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Results for “Biomarker variability”

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PubMed2006

Measuring cholinesterase activity in human saliva.

To assess the potential for using saliva in pesticide biomonitoring, the consistency of cholinesterase activity in human saliva collected over time was examined. In this pilot study, saliva was collected from 20 healthy adults once per week for 5 consecutive weeks using 2 different collection methods: a disposable plastic pipette, and a cotton-wool roll. A brief questionnaire was conducted each week to document changes in exposure to cholinesterase inhibitors for the duration of the sampling. To measure cholinesterase activity, an existing radiometric method was modified to make it suitable for human saliva. Using this method, cholinesterase activity was measurable in saliva, and duplicate samples showed reliable repeatability. Activity in both collection methods ranged from 3 to 265 nmol/h/ml saliva (mean = 52 +/- 37 [SD] nmol/h/ml saliva). For some individuals, enzyme activity was consistent over the five sampling weeks; for others, activity was highly variable. Coefficients of variation (CVs) were calculated to assess variability, and mean CVs were the same for both collection methods (about 35%). Adjusting for protein concentration in the pipette-collected samples did not change results. Both collection methods worked well for collecting between 1 and 3 ml saliva, but at the majority of visits (86%), participants preferred the cotton-wool roll. Results from this study suggest that saliva may be a useful indicator of potential neurotoxic effects from exposure to organophosphorus and carbamate pesticides, but that factors affecting variability should be explored further.

Adult↗

PubMed2003

Spread supplemented with moderate doses of vitamin E and carotenoids reduces lipid peroxidation in healthy, nonsmoking adults.

BACKGROUND: High doses of vitamin E have been shown to decrease lipid peroxidation in persons under oxidative stress. At present, the data are insufficient to predict whether lower doses offer the same benefit in healthy persons. OBJECTIVE: We studied the effect of moderate doses of a combination of vitamin E and carotenoids, incorporated into a food product, on markers of antioxidant status and lipid peroxidation in healthy persons. DESIGN: One hundred five healthy adults were randomly, evenly assigned in this double-blind, placebo-controlled, parallel, 11-wk intervention study. After a 2-wk stabilization period during which the subjects consumed a commercial unfortified spread, the subjects consumed 25 g/d of spread containing 43 mg alpha-tocopherol equivalents (alpha-TE; 2-3 fold the US dietary reference intake) and 0.45 mg carotenoids (spread A), 111 mg alpha-TE and 1.24 mg carotenoids (spread B), or 1.3 mg RRR-alpha-tocopherol without carotenoids (spread C). RESULTS: In subjects consuming spread A, plasma alpha-tocopherol concentrations increased 31% to 32 micromol/L, with small but significant increases in concentrations of alpha-carotene and lutein. This resulted in LDL with significantly higher total antioxidant capacity (17%) and an increased resistance to oxidation, as determined by lag time (18%). These improvements were dose dependent: larger increases in these variables were observed in subjects consuming spread B. Furthermore, consumption of spread B significantly reduced concentrations of the plasma lipid peroxidation biomarker F(2 alpha)-isoprostane (15%). CONCLUSION: The consumption of food products containing moderate amounts of vitamin E and carotenoids can lead to measurable and significant improvements in antioxidant status and biomarkers of oxidative stress in healthy persons.

Adult↗

PubMedDate not supplied

Psychosocial, hemostatic, and inflammatory correlates of delayed poststress blood pressure recovery.

OBJECTIVE: Delayed poststress cardiovascular recovery has been associated with cardiovascular disease risk. This study assessed relationships between systolic blood pressure (BP) recovery, psychosocial risk factors, and delayed recovery of inflammatory and hemostatic variables. METHOD: Data were analyzed from 228 middle-aged men and women from the Whitehall Psychobiology study who performed color/word and mirror-tracing tasks. Systolic BP recovery was assessed as the difference between baseline and levels recorded 40 to 45 minutes poststress. Associations were analyzed with socioeconomic markers (grade of employment, education, income), psychosocial factors (social isolation, hostility, mental health, financial strain), and recovery of heart rate, heart rate variability, von Willebrand factor, factor VIII clotting activity, plasma fibrinogen, and plasma viscosity. RESULTS: Systolic BP was on average 6.19 +/- 9.6 mm Hg higher on recovery than baseline. Delayed BP recovery was associated with lower grade of employment, lower education and lower income independently of age, gender, and systolic BP stress reactivity. Delayed BP recovery was related to social isolation and poor mental health independently of age, gender, socioeconomic position, and task reactivity. Delayed systolic BP recovery was also associated with delayed recovery in diastolic BP, heart rate, factor VIII, and plasma viscosity but not delayed heart rate variability recovery, independently of age, gender, body mass, and task reactivity. CONCLUSION: Socioeconomic and psychosocial risk factors for cardiovascular disease are related to delays in poststress recovery. Delayed systolic BP recovery may be a marker for prolonged responses in hemostatic variables that have a direct influence on cardiovascular disease pathogenesis.

Biomarkers↗

PubMed2005

An integrated feature selection and classification method to select minimum number of variables on the case study of gene expression data.

This paper introduces a novel generic approach for classification problems with the objective of achieving maximum classification accuracy with minimum number of features selected. The method is illustrated with several case studies of gene expression data. Our approach integrates filter and wrapper gene selection methods with an added objective of selecting a small set of non-redundant genes that are most relevant for classification with the provision of bins for genes to be swapped in the search for their biological relevance. It is capable of selecting relatively few marker genes while giving comparable or better leave-one-out cross-validation accuracy when compared with gene ranking selection approaches. Additionally, gene profiles can be extracted from the evolving connectionist system, which provides a set of rules that can be further developed into expert systems. The approach uses an integration of Pearson correlation coefficient and signal-to-noise ratio methods with an adaptive evolving classifier applied through the leave-one-out method for validation. Datasets of gene expression from four case studies are used to illustrate the method. The results show the proposed approach leads to an improved feature selection process in terms of reducing the number of variables required and an increased in classification accuracy.

Artificial Intelligence↗

PubMed2003

Association between plasma levels of monocyte chemoattractant protein-1 and long-term clinical outcomes in patients with acute coronary syndromes.

BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1) is a chemokine responsible for the recruitment of monocytes to sites of inflammation. MCP-1 appears to play a critical role at multiple stages in atherosclerosis, including the initiation of the fatty streak, promotion of plaque instability, and remodeling after myocardial infarction. METHODS AND RESULTS: MCP-1 was measured from frozen plasma specimens in 279 healthy volunteers and 2270 patients with acute coronary syndromes enrolled in the Oral Glycoprotein IIb/IIIa Inhibition with Orbofiban in Patients with Unstable Coronary Syndromes (OPUS-TIMI) 16 trial. Median [25th, 75th percentiles] MCP-1 levels were 157 [124, 196] pg/mL in healthy volunteers and 178 [128, 238] pg/mL in the OPUS-TIMI 16 population (P<0.001). In OPUS-TIMI 16, baseline MCP-1 levels were associated with older age, female sex, hypertension, diabetes, prior coronary disease, and renal insufficiency (P<0.01 for each) but not with smoking status, body mass index, ejection fraction, troponin I or C-reactive protein. After adjustment for differences in baseline characteristics, ECG changes, troponin I, and C-reactive protein, an MCP-1 level >75th percentile (corresponding to the 90th percentile in the healthy volunteers) was associated with an increased risk of death or myocardial infarction through 10 months of follow-up (adjusted hazard ratio, 1.53; 95% CI, 1.09 to 2.14; P=0.01). CONCLUSIONS: In a large cohort of patients with acute coronary syndromes, an elevated baseline level of MCP-1 was associated both with traditional risk factors for atherosclerosis as well as an increased risk for death or myocardial infarction, independent of baseline variables. Because it appears to play a crucial role at multiple stages of atherosclerosis, MCP-1 is attractive as a surrogate biomarker and merits further study as a potential therapeutic target.

Acute Disease↗

PubMed2003

Human epicardial adipose tissue is a source of inflammatory mediators.

BACKGROUND: Inflammatory mediators that originate in vascular and extravascular tissues promote coronary lesion formation. Adipose tissue may function as an endocrine organ that contributes to an inflammatory burden in patients at risk of cardiovascular complications. In this study, we sought to compare expression of inflammatory mediators in epicardial and subcutaneous adipose stores in patients with critical CAD. METHODS AND RESULTS: Paired samples of epicardial and subcutaneous adipose tissues were harvested at the outset of elective CABG surgery (n=42; age 65+/-10 years). Local expression of chemokine (monocyte chemotactic protein [MCP]-1) and inflammatory cytokines (interleukin [IL]-1beta, IL-6, and tumor necrosis factor [TNF]-alpha) was analyzed by TaqMan real-time reverse transcription-polymerase chain reaction (mRNA) and by ELISA (protein release over 3 hours). Significantly higher levels of IL-1beta, IL-6, MCP-1, and TNF-alpha mRNA and protein were observed in epicardial adipose stores. Proinflammatory properties of epicardial adipose tissue were noted irrespective of clinical variables (diabetes, body mass index, and chronic use of statins or ACE inhibitors/angiotensin II receptor blockers) or plasma concentrations of circulating biomarkers. In a subset of samples (n=11), global gene expression was explored by DNA microarray hybridization and confirmed the presence of a broad inflammatory reaction in epicardial adipose tissue in patients with coronary artery disease. The above findings were paralleled by the presence of inflammatory cell infiltrates in epicardial adipose stores. CONCLUSIONS: Epicardial adipose tissue is a source of several inflammatory mediators in high-risk cardiac patients. Plasma inflammatory biomarkers may not adequately reflect local tissue inflammation. Current therapies do not appear to eliminate local inflammatory signals in epicardial adipose tissue.

Adipose Tissue↗

PubMed2005

Quality control and quality assessment of data from surface-enhanced laser desorption/ionization (SELDI) time-of flight (TOF) mass spectrometry (MS).

BACKGROUND: Proteomic profiling of complex biological mixtures by the ProteinChip technology of surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) is one of the most promising approaches in toxicological, biological, and clinic research. The reliable identification of protein expression patterns and associated protein biomarkers that differentiate disease from health or that distinguish different stages of a disease depends on developing methods for assessing the quality of SELDI-TOF mass spectra. The use of SELDI data for biomarker identification requires application of rigorous procedures to detect and discard low quality spectra prior to data analysis. RESULTS: The systematic variability from plates, chips, and spot positions in SELDI experiments was evaluated using biological and technical replicates. Systematic biases on plates, chips, and spots were not found. The reproducibility of SELDI experiments was demonstrated by examining the resulting low coefficient of variances of five peaks presented in all 144 spectra from quality control samples that were loaded randomly on different spots in the chips of six bioprocessor plates. We developed a method to detect and discard low quality spectra prior to proteomic profiling data analysis, which uses a correlation matrix to measure the similarities among SELDI mass spectra obtained from similar biological samples. Application of the correlation matrix to our SELDI data for liver cancer and liver toxicity study and myeloma-associated lytic bone disease study confirmed this approach as an efficient and reliable method for detecting low quality spectra. CONCLUSION: This report provides evidence that systematic variability between plates, chips, and spots on which the samples were assayed using SELDI based proteomic procedures did not exist. The reproducibility of experiments in our studies was demonstrated to be acceptable and the profiling data for subsequent data analysis are reliable. Correlation matrix was developed as a quality control tool to detect and discard low quality spectra prior to data analysis. It proved to be a reliable method to measure the similarities among SELDI mass spectra and can be used for quality control to decrease noise in proteomic profiling data prior to data analysis.

Female↗

PubMed2007

Targeted interventions for difficult-to-treat asthma.

Chronic persistent asthma has a significant burden in terms of healthcare-related expenses, decreased productivity and reduced quality of life for patients. Currently available guideline-directed therapy can control the majority of patients, but roughly one-third of patients will require additional care. This article reviews the barriers that hinder the ability of practitioners and patients to gain and maintain control of asthma, including inaccurate assessment measures, variability in patient response, and poor adherence. Strategies aimed at controlling difficult-to-treat disease, such as the use of biomarkers to assess control, are discussed. Newer and developing therapies that cater to specific types of asthmatic patients and may lead to improved outcomes in those patients for whom standard care is insufficient are also looked at.

Anti-Asthmatic Agents↗

PubMed2006

Integrated microfluidic biochips for DNA microarray analysis.

A fully integrated and self-contained microfluidic biochip device has been developed to automate the fluidic handling steps required to perform a gene expression study of the human leukemia cell line (K-562). The device consists of a DNA microarray semiconductor chip with 12,000 features and a microfluidic cartridge that consists of microfluidic pumps, mixers, valves, fluid channels and reagent storage chambers. Microarray hybridization and subsequent fluidic handling and reactions (including a number of washing and labeling steps) were performed in this fully automated and miniature device before fluorescent image scanning of the microarray chip. Electrochemical micropumps were integrated in the cartridge to provide pumping of liquid solutions. A micromixing technique based on gas bubbling generated by electrochemical micropumps was developed. Low-cost check valves were implemented in the cartridge to prevent cross-talk of the stored reagents. A single-color transcriptional analysis of K-562 cells with a series of calibration controls (spiked-in controls) was performed to characterize this new platform with regard to sensitivity, specificity and dynamic range. The device detected sample RNAs with a concentration as low as 0.375 pM. Detection was quantitative over more than 3 orders of magnitude. Experiments also demonstrated that chip-to-chip variability was low, indicating that the integrated microfluidic devices eliminate manual fluidic handling steps that can be a significant source of variability in genomic analysis.

Biomarkers↗

PubMed2001

[Enzymes of the kynurenine pathway].

In this review, the role of kynurenine pathway enzymes (tryptophan 2,3-dioxygenase, indoleamine 2,3-dioxygenase, formamidase, kynurenine aminotransferase, kynurenine 3-hydroxylase, kynureninase, 3-hydroxyanthranilic acid oxygenase, picolinic carboxylase, quinolinic acid phosphoribosyltransferase) in the synthesis of tryptophan products degradation was described. Taking into account the importance of disorders, in which kynurenine metabolites may play pathogenic role. It was been postulated that kynurenine metabolites may be involved in pathogenesis of many diseases of clinical importance. Therefore evaluation of correlations between kynurenine metabolites and other variables, both clinical and biochemical, would be of interest. Attention was paid to the potential use of those biochemical parameter as biomarkers of many disease activity.

3-Hydroxyanthranilate 3,4-Dioxygenase↗

PubMed2006

E-cadherin status in breast cancer correlates with histologic type but does not correlate with established prognostic parameters.

Our objective was to assess the loss of E-cadherin (EC) as a diagnostic marker or a predictor of prognosis. We stained 276 breast carcinomas with monoclonal antibodies to EC (invasive lobular carcinomas [ILC] and variants, 59; invasive ductal carcinoma and ductal special types [IDC], 204; tubulolobular carcinoma [TLC], 4; and invasive carcinoma [IC], uncertain whether lobular or ductal type, 9). The results were as follows: EC+IDCs, 99.5%; EC-ILCs, 90%; EC+ILCs, 10%; EC+pleomorphic ILCs, 20%; EC-ICs, 44%. All 4 TLCs showed positive tubules while cords were negative. Statistically a correlation of EC loss with a positive diagnosis of ILC was found but there was no correlation with any prognostic tumor variables. A negative EC stain confirms the diagnosis of ILC (specificity, 97.7%; negative predictive value, 96.8%; sensitivity, 88.1%; positive predictive value, 91.2%). EC is helpful in classifying cases with indeterminate histologic features. EC loss is uncommon in nonlobular carcinomas with no correlation to currently established prognostic variables.

Adenocarcinoma↗

PubMed2007

Prognostic markers in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (estrogen receptor-negative, progesterone receptor-negative, and HER2-negative) is a high risk breast cancer that lacks the benefit of specific therapy that targets these proteins. METHODS: In this study, the authors examined a large and well characterized series of invasive breast carcinoma (n = 1944) with a long-term clinical follow-up (median, 56 months) by using tissue microarray. The series were also stained with concurrent immunohistochemical prognostic panels (estrogen receptor, progesterone receptor, HER-2, androgen receptor, epidermal growth factor receptor (EGFR), P-cadherin, E-cadherin, and basal (CK5/6, CK14), and p53), to characterize this specific subgroup of breast cancer and to identify prognostic markers that can identify tumors with more aggressive behavior. RESULTS: Of informative cases, 16.3% were of the triple-negative phenotype. The majority of these tumors were grade 3, ductal/no-specific-type carcinomas. There were positive associations with larger size, pushing margins, poorer Nottingham Prognostic Index, development of recurrence and distant metastasis, and poorer outcome. In addition, associations were found with loss of expression of androgen receptor and E-cadherin, and positive expression of basal cytokeratins (basal phenotype), P-cadherin, p53, and EGFR. In all tumors, tumor size, lymph node stage, and androgen receptor were the most useful prognostic markers. In the lymph node-positive subgroup, both size and androgen receptor retained their prognostic significance. However, in the lymph node-negative tumors, basal phenotype was the sole prognostic marker identified in this subgroup. Other parameters including age, histological grade, tumor size, vascular invasion or other biomarkers included in the current study were not significant. CONCLUSIONS: The authors concluded that assessment of androgen receptor and basal phenotype, in addition to the established pathologic variables, mainly lymph node status and tumor size, can be used to select high-risk and low-risk patients at the time of primary surgery and can provide valuable information on treatment options in these triple-negative tumors.

Adult↗

PubMed2006

Ret, Abl1 (cAbl) and Trp53 gene fragmentations in comet-FISH assay act as in vivo biomarkers of radiation exposure in C57BL/6 and CBA/J mice.

The International Commission on Radiation Protection (ICRP) has lowered the dose limits for workers and for the general public exposed to ionizing radiation. Consequently, a reliable dosimetric method for monitoring possible radiation-induced damage is of great importance in radioprotection. The counting of dicentric chromosomal aberrations and of micronuclei in peripheral blood lymphocytes is unreliable when it is applied to in vivo biopsies and for low-dose exposures. Single-cell gel electrophoresis (SCGE or comet assay), although sensitive and rapid, shows high variability when applied in vivo, probably due to prompt repair of the DNA breaks and confounding environmental factors. In this paper, we describe specific in situ hybridization of Ret, Abl1 (cAbl), and Trp53 gene fragmentations on SCGE slides (comet-FISH assay) in peripheral blood cells from C57BL/6 and CBA/J mice as an indicator of radiation-induced DNA damage. The results obtained from four mice for each experimental point (0, 1, 2 and 4 Gy of X rays) discriminated in a statistically significant way the effects of all doses when fragmentations were analyzed for the Ret, Ab1 and Trp53 genes. SCGE alone, when applied to the same specimens, produced no significant results because of interindividual and experimental variability.

Adaptor Proteins, Signal Transducing↗

PubMed2003

Leisure-time physical activity and reduced plasma levels of obesity-related inflammatory markers.

OBJECTIVE: This study investigated the relationship between physical activity and the obesity-related inflammatory markers C-reactive protein, interleukin-6, and soluble tumor necrosis factor receptors (sTNF-Rs) 1 and 2. Furthermore, we examined the relationship between physical activity and insulin sensitivity (insulin, C-peptide, and hemoglobin A(1c) levels) and whether inflammatory markers mediate this association. RESEARCH METHODS AND PROCEDURES: Biomarkers were measured in 405 healthy men and 454 healthy women from two large ongoing prospective studies. Information about physical activity and other variables was assessed by questionnaires. RESULTS: After adjustment for other predictors of inflammation, physical activity was inversely associated with plasma levels of sTNF-R1, sTNF-R2, interleukin-6, and C-reactive protein (p = 0.07, p = 0.004, p = 0.04, and p = 0.009). After further adjustment for BMI and leptin, as a surrogate for fat mass, most of these associations were no longer significant. Physical activity was also inversely related to insulin and C-peptide levels (p = 0.008 and p < 0.001); however, in contrast to BMI and leptin, levels of inflammatory markers explained only very little of this inverse relationship. DISCUSSION: These results suggest that frequent physical activity is associated with lower systemic inflammation and improved insulin sensitivity. These associations can partially be explained by a lower degree of obesity in physically active subjects. Although inflammatory markers may mediate obesity-dependent effects of physical activity on inflammatory related diseases such as type 2 diabetes or coronary heart disease, our study suggests that they do not directly account for the beneficial effects of physical activity on insulin resistance.

Adult↗

PubMed2006

Circulating concentrations of growth-differentiation factor 15 in apparently healthy elderly individuals and patients with chronic heart failure as assessed by a new immunoradiometric sandwich assay.

BACKGROUND: Growth-differentiation factor 15 (GDF15) is a member of the transforming growth factor beta (TGF-beta) cytokine superfamily. There has been increasing interest in using circulating GDF15 as a biomarker in patients, for example those with cardiovascular disease. METHODS: We developed an IRMA that uses a polyclonal, affinity chromatography-purified goat antihuman GDF15 IgG antibody, assessed the preanalytic characteristics of GDF15, and determined circulating GDF15 concentrations in 429 apparently healthy elderly individuals and 153 patients with chronic heart failure (CHF). RESULTS: The assay had a detection limit of 20 ng/L, an intraassay imprecision of < or =10.6%, and an interassay imprecision of < or =12.2%. Specificity was demonstrated with size-exclusion chromatography, parallel measurements with polyclonal and monoclonal anti-GDF15 antibody, and lack of cross-reactivity with TGF-beta. The assay was not appreciably influenced by the anticoagulant matrix or unrelated biological substances. GDF15 was stable at room temperature for 48 h and resistant to 4 freeze-thaw cycles. Apparently healthy, elderly individuals presented with a median GDF15 concentration of 762 ng/L (25th-75th percentiles, 600-959 ng/L). GDF15 concentrations were associated with age and with cystatin C and C-reactive protein concentrations. CHF patients had increased GDF15 concentrations that were closely related to disease severity. CONCLUSION: The IRMA can detect GDF15 in human serum and plasma with excellent sensitivity and specificity. The reference limits and confounding variables defined for apparently healthy elderly individuals and the favorable preanalytic characteristics of GDF15 are expected to facilitate future studies of GDF15 as a biomarker in various disease settings, including CHF.

Adult↗

PubMed2025

PROLONG: penalized regression for outcome guided longitudinal omics analysis with network and group constraints.

MOTIVATION: There is a growing interest in longitudinal omics data paired with some longitudinal clinical outcome. Given a large set of continuous omics variables and some continuous clinical outcome, each measured for a few subjects at only a few time points, we seek to identify those variables that co-vary over time with the outcome. To motivate this problem we study a dataset with hundreds of urinary metabolites along with Tuberculosis mycobacterial load as our clinical outcome, with the objective of identifying potential biomarkers for disease progression. For such data clinicians usually apply simple linear mixed effects models which often lack power given the low number of replicates and time points. We propose a penalized regression approach on the first differences of the data that extends the lasso + Laplacian method [Li and Li (Network-constrained regularization and variable selection for analysis of genomic data. Bioinformatics 2008;24:1175-82.)] to a longitudinal group lasso + Laplacian approach. Our method, PROLONG, leverages the first differences of the data to increase power by pairing the consecutive time points. The Laplacian penalty incorporates the dependence structure of the variables, and the group lasso penalty induces sparsity while grouping together all contemporaneous and lag terms for each omic variable in the model. RESULTS: With an automated selection of model hyper-parameters, PROLONG correctly selects target metabolites with high specificity and sensitivity across a wide range of scenarios. PROLONG selects a set of metabolites from the real data that includes interesting targets identified during EDA. AVAILABILITY AND IMPLEMENTATION: An R package implementing described methods called "prolong" is available at https://github.com/stevebroll/prolong. Code snapshot available at 10.5281/zenodo.14804245.

Humans↗

PubMed2026

Discovery and validation of a prognostic SPP1/PLAU signature in HPV-negative oropharyngeal squamous cell carcinoma.

BACKGROUND: This study aimed to identify and validate robust prognostic biomarkers for oropharyngeal squamous cell carcinoma (OPSCC), with a specific focus on the high-risk HPV-negative subtype. METHODS: Integrated bioinformatics analysis was performed on transcriptomic data from four GEO datasets (n = 418 samples). Differentially expressed genes (DEGs) were identified, and a protein-protein interaction (PPI) network was constructed for the most dysregulated genes. Key modules were analyzed via survival analysis and multivariate Cox regression. The top candidate genes were validated at the protein level using immunohistochemistry (IHC) in an independent cohort of 304 OPSCC patients. RESULTS: A 33-gene module related to extracellular matrix organization showed significant prognostic association. It stratified patients into high- and low-risk groups with markedly different overall survival (HR = 2.71, p < 0.001). From this module, SPP1 and PLAU were identified as independent prognostic factors through multi-step screening. Both genes were significantly overexpressed in tumors (approximately 20-fold and 10-fold, respectively, p < 0.001), with high expression strongly correlated with advanced tumor stage (p < 0.01) and, notably, the HPV-negative subtype (p < 0.001). In survival analysis, high expression of either SPP1 or PLAU was associated with poorer overall survival (SPP1: p < 0.001; PLAU: p < 0.001) and progression-free survival (p < 0.001). IHC validation confirmed high protein expression in 69.7% (SPP1) and 54.8% (PLAU) of cancer tissues. A prognostic nomogram integrating the SPP1/PLAU signature with clinical variables was constructed with strong predictive accuracy (C-index = 0.75). CONCLUSION: The SPP1/PLAU dual-gene signature is a robust and independent prognostic biomarker for OPSCC, with particular clinical utility for stratifying high-risk HPV-negative patients.

Humans↗

PubMed2005

Pharmacokinetic-pharmacodynamic relationships for the heat shock protein 90 molecular chaperone inhibitor 17-allylamino, 17-demethoxygeldanamycin in human ovarian cancer xenograft models.

PURPOSE: To establish the pharmacokinetic and pharmacodynamic profile of the heat shock protein 90 (HSP90) inhibitor 17-allylamino, 17-demethoxygeldanamycin (17-AAG) in ovarian cancer xenograft models. EXPERIMENTAL DESIGN: The effects of 17-AAG on growth inhibition and the expression of pharmacodynamic biomarkers c-RAF-1, CDK4, and HSP70 were studied in human ovarian cancer cell lines A2780 and CH1. Corresponding experiments were conducted with established tumor xenografts. The variability and specificity of pharmacodynamic markers in human peripheral blood lymphocytes (PBL) were studied. RESULTS: The IC50 values of 17-AAG in A2780 and CH1 cells were 18.3 nmol/L (SD, 2.3) and 410.1 nmol/L (SD, 9.4), respectively. Pharmacodynamic changes indicative of HSP90 inhibition were demonstrable at greater than or equal the IC50 concentration in both cell lines. Xenograft experiments confirmed tumor growth inhibition in vivo. Peak concentrations of 17-AAG achieved in A2780 and CH1 tumors were 15.6 and 16.5 micromol/L, respectively, and there was no significant difference between day 1 and 11 pharmacokinetic profiles. Reversible changes in pharmacodynamic biomarkers were shown in tumor and murine PBLs in both xenograft models. Expression of pharmacodynamic markers varied between human PBLs from different human volunteers but not within the same individual. Pharmacodynamic biomarker changes consistent with HSP90 inhibition were shown in human PBLs exposed ex vivo to 17-AAG but not to selected cytotoxic drugs. CONCLUSION: Pharmacokinetic-pharmacodynamic relationships were established for 17-AAG. This information formed the basis of a pharmacokinetic-pharmacodynamic-driven phase I trial.

Animals↗