👤 Suryakant Tripathi

The ability of neurons to communicate via synapses is called synaptic transmission, and it is an essential process of brain functioning and plasticity. Its interference has been discovered as a common molecular trait in a broad range of neurological and psychiatric ailments. Nevertheless, in spite of increasing evidence within the disease context, the existing knowledge is still rather disunified, and the molecular processes are poorly incorporated into coherent, cross-disorder models. This narrative review addresses this gap by concisely synthesising recent advances in molecular genetics, synaptic proteomics, neuroimaging, and systems neuroscience to provide an integrated overview of synaptic dysfunction across neurological and psychiatric disorders. It reviews the role of the changes in vesicle trafficking, calcium dynamics, neurotransmitter receptor signalling, brain-derived neurotrophic factor (BDNF) action, and glia-mediated synaptic plasticity in the pathophysiology of conditions like schizophrenia, autism spectrum disorder (ASD), Alzheimer's disease (AD), epilepsy, major depressive disorder (MDD), and Parkinson's disease (PD). The emerging tools that have translational relevance, as pointed out by the review, include single-cell RNA sequencing, spatial proteomics, and synaptic positron emission tomography (PET) imaging, with the capabilities of providing disease-specific and patient-level insights into the pathology of synapses. This review establishes the convergence of the dysfunction, as well as therapeutic potential, through the presentation of a systems-level, cross-diagnostic framework at the level of the synapse. It ends with a prospective report of where precision medicine, development of new biomarkers, and lifespan research efforts are required to incorporate synaptic biology in translational neuroscience. Show less

Advanced prostate cancer remains challenging, driven in part by Epidermal Growth Factor (EGF) signaling that promotes migration, invasion, and angiogenesis. We evaluated LA3IK ( The online version contains supplementary material available at 10.1038/s41598-026-41933-1. Show less

Alzheimer's disease widely affects millions of people worldwide, accounting for 60% of dementia cases. Clinically classified by the presence of cognition impairment, pathophysiological representation includes deposited senile plaques, neurofibrillary tangles, and neuroinflammation. The pathogenesis of Alzheimer's disease (AD) remains multifaceted and is governed by multiple hypotheses. However, it undeniably involves amyloid-β (Aβ) accumulation and hyperphosphorylated tau (p-tau) pathology as the crucial events in disease initiation. Substantial evidence has correlated Vitamin D Show less

Alzheimer's Disease (AD), a leading cause of dementia, is a known neurodegenerative disorder. Affecting millions of people worldwide, AD pathogenesis involves diverse risk factors such as lifestyle, environmental, and metabolic conditions that accelerate sporadic AD. Very recently, backed with substantial evidence, herpes simplex virus-1 (HSV-1) has been recognized as a potential causative factor that may play a pivotal role in sporadic AD. Latent virus is estimated to activate key underlying pathways, preferably Aβ and p-tau, to cause AD. Additionally, Antivirals such as Valacyclovir have emerged to impart a potential neuroprotective role in AD. Present research aimed to explore the neuroprotective role and mechanism of Valacyclovir in the streptozotocin-induced Alzheimer's disease model in rats. A single dose of 3 mg/kg ICV (intracerebroventricular) Streptozotocin (STZ) was administered to induce AD in rats. Two doses of Valacyclovir, i.e., 100 mg/kg and 150 mg/kg were evaluated with Donepezil 5 mg/kg as standard. Post 21 days of treatment, Valacyclovir demonstrated dose-dependent improvement in neurobehavioral parameters. Further, AD-specific parameters i.e. Aβ1-40 and Aβ1-42, p-tau, and BACE-1 were significantly (p < 0.001) reduced with parallel reduction in inflammatory (p < 0.001) and oxidative stress markers. Additionally, Valacyclovir also increased the levels of amyloid clearance enzymes i.e., neprilysin (NEP) (p < 0.001) and insulin-degrading enzyme (IDE) (p < 0.001). Results suggest promising neuroprotective action of valacyclovir via reducing Aβ-amyloid protein, p-Tau, BACE-1, as well as demonstrating anti-inflammatory and antioxidant activity. Show less

NSCLC-Squamous cell carcinoma (SCC) is characterized by poor survival largely due no definitive markers for targeted therapy. KRAS (Kirsten rat sarcoma viral oncogene homolog) is a proto-oncogene associated with resistance standard chemotherapy regimens. Discoidin domain receptor 2 (DDR2), fibroblast growth factor receptor-1(FGFR-1) and mesenchymal epithelial transition (MET) are receptor tyrosine kinases that regulate proliferation, apoptosis and invasion. The objectives were to assess frequency of FGFR1, DDR2,c-MET protein over-expression and KRAS mutations in NSCLC-SCC and to co-relate expression of molecular markers with clinico-pathological parameters. The study was a retrospective and prospective case series of 150 cases of NSCLC-SCC. Testing for KRAS, DDR-2, cMET and FGFR1 was done using immunohistochemistry (IHC). KRAS IHC was validated using real time polymerase chain reaction testing. Molecular marker expression was identified in 37.33% (n=56/150) cases, among which 80.35% (n=45/56) cases had a single mutation and 19.64% cases(n=11/56) had multiple mutations. FGFR-1 protein over-expression was identified in 8% cases and cMET protein over-expression in 4.67% cases. DDR-2 over-expression was present in 19.33% cases and KRAS protein over-expression in 14.67% cases. Co-expression of DDR-2 and KRAS was identified in 72.72% cases. DDR2 protein over-expression is identified in smokers and cases with distant metastasis. KRAS protein over-expression was more frequent in cases >40 years of age with advanced disease stage. The targets evaluated have potential drugs currently under trial phase. This may help to define the subgroup for use of targeted therapy in NSCLC-SCC and in designing new treatment protocols. Show less

Poly(ADP-ribose) (PAR) polymerase-1 (PARP1) has been implicated in DNA damage responses and neuroinflammation in Alzheimer's disease (AD), yet its role in amyloid-β (Aβ) pathology remains unclear. Here, we show that PARP1 activation drives Aβ pathology and neurodegeneration. Using a sensitive ELISA, we observed significantly elevated PAR levels in the cerebrospinal fluid (CSF) of patients with mild cognitive impairment (MCI) and AD compared to controls. Show less

This study aims to evaluate cognitive impairment utilizing the Montreal Cognitive Assessment (MoCA) scale, while also exploring the correlation between cognitive impairment and various serum biomarkers, including Brain-derived neurotrophic factor (BDNF), Beta Secretase-1 (BACE1), Vascular Endothelial Growth Factors (VEGF), Glial fibrillary acidic protein (GFAP), and Interleukin-1 (IL-1β) in adults living with epilepsy. In this study, 74 participants aged between 18 and 50 years, who were visiting neurology outpatient consultations, were included. The cognitive assessment was executed using the MoCA test. Serum levels of BDNF, BACE1, VEGF, GFAP, and IL-1β were evaluated through ELISA in patients with and without cognitive impairments. To determine the association between MoCA scores and the biomarkers, both Spearman and Pearson correlation analyses, as well as linear regression, were conducted. Among the 74 PWE, 61 exhibited cognitive impairment as determined by the MoCA assessment. Noteworthy alterations were detected across various MoCA subscales, encompassing visuospatial and executive functions, attention, language, abstraction, and delayed recall, with statistical significance established ( We conclude that adult PWE in India demonstrate a significant cognitive impairment. Further, our findings indicate that BDNF may serve as a potential biomarker for evaluating cognitive impairment in adult PWE. Further longitudinal, prospective and multi-center studies are required to confirm the same. Show less

Household contact (HHC) investigation helps in early identification of people with tuberculosis (TB) and initiation of TB preventive treatment (TPT) among those at high risk of developing TB. This cross-sectional study uses National TB Elimination Program data of all people notified with bacteriologically confirmed pulmonary TB and their HHCs from October to December 2023, from Chhattisgarh, a central Indian state, to assess coverage of HHC investigation, proportions identified with TB and put on TPT (all age groups and age < 5 years). Sociodemographic, clinical, and health system-related factors were used to identify predictors of HHC investigation not done, as determined through modified Poisson regression. Of the 4,221 people notified with TB, an HHC investigation was conducted for 3,177 (75%) cases. Among a total of 11670 contacts screened, TB was diagnosed in 0.9%(n = 109) for all age groups and 0.7%(n = 9) for children<5 years. TPT was initiated in 66% (n = 7740) for all age groups and 73% (n = 903) for children<5 years. Women (adjusted prevalence risk aPR 1.10; 95%CI:1.01-1.19), those notified from non-tribal districts (aPR 1.14; 95%CI:1.01-1.29), current facility being tertiary care (aPR 1.50; 95%CI:1.12-2.00) and private (aPR 1.42; 95%CI:1.08-1.86) facility, diagnosed with test other than sputum microscopy (aPR NAAT 3.19; 95%CI:2.39-4.28; LPA 8.88 95%CI:6.15-12.82; culture 9.69; 95%CI:5.99-15.68) and for whom diabetes (aPR 1.40; 95%CI:1.16-1.70) and HIV screening (aPR 1.55, 95% CI:1.17-2.05) was missing predicted higher risk of HHC investigation not done. The study highlights the need to improve HHC investigation, as well as the low yield of TB and TPT initiation. Predictors of HHC investigation not done suggest a need to decentralize it to the primary level and improve data-based program monitoring. A statewide capacity-building initiative for improving the investigation of HHC is the way forward. Show less

HNSCC is a highly aggressive cancer of the head and neck region, and there is an urgent need to find novel potential targets for its diagnosis and treatment. Long non-coding RNAs (lncRNAs) have emerged as important therapeutic and diagnostic targets for multiple cancers, including HNSCC. LINC01518 promotes the proliferation of oesophageal cancer cells, but the involvement of LINC01518 in HNSCC pathophysiology is unknown. We show that LINC01518 expression is significantly upregulated in high-grade HNSCC tumor samples in comparison to normal tissue, and transforming growth factor- β (TGF-β) promotes LINC01518 expression in HNSCC cell lines. Loss-of-function studies suggest that LINC01518 promotes cell proliferation, migration, and invasion in HNSCC cells. In addition, LINC01518 depletion sensitizes HNSCC cells to cisplatin-mediated apoptosis. Mechanistically, LINC01518 acts as a competitive endogenous RNA and binds to miR-1-3p and miR-216b-5p, resulting in up-regulation of their target genes Slug and GRP78, respectively. Our findings suggest that LINC01518 is an attractive therapeutic target for HNSCC. Show less

Despite significant research efforts, Alzheimer's disease (AD), the primary cause of dementia in older adults worldwide, remains a neurological challenge for which there are currently no effective therapies. There are substantial financial, medical, and personal costs associated with this condition.Important pathological features of AD include hyperphosphorylated microtubule-associated protein Tau, the formation of amyloid β (Aβ) peptides from amyloid precursor protein (APP), and continuous inflammation that ultimately results in neuronal death. Important histological markers of AD, amyloid plaques, and neurofibrillary tangles are created when Aβ and hyperphosphorylated Tau build-up. Nevertheless, a thorough knowledge of the molecular players in AD pathophysiology is still elusive. Recent studies have shown how noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), regulate gene expression at the transcriptional and posttranscriptional levels in a variety of diseases, including AD. There is increasing evidence to support the involvement of these ncRNAs in the genesis and progression of AD, making them promising as biomarkers and therapeutic targets. As a result, therapeutic approaches that target regulatory ncRNAs are becoming more popular as potential means of preventing the progression of AD. This review explores the posttranscriptional relationships between ncRNAs and the main AD pathways, highlighting the potential of ncRNAs to advance AD treatment. In AD, ncRNAs, especially miRNAs, change expression and present potential targets for therapy. MiR-346 raises Aβ through APP messenger Ribonucleic Acid (mRNA), whereas miR-107 may decrease Aβ by targeting beta-site amyloid precursor protein cleaving enzyme 1 (BACE1). They are promising early AD biomarkers due to their stability in cerebrospinal fluid (CSF) and blood. Furthermore, additional research is necessary to determine the role that RNA fragments present in AD-related protein deposits play in AD pathogenesis. Show less

Activation of the basal forebrain leads to increases in the expression of the nerve growth factor receptor, Tropomyosin receptor kinase A (TrkA) and decreases in expression of the beta amyloid cleavage enzyme 1 (BACE1) in the cerebral cortex of both sexes of 5xFAD mice. The studies described in this report were designed to determine if these changes were dependent on acetylcholine receptors. Mice were stimulated unilaterally in the basal forebrain for two weeks. Animals were administered a cholinergic antagonist, or saline, 30 minutes prior to stimulation. Animals administered saline exhibited significant increases in TrkA expression and decreases in BACE1 in the stimulated hemisphere relative to the unstimulated. While both nonselective nicotinic and muscarinic acetylcholine receptor blockade attenuated the BACE1 decline, only the nicotinic receptor antagonism blocked the TrkA increase. Next, we applied selective nicotinic antagonists, and the α7 antagonist blocked the TrkA increases, but the α4β2 antagonist did not. BACE1 declines were not blocked by either intervention. Mice with a loxP conditional knockout of the gene for the α7 nicotinic receptor were also employed in these studies. Animals were either stimulated bilaterally for two weeks, or left unstimulated. With or without stimulation, the expression of TrkA receptors was lower in the cortical region with the α7 nicotinic receptor knockdown. We thus conclude that α7 nicotinic receptor activation is necessary for normal expression of TrkA and increases caused by basal forebrain activation, while BACE1 declines caused by stimulation have dependency on a broader array of receptor subtypes. Show less

Migration and invasion enhancer 1 (MIEN1) overexpression characterizes several cancers and facilitates cancer cell migration and invasion. Leveraging conserved immunoreceptor tyrosine-based activation motif and prenylation motifs within MIEN1, we identified potent anticancer peptides. Among them, bioactive peptides LA3IK and RP-7 induced pronounced transcriptomic and protein expression changes at sub-IC50 concentrations. The peptides effectively inhibited genes and proteins driving cancer cell migration, invasion, and epithelial-mesenchymal transition pathways, concurrently suppressing epidermal growth factor-induced nuclear factor kappa B nuclear translocation in metastatic breast cancer cells. Specifically, peptides targeted the same signal transduction pathway initiated by MIEN1. Molecular docking and CD spectra indicated the formation of MIEN1-peptide complexes. The third-positioned isoleucine in LA3IK and CVIL motif in RP-7 were crucial for inhibiting breast cancer cell migration. This is evident from the limited migration inhibition observed when MDA-MB-231 cells were treated with scrambled peptides LA3IK SCR and RP-7 SCR. Additionally, LA3IK and RP-7 effectively suppressed tumor growth in an orthotopic breast cancer model. Notably, mice tolerated high intraperitoneal (ip) peptide doses of 90 mg/Kg well, surpassing significantly lower doses of 5 mg/Kg intravenously (iv) and 30 mg/Kg intraperitoneally (ip) used in both in vivo pharmacokinetic studies and orthotopic mouse model assays. D-isomers of LA3IK and RP-7 showed enhanced anticancer activity compared to their L-isomers. D-LA3IK remained stable in mouse plasma for 24 h with 75% remaining, exhibiting superior pharmacokinetic properties over D/L-RP-7. In summary, our findings mark the first report of short peptides based on MIEN1 protein sequence capable of inhibiting cancer signaling pathways, effectively impeding cancer progression both in vitro and in vivo. Show less

Jatropha variegata and Jatropha spinosa (family: Euphorbiaceae) are utilized in Yemeni traditional medicine to treat respiratory tract infection and in different skin conditions such as wound healing, as antibacterial and hemostatic. In this study, we evaluated the cytotoxicity and the antiviral activities of the methanolic J. variegata (leaves: Ext-1, stems: Ext-2, and roots: Ext-3), and J. spinosa extracts (aerial parts: Ext-4 and roots: Ext-5), in addition to their methylene chloride fractions of roots extracts (F-6 and F-7, respectively). All samples were tested against three human cancer cell lines in vitro (MCF-7, HepG2, and A549) and two viruses (HSV-2 and H1N1). Both plants showed significant cytotoxicity, among them, the methylene chloride fractions of roots of J. variegata (F-6) and J. spinosa roots (F-7) showed the highest activity on MCF-7 (IC Show less

HPV status in a subset of HNSCC is linked with distinct treatment outcomes. Present investigation aims to elucidate the distinct clinicopathological features of HPV-positive and HPV-negative HNSCC and investigate their association with the HNSCC patient survival. The total RNA of exosomes from HPV-positive (93VU147T) and HPV-negative (OCT-1) HNSCC cells was isolated, and the transcripts were estimated using Illumina HiSeq X. The expression of altered transcripts and their clinical relevance were further analyzed using publicly available cancer transcriptome data from The Cancer Genome Atlas (TCGA). Transcriptomic analyses identified 3785 differentially exported transcripts (DETs) in HPV-positive exosomes compared to HPV-negative exosomes. DETs that regulate the protein machinery, cellular redox potential, and various neurological disorder-related pathways were over-represented in HPV-positive exosomes. TCGA database revealed the clinical relevance of altered transcripts. Among commonly exported abundant transcripts, SGK1 and MAD1L1 showed high expression, which has been correlated with poor survival in HNSCC patients. In the top 20 DETs of HPV-negative exosomes, high expression of FADS3, SGK3, and TESK2 correlated with poor survival of the HNSCC patients in the TCGA database. Overall, our study demonstrates that HPV-positive and HPV-negative cells' exosomes carried differential transcripts cargo that may be related to pathways associated with neurological disorders. Additionally, the altered transcripts identified have clinical relevance, correlating with patient survival in HNSCC, thereby highlighting their potential as biomarkers and as therapeutic targets. Show less

Our case report is of an elderly male with a history of IgM κ lymphoplasmacytic lymphoma (LPL) presenting with generalized neuropathy and weakness. Due to his LPL history and worsening renal function, he underwent a renal biopsy revealing the presence of μ heavy and λ light chains, revealing a diagnosis of amyloidosis with unbound heavy & light chains (AHL), a rare type of amyloidosis. His bone marrow biopsy demonstrated κ light chain restriction by flow cytometry and amyloid deposition. The patient's serum had elevated free κ and λ light chains with a free light chain (FLC) ratio of 3.17. Serum immunofixation was positive for IgM κ and λ light chain clones. He completed six cycles of cyclophosphamide, bortezomib, dexamethasone, and rituximab (CyBorD+R), normalizing the FLC ratio. Still, he continued to present with persistently elevated M protein, IgM κ, and λ light chains on immunofixation. Thereafter, daratumumab, a human monoclonal antibody directed against CD38 expressed on myeloma cells was initiated, which led to a negative immunofixation study after two cycles accompanied by a reduction in protein excretion in the urine. The patient achieved a complete hematological response with daratumumab. To date, our case is the only reported μ heavy and λ light chain amyloidosis patient with bi-clonal (IgM κ and λ) gammopathy to be successfully treated with daratumumab. Show less

BACE1 (beta-site amyloid precursor protein (APP) cleaving enzyme) is a key target for Alzheimer's disease research because it catalyses the rate-limiting step in the formation of amyloid protein (Aβ). Natural dietary flavonoids have gained a lot of interest as potential Alzheimer's therapy candidates because of their anti-amyloidogenic, antioxidative, and anti-inflammatory properties. More research is needed, however, to learn more about the specific routes through which flavonoids may have neuroprotective benefits in Alzheimer's disease. Here, we report an in silico molecular modeling study for natural compounds, particularly flavonoids, as BACE-1 inhibitors. The interactions of flavonoids with the BACE-1 catalytic core were disclosed by demonstrating the predicted docking pose of flavonoids with BACE-1. The stability of flavonoids BACE-1 complex was analyzed by molecular dynamic simulation (standard dynamic cascade). Our findings imply that these flavonoids, which have methoxy group instead of hydroxy may be promising BACE1 inhibitors that could reduce Aβ formation in Alzheimer's disease. The molecular docking study revealed that flavonoids e bind with the BACE1's wide active site along with the catalytic residues Asp32 and Asp228. Further molecular dynamic investigation revealed that the average RMSD for all complexes ranged from 2.05 to 2.32 Å, indicating that the molecules were relatively stable during MD simulation. The RMSD analyses demonstrate that the flavonoids were structurally stable during the MD simulation. The RMSF was utilised to study the time-dependent fluctuation of the complexes. The N-terminal (~2.5 Å) fluctuates less than the C-terminal (~6.5 Å). Rutin and Hesperidin were highly stable in the catalytic region as compared to other flavonoids like Rhoifolin, Hesperidin, Methylchalcone, Phlorizin and Naringin. We were able to justify the flavonoids' selectivity for BACE-1 and crossing BBB for the treatment of Alzheimer's disease by using a combination of molecular modelling tools. Show less

The etiology of Alzheimer's dementia has been hypothesized in terms of basal forebrain cholinergic decline, and in terms of reflecting beta-amyloid neuropathology. To study these different biological elements, we activated the basal forebrain in 5xFAD Alzheimer's model mice and littermates. Mice received 5 months of 1 h per day intermittent stimulation of the basal forebrain, which includes cholinergic projections to the cortical mantle. Then, mice were behaviorally tested followed by tissue analysis. The 5xFAD mice performed worse in water-maze testing than littermates. Stimulated groups learned the water maze better than unstimulated groups. Stimulated groups had 2-3-fold increases in frontal cortex immunoblot measures of the neurotrophin receptors for nerve growth factor and brain-derived neurotrophic factor, and a more than 50% decrease in the expression of amyloid cleavage enzyme BACE1. Stimulation also led to lower Aβ42 in 5xFAD mice. These data support a causal relationship between basal forebrain activation and both neurotrophin activation and reduced Aβ42 generation and accumulation. The observation that basal forebrain activation suppresses Aβ42 accumulation, combined with the known high-affinity antagonism of nicotinic receptors by Aβ42, documents bidirectional antagonism between acetylcholine and Aβ42. Show less

Incretin therapy is one of the most potential approaches in the treatment of diabetes. In contrast to markedly available drugs, the herbal incretin modulators have lesser side effects with low economic cost. The main aim of this work was to analyze the potential of previously reported DPPIV inhibitor, aqueous extract of Pueraria tuberosa tubers (PTY-2) as incretin hormones receptor agonist against streptozotocin (STZ)-induced diabetes. Chronic diabetes was induced with STZ (65mg/kg bw) in rats for 60days and grouped into diabetic control and PTY-2. Expression of genes was assessed by PCR, IHC, and ELISA. Morphological analysis of tissue was observed using H & E stain. In silico molecular docking approach has been used to see the interaction of active phytochemicals of PTY-2 on the basis of their binding energy [kcal/mol] and dissociation constant [pM] using YASARA software. Interactive visualization was done using Discovery studio 3.0. In comparison to diabetic control, the size and number of islet cells along with the plasma level of GLP-1, GIP, and pancreatic expressions of GLP-1R, GIP-R, Bcl2, and insulin were enhanced significantly after PTY-2 treatment. Through in silico molecular docking, tuberostan showed the best interaction for GLP-1R with binding energy at 8.15kcal/mol and dissociation constant at 1061624.125 pM. Puererone showed the best interaction for GIP-R with binding energy at 8.31kcal/mol and dissociation constant at 810381 pM. In addition to previously studied DPPIV inhibitor, PTY-2 also acts as incretin receptors agonist and protects against STZ-induced diabetes by down regulating β cells apoptosis. Show less

Entamoeba histolytica, the causative agent of amoebic dysentery, liver abscess and colitis, exploits its vesicular trafficking machinery for survival and virulence. Rab family of small GTPases play a key role in the vesicular transport by undergoing the GTP/GDP cycle which is central to the biological processes. Amoebic genome encodes several atypical Rab GTPases which are unique due to absence of conserved sequence motif(s) or atypical residues in their catalytic site [Saito-Nakano et al., 2005 ]. Previously, EhRab21 has been reported to involve in amoebic invasion and migration [Emmanuel et al., 2015 ]. The conserved Glutamine of switch-II region is universally accepted to be crucial for GTP hydrolysis. Mutations that reduce the sidechain polarity of Glutamine render the protein GTPase activity deficient [Krengel et al., 1990]. Here, we report a catalytic role of atypical switch-I Arginine (R36) in intrinsic GTP hydrolysis catalysed by EhRab21. Unlike the GTPase activity deficient QL mutants, the GTPase activity of EhRab21Q64L was found to be marginally enhanced compared to the wild-type protein. Although EhRab21R36L mutant showed normal GTPase activity, the double mutant (R36L/Q64L) was found to be GTPase deficient. Thus, EhRab21 is a unique member of small GTPase family in which an atypical switch-I Arginine is capable of driving GTP hydrolysis independent of the conserved switch-II Glutamine. Show less

Liver kinase B1 ( LKB1 ) is a tumor suppressor in lung adenocarcinoma (LADC). We investigated the proteomic profiles of 45 LADC cell lines with and without LKB1 inactivation. Carbamoyl phosphate synthetase 1 (CPS1), the first rate-limiting mitochondrial enzyme in the urea cycle, was distinctively overexpressed in LKB1-inactivated LADC cell lines. We therefore assessed the role of CPS1 and its clinical relevance in LKB1-inactivated LADC. Mass spectrometric profiling of proteome and metabolome and function of CPS1 were analyzed in LADC cell lines. CPS1 and LKB1 expression in tumors from 305 LADC and 160 lung squamous cell carcinoma patients was evaluated by immunohistochemistry. Kaplan-Meier and Cox regression analyses were applied to assess the association between overall survival and CPS1 and LKB1 expression. All statistical tests were two-sided. CPS1 knockdown reduced cell growth, decreased metabolite levels associated with nucleic acid biosynthesis pathway, and contributed an additive effect when combined with gemcitabine, pemetrexed, or CHK1 inhibitor AZD7762. Tissue microarray analysis revealed that CPS1 was expressed in 65.7% of LKB1-negative LADC, and only 5.0% of LKB1-positive LADC. CPS1 expression showed statistically significant association with poor overall survival in LADC (hazard ratio = 3.03, 95% confidence interval = 1.74 to 5.25, P < .001). Our findings suggest functional relevance of CPS1 in LKB1-inactivated LADC and association with worse outcome of LADC. CPS1 is a promising therapeutic target in combination with other chemotherapy agents, as well as a prognostic biomarker, enabling a personalized approach to treatment of LADC. Show less