The contribution of tumor necrosis factor to multiple sclerosis: a possible role in progression independent of relapse?

Tumor necrosis factor (TNF) is a pleiotropic cytokine regulating many physiological and pathological immune-mediated processes. Specifically, it has been recognized as an essential pro-inflammatory cytokine implicated in multiple sclerosis (MS) pathogenesis and progression. MS is a chronic immune-mediated disease of the central nervous system, characterized by multifocal acute and chronic inflammatory demyelination in white and grey matter, along with neuroaxonal loss. A recent concept in the field of MS research is disability resulting from Progression Independent of Relapse Activity (PIRA). PIRA recognizes that disability accumulation since the early phase of the disease can occur independently of relapse activity overcoming the traditional dualistic view of MS as either a relapsing-inflammatory or a progressive-neurodegenerative disease. Several studies have demonstrated an upregulation in TNF expression in both acute and chronic active MS brain lesions. Additionally, elevated TNF levels have been observed in the serum and cerebrospinal fluid of MS patients. TNF appears to play a significant role in maintaining chronic intrathecal inflammation, promoting axonal damage neurodegeneration, and consequently contributing to disease progression and disability accumulation. In summary, this review highlights the current understanding of TNF and its receptors in MS progression, specifically focusing on the relatively unexplored PIRA condition. Further research in this area holds promise for potential therapeutic interventions targeting TNF to mitigate disability in MS patients.

Changes in immunophenotypes after neoadjuvant endocrine therapy for prostate cancer and their clinical significance.

Background: To investigate changes in the immunophenotypes of androgen receptor (AR), prostate-specific antigen (PSA), synaptophysin (Syn), chromogranin A (CgA), p53 and Ki-67 after neoadjuvant endocrine therapy (NET) for prostate cancer (PCa) and to analyze their clinical significance. Methods: Paired paraffin samples were collected from 40 PCa patients before and after NET, and immunohistochemistry were used to detect AR, PSA, Syn, CgA, p53 and Ki-67 expression. Based on The Cancer Genome Atlas (TCGA), Kaplan‒Meier survival curves were plotted for analysis of PSA and Ki-67 expression in relation to progression-free survival (PFS). Results: After NET, the mean scores for PSA and Ki-67 expression in PCa patients were lower than those before NET (P < 0.05), while the mean scores for Syn and CgA expression were higher than those before NET (P < 0.05). The mean Gleason score and WHO/ISUP (World Health Organization/International Society of Urological Pathology) grade after NET were lower than those before NET (P < 0.05). In PCa patients who had not yet received NET, PSA expression correlated positively with Gleason score and WHO/ISUP grade and negatively with Ki-67 expression (P < 0.05); p53 expression correlated negatively with Gleason score and WHO/ISUP grade (P < 0.05). TCGA showed that PFS was lower in PCa patients with high PSA and Ki-67 expression (P < 0.05). Conclusions: PSA and Ki-67 protein expressions decreased significantly in PCa patients after NET and can be used as biological markers for prognostic assessment of PCa patients. NETs may induce a neuroendocrine (NE) phenotype in PCa. Monitoring the immunophenotypes of PCa patients after NET may inform assessment of efficacy and prognosis.

Patients with multiple sclerosis who develop immunogenicity to interferon-beta have distinct transcriptomic and proteomic signatures prior to treatment which are associated with disease severity.

Anti-drug antibodies (ADA) reduce the efficacy of immunotherapies in multiple sclerosis (MS) and are associated with increased disease progression risk. Blood biomarkers predicting immunogenicity to biopharmaceuticals represent an unmet clinical need. Patients with relapsing remitting (RR)MS were recruited before (baseline), three, and 12 (M12) months after commencing interferon-beta treatment. Neutralising ADA-status was determined at M12, and patients were stratified at baseline according to their M12 ADA-status (ADA-positive/ADA-negative). Patients stratified as ADA-positive were characterised by an early dampened response to interferon-beta (prior to serum ADA detection) and distinct proinflammatory transcriptomic/proteomic peripheral blood signatures enriched for 'immune response activation' including phosphoinositide 3-kinase-γ and NFκB-signalling pathways both at baseline and throughout the treatment course, compared to ADA-negative patients. These immunogenicity-associated proinflammatory signatures significantly overlapped with signatures of MS disease severity. Thus, whole blood molecular profiling is a promising tool for prediction of ADA-development in RRMS and could provide insight into mechanisms of immunogenicity.

Targeting NETosis: nature's alarm system in cancer progression.

Neutrophils are recognized active participants in inflammatory responses and are intricately linked to cancer progression. In response to inflammatory stimuli, neutrophils become activated, releasing neutrophils extracellular traps (NETs) for the capture and eradication of pathogens, a phenomenon termed NETosis. With a deeper understanding of NETs, there is growing evidence supporting their role in cancer progression and their involvement in conferring resistance to various cancer therapies, especially concerning tumor reactions to chemotherapy, radiation therapy (RT), and immunotherapy. This review summarizes the roles of NETs in the tumor microenvironment (TME) and their mechanisms of neutrophil involvement in the host defense. Additionally, it elucidates the mechanisms through which NETs promote tumor progression and their role in cancer treatment resistance, highlighting their potential as promising therapeutic targets in cancer treatment and their clinical applicability.

Ultrasound characteristics of extravaginal testicular torsion at different stages of disease progression.

Background: Extravaginal testicular torsion has profound clinical implications in neonates, but its ultrasound characteristics may vary at different disease stages. The purpose of this study was to identify the ultrasound characteristics of neonatal extravaginal testicular torsion and their diagnostic value at different disease stages. Methods: A retrospective analysis of the clinical and ultrasound examination data of 20 infants aged 1-75 days with surgically and pathologically confirmed unilateral extravaginal testicular torsion (10 right, 10 left) was conducted. The infants were divided into three stages based on the ultrasound characteristics: double-ring effusion, calcification of the tunica vaginalis, and testicular atrophy. Results: In the double-ring effusion stage, the affected testicles were enlarged with axial abnormalities, with the parenchymal testicular blood flow signal significantly reduced or absent. Twisted paratesticular masses and a "double-ring effusion sign" were visible. In the tunica vaginalis calcification stage, the affected testicles were slightly smaller, with axial abnormalities, absent blood flow signals in the testicular parenchyma, and strong echogenicity of the tunica vaginalis. In the testicular atrophy stage, the affected testicles were markedly smaller, with enhanced echogenicity in the tunica vaginalis and parenchyma, and absent blood flow signal in the testicular parenchyma. The volumes of the affected testicles gradually decreased from the stage of double-ring effusion to that of tunica vaginalis calcification, and then to testicular atrophy (P<0.05). Conclusions: Neonatal extravaginal testicular torsion at different disease stages has distinct ultrasound features, and color doppler ultrasound plays an important role in the diagnosis and treatment of extravaginal testicular torsion.

Efficacy and safety of hypofractionated radiotherapy versus conventional fractionated radiotherapy in diffuse intrinsic pontine glioma: A systematic review and meta-analysis.

Background: Diffuse intrinsic pontine glioma (DIPG) stands as the predominant type of brainstem glioma. It is characterized by a notably brief median survival period, with the majority of patients experiencing disease progression within six months following radiation therapy. This systematic review and meta-analysis aims to assess the efficacy and safety of hypofractionated radiotherapy (HFRT) compared to conventionally fractionated radiotherapy (CFRT) in DIPG treatment. Materials and methods: A systematic literature search was conducted in four databases, and relevant studies comparing HFRT and CFRT in DIPG were included. Data were extracted and analyzed for overall survival (OS), progression-free survival (PFS), and treatment-related toxicities. Statistical analysis was performed using random-effects models with heterogeneity assessment. Results: Five studies met the inclusion criteria, comprising 518 patients. No significant difference in one-year OS was observed between HFRT and CFRT (29% vs. 22%, p = 0.94). The median OS was similar in both treatment groups (9.7 vs. 9.3 months, p = 0.324). Similarly, no significant difference in one-year PFS was found between HFRT and CFRT (19.8% vs. 16.6%, p = 0.82), with comparable median PFS (9.3 vs. 9.4 months, p = 0.20). In meta-regression analysis, there was no association of chemotherapy (p > 0.05) or radiation biologically effective dose (BED) (p > 0.05) regarding OS or PFS outcomes. There were no significant differences in treatment-related toxicities. Conclusions: HFRT yields one-year OS and PFS rates similar to CFRT in DIPG, with no significant differences in treatment-related toxicities. Chemotherapy and BED did not affect OS or PFS.

Uromodulin and progression of IgA nephropathy.

Background: This study investigates the link between genetic variants associated with kidney function and immunoglobulin A (IgA) nephropathy (IgAN) progression. Methods: We recruited 961 biopsy-proven IgAN patients and 651 non-IgAN end-stage renal disease (ESRD) patients from Ruijin Hospital. Clinical and renal pathological data were collected. The primary outcome was the time to ESRD. A healthy population was defined as estimated glomerular filtration rate >60 mL/min/1.73 m2 without albuminuria or hematuria. Fifteen single-nucleotide polymorphisms (SNPs) were selected from a genome-wide association study of kidney function and genotyped by the SNaPshot. Immunohistochemistry in renal tissue and ELISA in urine samples were performed to explore the potential functions of genetic variations. Results: The rs77924615-G was independently associated with an increased risk for ESRD in IgAN patients after adjustments for clinical and pathologic indices, and treatment (adjusted hazard ratio 2.10; 95% confidence interval 1.14-3.88). No significant differences in ESRD-free survival time were found among different genotypes in non-IgAN ESRD patients (log-rank, P = .480). Moreover, rs77924615 exhibited allele-specific enhancer activity by dual-luciferase reporter assay. Accordingly, the urinary uromodulin-creatinine ratio (uUCR) was significantly higher in healthy individuals with rs77924615 AG or GG than in individuals with AA. Furthermore, uromodulin expression in tubular epithelial cells was higher in patients with rs77924615 AG or GG. Finally, we confirmed that an increased uUCR (P = .009) was associated with faster IgAN progression. Conclusion: The SNP rs77924615, which modulates the enhancer activity of the UMOD gene, is associated with renal function deterioration in IgAN patients by increasing uromodulin levels in both the renal tubular epithelium and urine.

Non-target lesion progression: Unveiling critical predictors and outcomes in patients with in-stent restenosis.

BACKGROUND: Percutaneous coronary intervention (PCI) has become the primary treatment for coronary artery disease. However, while PCI effectively addresses severe stenosis or occlusive lesions in target vessels, the progression of non-target vessel plaque remains a critical determinant of long-term patient prognosis. AIMS: The purpose of this study was to investigate the impact of non-target vascular plaque progression on prognosis after PCI for ISR. METHODS: This study included 195 patients diagnosed with ISR and multivessel disease who underwent successful PCI with drug-eluting stent (DES) placement, along with intraoperative optical coherence tomography (OCT) assessment of the culprit stent. Subsequent rechecked coronary angiography categorized eligible patients into non-target lesion progression (N-TLP) and no-N-TLP groups. We evaluated the baseline morphological characteristics of N-TLP by OCT and investigated the relationship between N-TLP, non-culprit vessel-related major adverse cardiovascular events (NCV-MACE), and pan-vascular disease-related clinical events (PVD-CE) incidence. RESULTS: Multivariate logistic regression analysis revealed that diabetes mellitus (OR 3.616, 95% CI: 1.735-7.537; P = 0.001), uric acid level (OR 1.005, 95% CI: 1.001-1.009; P = 0.006), in-stent neoatherosclerosis (ISNA) (OR 1.334, 95% CI: 1.114-1.985; P = 0.047) and heterogeneous neointima morphology (OR 2.48, 95% CI: 1.18-5.43; P = 0.019) were independent predictors for N-TLP. Furthermore, N-TLP was associated with a high incidence of NCV-MACE (19.4% vs 6.9%, P = 0.009) and PVD-CE (83.9% [95% CI: 79.7%-88.3%] vs 93.1% [95% CI: 88.4%-98.0%], P = 0.038) after PCI in ISR patients. CONCLUSION: Diabetes, uric acid levels, ISNA, and heterogeneous neointima are predictive factors for subsequent rapid plaque progression, with N-TLP exacerbating the incidence of NCV-MACE and PVD-CE after PCI.

PRSS50-mediated inhibition of MKP3/ERK signaling is crucial for meiotic progression and sperm quality.

Serine protease 50 (PRSS50/TSP50) is highly expressed in spermatocytes. Our study investigated its role in testicular development and spermatogenesis. Initially, PRSS50 knockdown was observed to impair DNA synthesis in spermatocytes. To further explore this, we generated PRSS50 knockout ( Prss50 -/- ) mice ( Mus musculus), which exhibited abnormal spermatid nuclear compression and reduced male fertility. Furthermore, dysplastic seminiferous tubules and decreased sex hormones were observed in 4-week-old Prss50 -/- mice, accompanied by meiotic progression defects and increased apoptosis of spermatogenic cells. Mechanistic analysis indicated that PRSS50 deletion resulted in increased phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and elevated levels of MAP kinase phosphatase 3 (MKP3), a specific ERK antagonist, potentially accounting for testicular dysplasia in adolescent Prss50 -/- mice. Taken together, these findings suggest that PRSS50 plays an important role in testicular development and spermatogenesis, with the MKP3/ERK signaling pathway playing a significant role in this process.

[Possibilities of magnetic resonance morphometry and laboratory biomarkers in studying the progression of multiple sclerosis]. / Vozmozhnosti magnitno-rezonansnoi morfometrii i laboratornykh biomarkerov v izuchenii progressirovaniya rasseyannogo skleroza.

OBJECTIVE: To show that magnetic resonance morphometry and laboratory biomarkers are promising methods for early detection of progressive forms of multiple sclerosis (MS). MATERIAL AND METHODS: Eighty-one patients with MS were examined, magnetic resonance morphometry was performed in all of them, 60 patients were analyzed for neurofilament light chains (sNFL), phosphorylated neurofilament heavy chains (spNFH) and glial fibrillary protein (sGFAP) in serum by enzyme-linked immunosorbent assay. RESULTS: Brain volumes were negatively correlated with disease duration, EDSS score, 25-foot walk test score and 9-ring test and positively correlated with the Symbol-Numeric Test and the Montreal Cognitive Assessment. Patients with progressive types of MS (PMS) had smaller volumes of brain gray matter, cerebellar white matter, occipital lobes, caudate nucleus, hippocampus, pallidum, thalamus, and contiguous nucleus. A CSF volume greater than 15.06% could suggest progression (CI 54.79-91%) with a sensitivity of 77.78% and specificity of 70.18%. When patients were on DMT, they had larger thalamic volumes (median 1.09% [1.6; 1.16] vs 1.04% [0.95; 1.14]; p=0.02) and smaller CSF volumes (13.86±2.87% vs. 15.55±3.49%; p=0.03). The levels of sNFL and spNFH were not increased in PMS and during exacerbations, and the low obtained values of sNFL suggest poor sensitivity of the method. There were trends (p=0.374) towards higher sGFAP in patients with PRS (median 3.2 ng/mL [1.85; 4.6] compared to remitting MS (2.05 ng/mL [1.29; 4.52]). CONCLUSION: The results demonstrate the differences in brain volumes in patients with different types of MS and emphasize the importance of long-term follow-up to better assess disease progression.

Understanding the impact of slowing disease progression for individuals with biomarker confirmed early symptomatic Alzheimer's disease.

Recent advances in development of amyloid-targeting therapies support the potential to slow the rate of progression of Alzheimer's disease. We conducted a narrative review of published evidence identified through a targeted search of the MEDLINE and EMBASE databases (2020-2023), recent presentations at disease-specific conferences, and data updates from cohort studies in Alzheimer's disease to describe the trajectory of progression of Alzheimer's disease. Our findings enable interpretation of clinical trial results and the value associated with slowing disease progression across outcomes of relevance to patients, care partners, clinicians, researchers and policymakers.Even at the earliest stages, Alzheimer's disease imposes a substantial burden on individuals, care partners, and healthcare systems. The magnitude of burden increases with the rate of disease progression and symptom severity, as worsening cognitive decline and physical impairment result in loss of functional independence. Data from cohort studies also indicate that slowing disease progression is associated with decreased likelihood of needing extensive clinical care over at least 5 years, decreased care partner burden, and substantial individual and societal cost savings.Slowed disease progression is of significant benefit to individuals with Alzheimer's disease, their loved ones, and the healthcare system. As clinicians and policymakers devise strategies to improve access to treatment earlier in the disease spectrum, they should carefully weigh the benefits of slowing progression early in the disease (e.g., preservation of cognitive and functional abilities, as well as relative independence) to individuals, their loved ones, and broader society.

Estrogen Signals through ERß in Breast Cancer; What We Have Learned since the Discovery of the Receptor.

Estrogen receptor (ER) ß (ERß) is the second ER subtype that mediates the effects of estrogen in target tissues along with ERα that represents a validated biomarker and target for endocrine therapy in breast cancer. ERα was the only known ER subtype until 1996 when the discovery of ERß opened a new chapter in endocrinology and prompted a thorough reevaluation of the estrogen signaling paradigm. Unlike the oncogenic ERα, ERß has been proposed to function as a tumor suppressor in breast cancer, and extensive research is underway to uncover the full spectrum of ERß activities and elucidate its mechanism of action. Recent studies have relied on new transgenic models to capture effects in normal and malignant breast that were not previously detected. They have also benefited from the development of highly specific synthetic ligands that are used to demonstrate distinct mechanisms of gene regulation in cancer. As a result, significant new information about the biology and clinical importance of ERß is now available, which is the focus of discussion in the present article.

Transcriptomic analysis of mouse TRAMP cell lines and tumors provide insights into shared pathways and therapeutic targets.

The present study focused on comparing the gene expression profiles of different mouse models of prostate cancer, focusing on the TRAMP transgenic model and its derived cell lines and extending the comparisons to relevant genetically engineered mouse models and human prostate cancer datasets. Employing RNA sequencing, we examined different levels of prostate cancer aggressiveness from the original TRAMP cells to the TRAMP-C2 (TC2) derived cell line and extending to the aggressive TC2-Ras (TC2R) cells and tumors. TC2R acquire the ability to grow in bone tissue upon implantation, unlike the parental TC2 cells. Analysis identified upregulated genes in cell cycle regulation, immune response, and mitotic processes in TRAMP compared to wild-type tissues. TC2 cells exhibited unique gene profiles enriched in ECM organization and tissue development pathways, while TC2R cells showed increased cytokine signaling and motility genes, with decreased ECM and immune response pathways. In vivo TC2R models demonstrated enhanced ECM organization and receptor tyrosine kinase signaling in tumors, notably enriching immune processes and collagen degradation pathways in intratibial tumors. Comparative analysis among mouse and human datasets showed overlaps, particularly in pathways relating to mitotic cycle regulation, ECM organization, and immune interactions. A gene signature identified in TC2R tumors correlated with aggressive tumor behavior and poor survival in human datasets. Further immune cell landscape analysis of TC2R tumors revealed altered T cell subsets and macrophages, confirmed in single-cell RNA-seq from human samples. TC2R models thus hold significant promise in helping advance preclinical therapeutics, potentially contributing to improved prostate cancer patient outcomes.

The current role of dendritic cells in the progression and treatment of colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related deaths worldwide. Dendritic cells (DCs) constitute a heterogeneous group of antigen-presenting cells that are important for initiating and regulating both innate and adaptive immune responses. As a crucial component of the immune system, DCs have a pivotal role in the pathogenesis and clinical treatment of CRC. DCs cross-present tumor-related antigens to activate T cells and trigger an antitumor immune response. However, the antitumor immune function of DCs is impaired and immune tolerance is promoted due to the presence of the tumor microenvironment. This review systematically elucidates the specific characteristics and functions of different DC subsets, as well as the role that DCs play in the immune response and tolerance within the CRC microenvironment. Moreover, how DCs contribute to the progression of CRC and potential therapies to enhance antitumor immunity on the basis of existing data are also discussed, which will provide new perspectives and approaches for immunotherapy in patients with CRC.

[New therapeutic approaches for non-muscle invasive bladder cancer-is organ preservation also possible after BCG (Bacillus Calmette Guérin)?] / Neue Therapieansätze beim nicht-muskelinvasiven Urothelkarzinom der Harnblase ­ Ist der Organerhalt auch nach BCG (Bacillus Calmette-Guérin) möglich?

Bacillus Calmette-Guérin (BCG) therapy is the standard of care in the treatment of high-risk non-muscle invasive bladder cancer (NMIBC). In the absence of a response to BCG and persistent high-grade disease, cystectomy is recommended depending on the clinical risk. A variety of targeted therapy approaches, which aim at immune- and gene-based molecular targets, such as PD-(L)1 and FGFR, are currently being investigated in randomized studies for BCG-unresponsive NMIBC. Furthermore, novel forms of application for instillation therapy, such as the TAR device, in combination with gemcitabine or erdafitinib are being investigated in clinical trials in order to extend the duration of action of the active substance on the urothelium. Thus, there are now many developments that could make bladder-preserving therapy with comparable survival data possible as an alternative to BCG or in the event of BCG failure. In the future, it will be necessary to clarify how BCG response can be predicted by using molecular markers and how to define risk groups that should primarily be given an alternative therapy to BCG.

Elevated Exposure to Air Pollutants Accelerates Primary Glomerular Disease Progression.

Introduction: Environmental contributors to kidney disease progression remain elusive. We explored how residential air pollution affects disease progression in patients with primary glomerulopathies. Methods: Nephrotic Syndrome Study Network (NEPTUNE) and CureGlomerulonephropathy (CureGN) participants with residential census tract data and ≥2 years of follow-up were included. Using Cox proportional hazards models, the associations per doubling in annual average baseline concentrations of total particulate matter with diameter ≤2.5 µm (PM2.5) and its components, black carbon (BC), and sulfate, with time to ≥40% decline in estimated glomerular filtration rate (eGFR) or kidney failure were estimated. Serum tumour necrosis factor levels and kidney tissue transcriptomic inflammatory pathway activation scores were used as molecular markers of disease progression. Results: PM2.5, BC, and sulfate exposures were comparable in NEPTUNE (n = 228) and CureGN (n = 697). In both cohorts, participants from areas with higher levels of pollutants had lower eGFR, were older and more likely self-reported racial and ethnic minorities. In a fully adjusted model combining both cohorts, kidney disease progression was associated with PM2.5 (adjusted hazard ratio 1.55 [95% confidence interval: 1.00-2.38], P = 0.0489) and BC (adjusted hazard ratio 1.43 [95% confidence interval: 0.98-2.07], P = 0.0608) exposure. Sulfate and PM2.5 exposure were positively correlated with serum tumour necrosis factor (TNF) (P = 0.003) and interleukin-1ß levels (P = 0.03), respectively. Sulfate exposure was also directly associated with transcriptional activation of the TNF and JAK-STAT signaling pathways in kidneys (r = 0.55-0.67, P-value <0.01). Conclusion: Elevated exposure to select air pollutants is associated with increased risk of disease progression and systemic inflammation in patients with primary.

Optimal Management for Primary High Grade Ta Bladder Cancer: Role of re-staging TURBT and Intravesical Adjuvant Therapy.

Objective: This study aims to investigate the impact of risk group classification, restaging transurethral resection (re-TURBT), and adjuvant treatment intensity on recurrence and progression risks in high-grade Ta tumours in patients with non-muscle invasive bladder cancer (NMIBC). Materials and methods: Data from a comprehensive bladder cancer database were utilized for this study. Patients with primary high-grade Ta tumours were included. Risk groups were classified according to AUA/SUO criteria. Tumour characteristics and patient demographics were analysed using descriptive statistics. Cox proportional hazard regression models were used to assess the effect of re-TURBT and other clinical/treatment-related predictors on recurrence- and progression-free survivals. The survivals by selected predictors were estimated using Kaplan-Meier method, and groups were compared by the log-rank test. Results: Among 218 patients with high-grade Ta bladder cancer, those who underwent re-TURBT had significantly better 5-year recurrence-free survival (71.1% vs. 26.8%, p = 0.0009) and progression-free survival (98.6% vs. 73%, p = 0.0018) compared with those with initial TURBT alone. Full BCG treatment (induction and maintenance) showed lower recurrence risk, especially in high-risk patients. However, residual disease at re-TURBT did not significantly affect recurrence risk. Conclusions: This study highlights the significance of risk group classification, the role of re-TURBT, and the intensity of adjuvant treatment in the management of high-grade Ta tumours. A risk-adapted model is crucial to reduce the burden of unnecessary intravesical treatment and endoscopic procedures.

Upregulation of the tumor suppressor gene LIN9 enhances tumorigenesis and predicts poor prognosis of lung adenocarcinoma.

Background: LIN9, a gene associated with various cancers, is considered a tumor suppressor. However, the role of LIN9 in lung adenocarcinoma (LUAD) remains unknown. In this study, we aimed to assess the role of LIN9 in the occurrence and prognosis of LUAD. Methods: Using three-tier HTSeq count RNA sequencing data from The Cancer Genome Atlas, we assessed LIN9 expression for the LUAD dataset using the DESeq2 R package and RT-qPCR experiments. Biological functions were assessed using gene set enrichment analysis (clusterProfiler and GOplot). The expression of LIN9 and the infiltration of immune cells were assessed by Single-sample gene set enrichment analysis. We conducted correlation study using clinical characteristics and receiver operating characteristic curve analysis. The predictive value of LIN9 was determined using univariate and multivariate Cox regression as well as Kaplan-Meier analysis. Additionally, functional studies were conducted to validate its role in the progression of LUAD. Results: Expression of LIN9 was significantly elevated in LUAD, primarily influencing cell cycle, division, and signaling pathways. High LIN9 expression correlated positively with the infiltration of Th2 cells and inversely with that of plasmacytoid dendritic cells. Furthermore, LIN9 was associated with older age and advanced clinical stages, posing risks to overall, progression-free, and disease-specific survival. LIN9 served as a good diagnostic marker, particularly in females, patients aged over 65, and those with clinical N1-3 and M1 stages. Elevated LIN9 expression enhanced proliferation, migration, and invasion of LUAD cells. Conclusion: High LIN9 expression potentially contributes to LUAD occurrence through cell cycle regulation and chromosomal modification. It promotes the malignant characteristics of LUAD cells and holds prognostic value for affected patients.