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PubMed2025

Systematic meta-analysis of the toxicities and side effects of the targeted drug lenvatinib.

BACKGROUND: Lenvatinib, an effective targeted drug for various cancers, has clinical medication safety concerns due to its toxicities and side effects. OBJECTIVE: This study evaluated lenvatinib-induced any adverse events (any AEs) and nine aspects: vascular toxicities related to the circulatory system (vascular toxicities, blood system, and heart), toxicities of the skin and its appendages (skin/subcutaneous tissue and taste system), toxicities of the respiratory system (respiratory, thoracic, and mediastinal and respiratory tract), toxicities of the nervous system (nervous system and general), toxicities of the digestive system (gastrointestinal and liver), toxicities of the urinary system, toxicities of the endocrine and metabolic system (endocrine and metabolism/nutrition), toxicities of the musculoskeletal system, and other severe toxicities. Toxicities and side effects were stratified by severity into any and &#x2265;3 grades for analysis. PATIENTS/MATERIALS AND METHODS: Multiple databases were searched for lenvatinib cancer clinical studies (cohort studies and randomized controlled trials) from inception to December 31, 2024; toxicity and side effect data were extracted and analyzed. RESULTS: Nine high-quality studies were included, showing that lenvatinib is effective in cancers but has notable toxicities. Taking hypertension as an example, for any grade, the risk ratio (RR) was 2.34 with a 95% confidence interval (CI) of [2.09, 2.62], a Z-value of 14.74, and a P-value <0.00001; for grade &#x2265;3, the RR was 2.60 with a 95% CI of [2.21, 3.06], a Z-value of 11.44, and a P-value <0.00001. CONCLUSION: Lenvatinib is effective for cancer but toxic, and this study supports its rational clinical use.

Humans↗
PubMed2026

TNF-NF-&#x3ba;B signaling mediates immune-biomineralization crosstalk during shell repair under ocean acidification in Mytilus edulis.

Ocean acidification (OA) impairs biomineralization in bivalves, but its effects on immune-biomineralization crosstalk during shell repair remain unknown. Here, we exposed adult Mytilus edulis bearing standardized shell perforations to three pH levels (8.1, 7.9, and 7.7) for up to 40 days. OA slowed early repair and caused microstructural disorganization and an approximately 87% reduction of compressive strength at pH 7.7, yet the damaged area appeared largely closed by day 15, suggesting a decoupling between morphological closure and functional recovery. In addition, transcriptomic profiling of hemocytes and mantle tissue, based on an average of 6.5&#x202f;Gb of clean reads per sample mapped to the M. edulis reference genome (NCBI Assembly GCF_000511035.1), revealed that these shell-level defects were accompanied by coordinated immune and metabolic reprogramming. Hemocytes, the primary immune effector cells of bivalves, exhibited pH- and time-dependent shifts with moderate acidification (pH 7.9) promoting inflammatory transcripts, whereas severe acidification (pH 7.7) suppressed these signals while upregulating stress-associated pathways; both treatments consistently downregulated lysosomal proteases and NF-&#x3ba;B negative regulators. The mantle, a primarily mineralizing organ, paradoxically upregulated immune-related genes while suppressing oxidative phosphorylation and extracellular matrix pathways. This tissue-level imbalance, with hemocytes recruited but functionally constrained and mantle metabolically suppressed yet immunologically activated, points to TNF-NF-&#x3ba;B pathway modulation as a key mediator of shell repair under acidification. Our findings demonstrate that visible shell closure masks underlying structural and mechanical failure, and that immune regulation, rather than simple suppression or activation, critically shapes the repair outcome. These results advocate for multifunctional indicators beyond closure area to assess shell integrity in acidified marine environments.

Animals↗
PubMed2026

Urinary Small Extracellular Vesicle DNA as a Biomarker for the Non-Invasive Diagnosis of Bladder Cancer.

Existing diagnostic technologies for bladder cancer (BC) suffer from low sensitivity, low specificity, or a lack of validation. Therefore, validated, non-invasive diagnostic biomarkers with high sensitivity and specificity for early detection of BC are needed to complement and improve upon the limitations of existing diagnostic methods. We used low-pass whole genome sequencing (LP-WGS) technology to detect copy number variations (CNVs) in small extracellular vesicle (sEV) DNA isolated from urine samples of patients. Based on these results, we constructed and validated a diagnostic model to differentiate between benign and malignant bladder lesions. We conducted a receiver operating characteristic analysis and calculated the area under the curve (AUC) to evaluate the performance of the diagnostic model. The urine sEV-DNA LP-WGS data revealed CNV differences between benign and malignant samples. The diagnostic model achieved an AUC of 0.953, a sensitivity of 86.7%, and a specificity of 100% in the training cohort and an AUC of 0.985, a sensitivity of 90%, and a specificity of 100% in the validation cohort. Even at the lowest coverage depth of 0.01X, the performance of the diagnostic model remained relatively robust. Notably, the performance of this diagnostic model surpassed that of the biomarker neuron-specific enolase (sensitivity: 85.7% vs. 64.3%; specificity: 100% vs. 87.5%) and urinary cytology (sensitivity: 100% vs. 66.7%; specificity: 100% vs. 94.1%). Our study demonstrates that urine sEV-DNA exhibits high discriminatory power in distinguishing between benign and malignant bladder lesions, making it a promising tool for auxiliary diagnosis of BC.

Humans↗
PubMed2026

Proteomic insights into the immunomodulatory effects of Ca/Sr co-doped sol-gel coatings for titanium implants.

Ionic functionalization of biomaterial coatings has emerged as a powerful strategy to regulate early host responses at the implant interface. However, how combined Ca/Sr incorporation governs the adsorbed proteome and downstream immune signaling remains poorly understood. This study analyses, employing in vitro tests and proteomics, the effect of adding Sr and Ca to Si-based coatings designed to bioactivate Ti implants. Hybrid Si-based coatings were synthesized by the sol-gel route with a fixed Ca content (0.5&#x202f;wt%) and increasing Sr contents (0.5, 1.0, 1.5&#x202f;wt%), and their physicochemical properties, ion release kinetics, and hydrolytic stability were characterized. The coatings remained highly crosslinked despite Ca/Sr incorporation, whereas the highest Sr content increased hydrolytic degradation to around 70% after 56 days. Proteomic analysis identified 183 adsorbed proteins, of which 56 were differentially adsorbed on Ca/Sr-coatings, mainly associated with immune and coagulation pathways. In vitro, RAW 264.7 showed increased gene expression of TNF-&#x3b1; and TGF-&#x3b2;; with an enhanced TNF-&#x3b1; secretion by the addition of Ca and Sr. In parallel, MC3T3-E1 indicated that Ca/Sr-coatings were not cytotoxic and did not impair cell proliferation. However, ALP activity was reduced in the co-doped groups, indicating that the immunomodulatory effects induced by Ca/Sr incorporation were not accompanied by enhanced early osteogenic differentiation. The Ca/Sr combination induced alterations in the adsorption of immune-related proteins, which correlated with the in vitro findings. The deeper insight into how Ca/Sr mixtures modulate protein adsorption on biomaterial surfaces may be key to understanding the immunomodulatory capacity of these bioactive cations.

Animals↗
PubMed2026

METTL14-mediated m6A modification of CCNE1 accelerates progression of myelodysplastic syndromes via MAPK-ERK and PI3K-AKT signaling pathways.

BACKGROUND: N6-methyladenosine (m6A) is the most common RNA modification and plays a key role in the initiation, progression, and relapse of multiple cancers, including hematologic malignancies. However, the role of m6A and m6A regulatory genes in myelodysplastic syndromes (MDS) remains unclear. This study aims to elucidate the function and molecular mechanism of methyltransferase METTL14 in MDS. METHODS: RT-qPCR was used to assess the expression of multiple m6A regulators, focusing on METTL14 in MDS patients and cell lines. METTL14 overexpressing and knockdown cell lines were established, and CCK-8, EdU, and flow cytometry assays were performed to explore the biological functions of METTL14.Dot blot, MeRIP-Seq, MeRIP-qPCR, RT-qPCR, and Western blot were employed to investigate the underlying molecular mechanism. RESULTS: Dysregulation of multiple m6A regulators was observed in MDS, among which METTL14 was upregulated. Elevated METTL14 expression increases MDS risk and adverse prognosis, emerging as a biomarker for poor prognosis. METTL14 promoted proliferation and cell-cycle progression of MDS cells while inhibiting apoptosis; corresponding changes were observed in cell cycle and apoptosis markers. METTL14 regulated cellular m6A levels. Downstream targets of METTL14 were enriched in cell cycle-related pathways, with CCNE1 identified as a critical target. Knockdown of METTL14, actinomycin D, or S-adenosylhomocysteine treatment reduced CCNE1 mRNA and protein levels. Furthermore, METTL14 activated MAPK-ERK and PI3K-AKT signaling via CCNE1 in an m6A-dependent manner, thereby promoting proliferative MDS cells' capacity. CONCLUSIONS: This study delineates a METTL14/m6A/CCNE1 signaling axis in MDS progression and suggests that METTL14-mediated m6A modification may be a potential therapeutic target for MDS.

Humans↗
PubMed2026

Feasibility of routine clinical liquid-based cytology for lung cancer compact panel testing.

BACKGROUND: The Lung Cancer Compact Panel (cPANEL) is a recently approved highly sensitive multiplex gene panel in Japan that supports both DNA- and RNA-based next-generation sequencing. Although cytological specimens are acceptable for cPANEL, unfixed cell pellets or dedicated preservation tubes are typically recommended. However, evidence remains limited regarding whether residual liquid-based cytology (LBC) cell suspensions prepared for routine cytological diagnosis can be used directly for cPANEL testing without dedicated molecular preservation or additional preanalytical processing. In this study, we evaluated the feasibility of applying LBC specimens that are widely used in contemporary clinical practice to cPANEL. METHODS: We analyzed DNA and RNA quality in 69 clinical LBC specimens. Among these, 51 specimens containing non-small cell lung cancer cells with previously determined driver alteration status were subjected to cPANEL testing to evaluate assay concordance with clinical companion diagnostic results. RESULTS: DNA integrity was generally well preserved (DNA Integrity Number [DIN]: 6.2&#xa0;&#xb1;&#xa0;1.5). In contrast, RNA integrity showed greater variability (DV200: 16.4&#xa0;&#xb1;&#xa0;12.1%). ThinPrep-fixed specimens demonstrated lower DIN and DV200 values compared with CytoRich Red-fixed specimens. Although all samples successfully passed the DNA-based cPANEL assay, six cases (11.8%) failed the RNA-based assay, with RNA yield being a major contributing factor. Among the 46 evaluable specimens, concordance was 95.7% and sensitivity was 92.3%, or 88.9% including RNA module failures as cPANEL-negative. CONCLUSIONS: With appropriate fixative selection and adequate cellularity, cPANEL using clinical LBC specimens may serve as a practical diagnostic platform. We demonstrated that routine LBC specimens can be directly applied to cPANEL without special preanalytical processing.

Humans↗
PubMed2026

Bone progression in multiple myeloma: Benefit of zoledronic acid for patients achieving at least Very Good Partial Response and prognostic value of bone turnover markers.

The Magnolia study demonstrated that continuation of zoledronic acid (ZOL) beyond 2&#x2009;years reduces the risk of progressive bone disease (PBD) in patients with multiple myeloma (MM). This follow-up study investigated the effects of ZOL in patients achieving very good partial response (VGPR) compared to patients who did not and whether bone turnover markers could identify patients at an increased risk of PBD following treatment cessation. Two Magnolia trial subgroups were analysed: patients with VGPR or better after 2&#x2009;years of ZOL, randomized to either continued treatment or observation, and patients randomized to observation in whom serial bone markers (C-terminal cross-linked telopeptide of type I collagen [CTX], procollagen type I N-terminal propeptide [P1NP], bone-specific alkaline phosphatase [BAP], tartrate-resistant acid phosphatase isoform 5b [TRAcP]) were measured for up to 4&#x2009;years. Continued monthly ZOL beyond 2&#x2009;years significantly reduced the risk of PBD (hazard ratio 0.40; 95% confidence interval [CI] 0.16-0.92) in patients with VGPR or better (subgroup 1). After ZOL discontinuation, bone markers increased gradually. Elevated CTX (&#x2265;0.30&#x2009;&#x3bc;g/L) and TRAcP (&#x2265;4&#x2009;U/L) levels were associated with increased 6-month PBD risk (29% and 15% respectively) (subgroup 2). Continuation of ZOL beyond 2&#x2009;years seems to reduce skeletal progression risk in patients achieving VGPR or better. Elevated CTX or TRAcP levels may help identify patients who could benefit from re-initiating ZOL.

Humans↗
PubMed2026

Complicated urinary tract infections: evolving definitions, clinical burden, and treatment landscape amid antimicrobial resistance.

INTRODUCTION: Complicated urinary tract infection (cUTI) is a common and heterogeneous infection associated with substantial morbidity, high healthcare utilization, and increasing antimicrobial resistance. Evolving definitions, increasing device use, and changing patient populations have altered its epidemiology and management. Marked variability in diagnostic criteria, clinical trial endpoints within and outside registrational settings, and treatment strategies complicates clinical decision-making and interpretation of therapeutic advances. AREAS COVERED: This review examines contemporary cUTI epidemiology, classification frameworks, and drivers of disease burden. It evaluates resistance trends and their therapeutic implications, alongside stewardship-based management strategies, including empiric antibiotic selection, intravenous-to-oral transition, treatment duration, and source control. Challenges in catheter-associated infection, recurrence, and regulatory endpoint design are discussed, together with the emerging role of novel agents targeting resistant Gram-negative pathogens. EXPERT OPINION: Rising multidrug resistance and limited oral options are reshaping cUTI management, necessitating individualized, stewardship-aligned therapy guided by illness severity and local epidemiology. Current regulatory endpoints inadequately reflect patient-centered outcomes, particularly in the context of asymptomatic bacteriuria. Expanding availability of effective oral agents may enable earlier discharge and outpatient care. Integration of rapid diagnostics and risk stratification will be essential to optimize therapy, limit resistance, and improve outcomes.

Humans↗
PubMed2026

Promoter Methylation of HOXA5 and NDRG2 in Multiple Myeloma Patients with Renal Impairment.

Renal impairment (RI) is frequently caused by multiple myeloma (MM), which makes clinical care more difficult if renal function deteriorates or renal failure develops. Thus, in this investigation, we looked at the relationship between HOXA5&NDRG2 promoter methylation in MM patients and evaluated their prognostic potential in predicting RI risk in MM patients.&#xa0;This study included 60 control volunteers and 120 MM patients. The promoter methylations of HOXA5&NDRG2 were quantitatively evaluated by real-time PCR (qPCR) after the extraction of gDNA from whole blood and then treated with bisulfite.&#xa0;The promoter methylation percentages of HOXA5&NDRG2 were significantly increased in MM patients (77.16&#x2009;&#xb1;&#x2009;2.43&45.49&#x2009;&#xb1;&#x2009;2.16;p&#x2009;<&#x2009;0.05) when compared to controls (4.47&#x2009;&#xb1;&#x2009;0.61&3.33&#x2009;&#xb1;&#x2009;0.31,respectively), in stage II&III patients when compared to stage I patients and in patients with age&#x2009;&#x2265;&#x2009;60 years when compared to patients with age&#x2009;<&#x2009;60 years. While only the methylation percentage of NDRG2 promoter was significantly increased in MM patients with RI (53.61&#x2009;&#xb1;&#x2009;3.21,p&#x2009;<&#x2009;0.05) when compared to MM patients without RI (37.37&#x2009;&#xb1;&#x2009;2.04). Results obtained from ROC curve revealed that both HOXA5&NDRG2 promoter methylation were good diagnostic tools for MM. The NDRG2 promoter methylation was good prognostic biomarker could predict renal while HOXA5 promoter in the prediction of MM staging. The Kaplan-Meier survival test showed that patients with higher HOXA5&NDRG2 promoter methylation had a shorter OS and a worse prognosis. Only NDRG2 promoter hypermethylation was significantly associated with the risk of RI development in MM patients.&#xa0;HOXA5&NDRG2 promoter hypermethylation may have roles in the molecular etiology of MM and could be used as a treatment regimen.

Humans↗
PubMed2026

PGR expression as a pharmacogenomic companion biomarker to GENE70-derived genomic risk in ER-positive/HER2-negative breast cancer.

BACKGROUND: The biology of the estrogen receptor-positive (ER+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancers is heterogeneous even when they are categorized by their risk via genomics. Transcriptomic PGR expression reflects endocrine pathway activity and may provide complementary biological information within established GENE70-derived genomic-risk categories. Whether this molecular marker improves the biological interpretation of genomic-risk stratification beyond conventional clinicopathological assessment remains uncertain. OBJECTIVES: The aim of this study was to determine whether transcriptomic PGR expression provides complementary biological and prognostic information within reconstructed GENE70-derived genomic-risk categories and refines the characterization of endocrine-related tumour biology in ER-positive/HER2-negative breast cancer. METHODS: This study analysed publicly available transcriptomic and clinical data from three cohorts: METABRIC (discovery cohort), GSE96058/SCAN-B cohort (validation cohort) and TCGA-BRCA cohort (molecular validation cohort). The GENE70-derived genomic-risk score was reconstructed for each cohort using matched genes. Cox regression, Kaplan-Meier analysis and subgroup comparisons were used to assess relationships between PGR expression, clinicopathologic variables, molecular features and survival outcomes. RESULTS: Across the three independent cohorts, low transcriptomic PGR expression was consistently associated with higher GENE70-derived genomic risk, increased MKI67 expression, reduced ESR1 expression and enrichment of the Luminal B subtype. Survival findings differed between cohorts. In the discovery METABRIC cohort, transcriptomic PGR expression showed heterogeneous associations with survival, particularly within GENE70-derived high-risk subgroups, whereas the external GSE96058/SCAN-B validation cohort demonstrated consistent associations between low PGR expression and poorer overall survival in both the overall ER-positive/HER2-negative population and GENE70-derived high-risk subgroups. CONCLUSION: These findings suggest that transcriptomic PGR provides complementary biological and prognostic information within GENE70-derived genomic-risk categories. However, because treatment response was not evaluated in the present study, the findings should not be interpreted as evidence of predictive or pharmacogenomic utility and prospective studies incorporating treatment-response analyses are required before such applications can be established.

Humans↗
PubMed2026

Association of cancer antigen 15-3 with distant recurrence in immunohistochemically defined breast cancer subtypes in Canadian Cancer Trials Group MA.32.

BACKGROUND: Circulating levels of cancer antigen (CA) 15-3 have been associated with distant breast cancer recurrence; data on breast cancer subtypes are sparse. We examined associations of CA 15-3 with outcomes across immunohistochemically defined breast cancer subtypes in MA.32. METHODS: A total of 3649 participants with T1-3, N0-1, M0 breast cancer were randomly assigned; 2740 (75.1%) provided blood at entry (mean = 278&#x2009;days postdiagnosis) and 6&#x2009;months later. Prognostic associations of baseline and 6-month change in CA 15-3 with distant recurrence-free survival (RFS) were examined in luminal (estrogen receptor-positive and/or progesterone receptor-positive, HER2-negative), triple-negative (estrogen receptor, progesterone receptor, HER2 negative) and HER2-positive (any estrogen receptor, progesterone receptor) breast cancer using Cox proportional hazards models. RESULTS: Mean age was 52&#x2009;years. Breast cancer was luminal in 1589 (58.7%), triple negative in 655 (24.2%), and HER2 positive in 464 (17.1%) participants. Median follow-up was 96&#x2009;months. CA 15-3 at study entry was not associated with outcome in any subtype. Rising CA 15-3 at 6&#x2009;months was associated with poor distant RFS in luminal and triple-negative breast cancer (hazard ratio [HR] per 25% increase&#x2009;=&#x2009;1.41, P&#x2009;<&#x2009;.0001, and HR = 1.35, P&#x2009;<&#x2009;.0001, respectively). New elevations in CA 15-3 at 6&#x2009;months were adversely associated with distant RFS in those with luminal or triple-negative breast cancer (HR = 4.14, 95% CI = 2.69 to 6.38; P&#x2009;<&#x2009;.001; and HR = 3.57, 95% CI = 1.59 to 7.99; P&#x2009;=&#x2009;.002, respectively). In HER2-positive breast cancer, CA15-3 was not associated with distant RFS. CONCLUSION: Rising CA 15-3 was associated with reduced distant RFS in luminal and triple-negative breast cancer but not in HER2-positive breast cancer. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT01101438.

Humans↗
PubMed2026

Effectiveness of chlorhexidine gluconate-impregnated dressings in preventing central line-associated bloodstream infection in a paediatric intensive care unit: A randomised controlled trial.

OBJECTIVES: To compare the effectiveness and dermatological safety of chlorhexidine gluconate (CHG)-impregnated dressings versus conventional transparent dressings in preventing central line-associated bloodstream infection (CLABSI) in paediatric patients admitted to a PICU. METHODS: A single-blind, randomised controlled trial with a 1:1 allocation ratio was conducted in a tertiary PICU. A total of 250 paediatric patients with a central venous catheter were included (125 per group). Patient characteristics, catheter-related variables, catheter dwell time and skin alterations were recorded. The primary outcome was CLABSI, defined according to CDC/NHSN criteria. Bivariate analyses and multivariable logistic regression were performed, including clinically relevant covariates related to catheter exposure, dressing type, and vaccination status. The trial was registered at ClinicalTrials.gov (NCT07175116). RESULTS: CLABSI incidence was significantly lower in the CHG group compared with the conventional dressing group (2.4% vs. 18.4%; p&#xa0;<&#xa0;0.001). In multivariable analysis, CHG-impregnated dressings were independently associated with reduced CLABSI risk (OR = 0.15; 95% CI: 0.04-0.58). Longer catheter dwell time (OR = 1.13 per day; 95% CI: 1.04-1.22) and absence of complete vaccination (OR = 8.68; 95% CI: 2.48-30.47) were also associated with increased infection risk. Incomplete vaccination showed a similar trend without reaching statistical significance (OR = 6.48; 95% CI: 0.95-44.20). Skin alterations were more frequent in the CHG group (16.8% vs. 11.2%), predominantly in younger infants. CONCLUSIONS: CHG-impregnated dressings were associated with a significant reduction in CLABSI incidence in critically ill paediatric patients, although their use was linked to a modest increase in mild skin reactions. IMPLICATIONS FOR CLINICAL PRACTICE: CHG-impregnated dressings may be considered as part of a multifaceted infection prevention strategy, alongside appropriate catheter management, minimisation of catheter manipulation and proactive skin monitoring, with cautious and individualised use in infants.

Humans↗
PubMed2026

Genomic epidemiology of clinically critical antibiotic resistance in Salmonella enterica causing bloodstream infections across six Chinese provinces, 1994-2023.

Clinically critical antibiotic-resistant Salmonella enterica (S. enterica) causing bloodstream infections remains a public health challenge. Here, we aim to reveal the emergence and trends of clinically important antibiotic resistance in S. enterica causing bloodstream infections using 833 isolates from six Chinese provincial-level administrative areas during 1994-2023. We identified 48 serovars and 64 sequence types (STs). Overall, 8.52% of 833 isolates were resistant or had decreased susceptibility to ciprofloxacin, 4.32% and 6.84% reported resistance or decreased susceptibility to third- and fourth-generation cephalosporins (3GCs and 4GCs), 1.80% reported resistance to fosfomycin, and 2.16% reported resistance to azithromycin. Across these six regions, azithromycin and fosfomycin resistance is increasing, as is decreased susceptibility or resistance to ciprofloxacin, 3GCs, and 4GCs, especially among younger children and elderly people. Clinically prioritized antibiotic resistance also varies by region, serovar, and age group. S. Paratyphi A genotype 2.3.3 strains are mainly divided into 2 lineages distributed in Guangxi and Shanghai. Within the scope of this passive surveillance dataset, S. Typhi genotype 4.3.1.2.1 was identified as the earliest documented case among the collected isolates. Our retrospective and longitudinal genomic epidemiology study provides critical data for the formulation of treatment guidelines and policies for bloodstream infections and for the monitoring and control of antimicrobial resistance.

Humans↗
PubMed2026

A novel peptide encoded by circTLL1 drives osimertinib resistance in lung cancer by modulating the NT5C2/Ras/PI3K axis.

BACKGROUND: Acquired resistance to osimertinib, a third-generation EGFR tyrosine kinase inhibitor, remains a major clinical challenge in the treatment of non-small cell lung cancer (NSCLC). Although circular RNAs (circRNAs) have been increasingly implicated in drug resistance, most studies have focused on their canonical role as microRNA sponges, while their capacity to encode functional micropeptides remains largely unexplored. This study aimed to identify novel circRNAs involved in osimertinib resistance and to characterize their regulatory functions at the protein level. METHODS: Osimertinib-resistant (OR) NSCLC cell lines were established and validated. High-throughput RNA sequencing was performed to compare the circRNA expression profiles between parental and OR cells. The function of the candidate circRNA was assessed through a series of in vitro and in vivo experiments, including cell viability assays, apoptosis analysis, and xenograft mouse models. Mechanistic investigations involved mass spectrometry, co-immunoprecipitation and western blotting to explore its protein-coding potential and downstream signaling pathways. RESULTS: We identified a novel circRNA, termed circTLL1, that was stably and significantly upregulated in OR-NSCLC cells. Functionally, overexpression of circTLL1 promoted osimertinib resistance, whereas its knockdown restored drug sensitivity both in vitro and in vivo. Mechanistically, we discovered that circTLL1 harbors an open reading frame (ORF) that is translated into a novel 90-amino-acid protein, which we designated circTLL1-90aa. Further investigation revealed that circTLL1-90aa directly interacts with and promotes the degradation of 5'-nucleotidase, cytosolic II (NT5C2), thereby uncoupling nucleotide metabolism from its normal regulatory constraints. The consequent downregulation of NT5C2 leads to elevated GTP levels and leading to the sustained activation of the downstream Ras/PI3K/AKT signaling pathway. CONCLUSION: Our findings unveil a previously unrecognized circRNA/micropeptide/metabolism cascade underlying osimertinib resistance. The identification of the circTLL1-90aa/NT5C2/Ras/PI3K axis not only expands the functional repertoire of the non-coding genome but also provides new insights into the complexity of drug resistance. Given its selective upregulation in resistant cells, circTLL1-90aa holds promise both as a predictive biomarker for treatment stratification and as an actionable therapeutic target, offering a novel strategy to overcome osimertinib resistance in NSCLC patients.

Pyrimidines↗