/HDA1)-type histone deacetylase OsHDA716 and plant U-box (PUB) E3 ubiquitin ligase OsPUB75 form a complex to regulate rice drought response via deactivation and degradation of basic leucine zipper (bZIP) transcription factor OsbZIP46 in rice (Oryza sativa). OsHDA716 decreases ABA-induced drought tolerance, and mechanistic investigations showed that OsHDA716 interacts with and deacetylates OsbZIP46, a key regulator in ABA signaling and drought response, thus inhibiting its transcriptional activity. Furthermore, OsHDA716 recruits OsPUB75 to facilitate ubiquitination and degradation of deacetylated OsbZIP46. Therefore, the OsPUB75-OsHDA716 complex exerts double restrictions on the transcriptional activity and protein stability of OsbZIP46, leading to repression of downstream drought-responsive gene expression and consequently resulting in reduced drought tolerance. Conversely, OsbZIP46 acts as an upstream repressor to repress OsHDA716 expression, and therefore OsHDA716 and OsbZIP46 form an antagonistic pair to reciprocally inhibit each other. Genetic evidence showed that OsHDA716 works with OsbZIP46 in a common pathway to antagonistically regulate rice drought response, revealing that plants can fine-tune stress responses by the complex interplay between chromatin regulators and transcription factors. Our findings unveil an acetylation-dependent regulatory mechanism governing protein functions and shed light on the precise coordination of activity and stability of key transcription factors through a combination of different post-translational modifications.

Stress Hormones: Unveiling the Role in Accelerated Cellular Senescence.

Cellular senescence is a complex process involving multiple factors, such as genetics, environment, and behavior. However, recent studies have shown that stress also plays a crucial role in inducing cellular senescence. Stress can affect cellular function and structure through various pathways, leading to accelerated aging. Exposure to stressful conditions can alter the neuroendocrine system, activate the hypothalamus-pituitary-adrenal axis and sympathetic adrenal medullary axis, and release cortisol and catecholamines, causing mitochondrial dysfunction, generating excessive reactive oxygen species, and inducing oxidative stress, DNA damage, and inflammatory reactions, ultimately resulting in accelerated cellular senescence. The process of stress-induced cellular senescence has been implicated in a number of chronic diseases, including age-related macular degeneration, chronic kidney disease, type 2 diabetes, cardiovascular disease and obstructive sleep apnea. In this review, we integrate recent progress research progress in our understanding of the mechanisms of stress-induced cellular senescence and discuss its underlying mechanisms from the perspective of stress hormones. We review potential therapeutic targets for stress-induced premature senescence and discuss the advantages and limitations of existing pharmacological agents capable of ameliorating stress-induced premature senescence.

Unveiling axolotl transcriptome for tissue regeneration with high-resolution annotation via long-read sequencing.

Axolotls are known for their remarkable regeneration ability. Exploring their transcriptome provides insight into regenerative mechanisms. However, the current annotation of the axolotl transcriptome is limited, leaving the role of unannotated transcripts in regeneration unknown. To discourse this challenge, we exploited long-read sequencing technology, which enables direct observation of full-length RNA transcripts, greatly enhancing the coverage and accuracy of axolotl transcriptome annotation. By utilizing this method, we identified 222 novel gene loci and 4775 novel transcripts, which were quantified using short-read sequencing data. Through the inclusive analysis, we discovered novel homologs, potential functional proteins, noncoding RNAs, and alternative splicing events in key regeneration pathways. In particular, we identified novel transcripts with high protein-coding potential implicated in cell cycle regulation and musculoskeletal development, and regeneration were identified. Interestingly, alternative splice variants were also detected across diverse pathways critical to regeneration. This specifies that these novel transcripts potentially play vital roles underpinning the robust regenerative capacities of axolotls. Single-cell transcriptomic analysis further revealed these isoforms to predominantly exist in axolotl limb chondrocytes and mature tissue cell populations. Overall, the findings significantly advanced consideration of the axolotl transcriptome and provided a new perspective for understanding the mechanisms of regenerative abilities of axolotls.

Tailoring near-infrared amyloid-ß probes with high-affinity and low background based on CN and amphipathic regulatory strategies and in vivo imaging of AD mice.

Amyloid-ß (Aß) species (Aß fibrils and Aß plaques), as one of the typical pathological markers of Alzheimer's disease (AD), plays a crucial role in AD diagnosis. Currently, some near-infrared I (NIR I) Aß probes have been reported in AD diagnosis. However, they still face challenges such as strong background interference and the lack of effective probe design. In this study, we propose molecular design strategy that incorporates CN group and amphiphilic modulation to synthesize a series of amphiphilic NIR I Aß probes, surpassing the commercial probe ThT and ThS. Theoretical calculations indicate that these probes exhibit stronger interaction with amino acid residues in the cavities of Aß. Notably, the probes containing CN group display the ability of binding two distinct sites of Aß, which dramatically enhanced the affinity to Aß species. Furthermore, these probes exhibit minimal fluorescence in aqueous solution and offer ultra-high signal-to-noise ratio (SNR) for in vitro labeling, even in wash-free samples. Finally, the optimal probe DM-V2CN-PYC3 was utilized for in vivo imaging of AD mice, demonstrating its rapid penetration through the blood-brain barrier and labelling to Aß species. Moreover, it enabled long-term monitoring for a duration of 120 min. These results highlight the enhanced affinity and superior performance of the designed NIR I Aß probe for AD diagnosis. The molecular design strategy of CN and amphiphilic modulation presents a promising avenue for the development Aß probes with low background in vivo/in vitro imaging for Aß species.

Two-dimensional crystalline platinum oxide.

Platinum (Pt) oxides are vital catalysts in numerous reactions, but research indicates that they decompose at high temperatures, limiting their use in high-temperature applications. In this study, we identify a two-dimensional (2D) crystalline Pt oxide with remarkable thermal stability (1,200 K under nitrogen dioxide) using a suite of in situ methods. This 2D Pt oxide, characterized by a honeycomb lattice of Pt atoms encased between dual oxygen layers forming a six-pointed star structure, exhibits minimized in-plane stress and enhanced vertical bonding due to its unique structure, as revealed by theoretical simulations. These features contribute to its high thermal stability. Multiscale in situ observations trace the formation of this 2D Pt oxide from α-PtO2, providing insights into its formation mechanism from the atomic to the millimetre scale. This 2D Pt oxide with outstanding thermal stability and distinct surface electronic structure subverts the previously held notion that Pt oxides do not exist at high temperatures and can also present unique catalytic capabilities. This work expands our understanding of Pt oxidation species and sheds light on the oxidative and catalytic behaviours of Pt oxide in high-temperature settings.

Endothelial Foxo1 Phosphorylation Inhibition via Aptamer-Liposome Alleviates OPN-Induced Pathological Vascular Remodeling Following Spinal Cord Injury.

Reconstruction of the neurovascular unit is essential for the repair of spinal cord injury (SCI). Nonetheless, detailed documentation of specific vascular changes following SCI and targeted interventions for vascular treatment remains limited. This study demonstrates that traumatic pathological vascular remodeling occurs during the chronic phase of injury, characterized by enlarged vessel diameter, disruption of blood-spinal cord barrier, endothelial-to-mesenchymal transition (EndoMT), and heightened extracellular matrix deposition. After SCI, osteopontin (OPN), a critical factor secreted by immune cells, is indispensable for early vascular regeneration but also contributes to traumatic pathological vascular remodeling. This work further elucidates the mechanism by which OPN influences spinal cord microvascular endothelial cells, involving Akt-mediated Foxo1 phosphorylation. This process facilitates the extranuclear transport of Foxo1 and decreases Smad7 expression, leading to excessive activation of the TGF-ß signaling pathway, which ultimately results in EndoMT and fibrosis. Targeted inhibition of Foxo1 phosphorylation through an endothelium-specific aptamer-liposome small molecule delivery system significantly mitigates vascular remodeling, thereby enhancing axon regeneration and neurological function recovery following SCI. The findings offer a novel perspective for drug therapies aimed at specifically targeting pathological vasculature after SCI.

Efficacy and safety of different regimens of neoadjuvant therapy in patients with hormone receptor-positive, her2-negative breast cancer: a network meta-analysis.

Introduction: The objective of this systematic review and network meta-analysis (NMA) is to assess the effectiveness and safety of various neoadjuvant treatment protocols in individuals diagnosed with hormone receptor-positive, her2 negative(HR+/HER2-) breast cancer. Materials and methods: A systematic search was conducted in four databases (Medline, Embase, Web of Science, and CENTRAL) from the inception of the databases to January 16, 2024, to identify randomized controlled trials (RCTs) to various neoadjuvant therapy options in patients diagnosed with hormone receptor-positive, HER2-negative breast cancer. A network meta-analysis was conducted to evaluate pathological complete response (pCR). Results: There were 17 randomized controlled trials (RCTs) included in the analysis. These trials examined 16 different treatment regimens and involved a total of 5752 participants. The analysis revealed that the six most effective neoadjuvant treatment regimens for HR+/HER2- breast cancer were: CT(A)+olaparib (82.5%), CT(A)+nivolumab (76.5%), Com (74.9%), CT (72.1%), Mono+eribulin (72.0%), and CT(A)+pembrolizumab (70.4%).Paired meta-analysis for pathological complete response (pCR) found no statistically significant distinction between treatment regimens that included both anthracycline and immunosuppressants and regimens that relied solely on anthracycline chemotherapy(OR:1.14, 95%ci 0.79-1.64, I2 = 71%, P=0.50). Similarly, there was no significant difference between platinum-based chemotherapy and anthracycline-basedchemotherapy(OR:1.37, 95%ci 0.53- 3.56, I2 = 11%, P=0.52). With regards to safety, adverse effects of grade 3-5 were observed, which included haematological toxicity, gastrointestinal reactions, skin and mucous membrane reactions, neuropathy, hepatotoxicity, and cardiac disorders. Conclusions: The CT(A)+Olaparib and CT(A)+nivolumab groups demonstrated superior efficacy in neoadjuvant therapy for HR+/HER2- breast cancer. Furthermore, it is crucial to focus on effectively managing the adverse effects of the treatment plan to enhance patient's ability to tolerate it. Given the constraints of the current research, additional well-executed and suitable RCTs are necessary to validate the findings of this investigation. Although pCR is valuable in assessing the effect of neoadjuvant therapy in some cases, prognostic prediction and efficacy assessment in patients with HR+/HER2- breast cancer should be based on a combination of broader clinical and biological characteristics. Systematic review registration: PROSPERO https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024534539, CRD42024501740.

Comparative complications of prepectoral versus subpectoral breast reconstruction in patients with breast cancer: a meta-analysis.

Introduction: This meta-analysis aims to evaluate the complications associated with prepectoral breast reconstruction (PBR) compared to subpectoral breast reconstruction (SBR) in patients diagnosed with breast cancer. Materials and methods: A comprehensive search was performed in four databases, including Medline, Embase, Web of Science and CENTRAL, to collect literature published up until December 31, 2024. In addition, we conducted a thorough manual examination of the bibliographies of the identified papers, as well as pertinent reviews and meta-analyses. We conducted a search on three clinical trial registries, namely ClinicalTrials.gov, Controlled-trials.com, and Umin.ac.jp/ctr/index.htm. Meta-analyses were conducted on total complications, hematoma, infection, wound healing issues, necrosis, capsular contracture, rippling, animation deformity, and reoperation. Results: A total of 40 studies were included in the meta-analysis. Compared with SBR, PBR significantly reduced the incidence of animated malformations (OR=0.37, 95% CI: 0.19 to 0.70, P=0.003, I ²=12%), but increased the incidence of ripples (OR=2.39, 95% CI: 1.53 to 3.72, P=0.0001, I ²=10%) and seroma (OR=1.55, 95% CI: 1.02 to 2.35, P=0.04, increasing I ²=70%). Conclusions: Our findings indicate that PBR and SBR have comparable safety profiles, with similar total complication rates. Specifically, PBR is more likely to cause rippling and seroma, whereas SBR is more prone to causing animation deformity. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024565837, identifier CRD42024565837.

Schnurri-3 inhibition rescues skeletal fragility and vascular skeletal stem cell niche pathology in the OIM model of osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a disorder of low bone mass and increased fracture risk due to a range of genetic variants that prominently include mutations in genes encoding type I collagen. While it is well known that OI reflects defects in the activity of bone-forming osteoblasts, it is currently unclear whether OI also reflects defects in the many other cell types comprising bone, including defects in skeletal vascular endothelium or the skeletal stem cell populations that give rise to osteoblasts and whether correcting these broader defects could have therapeutic utility. Here, we find that numbers of skeletal stem cells (SSCs) and skeletal arterial endothelial cells (AECs) are augmented in Col1a2oim/oim mice, a well-studied animal model of moderate to severe OI, suggesting that disruption of a vascular SSC niche is a feature of OI pathogenesis. Moreover, crossing Col1a2oim/oim mice to mice lacking a negative regulator of skeletal angiogenesis and bone formation, Schnurri 3 (SHN3), not only corrected the SSC and AEC phenotypes but moreover robustly corrected the bone mass and spontaneous fracture phenotypes. As this finding suggested a strong therapeutic utility of SHN3 inhibition for the treatment of OI, a bone-targeting AAV was used to mediate Shn3 knockdown, rescuing the Col1a2oim/oim phenotype and providing therapeutic proof-of-concept for targeting SHN3 for the treatment of OI. Overall, this work both provides proof-of-concept for inhibition of the SHN3 pathway and more broadly addressing defects in the stem/osteoprogenitor niche as is a strategy to treat OI.

C3 Selective Hydroxylation of Pyridines via Photochemical Valence Isomerization of Pyridine N-Oxides.

The C-H hydroxylation of the pyridine C3 position is a highly desirable transformation but remains a great challenge due to the inherent electronic properties of this heterocycle core which bring difficulties in chemical reactivity and regioselectivity. Herein we present an efficient method for formal C3 selective hydroxylation of pyridines via photochemical valence isomerization of pyridine N-oxides. This metal-free transformation features operational simplicity and compatibility with a diverse array of functional groups, and the resulting hydroxylated products are amenable to further elaboration to synthetically useful building blocks. The synthetic utility of this strategy is further demonstrated in the effective late-stage functionalization of pyridine-containing medicinally relevant molecules and versatile derivatizations of 3-pyridinols.

Optimizing the affinity selection mass spectrometry workflow for efficient identification and ranking of potent USP1 inhibitors.

An optimized Affinity Selection-Mass Spectrometry (AS-MS) workflow has been developed for the efficient identification of potent USP1 inhibitors. USP1 was immobilized on agarose beads, ensuring low small molecule retention, efficient protein capture, and protein stability. The binding affinity of 49 compounds to USP1 was evaluated using the optimized AS-MS method, calculating binding index (BI) values for each compound. Biochemical inhibition assays validated the AS-MS results, revealing a potential correlation between higher BI values and lower IC50 values. This optimized workflow enables rapid identification of high-quality USP1 inhibitor hits, facilitating structure-activity relationship studies and accelerating the discovery of potential cancer therapeutics.

Multivendor comparison of quantification accuracy of effective atomic number by Dual-Energy CT: A phantom study.

PURPOSE: Our study aimed to compare the accuracy of the effective atomic number (Zeff) of five dual-energy CT (DECT) from three vendors and different generations under different scanning parameters. METHODS: Zeff accuracy of five DECT scanners with twelve tube voltage configurations was evaluated by using the TomoTherapy cheese phantom. The potential dose dependence of the Zeff was investigated using three radiation dose (5, 15, and 25 mGy), and the robustness of Zeff was simulated for different organs of the body by placing the inserts at different positional depths. Bias and mean absolute percentage error (MAPE) were used to characterize the accuracy of Zeff. Data underwent analysis using one-way ANOVA, followed by the Turky and LSD post hoc tests, simple linear regression, and linear mixed models. RESULTS: All tube voltage configurations had a bias of less than 1. Dual layer detector DECT (dl-DECT) -140 kV has the lowest MAPE (1.79 %±1.93 %). The third generation dual source DECT (ds-DECT) and the second generation rapid switch DECT (rs-DECT) have higher MAPE than their predecessor DECT. The results of the linear mixed model showed that tube voltage configuration (F=16.92, p < 0.001) and insert type (F=53.26, p < 0.001) significantly affect the MAPE. In contrast, radiation dose only has a significant effect on the MAPE of rs-DECT. The inserts position does not affect the final MAPE. CONCLUSION: When scanning different inserts, Zeff accuracy varies by vendor and DECT generation. Of all the scanners, dl-DECT had the highest Zeff accuracy. Upgrading DECT generation doesn't lead to higher accuracy, or even lower.

Comparison of endoscopic breast-conserving surgery versus conventional breast-conserving surgery for the treatment of early-stage breast cancer: a meta-analysis.

Introduction: This meta-analysis seeks to evaluate the efficacy and safety of endoscopic breast-conserving surgery (E-BCS) compared to conventional breast cancer surgery (C-BCS) in patients diagnosed with early-stage breast cancer. Materials and methods: Four databases (Medline, Embase, Web of Science and CENTRAL) were searched published from establishment of database to January 30,2024, for articles studying E-BCS compared to C-BCS in patients diagnosed with early-stage breast cancer. Meta-analyses of procedure time, blood loss, length of incision, drainage duration, total postoperative drainage volume, average duration of hospital stay, positive rate of margin, complication rate, recurrence rate, metastasis rate and cosmetic scoring were performed. Results: Totally 11 studies were included for meta-analysis. Compared with C-BCS, E-BCS exhibited significantly reduced incision length (WMD = -6.44, 95%CI: -10.78 to -2.11, P=0.004, I2 = 99.0%) and superior cosmetic scoring (WMD = 2.69, 95%CI: 1.46 to 3.93, P=0.001, I2 = 93.2%), but had significantly longer operation time (WMD = 34.22, 95%CI: 20.89~47.55, P=0.000, I2 = 90.7%) and blood loss (WMD = 3.65, 95%CI: -3.12 to 10.43, P=0.291, I2 = 86.8%). There was no significant difference in terms of recurrence rate, metastasis rate, positive rate of tumor resection margins, drainage duration, drainage volume, complication rate and hospital days. Conclusions: Our research findings indicate that E-BCS is a viable and secure method for treating breast cancer in its early stages. E-BCS provides distinct advantages in terms of the length of the incision and the aesthetic result, without demonstrating an elevated recurrence rate or metastasis rate. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024535164, identifier CRD42024535164.

Synthesis of nimbolide and its analogues and their application as poly(ADP-ribose) polymerase-1 trapping inducers.

Nimbolide, a ring seco-C limonoid natural product, was recently found to inhibit the poly(ADP)-ribosylation (PARylation)-dependent ubiquitin E3 ligase RNF114. In doing so, it induces the 'supertrapping' of both PARylated PARP1 and PAR-dependent DNA-repair factors. PARP1 inhibitors have reshaped the treatment of cancer patients with germline BRCA1/2 mutations partly through the PARP1 trapping mechanism. To this end, modular access to nimbolide analogues represents an opportunity to develop cancer therapeutics with enhanced PARP1 trapping capability. Here we report a convergent synthesis of nimbolide through a late-stage coupling strategy. Through a sulfonyl hydrazone-mediated etherification and a radical cyclization, this strategy uses a pharmacophore-containing building block and diversifiable hydrazone units to enable the modular synthesis of nimbolide and its analogues. The broad generality of our synthetic strategy allowed access to a variety of analogues with their preliminary cellular cytotoxicity and PARP1 trapping activity reported.

Prevalence and genotypes of Chlamydia psittaci in birds and related workers in three cities of China.

Chlamydia psittaci-a zoonotic pathogen in birds-may be transmitted to humans, causing severe respiratory disease. Individuals working in or living near poultry farms are highly susceptible to C. psittaci infection. In this study, we assessed the prevalence and genotypes of C. psittaci in poultries and humans in three cities of China by collecting fecal samples from different poultry species and throat swab samples and serum samples from workers in poultry farms and zoos. These samples were screened by real-time fluorescence quantitative PCR (qPCR) targeting C. psittaci ompA. The positive samples were subjected to PCR amplification and sequencing of ompA. The strains detected in the samples were genotyped on the basis of the phylogenetic analysis of ompA sequences. In total, 3.13% (40/1278) poultry fecal samples were positive in the qPCR assay, whereas 3.82% (6/157) of throat swab samples and 42.59% (46/108) of serum samples from the workers were positive in the qPCR and indirect fluorescent antibody assays, respectively. The strains detected in the 32 poultry samples and 6 human samples were genotyped as type A, indicating that the workers were infected with C. psittaci that originated in poultry birds in farms. Additionally, eight peacocks showed strains with the genotype CPX0308, which was identified in China for the first time. Elucidating the distribution of C. psittaci in animals and poultry-related workers may provide valuable insights for reducing the risk of C. psittaci infection within a population.

Discovery of novel ULK1 inhibitors through machine learning-guided virtual screening and biological evaluation.

Aim: Build a virtual screening model for ULK1 inhibitors based on artificial intelligence.Materials & methods: Build machine learning and deep learning classification models and combine molecular docking and biological evaluation to screen ULK1 inhibitors from 13 million compounds. And molecular dynamics was used to explore the binding mechanism of active compounds.Results & conclusion: Possibly due to less available training data, machine learning models significantly outperform deep learning models. Among them, the Naive Bayes model has the best performance. Through virtual screening, we obtained three inhibitors with IC50 of µM level and they all bind well to ULK1. This study provides an efficient virtual screening model and three promising compounds for the study of ULK1 inhibitors.

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A novel variant of Chlamydia psittaci causing human psittacosis in China.

From January 2022 to November 2022, sporadic psittacosis occurred in Lishui city, China. The patients were presented with fever, cough, and pulmonary infiltration. Their clinical symptoms were not relieved after receiving cephalosporin, penicillin, beta-lactamase inhibitors, and quinolones. Metagenomic next-generation sequencing of bronchoalveolar lavage fluid samples from the patients revealed Chlamydia psittaci infection. Then, three C. psittaci strains were isolated from the patients. Their whole genome sequences (WGSs) were obtained, and a core genome multilocus sequence typing (cgMLST) method was developed to study the population structure of C. psittaci. Using the constructed cgMLST method, 72 WGSs were divided into four related groups and ten sub-clusters. The Lishui strains formed a unique population of C. psittaci, which might represent a new variant of C. psittaci. In vitro antimicrobial susceptibility testing suggested that the Lishui strains were sensitive to tetracycline, macrolides, quinolones, and no drug-resistance was observed.

Comparative long-term outcomes of pembrolizumab plus chemotherapy versus pembrolizumab monotherapy as first-line therapy for metastatic non-small-cell lung cancer: a systematic review and network meta-analysis.

Introduction: This systematic review and network meta-analysis(NMA) was designed to compare the long-term outcomes of pembrolizumab monotherapy and pembrolizumab plus chemotherapy as first-line therapy for metastatic non-small-cell lung cancer(NSCLC). Materials and Methods: Four databases(Medline, Embase, Web of Science and CENTRAL were searched published from establishment of database to August 17, 2023, for articles studying pembrolizumab monotherapy or pembrolizumab plus chemotherapy for non-small cell lung cancer (NSCLC). Network meta-analyses of progression-free survival(PFS), overall survival(OS), objective response rate(ORR), treatment-related adverse events(trAEs) and immune-related adverse events(irAEs) were performed. Results: A total of five studies were considered for NMA. This NMA includes a cohort of 2878 patients diagnosed with advanced NSCLC. Among them, 791 patients received pembrolizumab monotherapy, 1337 patients received chemotherapy, and 748 patients received pembrolizumab plus chemotherapy. The IPDformKM software was utilized to reconstruct Kaplan-Meier curves for OS and PFS, offering a lucid and intuitive depiction of oncological outcomes. For patients who have high levels of programmed death-ligand 1(PD-L1) expression (≥50%), pembrolizumab plus chemotherapy was more effective than using pembrolizumab alone as first-line therapy in terms of PFS (median survival time: 10.41 months versus 7.41 months, HR: 0.81, 95%CI 0.67 to 0.97, P=0.02) and ORR (RR:1.74, 95% CI: 1.25-2.43). Nevertheless, there was no statistically significant difference observed between the two groups in terms of OS (median survival time: 22.54 months versus 22.62 months, HR: 0.89, 95%CI 0.73 to 1.08, P=0.24). Furthermore, pembrolizumab plus chemotherapy provided a more advantageous long-term survival advantage in terms of OS (median survival time: 20.88 months versus 13.60 months, HR: 0.77, 95%CI: 0.62 to 0.95, P=0.015) compared to pembrolizumab monotherapy in patients with low PD-L1 expression levels (1% to 49%). With regards to safety, there was no statistically significant disparity between the two groups in relation to any irAEs (RD=0.02, 95% CI: -0.12 to 0.16) or Grade≥ 3 irAEs (RD=0.01, 95% CI: -0.10 to 0.12). Nevertheless, pembrolizumab plus chemotherapy exhibited a greater likelihood of encountering any trAEs (RD=0.23, 95% CI: 0.17 to 0.30) and Grade≥ 3 trAEs (RD=0.28, 95% CI: 0.21 to 0.35) in comparison to pembrolizumab monotherapy. Conclusions: The present network meta-analysis reported comparative long-term outcomes of pembrolizumab plus chemotherapy versus pembrolizumab monotherapy as first-line therapy for metastatic non-small-cell lung cancer. Pembrolizumab plus chemotherapy led to improved PFS and ORR in patients with advanced NSCLC who had a PD-L1 expression level of 50% or above. However, there was no noticeable benefit in terms of OS when pembrolizumab was paired with chemotherapy compared to utilizing pembrolizumab alone. In addition, pembrolizumab plus chemotherapy offered a greater long-term survival benefit in terms of OS when compared to utilizing pembrolizumab alone in patients with PD-L1 expression levels ranging from 1% to 49%. Furthermore, the increased effectiveness of pembrolizumab plus chemotherapy was accompanied by an increase in adverse side effects. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42024501740.