Dual Biomarkers Research Articles

Comparison of the clinical chemistry score to other biomarker algorithms for rapid rule-out of acute myocardial infarction and risk stratification

Abstract Background The clinical chemistry score (CCS) comprising high-sensitivity (hs) cardiac troponins (cTn), glucose and estimated glomerular filtration rate has been previously validated with superior accuracy for detection and risk stratification of acute myocardial infarction (AMI) compared to hs-cTn alone. Methods The CCS was directly compared to other biomarker-based algorithms for rapid rule-out and prognostication of AMI including the hs-cTnT limit-of-blank (LOB, <3 ng/L) or limit-of-detection (LOD, <5 ng/L) and the dual marker strategy (DMS) (copeptin <10 pmol/L and hs-cTnT ≤14 ng/L) in 1506 patients presenting to the emergency department (ED) with symptoms suggestive of acute coronary syndrome. Negative predictive values (NPV) and sensitivities for rule-out of AMI were assessed and outcomes included rates of the combined end-point of all-cause mortality, myocardial re-infarction and stroke within 12 months. Results NPVs of 100% (98.3-100%) could be found for a CCS=0, hs-cTnT LoB and hs-cTnT LoD with rule-out efficacies of 11.1%, 7.6% and 18.3% as well as specificities of 13.0% (9.9-16.6%), 8.8% (7.3-10.5%) and 21.4% (19.2-23.8%), respectively. A CCS≤ 1 achieved a rule-out in 32.2% of all patients with a NPV of 99.6% (98.4-99.9%) and specificity of 37.4% (34.2-40.5%) compared to a rule-out efficacy of 51.2%, NPV of 99.0 (98.0-99.5) and specificity of 59.7% (57.0-62.4%) for the DMS. Rates of the combined end-point of death/AMI within 30 days ranged between 0.0% and 0.5% for all fast-rule-out protocols. Conclusions The CCS enables a reliable rule-out of AMI with low outcome rates in short and long-term follow-up for a specific population of ED patients. However, compared to a single or dual biomarker strategy, the CCS rule-out is attenuated by a loss of specificity and lower efficacy. Thus, the clinical benefit of the CCS in clinical practice seems to be negligible.

Targeted K-Edge Nanoprobes From Praseodymium and Hafnium for Ratiometric Tracking of Dual Biomarkers using Spectral Photon Counting CT.

Utilizing metal nanoprobes with unique K-edge identities to visualize complementary biological activities simultaneously can provide valuable information about complex biological processes. This study describes the design and preparation of an innovative pair of K-edge metal nanoprobes and demonstrates the feasibility of their simultaneous quantitative detection using spectral photon-counting computed tomography (SPCCT). Glycosaminoglycan (GAG) capped nanoparticles (ca. 15-20nm) targeting two distinct components of the cartilage tissue, namely, aggrecan (acan) and aggrecanase (acanase) are designed and synthesized. These targeted nanoparticles comprised of praseodymium (Pr) and hafnium (Hf), with well-separated K-edge energies, enable simultaneous and ratiometric imaging of dual biomarkers in cartilage tissue. Following extensive physico-chemical characterization of the ligand-targeted particles, the feasibility of homing dual biomarkers in vitro is demonstrated. The material discrimination and simultaneous quantification of these targeted particles are also achieved and corroborated with inductively coupled plasmon spectroscopy. For the first time, the use of praseodymium is reported as a contrast agent for SPCCT imaging and demonstrates the ability to pair it with hafnium nanoprobes for multicontrast imaging of diseases. Importantly, the potential for ratiometric molecular imaging and tracking of osteoarthritis (OA) progression is shown with SPCCT K-edge based imaging approach.

Keratin 17 and A2ML1 are negative prognostic biomarkers in non-small cell lung cancer

Although the overall prognosis for patients with non-small cell lung cancer (NSCLC) has improved over the past several decades, there are still survival differences that are not accurately defined by clinicopathological factors. Thus, there is an unmet clinical need to develop novel approaches to enhance prognostic accuracy for these patients. Keratin 17 (K17) is a negative prognostic biomarker in a wide range of cancer types, including pancreatic ductal adenocarcinoma, head and neck squamous cell carcinoma, and pulmonary adenocarcinoma (LUAD), but has yet to be investigated as a prognostic biomarker in primary lung squamous cell carcinoma (LSCC). Based on TCGA RNA-seq data, alpha-2-macroglobulin like 1 (A2ML1), a protease inhibitor, is highly correlated with K17 in other solid tumors, including pancreatic ductal adenocarcinoma and is also a prognostic biomarker for LSCC, although the prognostic accuracy of A2ML1 for LUAD has not been tested. Thus, we hypothesized that A2ML1 expression correlates with K17 expression and that K17/A2ML1 co-testing could provide complementary prognostic data for NSCLC. The aims of this study were to explore K17 and A2ML1 as dual prognostic biomarkers, using publicly available gene expression databases [The Cancer Genome Atlas (TCGA)] LSCC (n=266), LUAD (n=271)] and multiplexed immunohistochemistry (mIHC) on representative sections of LSCC (n=104) and LUAD (n=107) from two major academic medical centers. Our results suggest that using either mRNA or mIHC-based methods, combined K17 and A2ML1 testing provides information, independent of other clinicopathologic variables, that could impact treatment decisions for patients with NSCLC.

Immobilization coupling with aptamer assisted dual cycle amplification for sensitive sEVs isolation and analysis.

Precise identification of small extracellular vesicles (sEVs) is crucial for improving disease diagnosis and treatments, such as bladder cancer. However, accurate isolation and simultaneously quantification of sEVs remain a huge challenge. We have introduced a new technique that combines immobilization with aptamer-assisted dual cycle amplification to isolate and analyze sEVs with high sensitivity. In this method, the CD9 protein antibody is attached to the plate's surface for the initial identification of sEVs, while an aptamer probe is used to detect the exosomal surface protein CD63. We have created an sEVs-surface method that combines target recognition initiated signal recycling and rolling circle amplification (RCA) for signal amplification. This approach allows for the "AND" logic analysis of dual biomarkers, enabling both sEVs quantification and tracing. The proposed approach has a broad detection range and a low limit of detection. Moreover, the established method showed good stability in detecting sEVs with a low coefficient of variation. Our method can effectively isolate certain sEVs and accurately identify them, making it suitable for many uses in biological science, biomedical engineering, and personalized medicine.

Liquid biopsy in prostate cancer: A novel dual biomarker analysis approach integrating circulating tumor cells and circulating tumor DNA data.

This study aimed to explore the potential of liquid biopsy as a diagnostic tool by integrating two key biomarkers, Circulating Tumor Cells (CTCs) and Circulating Tumor DNA (ctDNA), and to enhance the detection fidelity of prostate cancer. A dual biomarker analysis approach was employed to synergize the sensitivities of CTCs and ctDNA. Various genetic mutations of ctDNA and tissues were scrutinized, investigating their prevalence, co-existence, and mutual exclusivity. The findings uncovered a more intricate mutation landscape than previously anticipated, indicating a complex interplay between cellular and genetic aberrations in prostate cancer. Through harnessing the combined power of CTCs and ctDNA, our dual biomarker approach provides a more comprehensive understanding of prostate cancer genetics. This has the potential to revolutionize early detection and guide personalized therapeutic interventions.

1478P Dual single-nucleotide polymorphism biomarker combination to select opioid for cancer pain management

1478P Dual single-nucleotide polymorphism biomarker combination to select opioid for cancer pain management

Dual oxidative stress biomarkers co-recognition in periodontal microenvironment: A flexible and low-power consumption nanozyme sensing platform

Sensing platforms with high interference immunity and low power consumption are crucial for the co-detection of dual oxidative stress biomarkers and clinical diagnosis of periodontitis. Herein, we constructed a bifunctional nanozyme to identify hydrogen peroxide (H2O2) and ascorbic acid (AA) with low crosstalk at zero or low bias voltage. To target H2O2 and AA, Fe(III) meso-tetra(4-carboxyphenyl) porphine (TCPP(Fe)) and Pt nanoclusters were selected as active sites respectively, and titanium carbide nanosheets were additionally introduced as a sensitizer. Due to their highly efficient catalytic properties, self-powered detection of H2O2 without bias voltage and distinguishable AA detection at 0.45 V were successfully achieved. Density functional theory calculations further confirmed the binding sites for target molecules and elucidated the sensing mechanism. On this basis, a dual-channel screen-printed electrode was fabricated to further ensure the discriminative detection of dual biomarkers at the device level. The constructed flexible, low-power consumption sensing platform was successfully applied to raw clinical samples, effectively distinguishing between healthy individuals and patients with varying degrees of periodontitis. This work is expected to provide new insights into the design of highly specific nanozymes and low-power consumption electrochemical sensing systems, which will contribute to the accurate and convenient diagnosis of periodontitis.

Dual biomarker traceability and ecological risk assessment of centennial organic contamination in South Dongting Lake

Enhanced anthropogenic activity strength has altered the watershed particulate transport and material cycle resulting in organic pollutant deposition changes in Dongting Lake associated with unclear ecological risk. In the present study, dual biomarkers i.e. n-alkanes and polycyclic aromatic hydrocarbon (PAHs) were applied in the 210Pb-dated sediment cores for traceability of centennial organic pollutants in the lake mouth area. The partial least squares path model and risk quotients method were used to explore the controlling pathways and ecological risk. The results show a range of sedimentary organic carbon (C), nitrogen (N), and phosphorus (P) was at 1.76–185.66, 0.97–89.80, and 0.01–0.97 g m−2 yr−1 with total reserves of 51.68, 18.44, and 0.27 t ha−1, respectively, over the past 179 years. The presence of PAHs rapidly increased by 2.47 fold from 535.60 ng g−1, while PAHs and carcinogenic PAHs (ΣCPAHs) burial fluxes increased by about 6 and 5 folds, respectively. Accompanied by anthropogenic activities and climate change, the exotic sources gradually becoming predominant. The n-alkane diagnostic ratios indicated a shift of organic matter (OM) from autotrophic bacteria, algae, and phytoplankton-derived sources to macrophyte and terrestrial plants. The exotic origins rose to approximately 73.61 %, while endogenous sources decreased to 26.39 %. The direct effects of anthropogenic activities and their indirect negative impacts on climate and sedimentary structure are the key ways for sediment material loading. The nutrient accumulation in sediments coincides with the lake's eutrophication history over the past decades. The ΣCPAHs accounted for about 89.37 ± 17.14 % of the total TEQ, reflecting a strong ecological risk. The contribution of anthropogenic activities such as fuel usage, fertilizer application, hard pavement coverage, and OM loss from the ecosystem to the sources of organic pollutants and their component types may be a focus of attention in the middle reaches of the Yangtze River plain lake.

A "Dual-Key-and-Lock" MRI Contrast Agent with T1-T2 Switchable Function for Accurate Diagnosis of Tumors.

Extremely small iron oxide nanoparticle (ESIONP)-based stimuli-responsive switchable MRI contrast agents (CAs) show great promise for accurate detection of tumors due to their outstanding advantages of high specificity and low background signal. However, currently developed ESIONP-based switchable CAs often suffer single-biomarker-induced responses, which lack absolute specificity to pathological tissues, potentially diminishing diagnostic accuracy. In this study, weak acidity and hypoxia, two of the most remarkable characteristics of tumors, are introduced as dual biomarker stimuli to construct an ESIONP-based switchable MRI CA (DKL-CA), with its signal switch controlled by a "dual-key-and-lock" strategy. Only when DKL-CA is exposed to a coexisting weakly acidic and hypoxic environment can monodispersed ESIONPs form nanoclusters, thereby realizing a switch from the T1 to T2 contrast. Moreover, DKL-CA exhibits favorable biosafety and the capacity for precise tumor diagnosis in tumor-bearing mice. Overall, DKL-CA paves the way for designing highly accurate ESIONP-based MRI CAs for tumor diagnosis.

Using SWATH-MS to identify new molecular biomarkers in gingival crevicular fluid for detecting periodontitis and its response to treatment.

To identify new biomarkers to detect untreated and treated periodontitis in gingival crevicular fluid (GCF) using sequential window acquisition of all theoretical mass spectra (SWATH-MS). GCF samples were collected from 44 periodontally healthy subjects and 40 with periodontitis (Stages III-IV). In the latter, 25 improved clinically 2 months after treatment. Samples were analysed using SWATH-MS, and proteins were identified by the UniProt human-specific database. The diagnostic capability of the proteins was determined with generalized additive models to distinguish the three clinical conditions. In the untreated periodontitis vs. periodontal health modelling, five proteins showed excellent or good bias-corrected (bc)-sensitivity/bc-specificity values of >80%. These were GAPDH, ZG16B, carbonic anhydrase 1, plasma protease inhibitor C1 and haemoglobin subunit beta. GAPDH with MMP-9, MMP-8, zinc-α-2-glycoprotein and neutrophil gelatinase-associated lipocalin and ZG16B with cornulin provided increased bc-sensitivity/bc-specificity of >95%. For distinguishing treated periodontitis vs. periodontal health, most of these proteins and their combinations revealed a predictive ability similar to previous modelling. No model obtained relevant results to differentiate between periodontitis conditions. New single and dual GCF protein biomarkers showed outstanding results in discriminating untreated and treated periodontitis from periodontal health. Periodontitis conditions were indistinguishable. Future research must validate these findings.

Engineering Tb(III)-functionalized HOF fluorescence sensing system for intelligent visual detection of two biomarkers of hepatocellular carcinoma

Abnormal levels of bilirubin and human serum albumin are precursors to hepatocellular carcinoma and many fatal diseases. Establishing a portable, highly sensitive and intuitive dual biomarker detection method for bilirubin and human serum albumin is important to protect human health. Combined with the excellent photoluminescence properties of lanthanide functionalized hydrogen bond organic framework, a novel ratiometric fluorescence intelligent sensing system was engineered with the outstanding features of large Stokes shifts, high luminous stability and the self-calibration effect of dual emission centers in this paper. With the advantage of high sensitivity, strong stability and strong anti-interference, the simultaneous detection of dual biomarkers was realized successfully. The developed fluorescence sensing system had a wide detection range of bilirubin and human serum albumin (13.5 nM ∼ 30.0 μM and 448 nM ∼ 15.0 μM), low detection limits (7.20 nM and 15.6 nM). Furthermore, the developed sensing system realized the smartphone-assisted fluorescence visual detection of bilirubin and human serum albumin in serum and urine successfully with the detection limit of 85 nM and 163 nM, providing a promising detection strategy for the early diagnosis of hepatocellular carcinoma.

Heart proteomic profiling discovers MYH6 and COX5B as biomarkers for sudden unexplained death

Sudden unexplained death (SUD) is not uncommon in forensic pathology. Yet, diagnosis of SUD remains challenging due to lack of specific biomarkers. This study aimed to screen differentially expressed proteins (DEPs) and validate their usefulness as diagnostic biomarkers for SUD cases. We designed a three-phase investigation, where in the discovery phase, formalin-fixed paraffin-embedded (FFPE) heart specimens were screened through label-free proteomic analysis of cases dying from SUD, mechanical injury and carbon monoxide (CO) intoxication. A total of 26 proteins were identified to be DEPs for the SUD cases after rigorous criterion. Bioinformatics and Adaboost-recursive feature elimination (RFE) analysis further revealed that three of the 26 proteins (MYH6, COX5B and TNNT2) were potential discriminative biomarkers. In the training phase, MYH6 and COX5B were verified to be true DEPs in cardiac tissues from 29 independent SUD cases as compared with a serial of control cases (n = 42). Receiver operating characteristic (ROC) analysis illustrated that combination of MYH6 and COX5B achieved optimal diagnostic sensitivity (89.7 %) and specificity (84.4 %), with area under the curve (AUC) being 0.91. A diagnostic software based on the logistic regression formula derived from the training phase was then constructed. In the validation phase, the diagnostic software was applied to eight authentic SUD cases, seven (87.5 %) of which were accurately recognized. Our study provides a valid strategy towards practical diagnosis of SUD by integrating cardiac MYH6 and COX5B as dual diagnostic biomarkers.

APOE expression in papillary thyroid carcinoma: Influencing tumor progression and macrophage polarization

BackgroundAs metastatic papillary thyroid carcinoma becomes increasingly challenging to treat, immunotherapy has emerged as a new research direction. Tumor-associated macrophages (TAMs) influence the occurrence, invasion, and metastasis of tumors. Apolipoprotein E (APOE) can regulate the polarization changes of macrophages and participate in the remodeling of the tumor microenvironment. However, the role of APOE in regulating the polarization and biological functions of TAMs in papillary thyroid carcinoma (PTC) remains unclear, as it acts as a dual biomarker. MethodsWe probed APOE expression in PTC tissues using immunohistochemical staining. A cell co-culture model was established where different APOE-expressing K1 cells were co-cultured with THP-1-derived M0 macrophages. An in-depth analysis of macrophage polarization behavior was performed using real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting. Subsequently, the impact of APOE-regulated macrophages on tumor cell behavior, especially proliferation, migration, and invasion, was evaluated utilizing IncuCyte ZOOM system, flow cytometry, colony formation, and scratch experiments. Finally, we used a xenograft model to confirm the effects of APOE on PTC tumorigenesis. ResultsTumor dimensions, stage, and lymphatic metastases were significantly associated with increased APOE expression in PTC tissues. K1 cells were markedly limited in their proliferation, migration, and invasion abilities when APOE expression was silenced, a process mediated by the PI3K/Akt/NF-κB signaling axis. Moreover, APOE is a key facilitator of the enhancement of the anti-inflammatory cytokines IL-10 and TGF-β1. In PTC cellular models, APOE contributed to the phenotypic shift of THP-1 derived macrophages towards an M2 phenotypic polarization, predominantly through the modulation of IL-10. Furthermore, in vivo studies involving athymic nude mice have demonstrated pivotal role of APOE in tumor progression and the induction of M2-like TAM polarization. ConclusionOur results elucidated that APOE could promote the shift of TAMs from M0-type to M2-type polarization by regulating inflammatory factors expressions in K1 cell through the PI3K/Akt/NF-κB pathway. These findings are crucial for understanding the molecular mechanisms underlying PTC pathogenesis and for developing immunological drugs to treat this disease.

Impact of circulating tumor DNA genomic mutations and circulating tumor cells biomarker duo on clinical concordance in localized, progressive, and metastatic disease.

e14546 Background: Genomic mutations have been identified from circulating tumor DNA (ctDNA) that correlates positively with clinical disease status. EGFR and intracellular cell progression/proliferation pathway-BRCA1/2 and TP53 genes drive high ctDNA load in progressive cancer patients. Circulating tumor cells (CTC) indicate Cellular Residual Disease (CRD). ctDNA and CTC as dual biomarkers offer prediction of tumor progression and metastasis implicative for early detection and treatment modifications. Methods: Retrospectively in 96 cancer patients (lung, colon-rectal, breast, stomach, etc.) who recently underwent treatment were investigated for presence of CTCs and genomic mutations from ctDNA using OncoMonitor Test. Libraries were prepared using a hybridization-capture method covering 1000 targets with mean sequencing depth 5000X on Illumina Nextseq 2000. Test detected genomic alterations from single nucleotide variation (SNVs), small insertions and deletions (INDELs), copy number variations (CNVs), and translocations (fusions) using a 96 gene panel. CTCs were isolated using the OncoDiscover platform, with CK18+, PD-L1+, CD45- in1.5 ml of blood. Results: In 96 pan-cancer patients, 15.6% patients (n=15) were identified with localized progressive disease with no metastasis from radiological findings, of which 60% (n=9) patients showed at least 1 genomic finding from ctDNA.12.5% (n=12) patients were identified as metastatic from their radiological findings of which 58.3% (n=7) showed presence of at least 1 CTC. 33.3% (n=4) patients showed 2 CTCs and 5 patients had no CTCs. In addition, these metastatic patients showed the presence of ctDNA load in 66.6% (n=8) patients with at least 1 genomic finding. In metastatic disease cohort, CTC enumeration showed concordance of 58.3% (n=7) with metastatic radiological findings and genomic findings from ctDNA showed concordance in 66.6% (n=8) patients with metastatic radiological findings. 23.9% (n=23) patients from the cohort were radiological identified with stable/treatment responsive disease of which 73.9% (n=17) patients were not detected with genomic mutations from ctDNA and 26.0% (n=6) patients were CTC -ve, concordant with radiological findings. 26.0% (n=6) patients had at least 1 genomic finding contributing to discordance with the radiological findings. Genomic findings from duo offered concordance with radiological findings in 26.6% (n=4) patients with progressive disease, 41.6% (n=5) in metastatic disease, and 17.3% (n=4) in patients with stable/treatment responsive disease. Conclusions: Patients with progressive and metastatic disease from radiological findings showed concordance with the dual ctDNA and CTC biomarkers. Concordance of ctDNA in progressive disease and CTC in metastatic disease is indicative of individual significance.

Selective detection of exosomes by elemental labeling ICP-MS based on cholesterol-EpCAM aptamer proximity ligation mediated MNAzyme assembly

Exosomes, carrying cancer-related proteins derived from parental cells, provide a liquid biopsy probability for early cancer diagnosis. However, the direct analysis of tumor derived exosomes in complex human fluids is still challenging due to the matrix interferences and the low proportion of cancer derived exosomes. Herein, a cholesterol-epithelial cell adhesion molecule (EpCAM) aptamer-mediated proximity ligation assay triggering multicomponent nucleic acid enzyme (MNAzyme) assembly was proposed for detection of exosomes by lanthanide elemental labeling inductively coupled plasma mass spectrometry (ICP-MS). Specifically, the exosomes were recognized through EpCAM aptamer and cholesterol, allowing aptamerEpCAM-partzyme A and cholesterol-partzyme B to hybridize with each other, and assembling into the exosome-MNAzyme complex. With the presence of the cofactor Mn2+, the exosome-MNAzyme complex could catalyze the cleavage of the ribonucleobase-containing substrate deoxyribonucleic acid (DNA) on the Tb-substrate DNA-magnetic beads, releasing Tb tags as readout signal for ICP-MS detection. Due to the recognition of dual exosome surface biomarkers through the proximity probes, the selectivity for the detection of tumor derived exosomes was greatly improved. The developed approach was used for the direct analysis of exosomes in human plasma samples from oral squamous cell carcinoma (OSCC) patients and healthy volunteers, and the concentration of exosomes in the OSCC patient group was found to be significantly higher than that in the healthy group. It manifested that the proposed strategy can easily distinguish healthy volunteers from cancer patients by purification-free quantification of exosomes in human plasma, exhibiting good potential of the developed strategy in early cancer diagnosis.

Tumor Microenvironment-Activatable Phototheranostic: Leveraging Nitric Oxide and Weak Acidity as Dual Biomarkers for Ratiometric Fluorescence, Photoacoustic Imaging, and Photothermal Therapy.

Tumor microenvironment-responsive phototheranostic agents are highly sought after for their ability to improve diagnostic accuracy and treatment specificity. Here, we introduce a novel single-molecule probe, POZ-NO, which is activated by nitric oxide (NO) and weak acidity, enabling dual-mode imaging and photothermal therapy (PTT) of tumors. In acidic environments with elevated NO levels, POZ-NO exhibits a distinctive ratiometric fluorescence signal shift from the red to near-infrared, accompanied by a 700 nm photoacoustic signal. Additionally, POZ-NO demonstrated potent photothermal effects upon NO and acidity activation, achieving an impressive conversion efficiency of 74.3% under 735 nm laser irradiation. In vivo studies confirm POZ-NO's ability to accurately image tumors through ratiometric fluorescence and photoacoustic modes while selectively treating tumors with PTT.

Comparison of the clinical chemistry score to other biomarker algorithms for rapid rule-out of acute myocardial infarction and risk stratification

Abstract Funding Acknowledgements None. Background The clinical chemistry score (CCS) comprising high-sensitivity (hs) cardiac troponins (cTn), glucose and estimated glomerular filtration rate has been previously validated with superior accuracy for detection and risk stratification of acute myocardial infarction (AMI) compared to hs-cTn alone. Methods The CCS was directly compared to other biomarker-based algorithms for rapid rule-out and prognostication of AMI including the hs-cTnT limit-of-blank (LOB, <3 ng/L) or limit-of-detection (LOD, <5 ng/L) and the dual marker strategy (DMS) (copeptin <10 pmol/L and hs-cTnT ≤14 ng/L) in 1506 patients presenting to the emergency department (ED) with symptoms suggestive of acute coronary syndrome. Negative predictive values (NPV) and sensitivities for rule-out of AMI were assessed and outcomes included rates of the combined end-point of all-cause mortality, myocardial re-infarction and stroke within 12 months. Results NPVs of 100% (98.3-100%) could be found for a CCS=0, hs-cTnT LoB and hs-cTnT LoD with rule-out efficacies of 11.1%, 7.6% and 18.3% as well as specificities of 13.0% (9.9-16.6%), 8.8% (7.3-10.5%) and 21.4% (19.2-23.8%), respectively. A CCS≤ 1 achieved a rule-out in 32.2% of all patients with a NPV of 99.6% (98.4-99.9%) and specificity of 37.4% (34.2-40.5%) compared to a rule-out efficacy of 51.2%, NPV of 99.0 (98.0-99.5) and specificity of 59.7% (57.0-62.4%) for the DMS. Rates of the combined end-point of death/AMI within 30 days ranged between 0.0% and 0.5% for all fast-rule-out protocols. Conclusions The CCS enables a reliable rule-out of AMI with low outcome rates in short and long-term follow-up for a specific population of ED patients. However, compared to a single or dual biomarker strategy, the CCS rule-out is attenuated by a loss of specificity and lower efficacy. Thus, the clinical benefit of the CCS in clinical practice seems to be negligible.

Single-sEV profiling identifies the TACSTD2 + sEV subpopulation as a factor of tumor susceptibility in the elderly

BackgroundAging is a very complex physiological phenomenon, and sEVs are involved in the regulation of this mechanism. Serum samples from healthy individuals under 30 and over 60 years of age were collected to analyze differences in sEVs proteomics.ResultsBased on PBA analysis, we found that sEVs from the serum of elderly individuals highly express TACSTD2 and identified a subpopulation marked by TACSTD2. Using ELISA, we verified the upregulation of TACSTD2 in serum from elderly human and aged mouse. In addition, we discovered that TACSTD2 was significantly increased in samples from tumor patients and had better diagnostic value than CEA. Specifically, 9 of the 13 tumor groups exhibited elevated TACSTD2, particularly for cervical cancer, colon cancer, esophageal carcinoma, liver cancer and thyroid carcinoma. Moreover, we found that serum sEVs from the elderly (especially those with high TACSTD2 levels) promoted tumor cell (SW480, HuCCT1 and HeLa) proliferation and migration.ConclusionTACSTD2 was upregulated in the serum of elderly individuals and patients with tumors, and could serve as a dual biomarker for aging and tumors.

Abstract CT053: Exploration of potential biomarkers correlated with efficacy of ociperlimab (anti-TIGIT) plus tislelizumab (anti-PD-1) in 1L PD-L1+ non-small cell lung cancer (NSCLC)

Abstract Background: PD-L1 expression was associated with anti-immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) + anti-PD-(L)1 treatment, in which a high PD-L1 subgroup showed improved efficacy. We investigated if anti-TIGIT mechanism of action (MOA)-related markers were associated with the efficacy of ociperlimab + tislelizumab in Cohort 3 (1L PD-L1+ NSCLC) of the phase 1/1b AdvanTIG-105 trial (NCT04047862) and evaluated a potential patient-enrichment strategy based on tumor tissue gene expression profile (GEP). Methods: Tumor tissue GEP was tested using TruSeq RNA Access technology. Ventana SP263 PD-L1 immunohistochemistry (IHC) assay was used to evaluate PD-L1 expression. Median progression-free survival (mPFS) by investigator was calculated descriptively by Kaplan-Meier methodology. 95% confidence intervals for mPFS were generated using the Brookmeyer method. The primary inferential PFS comparison used unstratified log-rank test with 2-sided descriptive P-values. Results: At data cutoff (Feb 2, 2023), 24 of 45 patients had GEP results. Anti-TIGIT MOA-related genes and signatures correlated with ociperlimab + tislelizumab treatment response. Patients with high (H) vs low (L) expression of TIGIT, CD226, CCR8, or a tumor-associated macrophage (TAM) signature had significantly longer mPFS (Table). Dual biomarkers combining both anti-PD-L1 (PD-L1 IHC) and one of the anti-TIGIT MOA-related factors (TIGIT, CCR8, TAM signature GEP) identified subgroups of PD-L1 H + TIGIT MOA-related factor H patients with improved PFS vs other subgroups (Table). A highly overlapped PD-L1 H + TIGIT H + CCR8 H + TAM signature H patient population was observed in dual biomarker analyses. Conclusions: Anti-TIGIT MOA-related genes and signatures correlated with efficacy in ociperlimab + tislelizumab-treated 1L PD-L1+ NSCLC. Combining anti-TIGIT MOA-related factors with PD-L1 expression identified a subgroup of patients with improved efficacy. TABLE 1. NAND Table. Efficacy Analyses in Patient Subgroups TIGITa CD226b CCR8b TAMb Subgroup H L H L H L H L n 8 16 12 12 12 12 12 12 mPFS, months (95% CI) NR (2.6, NR) 5.26 (2.07, 11.86) NR (4.21, NR) 4.68 (1.41, 15.05) 15.21 (2.6, NR) 4.7 (1.71, 7.16) 15.21 (4.21, NR) 4.17 (1.71, 5.45) PFS, P-value 0.0326 0.0327 0.0131 0.0153 PD-L1c + TIGITb PD-L1c + CCR8b PD-L1c + TAMb Subgroup TIGITHPD-L1H TIGITHPD-L1L TIGITLPD-L1H TIGITL PD-L1L CCR8HPD-L1H CCR8HPD-L1L CCR8LPD-L1H CCR8L PD-L1L TAMHPD-L1H TAMHPD-L1L TAMLPD-L1H TAML PD-L1L n 8 4 8 4 11 1 5 7 9 3 7 5 mPFS, months (95% CI) NR (1.41,NR) 4.76 (2.6,NR) 8.62 (2.07,NR) 2.94 (1.25,NR) NR (1.41,NR) 2.6 (NR,NR) 5.19 (2.07,NR) 4.21 (1.25,7.16) 23.89 (1.41,NR) 5.32 (4.21,NR) 5.29 (2.07,NR) 2.6 (1.25,NR) Cutoff: aTop 1/3; bMedian; cTC≥25% Citation Format: Se Hyun Kim, Jiayuan Zhang, Wei Tan, Han Yan, Tian Tian, Hao Zheng, Ziqi Zhou, Ruihua Wang, Yun Zhang, Zhirong Shen, Hye Ryun Kim, Diansheng Zhong, Shun Lu. Exploration of potential biomarkers correlated with efficacy of ociperlimab (anti-TIGIT) plus tislelizumab (anti-PD-1) in 1L PD-L1+ non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT053.

Abstract 7486: Development and analytic validation of an ARv7/PSMA dual biomarker circulating tumor cell assay

Abstract Background Prostate cancer drug targets and biomarkers may be investigated non-invasively on circulating tumor cells (CTCs) obtained via liquid biopsies. PSMA is an important drug target in prostate cancer, and ARv7 is a splice variant that confers resistance to second-generation androgen receptor inhibitors. In this study, we describe the development and analytic validation of a novel assay to quantify ARv7 and PSMA protein expression on CTCs. The assay was validated with blood samples from patients with Stage IV prostate cancer to demonstrate clinical feasibility. To our knowledge, a PSMA/ARv7 dual protein assay for CTCs has not previously been reported. Methods LNCaP (PSMA positive), PC3 (PSMA negative), 22Rv1 (ARv7 positive), and BT474 (ARv7 negative) cells were spiked into healthy donor blood to generate model CTCs. Nucleated cells were collected from these spike-in samples using the AccuCyte® sample preparation kit and spread onto microscope slides. Slides were fixed and stained with antibodies to cytokeratin, EpCAM, and CD45 to detect CTCs and exclude white blood cells (WBCs), and with PSMA and ARv7 to evaluate protein expression on identified CTCs. The slides were imaged with the CyteFinder® automated immunofluorescence scanning microscope that identifies CTCs for confirmation by trained reviewers based on machine learning algorithms and quantitatively measures biomarker signal mean fluorescence intensity (MFI). Results For ARv7/PSMA expression classification of the model CTCs, the dual biomarker assay showed analytic sensitivity of 83%/97% and specificity 98%/99%, yielding accuracy of 90.2%/97.9%, respectively. The dynamic range of MFI for both biomarkers was approximately three orders of magnitude. Inter-run reproducibility CV was 13.6% (ARv7) and 6.9% (PSMA). Slide repeatability mean CV was 11.1% (ARv7) and 12.0% (PSMA). Clinical feasibility of the assay was investigated in 9 progressing Stage IV prostate cancer patient blood samples. CTCs were identified in all clinical samples (median 4, range 1 - 384). Thresholds for biomarker positivity were established based on MFI measurements of positive and negative control cell lines. ARv7 positivity in clinical samples ranged from 33% to 100%, and PSMA positivity ranged from 0% to 75%. Conclusions We have developed a dual ARv7/PSMA assay that simultaneously measures protein expression of both biomarkers on individual CTCs. The assay is accurate and reproducible for the assessment of ARv7 and PSMA expression by liquid biopsy in clinical studies. Citation Format: Jon Ladd, Erin Bayer, Brock Bartels, Eric Kaldjian, Arturo Ramirez. Development and analytic validation of an ARv7/PSMA dual biomarker circulating tumor cell assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7486.