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Tumor genomic landscape of older patients with metastatic breast cancer☆.

BACKGROUND: Metastatic breast cancer (MBC) in older patients has distinct clinical and histologic characteristics. Elucidating the genomic basis of MBC helps identify potential therapeutic targets to improve outcomes for older patients with MBC. PATIENTS AND METHODS: Using a prospective database and targeted DNA sequencing (OncoPanel), we examined MBC's genomic landscape in older patients (age &#x2265;70 years at MBC diagnosis) and compared findings with those in younger (aged <50 years) and middle-aged (aged 50-69 years) patients. After classifying single nucleotide variants (SNVs) and copy number variations (CNVs) as oncogenic (via OncoKB), the frequencies of SNVs and CNVs, tumor mutational burden (TMB), and oncogenic signaling pathways were compared by age group using Fisher's exact tests. We estimated the association between continuous age at MBC diagnosis and mutations via multivariate logistic regression analysis, adjusting for race, stage at initial diagnosis, subtype, histology, and sample tested (primary versus metastatic). RESULTS: Our study included 2379 patients [853 (35%) younger, 1311 (55%) middle-aged, and 215 (9%) older] who underwent OncoPanel testing between 2013 and 2020. The most frequent tumor alterations in older patients were SNVs in PIK3CA (44%), TP53 (33%), CDH1 (22%) and amplifications in CCND1 (18%). After adjustment, older age was associated with higher frequency of SNVs in CDH1 [odds ratio (OR) = 1.43, 95% confidence interval (CI) 1.21-1.68, q < 0.001], MAP3K1 [OR = 1.30, 95% CI 1.10-1.54, q = 0.008], and PIK3CA [OR = 1.21, 95% CI 1.11-1.31, q < 0.001] and fewer SNVs in TP53 [OR = 0.84, 95% CI 0.77-0.91, q < 0.001]. Patients in the older group were more likely to have tumors with &#x2265;10 mutations/megabase than the youngest patients (26% versus 17%, P = 0.003). CONCLUSIONS: In this large cohort of patients with MBC, the tumor genomic landscape differed between older and younger patients even after accounting for tumor subtype. Older patients were more likely to have high-TMB and PIK3CA-mutated tumors, highlighting the importance of genomic testing for treatment applications in this population.

NGS↗

FGF19 as a site-specific candidate biomarker in colorectal neuroendocrine carcinomas.

PURPOSE: Gastrointestinal neuroendocrine carcinomas (GI-NECs) are aggressive tumors with marked site-specific heterogeneity, yet molecular markers for colorectal origin are lacking. This study characterized genomic and protein expression profiles to identify origin-specific biomarkers. METHODS: Nineteen GI-NECs (7 esophageal, 6 gastric, 6 colorectal) were analyzed by targeted next-generation sequencing (NGS) of 425 genes and immunohistochemistry (IHC). Genetic variations across primary sites were compared, and associations between FGF19 expression, clinicopathological features, microsatellite (MS) status, and tumor mutational burden (TMB) were assessed. FGF19 transcriptional expression was further examined in The Cancer Genome Atlas (TCGA) colorectal cohort using the UALCAN platform. RESULTS: A total of 163 genomic alterations were identified. FGF19 was the only gene showing site-specific alterations, being exclusively mutated or amplified in colorectal NECs (50%, 95% CI: 11.8-88.2%) with significantly elevated protein expression (83.3%, 95% CI: 35.9-99.6%) compared with other sites. A microsatellite instability-high (MSI-H) subgroup (10.5%, 95% CI: 1.3-33.1%) exhibited markedly higher TMB. TCGA data confirmed upregulated FGF19 in colorectal tumors but showed no survival association, consistent with the prognostic neutrality in our cohort. CONCLUSIONS: FGF19 may act as a site-specific candidate biomarker for colorectal NECs, with 83.3% protein positivity and exclusive site-specific alterations in 50% of cases. Detection of MSI-H suggests that mismatch repair (MMR) testing may be considered in selected patients with suggestive clinical or family histories to inform immunotherapy decisions.

FGF19↗

A targetable dependency on nonsense-mediated decay for cellular homeostasis and immune control in small cell lung cancer.

Small cell lung cancer (SCLC) is one of the most aggressive malignancies, characterized by rapid metastatic dissemination and poor overall survival. Despite harboring excessive alterations, expectedly resulting in immunogenic neoantigens, patients with SCLC remain largely refractory to immunotherapy. We found abundant frameshift mutations in SCLC, regarded as highly immunogenic, counterbalanced by a hyperactive nonsense-mediated decay (NMD) pathway, responsible for frameshift-mRNA degradation. NMD activity correlated with tumor mutational burden (TMB) across cancers, suggesting that SCLC and other TMBhigh cancers may depend on NMD to limit the accumulation of mutation-derived byproducts in order to maintain cellular homeostasis and evade immune recognition. In TMBhigh SCLC models, inhibition of NMD impaired cell proliferation and induced ER stress-dependent apoptosis due to the accumulation of misfolded proteins. Genetic and pharmacological NMD inhibition in vivo effectively controlled TMBhigh tumor growth without overt toxicity. By integrating genome and transcriptome sequencing with MHC-I immunopeptidomics and functional in vitro and in vivo assays, we identified that NMD inhibition boosted neoantigen expression and presentation by tumor cells and increased T cell recognition, thus enhancing overall tumor immunogenicity and further improving immunotherapy efficacy in vivo. Our work shows that SCLC - as a TMBhigh cancer - relies on NMD for survival and immune escape, uncovering a novel TMB-dependent tractable vulnerability for this devastating disease.

Humans↗

Calcium and calmodulin regulate lipopolysaccharide-induced alveolar macrophage production of tumor necrosis factor and procoagulant activity.

BACKGROUND: Alterations in macrophage (M phi) function are responsible, in part, for adult respiratory distress syndrome and multiple organ failure developing in patients with sepsis. Elucidation and control of these M phi mechanisms during sepsis are crucial to our understanding of this disease and, ultimately, to improving survival of these patients. OBJECTIVE: To investigate the involvement of calcium flux in endotoxin-induced alveolar M phi production of tumor necrosis factor (TNF) and procoagulant (PC) activity. DESIGN: Rabbit alveolar M phi obtained by bronchoalveolar lavage were exposed to endotoxin in the form of lipopolysaccharide (LPS) extracted from Escherichia coli 0111:B4 in the presence of different specific calcium agonists and antagonists. The TNF expression was measured in the supernatant by L929 bioassays. The PC activity was determined in cell lysates by a one-step coagulation assay. RESULTS: Macrophages activated by LPS produce enormous levels of TNF and PC. Either W7 (20 mumol/L), a calmodulin antagonist, or TMB-8 (50 mumol/L), which prevents calcium release from the endoplasmic reticulum, inhibited production of both TNF and PC activity. Verapamil (50 mumol/L) alone or combined with TMB-8 significantly inhibited both TNF and PC production by LPS-stimulated M phi. Elevating intracellular calcium ([Ca2+]i), using the calcium ionophore, A23187, or thapsigargin alone, did not induce M phi production of TNF but significantly augmented LPS-stimulated TNF production. CONCLUSION: Our results indicate that increased intracellular calcium causing signal transduction activation through the calmodulin pathway is a necessary, but insufficient, component of the LPS signaling in M phi.

Animals↗

Regulatory volume decrease and associated osmolyte fluxes in cerebellar granule neurons are calcium independent.

To investigate a possible role for Ca as a transduction signal for regulatory volume decrease (RVD), the effects of external Ca removal, Ca channel blockers (Cd, Co, La, Gd, verapamil, diltiazem, dihydropyridines) and inhibitors of endoplasmic reticulum Ca release (dantrolene, ryanodine, TMB-8) were examined on RVD and on the swelling-activated efflux of two main osmolytes: Cl (traced by 125I) and [3H]taurine. Omission of Ca plus EGTA did not affect RVD or osmolyte release but when BAPTA was the chelator, RVD decreased 20%, 125I fluxes were unaffected and taurine stimulated efflux decreased (20%) while the basal efflux slightly increased (<10%). Verapamil, diltiazem, Co, Cd, La and Gd did not affect RVD or osmolyte fluxes. Nimodipine and nitrendipine (25-50 microM) markedly decreased RVD and osmolyte fluxes (>90%) through a mechanism independent of extracellular Ca. Swelling elicited an increase in cytosolic Ca measured by fura-2, which was notably variable ranging 50-350 nM. However, RVD and osmolyte fluxes were not affected by the blockers of endogenous Ca release dantrolene, ryanodine and TMB-8 or by the permeable Ca chelator BAPTA-AM, even when the cytosolic Ca increase was abolished by the chelator. These results indicate that 1) RVD and osmolyte fluxes are independent of extracellular Ca 2) RVD, osmolyte release and cytosolic Ca raise are only coincident events. Consequently, Ca is unlikely to be a transducing signal for RVD in neurons.

Animals↗

Regulation of activation state and flagellar wave form in epididymal rat sperm: evidence for the involvement of both Ca2+ and cAMP.

Rat sperm from the cauda epididymis exhibit increased motility, longevity, and a distinct circular pattern of flagellar curvature in response to 5 mM procaine-HCl or 0.1 mM 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB-8), reagents that are thought to play a role in the immobilization of free cellular calcium. Triton X-100-extracted sperm models will exhibit the same pattern of motility and curvature as procaine- or TMB-8-activated cells, but only when calcium is removed by a strong chelating agent, and in the presence of cAMP (3 microM). Demembranated sperm models produced from epididymal rat sperm are quiescent unless cAMP is added. In these sperm models, the presence or absence of free calcium mediates a transition in flagellar curvature. The increased activity of the procaine-treated intact cells was not accompanied by a change in cellular ATP content, nor was ATP availability the limiting factor in the quiescent sperm. Therefore, the increased motility produced by procaine is probably mediated by a fall in free intracellular Ca2+ accompanied by a rise in cAMP. Our finding that calcium controls the curvature of sperm flagella may explain altered patterns of flagellar beating, such as the hyperactivated motility that sperm exhibit in the female reproductive tract.

Adenosine Triphosphate↗

The location of cerebellar-projecting neurons within the lumbosacral spinal cord in the cat. An anatomical study with HRP and retrograde chromatolysis.

The locations of lumbosacral spinocerebellar neurons were examined by two anatomical methods in kittens. In one group of animals chromatolytic changes were provoked by cerebellar lesions. In another group horseradish peroxidase (HRP) was injected into the cerebellum. Projection laterality was investigated by making unilateral spinal lesions prior to the cerebellar HRP injections. Diaminobenzidine (DAB) or tetramethylbenzidine (TMB) was used as substrate fo HRP. The morphological characteristics of HRP-labeled neurons in the TMB-processed material were examined. Neurons marked by the two methods were located within the same regions. A greater number of cells were marked with the HRP method, however, than with the retrograde chromatolysis method. Spinocerebellar neurons were found in laminae IV-IX with large differences with regard to specific locations depending on segmental level. Numerous marked neurons were found in the following areas: laminae IV-Vi in L3-L7, the column of Clarke in L3-L4, the medial part of lamina VII in L6-L7, the lateral part of lamina VII in L3-L4, the dorsolateral nucleus of lamina IX in L3-L6, the ventrolateral nucleus of lamina IX in L4-L5, and the ventromedial nucleus of lamina IX in S3 (and Ca1). Dorsally located neurons were in general more likely to project ipsilaterally than ventrally located neurons. Marked structural differences were frequently observed between spinocerebellar neurons in different locations. These results provide additional information on the anatomical complexity of the spinocerebellar pathways from the lumbosacral region in the cat. Together with results from some other recent anatomical studies on spinocerebellar tracts, they also form a basis for further anatomical and physiological investigations which could contribute to a better understanding of the organization of the spinocerebellar tracts.

Animals↗

Alterations of the blood-brain barrier after transplantation of autonomic ganglia into the mammalian central nervous system.

Autonomic (superior cervical) ganglia, the vessels of which are freely permeable to macromolecules, from mature rat donors (allografts or autografts) were transplanted to different sites in the central nervous system (CNS). Minimal trauma was caused by grafts into the IVth ventricle while grafts to intraparenchymal locations such as cerebral cortex and spinal cord were necessarily traumatic and produced glial scarring. Postoperative periods were between 4 weeks and 30 months. A potentially significant aspect of neural transplantation is the functional vascular connections between host and graft. It is highly likely that grafting procedures alter the blood-brain barrier (BBB) in the recipient brain. In order to determine permanent BBB changes, the glycoprotein horseradish peroxidase (HRP) (M.W. 40,000) was injected intravascularly for circulation periods ranging between 50 seconds and 90 minutes. Protein exudation was monitored by using the chromogens DAB and the highly sensitive TMB. All autonomic ganglia transplants, regardless of postoperative or HRP circulation times, were permeable to the injected protein; no qualitative differences were found between allografts and autografts. The blood-borne protein traversed the autonomic graft and infiltrated into the host brain for distances between 200 micron in intraparenchymal grafts to over 1 mm in intraventricular grafts; a smaller exudate was found in the intraparenchymal model than in the intraventricular site probably due to glial scarring that impeded the protein movement in the interstitial spaces. Significantly, TMB demonstrated that the systemic protein entered the cerebrospinal fluid. HRP was detected on the ventricular floor and in the perivascular spaces of the microvasculature. Transplantation of an autonomic ganglion into the brain provides a biological portal that bypasses normal barriers to macromolecules. The vascular and extracellular confluences between host and graft could provide direct access for systematically administered substances to enter brain regions where they, normally, would be excluded.

Animals↗

Multi-Omics Integration Identifies a Five-Gene Metabolic Signature With Experimental Validation in Clear Cell Renal Cell Carcinoma.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is hallmarked by profound metabolic reprogramming; however, its intricate crosstalk with the tumor immune microenvironment (TIME) and its clinical ramifications remain inadequately elucidated. This study aims to systematically decipher the metabolic-immune interplay in ccRCC through multi-omics integration, with the goal of identifying robust prognostic biomarkers and actionable therapeutic vulnerabilities. AIMS: This study aims to systematically decipher the metabolic-immune interplay in clear cell renal cell carcinoma (ccRCC) through multi&#x2011;omics integration, and to identify robust prognostic biomarkers and actionable therapeutic vulnerabilities that can inform precision risk stratification and individualized treatment strategies. METHODS: We integrated bulk transcriptomic, genomic, and clinical data from multiple ccRCC cohorts. Differential expression and functional enrichment analyses were performed to characterize metabolic pathway alterations. Mendelian randomization (MR) was employed to infer causal relationships between metabolic disorders and ccRCC risk. A machine learning-based prognostic framework, incorporating SHAP (SHapley Additive exPlanations) for feature interpretability, was constructed and rigorously validated. TIME heterogeneity was dissected using deconvolution algorithms, while drug sensitivity, tumor mutation burden (TMB), and TIDE scores were utilized to assess therapeutic responses and immune evasion. Candidate gene function was evaluated through in&#xa0;vitro gain- and loss-of-function assays, with expression validated via TCGA, HPA, western blot, and qRT-PCR. RESULTS: Enrichment analysis identified coordinated dysregulation in lipid metabolism, energy homeostasis, and hypoxia response pathways. MR analysis confirmed lipid metabolism disorders as a causal risk factor for ccRCC. Our machine-learning model, centered on five core SHAP-identified features (SUCLA2, ACAT1, PC, SUCLG1, and HMGCS2), demonstrated superior predictive accuracy over conventional clinical staging. Immune profiling unveiled dichotomous TIME states: the low-risk group retained active immune surveillance, whereas the high-risk group was enriched with immunosuppressive subsets. Drug sensitivity screening pinpointed LY2109761 and carmustine as high-risk-specific candidate agents. Furthermore, TMB and TIDE analyses stratified high-risk patients displaying genomic instability and immune evasion phenotypes. Functionally, SUCLA2 knockdown significantly enhanced ccRCC cell proliferation and invasion, while its overexpression suppressed these malignant phenotypes, corroborating its tumor-suppressive role. Expression patterns of the hub genes were consistently validated across multi-level datasets and experimental assays. CONCLUSION: This study establishes a precision oncology framework for ccRCC by functionally linking metabolic biomarkers, immunophenotypes, and stratified therapeutic strategies. Importantly, we identify SUCLA2 as a potential functional tumor suppressor and a promising target for further mechanistic and translational investigation.

Humans↗

Photoinduced interactions between oxidized and reduced lipoic acid and riboflavin (vitamin B2).

As a powerful natural antioxidant, lipoic acid (LipSS) and its reduced form dihydrolipoic acid (DHLA) exert significant antioxidant activities in vivo and in vitro by deactivation of reactive oxygen and nitrogen species (ROS and RNS). In this study the riboflavin (RF, vitamin B2) sensitized UVA and visible-light irradiation of LipSS and DHLA was studied employing continuous irradiation, fluorescence spectroscopy, and laser flash photolysis (LFP). Our results indicate that LipSS and DHLA quench both the singlet state (1RF*) and the triplet state (3RF*) of RF by electron transfer to produce the riboflavin semiquinone radical (RFH.) and the radical cation of LipSS and DHLA, respectively. The radical cation of DHLA is rapidly deprotonated twice to yield a reducing species, the radical anion of LipSS (LipSS.-). When D2O was used as solvent, it was confirmed that the reaction of LipSS with 3RF* consists of a simple electron-transfer step, while loss of hydrogen occurs in the case of DHLA oxidation. Due to the strong absorption of RFH. and the riboflavin ground state, the absorption of the radical cation and the radical anion of LipSS can not be observed directly by LFP. N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) and N,N,N',N'-tetramethyl benzidine (TMB) were added as probes to the system. In the case of LipSS, the addition resulted in the formation of the radical cation of TMPD or TMB by quenching of the LipSS radical cation. If DHLA is the reducing substrate, no formation of probe radical cation is observed. This confirms that LipSS.- is produced by riboflavin photosensitization, and that there is no oxidizing species produced after DHLA oxidization.

Antioxidants↗

Beta-adrenergic stimulation inhibits calcium efflux and alters the morphology of cultured arterial muscle cells.

Beta-adrenoreceptor stimulation with isoproterenol (IP) rapidly and reversibly rounded and arborized smooth muscle cells (SMC) cultured from rat aorta. The arborized SMC remained firmly attached to the substratum via a network of long, dendritelike processes. Arborization of the SMC correlated closely with increases in cellular cAMP produced by IP and a variety of other compounds. The intracellular calcium antagonist 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB-8) also rounded and arborized the SMC. Antitubulin compounds potently blocked arborized by IP, dibutyryl cAMP, and TMB-8. The release of cell-bound 45Ca2+ was followed in the presence and absence of IP. IP strikingly increased the amount of 45Ca2+ that remained cell bound between 20 and 120 min. Propranolol and colchicine prevented IP from inhibiting the release of cell-bound 45Ca2+. These results suggest that the modulation of Ca2+ transport is involved in the arborization of cultured SMC by cAMP.

1-Methyl-3-isobutylxanthine↗

Sources of calcium and the involvement of calmodulin during steroidogenesis and oocyte maturation in follicles of Rana pipiens.

In the amphibian ovarian follicle, progesterone production is thought to induce maturation of the enclosed oocyte. Intracellular mechanisms regulating these events in the somatic and germ cells are incompletely understood. However, calcium appears to play a role in the production and action of progesterone. Experiments using calcium antagonists were carried out to delineate the role of extra- and intracellular calcium during in vitro stimulation of follicular steroidogenesis and oocyte maturation. Calcium-free medium, verapamil, and La3+ were used to block Ca2+ influx and inhibited follicular progesterone accumulation in response to frog pituitary homogenate (FPH) or exogenous cAMP + IBMX. Progesterone accumulation was not impaired under identical conditions when pregnenolone was added to cultured follicles. TMB-8, an inhibitor of intracellular Ca2+ mobilization, partially inhibited progesterone levels stimulated by FPH at low doses but not higher doses of the inhibitor. However, TMB-8 inhibited FPH-induced oocyte germinal vesicle breakdown (GVBD) in a dose-dependent manner, as well as maturation due to exogenous progesterone or La3+. Calmodulin antagonists, W-7, R24571, and trifluoperazine, were used to assess the involvement of calmodulin in the responses of these two cell types. All three antagonists inhibited progesterone accumulation induced by FPH with the apparent order of potency being R24571 greater than W-7 greater than TFP. W-7 inhibited cAMP-induced progesterone elevation, but had no effect on conversion of pregnenolone to progesterone. Of these three calmodulin antagonists, only R24571 exhibited a dramatic ability to inhibit GVBD induced by exogenous progesterone and was associated with morphologic alterations in the oocytes. These data suggest that Ca2+, acting through calmodulin at some specific step(s) distal to cAMP elevation and prior to pregnenolone formation, is involved in FPH-induced progesterone accumulation, apparently with the participation of both extracellular and intracellular pools of Ca2+. In the oocyte, mobilization of Ca2+ from intracellular stores appears to be of primary importance to maturation while extracellular Ca2+ is not. These data provide further evidence that Ca2+ mediates the hormonally provoked responses in both cell types in the intact follicle, but that the source of Ca2+ may differ. Using intact follicles it seems apparent that exploiting this difference with selective inhibitors provides a means for differential modulation and functional uncoupling of these cells with regard to steroidogenesis and steroid action.

1-Methyl-3-isobutylxanthine↗

A new, one-step assay on whole cell suspensions for peroxidase secretion by human neutrophils and eosinophils.

The degranulation of neutrophils and eosinophils is frequently monitored by assaying myeloperoxidase (MPO) and eosinophil peroxidase (EPO) activity in the cell-free supernatant of degranulating cells, after removal of the cells by centrifugation. This procedure leads to underestimation of the extent of degranulation, since both peroxidases tend to stick to cell surfaces, to test tube walls, and to particulate stimuli used to elicit degranulation, because of their highly cationic nature. In this paper we describe a method for assaying MPO and EPO secretion in whole cell suspensions that avoids separation of the cells from the incubation medium. The least toxic and thus safest among the sensitive peroxidase substrates, 3,3',5,5'-tetramethylbenzidine (TMB), was employed for peroxidase assay. The method we describe here is applied to the detection of peroxidase release by neutrophil and eosinophil cell suspensions incubated in either polypropylene test tubes or flat-bottomed microtiter plate wells. Because of the omission of the centrifugation step, the TMB method offers two major advantages over the currently used techniques: (1) higher estimates of degranulation, which permits the use of a smaller number of cells (in the microassay version, 150,000 neutrophils and 50,000 eosinophils) and smaller amounts of the secretagogues, and (2) rapidity, since the degranulation assay can be performed immediately on completion of the cell incubation with the secretagogue.

Calcimycin↗

Comprehensive Analysis of Clinical and Molecular Features in Cancer Patients Associated With Major Human Oncoviruses.

Viral infections contribute to a higher incidence of cancer than any other individual risk factor. This study aimed to compare the clinical and molecular features of four viral-associated cancers: stomach adenocarcinoma (STAD), head and neck squamous cell carcinoma (HNSC), liver hepatocellular carcinoma (LIHC), and cervical squamous cell carcinoma (CESC). Patients were categorized based on viral infection status, as provided in the clinical data, into virus-associated and non-virus-associated groups, followed by a comprehensive comparison of clinical and molecular features. Our analysis disclosed that viral infections confer unique clinical and molecular signatures to their associated tumors. Specifically, human papillomavirus-associated (HPV+) HNSC and hepatitis B virus-associated (HBV+) LIHC patients were predominantly male, younger, and exhibited better clinical prognoses. Virus-associated tumors displayed enhanced immune microenvironments and high DNA damage response scores, while non-virus-associated tumors were enriched in stromal signatures. HPV+&#x2009;HNSC and Epstein-Barr virus-associated (EBV+) STAD showed similarities across multi-omics features, including better responses to immunotherapy, lower TP53 mutation rates, tumor mutation burden (TMB), and copy number alteration (CNA). Conversely, HBV+, Hepatitis C virus-associated (HCV+) LIHCs and HPV+&#x2009;CESC were more genomically unstable due to high TP53 mutation rates, TMB, and CNA. At the protein level, Caspase-7 and Syk were upregulated in HPV+&#x2009;HNSC and EBV+&#x2009;STAD, and positively correlated with the enrichment levels of CD8&#x2009;+&#x2009;T cell, PD-L1, and cytolytic activity. Patient stratification based on infection status has significant clinical implications, particularly for patient prognosis and drug response.

Humans↗

Sodium Overload-Related Molecular Subtypes and a Four-Gene Prognostic Signature Predict Survival, Immune Landscape, and Therapeutic Response in Acute Myeloid Leukemia.

Sodium overload has recently emerged as a critical metabolic stressor involved in cancer progression; however, its molecular characteristics and clinical relevance in acute myeloid leukemia (AML) remain unexplored. RNA-seq data sets, clinical annotations, and mutational profiles of AML patients were annotations from The Cancer Genome Atlas and integrated with Genotype-Tissue Expression normal samples. Sodium overload-related genes (SORGs) were obtained from GeneCards. Differentially expressed SORGs (DESORGs) screened by applying the limma statistical model, followed by univariate Cox proportional hazards regression, consensus clustering, functional enrichment, immune infiltration analysis, and pathway evaluation. A prognostic signature was developed through least absolute shrinkage and selection operator regression followed by multivariate Cox modeling. The model's performance was further verified in two external GEO data sets (GSE71014 and GSE37642). Nomogram construction, subgroup analysis, tumor mutational burden (TMB) assessment, drug sensitivity prediction, transcription factor (TF) analysis, and competing endogenous RNA (ceRNA) network analyses were also performed. A total of 57 DESORGs were identified, and 2 sodium overload-related molecular subtypes exhibited distinct survival, immune infiltration, and inflammatory pathway activation. A robust four-gene signature (DOCK1, GABRE, HTR7, ACSM1) stratified patients into high- and low-risk categories with significantly different survival across training and validation cohorts. High-risk patients displayed increased immune infiltration, higher TMB, reduced sensitivity to multiple chemotherapeutic drugs, and inferior predicted response to PD-L1 blockade. TF and ceRNA networks revealed multilayered transcriptional and post-transcriptional regulation of the signature genes. This study identifies sodium overload-related molecular heterogeneity in AML and establishes a validated four-gene prognostic signature that integrates genomic, immunologic, and therapeutic features, offering potential utility for personalized risk assessment and treatment optimization.

Humans↗

Granule exocytosis in a cultured human natural killer cell-rich population induced by K562 target cells and by PMA/A23187.

Granule exocytosis in natural killer (NK) cells induced by K562 target cells and by PMA/A23187 was examined by measuring N-benzyloxycarboxy-L-lysine esterase activity. We obtained a cultured human NK cell-rich population containing around 90% of CD16+ cells by culturing peripheral blood mononuclear cells with mitomycin C-treated Daudi cells in the presence of IL-2. Granule exocytosis in the cultured NK cells was induced by K562 cells in a target/effector cell ratio-dependent manner. The granule exocytosis induced by K562 cells was inhibited neither by EGTA nor by TMB-8, an intracellular calcium antagonist, nor by a combination of these two reagents, while the exocytosis induced by PMA/A23187 was inhibited in a dose-dependent manner both by EGTA and by TMB-8. However, the cytotoxic activity of the cultured NK cells was inhibited by EGTA, suggesting that calcium is required not for the induction of granule exocytosis but for other steps including its requirement for the exertion of perforin activity.

Cells, Cultured↗

Intracellular mechanisms of hydrogen peroxide-mediated neutrophil adherence to cultured human endothelial cells.

We examined which endothelial second messengers are involved in peroxide-mediated endothelial-neutrophil adhesion with respect to endothelial P-selectin expression and platelet-activating factor (PAF). Peroxide (0.5 mM)-mediated adhesion was blocked by a protein kinase C (PKC) inhibitor, Gö6976 (10 nM); an intracellular calcium chelator, TMB-8 (0.1 mM); and a protein kinase G (PKG) inhibitor, KT5823 (0.5 microM); but not by a tyrosine kinase inhibitor, genistein (1 microM), or a protein kinase A inhibitor, H-89 (0.1 microM). These data were consistent with the proadhesive effects of PMA (0.1 microM), a PKC activator; a calcium ionophore, A23187 (1 microM); and dibutyryl cGMP (0.5 and 1 mM); but not phenylarsine oxide (0.1 mM), a tyrosine phosphatase inhibitor, or dibutyryl cAMP (1 mM). Conversely, peroxide-mediated P-selectin expression was blocked by Gö6976 and KT5823, but not by TMB-8. These data are strengthened by the observation that PMA and dibutyryl cGMP, but not A23187, increased P-selectin expression. WEB 2086 (10 microM), a PAF-receptor antagonist, blocked peroxide-, PMA-, and A23187-mediated adhesion, but not peroxide-mediated P-selectin expression. PAF itself (10 nM) stimulated adhesion, but not P-selectin expression. These data indicate that PKC and PKG are involved in peroxide-mediated neutrophil adhesion via P-selectin mobilization and PAF synthesis; however, intracellular calcium appears to mediate adhesion only through PAF synthesis.

Azepines↗

Protection against methoxyacetic-acid-induced spermatocyte apoptosis with calcium channel blockers in cultured rat seminiferous tubules: possible mechanisms.

A calcium-mediated mechanism underlying spermatocyte apoptosis induced by 2-methoxyethanol (2-ME) has been previously proposed. This hypothesis was tested in vitro in the present study using cultured juvenile (25 days old) and adult rat seminiferous tubules (JRST and ARST, respectively) with methoxyacetic acid (MAA, the active metabolite of 2-ME). In JRST, spermatocyte degeneration was morphologically obvious 19 hr after a 5-hr exposure to 5 mM MAA. The lesion was unaffected by the presence or absence of extratubular Ca2+. However, MAA-induced cell death was significantly prevented by cotreatment with the dihydropyridines (DHP) nifedipine (50 microM) and nicardipine (20 microM), as well as verapamil (50 microM) and TMB-8 (50 microM), all of which are able to inhibit calcium movement through plasma membranes. However, neither ryanodine, dantrolene, nor cyclosporin A and ruthenium red, which inhibit Ca2+ mobilization from intracellular stores (endoplasmic reticulum and mitochondria), affected the MAA-induced cell death. Inhibition of calcium mobilization through IP3-sensitive pathways by blocking the product of IP3 with manoalide, neomycin, and U73122 did not block the MAA-induced lesion. The protective effects of 50 microM nifedipine and 50 microM TMB-8 were also observed in ARSTs treated with 10 mM MAA for 5 hr. However, when rat testicular sections were immunohistochemically stained with monoclonal antibodies specific for the alpha 1 (the DHP receptor) or the alpha 2 subunits of DHP-sensitive calcium channels, no positive staining was found. Finally, in an attempt to see whether the intracellular free calcium concentrations ([Ca2+]i) in germ cells were increased after the MAA treatment, intact seminiferous tubules were loaded with indo-1 and were measured using laser-scanning confocal microscopy. No detectable increase in the signal in MA A-sensitive spermatocytes was observed, while a 34-54% increase in the signal could be detected in the same cell types when tubules were exposed to 10 microM of the calcium ionophore 4-bromo-A23187 for 5 min. Collectively, these data suggest that the protective effect of calcium channel blockers against the MAA-induced spermatocyte apoptosis is probably not through their blocking effect on DHP-sensitive calcium channels. We postulate alternate mechanisms based on stabilization of cells membranes, or interactions with calmodulin or protein kinase C.

4-Aminopyridine↗