Sera Of Healthy Donors Research Articles

Free radical fragmentation and oxidation in the polar part of lysophospholipids: Results of the study of blood serum of healthy donors and patients with acute surgical pathology

The interaction of reactive oxygen species with cell membrane lipids is usually considered in the context of lipid peroxidation in the nonpolar component of the membrane. In this work, for the first time, data were obtained indicating that damage to human cell membranes can occur in the polar part of lysophospholipids at the interface with the aqueous environment due to free radical fragmentation (FRF) processes. FRF products, namely 1-hexadecanoyloxyacetone (PAc) and 1-octadecanoyloxyacetone (SAc), were identified in human serum, and a GC-MS method was developed to quantify PAc and SAc.The content of FRF products in serum samples of 52 healthy donors was found to be in the range of 1.98–4.75 μmol/L. A linear regression equation, CPAc&SAc (μmol/L) = 0.51 + 0.064 × years, was derived to describe the relationship between age and content of FRF products. In 70 patients with acute surgical pathology in comparison with the control group of healthy donors, two distinct clusters with different concentration levels of FRF products were revealed. The first cluster: groups of 43 patients with various localized inflammatory-destructive lesions of hollow organ walls and bacterial translocation (septic inflammation) of abdominal cavity organs. These patients showed a 1.5–1.9-fold (p = 0.012) decrease in the total concentration of PAc and SAc in serum. In the second cluster: groups of 27 patients with ischemia-reperfusion tissue damage (aseptic inflammation), – a statistically significant increase in the concentration of FRF products was observed: in 2.2–4.0 times (p = 0.0001).The obtained data allow us to further understand the role of free-radical processes in the damage of lipid molecules. FRF products can potentially be used as markers of the degree of free-radical damage of hydroxyl containing phospholipids.

Extracellular Vesicle - MDM2-DNA as a Potential Liquid Biopsy Biomarker for Disease Identification in Retroperitoneal Liposarcoma.

We aimed to assess the levels of MDM2-DNA within extracellular vesicles (EVs) isolated from the serum of retroperitoneal liposarcoma (RLS) patients versus healthy donors, as well as within the same patients at the time of surgery versus post-operative surveillance visits. To determine whether EV-MDM2 may serve as a possible first-ever biomarker of liposarcoma recurrence. A hallmark of well-differentiated and de-differentiated (WD/DD) retroperitoneal liposarcoma is elevated MDM2 due to genome amplification, with recurrence rates of >50% even after complete resection. Imaging technologies frequently cannot resolve recurrent WD/DD-RLS versus postoperative scarring. Early detection of recurrent lesions, for which biomarkers are lacking, would guide surveillance and treatment decisions. WD/DD-RLS serum samples were collected both at the time of surgery and during follow-up visits from 42 patients, along with sera from healthy donors (n=14). EVs were isolated, DNA purified and MDM2-DNA levels determined through q-PCR analysis. Non-parametric tests were employed to compare EV-MDM2 DNA levels from patients versus control group, as well as the time of surgery versus post-surgery conditions. EV-MDM2 levels were significantly higher in WD/DD-RLS than controls (P= 0.00085). Moreover, EV-MDM2 levels were remarkably decreased in WD/DD-RLS patients after resection (P=0.00036), reaching values comparable to control group (P=0.124). During post-operative surveillance, significant increases of EV-MDM2 was observed in some patients, correlating with CT scan evidence of recurrent or persistent post-resection disease. Serum EV-MDM2 may serve as a potential biomarker of early recurrent or post-operatively persistent WD/DD-RLS, a disease currently lacking such determinants.

Identification of autoantibodies against PsoP27 in synovial fluid derived from psoriatic arthritis and rheumatoid arthritis patients

PsoP27 is an antigen expressed in psoriatic lesions. It plays an inflammatory role in psoriasis. This study objective was to characterize antibodies (Abs) against PsoP27 in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA). Levels of Abs against native and citrullinated PsoP27 in PsA and RA patients’ synovial fluid (SF) and sera were determined by ELISA. SF of osteoarthritis (OA) patients and sera of healthy donors were used as controls. Levels of Abs against PsoP27 were correlated with disease activity scores. Abs against native and citrullinated PsoP27 levels in SF of PsA (n = 48; 0.38 ± 0.03 and 0.44 ± 0.04, respectively) and RA (n = 22; 0.57 ± 0.1 and 0.62 ± 0.09, respectively) were significantly higher than in OA patients (n = 23; 0.14 ± 0.01 and 0.15 ± 0.01, respectively) (p < .0001). For both Abs, there were no significant differences between their level in PsA and RA patients. There was no difference in the level of Abs against citrullinated PsoP27 in SF of seronegative versus seropositive RA patients. Levels of Abs against both native and citrullinated PsoP27 in the SF and level of systemic C-reactive protein in PsA correlated positively, while in RA there were no significant correlations with disease activity scores. No differences in level of Abs against PsoP27 were found in the sera of all three study groups. Abs against native and citrullinated PsoP27 are present in PsA and RA SF but not in those of OA patients, suggesting a potential role of those Abs in inflammatory joint diseases.

305 Extracellular Vesicular mRNA and miRNA Biomarkers in Patients With Glioblastoma

INTRODUCTION: Glioblastoma (GBM) is a highly lethal primary brain cancer that is resistant to conventional immunotherapies. However, currently, there is a lack of reliable biomarkers for clinical practice. Extracellular vesicles (EVs) present in biofluids are a potential biomarker for GBM diagnosis. METHODS: EVs from cell culture medium, healthy donor and GBM patient serum were purified using tangential flow filtration (TFF). Morphology, size, and numbers of EVs were characterized by TEM and qNano, respectively. EVs from healthy donor and GBM patient serum were compared against other cancer EV samples using bulk mRNA and miRNA sequencing analysis. Selected mRNA and miRNA name are not mentioned due to patents being drafted. mRNA and miRNA expression in EVs were quantified by a fluorescent nucleic acid detection method using a biochip platform at a single-EV level. Fluorescence images were recorded using high-resolution total internal reflection fluorescence (TIRF) microscopy. RESULTS: From bulk mRNA and miRNA sequencing and bioinformatics analysis, three miRNA and two mRNA were selected as potential candidate biomarkers for GBM. Subsequently, EVs from the serum of GBM patients (n = 39) were evaluated through our biochip platform. mRNA and miRNA expression of these biomarkers were positive in single EVs, for which we detected colocalization of protein/RNAs or multiple RNAs in subpopulations of EVs. Our platform was benchmarked with a standard PCR method showing 100X more sensitivity. Moreover, levels of expression of the different RNAs were compared to a cohort of serum from healthy donors (n=20), and showing significant differences between the two groups. CONCLUSIONS: Our non-invasive biochip assay outperformed qRT-PCR for EV RNA detection. Selected mRNAs and miRNAs in subpopulations of EVs could be used as potential GBM biomarkers.

LncRNA Profiling of Exosomes and Its Communication Role in Regulating Silica-Stimulated Macrophage Apoptosis and Fibroblast Activation.

Long-term silica particle exposure leads to interstitial pulmonary inflammation and fibrosis, called silicosis. Silica-activated macrophages secrete a wide range of cytokines resulting in persistent inflammation. In addition, silica-stimulated activation of fibroblast is another checkpoint in the progression of silicosis. The pathogenesis after silica exposure is complex, involving intercellular communication and intracellular signaling pathway transduction, which was ignored previously. Exosomes are noteworthy because of their crucial role in intercellular communication by delivering bioactive substances, such as lncRNA. However, the expression profile of exosomal lncRNA in silicosis has not been reported yet. In this study, exosomes were isolated from the peripheral serum of silicosis patients or healthy donors. The exosomal lncRNAs were profiled using high-throughput sequencing technology. Target genes were predicted, and functional annotation was performed using differentially expressed lncRNAs. Eight aberrant expressed exosomal lncRNAs were considered to play a key role in the process of silicosis according to the OPLS-DA. Furthermore, the increased expression of lncRNA MSTRG.43085.16 was testified in vitro. Its target gene PARP1 was critical in regulating apoptosis based on bioinformatics analysis. In addition, the effects of exosomes on macrophage apoptosis and fibroblast activation were checked based on a co-cultured system. Our findings suggested that upregulation of lncRNA MSTRG.43085.16 could regulate silica-induced macrophage apoptosis through elevating PARP1 expression, and promote fibroblast activation, implying that the exosomal lncRNA MSTRG.43085.16 might have potential as a biomarker for the early diagnosis of silicosis.

Blood Serum and Drainage Microbial and Mitochondrial Metabolites in Patients after Surgery for Pancreatic Cancer.

Pancreatic cancer (PC) has the highest mortality rate of all major cancers in the world despite improvements in clinical care and an understanding of the biology of pancreatic cancer. A study of 64 patients with verified pancreatic cancer who underwent surgery was included. Sampling was carried out at three points: before surgery and on days 1-3 after surgery and 5-7 days after surgery. Drainage fluid collection was taken from the drains installed intraoperatively one day after surgery. Tyrosine and phenylalanine metabolites and two mitochondrial metabolites, namely succinic and fumaric acids, were identified and quantified by GC-MS in the serum of healthy donors and patients. Differences in the metabolomic profile were found between the patients and healthy people. A statistically significant decrease in the level of p-hydroxyphenyllactic acid (p-HPhLA), the amount of sum 3 sepsis-associated metabolites (Σ 3AMM), as well as fumaric and succinic acids in patients was observed. It was also noted that p-hydroxyphenyllactic acid in the preoperative period may be considered as a predictor of complications and longer postoperative recovery.

Soluble B7-H3 in Colorectal Cancer.

We present the results of comparative ELISA of the concentration of soluble form of immunity checkpoint B7-H3 (sB7-H3) in the serum of patients with colorectal cancer (CRC) at different stages before treatment and healthy control donors. The analysis revealed a statistically significant difference between the median levels of sB7-H3 in the blood serum of CRC patients (19.66 ng/ml) and healthy donors (16.76 ng/ml) (p=0.0025). ROC analysis showed 62.9% sensitivity and 56.7% specificity for CRC patients (cut-off 17.62 ng/ml; p=0.0028). An association of sB7-H3 levels with tumor progression was revealed. We demonstrated that sB7-H3 levels were significantly lower in patients with regional metastases than in patients without metastases (p=0.039) and that sB7-H3 concentration tends to decrease at the late stages of the disease. Thus, high serum level of sB7-H3 in CRC patients can be a favorable prognostic factor in future.

SOLUBLE FORMS OF THE NKG2D RECEPTOR AND LIGAND NKG2DL1 IN PATIENTS WITH COLORECTAL CANCER

Relevance. Natural killer (NK) cells are considered to be effective cytotoxic cells of the tumor microenvironment, whose function is to effectively eliminate tumor cells. Their activation can occur when the NKG2D receptor interacts with the NKG2DL ligand expressed, for example, on tumor cells, which leads to the death of the latter. The aim of the study was a comparative study of the content of soluble forms of the sNKG2D receptor and its ligand sNKG2DL1 in the blood serum of healthy donors and patients with colorectal cancer (CRC), taking into account the clinical and morphological characteristics of the disease and prog-nosis. Material and methods. We examined 65 patients with CRC (32 women and 33 men), who were treated at the “National Medical Research Center of Oncology named after N.N. Blokhin” of the Ministry of Health of Russia aged (median 60 years) and 30 healthy donors (20 women and 10 men) aged (median 47 years). The clinical diagnosis in all patients was confirmed by the data of the morphological study of the tumor according to the Interna-tional Histological Classification of Tumors of the Digestive System (WHO, 2019), all had adenocarcinoma. The concentration of NKG2D and NKG2DL proteins was determined by ELISA in blood serum before treatment with Human B7-H3 Quantikine ELISA Kit reagents firm R&amp;D (USA) in accordance with the manufacturer's instructions. The measurements were carried out on an automatic enzyme immunoassay analyzer BEP 2000 Advance (Siemens Healthcare Diagnostics, Germany). Statistical analysis of the obtained results was carried out using GraphPad Prizm v. 9. Overall survival analysis was performed by constructing survival curves using the Kaplan-Meier method. Results. In patients with colorectal cancer, a significant increase in the content of sNKG2DL in blood serum was found compared to the control group. sNKG2D concentrations did not differ between controls and CRC patients. No significant associations were found between the content of sNKG2D and sNKG2DL1 proteins in the blood serum of CRC patients and the main clinical and morphological characteristics of the disease. A decrease in the con-centration of sNKG2D was noted with the progression of the disease, and the highest content of sNKG2D was found in the localization of the tumor in the caecum. For the ligand sNKG2DL1, the opposite pattern was observed, namely, its lowest concentration in blood serum in tumors located in the caecum. For the ligand sNKG2DL1, the opposite pattern was observed, namely, its lowest concentration in blood serum in tumors located in the cae-cum. At the same time, the levels of sNKG2D and sNKG2DL1 in the control group directly and significantly correlated with each other (r=0.453; p=0.014), while no such pattern was found in the group of CRC patients (r=0.014; p=0.935). sNKG2DL1 concentrations are not a prognostic factor in CRC, while high levels of sNKG2D tended to lead to a favorable prognosis of the disease, which indirectly confirms the positive significance of tumor in-filtration by NK cells. Conclusions. The mechanisms of the relationship between CRC avoidance of immune surveillance and the expression of the sNKG2D receptor and the sNKG2DL ligand are discussed as one of the directions in the study of immune checkpoints. We believe that the effect of CRC immunotherapy can be achieved by increasing the expression of NKG2D on immune cells and inducing the expression of NKG2DL in tumor cells, which is the basis of the con-cept of this line of research.

IL8 derived from macrophages inhibits CD8+ T-cell function by downregulating TIM3 expression through IL8-CXCR2 axis in patients with advanced colorectal cancer.

T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) is a vital immune checkpoint that regulates the immune response. However, the specific role of TIM3 in patients with colorectal cancer (CRC) have rarely been studied. In this study, we investigated the effect of TIM3 on CD8+ T cells in CRC and explored the mechanism of TIM3 regulation in tumor microenvironment (TME). Peripheral blood and tumor tissues of patients with CRC were collected to evaluate TIM3 expression using flow cytometry. Cytokines in the serum of healthy donors and patients with early- and advanced-stage CRC were screened using a multiplex assay. The effects of interleukin-8 (IL8) on TIM3 expression on CD8+ T cells were analyzed using cell incubation experiments in vitro. The correlation between TIM3 or IL8 and prognosis was verified using bioinformatics analysis. TIM3 expression on CD8+ T cells was obviously reduced in patients with advanced-stage CRC, whereas a lower TIM3 expression level was associated with poorer prognosis. Macrophage-derived IL8, which could inhibit TIM3 expression on CD8+ T cells, was significantly increased in the serum of patients with advanced CRC. In addition, the function and proliferation of CD8+ and TIM3+CD8+ T cells were inhibited by IL8, which was partly depending on TIM3 expression. The inhibitory effects of IL8 were reversed by anti-IL8 and anti-CXCR2 antibodies. In summary, macrophages-derived IL8 suppresses TIM3 expression on CD8+ T cells through CXCR2. Targeting the IL8/CXCR2 axis may be an effective strategy for treating patients with advanced CRC.

429 Differentiation of IL-22 levels in inflammatory diseases using a high sensitivity ELISA

Abstract Interleukin-22 (IL-22), an IL-10 cytokine family member, is produced by a variety of immune cells including Th1, Th17 and Th22 T helper cells, CD8+ T-cells, NK cells, ILC3, neutrophils and macrophages. Interleukin-22 crucially participates in regulating the integrity of epithelial barriers by modulating inflammation, mucus production, additional aspects of wound healing and has been noted to be substantially induced in patients with various chronic inflammatory conditions. Upregulation of IL-22 in psoriasis (PS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) inflammatory bowel disease, Crohn’s disease, cystic fibrosis and atopic dermatitis (AD) has been well documented, with IL-22 often considered a hallmark of IL-1-driven immune responses. Furthermore, IL-22 protein has been proposed as a stratification biomarker for psoriatic arthritis therapeutic choice between IL-17 and TNF inhibitions, to correlate with the severity of clinical sequelae of Sjogren’s Syndrome, and IL-22 mRNA expression stratifies AD responses to fezakinumab. In healthy individuals, IL-22 activity resulting from low level expression may be functionally neutralized, at least in selected tissues such as the intestinal tract, by binding to soluble IL-22 binding protein (IL-22BP) expressed locally by dendritic cells. However, in these pathologies, inhibition of IL-22 by IL-22BP is presumably overcome by elevated expression of IL-22 protein. Explore ranges of IL-22 serum concentrations to differentiate between healthy donors (HD) and select autoimmune disease patients with a simple-to-use, high sensitivity ELISA. A commercial sandwich ELISA (PBL Assay Science, 41701-1) quantifying human IL-22 was characterized and used to assess IL-22 concentration in sera from HD and patients exhibiting one of several autoimmune diseases. This high sensitivity ELISA, having a manufacturer-stated LLOQ of 0.78 pg/ml, exhibited good assay precision, dilutional linearity and spike recovery using HD serum. Parallelism was demonstrated using serum samples from four patients with AD and three HD. Addition of a 10- to 100-fold mass excess of exogenous recombinant IL-22BP reduced the ability of the assay to quantify IL-22 suggesting that at least one antigenic region recognized by ELISA antibodies may be sterically hindered by IL-22BP binding to IL-22. However, such high levels of 10 and 100 ng/ml of IL-22BP are unlikely to be achieved in vivo, and therefore may not adversely affect quantitation of physiological levels of IL-22 protein by this assay. Commercially sourced HD sera concentrations of IL-22 exceeded the assay LLOQ in 23 of 24 samples (96%) with a mean IL-22 concentration of 1.84 ± 1.33 pg/ml. Commercial sera from patients with AD (n = 10, 100%), PS (n = 10, 100%), RA (n = 10, 100%), SLE (n = 10, 100%) were similarly analysed and yielded mean levels of 14.8 ± 11.2, 5.1 ± 2.4, 5.6 ± 0.91 and 3.1 ± 0.74 pg/mL, respectively. Interleukin-22 measured in AD (and PS) sera exhibited sufficiently broad ranges of concentrations such that statistical differences between AD and all other groups were not readily achievable with this number of samples. Notably, these commercially obtained serum samples were not controlled for overall severity of any disease at the time of sample collection. Sample sets were randomly obtained from a population of individuals self-identifying as AD sufferers, as were the other patient samples. With mean serum IL-22 in AD appearing to trend as substantially elevated, an opportunity exists to explore IL-22 trends along with other biomarkers in clinically identified and possibly symptom-stratified populations of patients with AD. Should this trend toward IL-22 elevation be fully substantiated in AD, therapeutic stratification and precision medicine approaches may be conceivable based on serum IL-22 protein concentrations, supporting other investigators’ earlier work examining IL-22 mRNA. The baseline readability of endogenous IL-22 in HD sera using this ELISA is also highly advantageous.

A comprehensive evaluation of serum tRF-29-R9J8909NF5JP as a novel diagnostic and prognostic biomarker for gastric cancer.

Gastric cancer (GC) is a common malignant digestive system tumor. Since the early symptoms of GC are usually vague and the positive rate of common biomarkers of GC is low, it is of urgent need to find new biomarkers with good sensitivity and specificity to screen and diagnose GC patients. The tRNA-derived small RNAs (tsRNAs) are emerging small noncoding RNAs that play an essential role in cancer progression. In this study, we explored whether novel tsRNAs have the potential to serve as biomarkers for GC. Three tsRNAs significantly upregulated in GC were screened by the tsRFun database. The expression level of tRF-29-R9J8909NF5JP was detected by real-time fluorescence quantitative polymerase chain reaction. Agarose gel electrophoresis and Sanger sequencing were used to verify the characteristics of tRF-29-R9J8909NF5JP. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of tRF-29-R9J8909NF5JP. The χ2 test was used to analyze the correlation between tRF-29-R9J8909NF5JP expression level and clinicopathological parameters. Kaplan-Meier survival curves were used to analyze the correlation between tRF-29-R9J8909NF5JP expression levels and survival time of GC patients. In this study, the expression level of tRF-29-R9J8909NF5JP was significantly increased in GC tissues. The expression level of tRF-29-R9J8909NF5JP was considerably higher in the serum of GC patients than in the serum of gastritis patients and in the serum of healthy donors, and the expression level of tRF-29-R9J8909NF5JP was significantly decreased in the serum of GC patients after surgery. In addition, the χ2 test showed that the expression level of tRF-29-R9J8909NF5JP in GC serum was correlated with differentiation grade, T-stage, lymph node metastasis, tumor node metastasis stage, and neurological/vascular invasion. The results of the survival curve showed that the high expression of serum tRF-29-R9J8909NF5JP was associated with a low survival rate. ROC analysis showed that serum tRF-29-R9J8909NF5JP had higher diagnostic efficiency than common GC biomarkers, and the diagnostic efficiency was further improved by combining them. At the end of the study, we predicted the downstream of tRF-29-R9J8909NF5JP. The expression level of tRF-29-R9J8909NF5JP in the serum of GC patients can effectively identify GC patients and has higher efficacy than conventional biomarkers. In addition, serum tRF-29-R9J8909NF5JP can monitor the postoperative condition of GC patients, suggesting that it has the potential to become a biomarker for GC.

MiR-3960 inhibits bladder cancer progression via targeting of DEXI

PurposeMicroRNAs (miRNAs) are dominant cargo in exosomes and act as master regulators of cell function, inhibiting mRNA translation and affecting gene silencing. Some aspects of tissue-specific miRNA transport in bladder cancer (BC) and its role in cancer progression are not fully understood. Materials and methodsA microarray was used to identify miRNAs in mouse bladder carcinoma cell line MB49 exosomes. Real-time reverse transcription polymerase chain reaction was used to examine the expression of miRNAs in BC and healthy donor serum. Western blotting and immunohistochemical staining were used to examine the expression of dexamethasone-induced protein (DEXI) in patients with BC. CRISPR-Cas 9 was used to knock out Dexi in MB49, and flow cytometry was performed to test cell proliferation ability and apoptosis under chemotherapy. Human BC organoid culture, miR-3960 transfection, and 293T-exosome-loaded miR-3960 delivery were used to analyze the effect of miR-3960 on BC progression. ResultsThe results showed that miR-3960 levels in BC tissue were positively correlated with patient survival time. Dexi was a major target of miR-3960. Dexi knockout inhibited MB49 cell proliferation and promoted cisplatin- and gemcitabine-induced apoptosis. Transfection of miR-3960 mimic inhibited DEXI expression and organoid growth. In parallel, 293T-exosome-loaded miR-3960 delivery and Dexi knockout significantly inhibited subcutaneous growth of MB49 cells in vivo. ConclusionOur results demonstrate the potential role of miR-3960-mediated inhibition of DEXI as a therapeutic strategy against BC.

Detection of serum M-protein in acetonitrile pecipitates by MALDI-TOF mass spectrometry: A novel, low-cost methodology.

Several studies have demonstrated the analytical sensitivity of MALDI-TOF mass spectrometry (MALDI-TOF MS) by immunoenrichment for M-protein analysis. We report the results of a novel, low-cost, reagent-based extraction process using acetonitrile (ACN) precipitation to enrich for κ and λ light chains which can be analysed by MALDI-TOF MS. Institutional Ethics committee approval was obtained. Serum samples from patients with monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma (MM), plasmacytoma, AL amyloidosis and Waldenström macroglobulinemia (WM) underwent ACN precipitation. The images obtained were overlaid on apparently healthy donor serum samples to confirm the presence of M-protein. A sample was considered positive for M-protein if there was a sharp or broad peak within the κ or λ mass/charge (m/z) range: m/z- [M + 2H]2+: 11,550-12,300Da and λ m/z- [M + 2H]2+: 11,100-11,500Da. Images were acquired at a m/z range of 10,000-29,000Da. Corresponding serum protein electrophoresis (SPEP), serum immunofixation electrophoresis (IFE) and serum free light chain (sFLC) assay by nephelometry were performed for all the samples. Two-hundred-and-two serum samples were included in the study: MM- 184 (91%); AL amyloidosis- 2 (1%); plasmacytoma- 8 (4%); MGUS- 6 (3%) and WM- 2 (1%). All the SPEP positive samples were identified by MALDI-TOF MS. Out of 179 samples positive for M-protein by IFE, MALDI-TOF MS was positive in 176 samples (98%). Compared to IFE, the sensitivity and specificity of M-protein identification by MALDI-TOF MS were 98.3% and 52.2%, respectively. This study demonstrates the feasibility of qualitatively identifying M-protein without the need for antibody-based immunoenrichment, making the technique cost-effective.

Abstract 601: Serological responses to tumor-associated adducts in pancreatic cancer

Abstract The incidence of pancreatic cancer has increased over the past several decades and is now the fourth leading cause of cancer death in the USA. Only 8.5% of the patients live beyond 5 years after their initial diagnosis. This dismal survival rate is partly explained by the fact that most pancreatic cancer cases are detected late when treatment options are limited. Novel biomarkers are crucially needed. It has long been recognized that cancer cells abnormally accumulate chemical groups covalently linked to proteins, DNA and other molecules. Humoral responses to these “adducts” have not been thoroughly explored. To investigate these responses, we developed an ELISA platform for the detection of serum IgG reactive to 93 adducts, including post-translational modifications known to contribute to tumorigenesis, progression, and metastasis. Our panel also includes oxidation-related modification, advanced glycation end products, and certain co-enzymes that qualify as adducts based on their binding properties. Using this assay, we measured anti-adduct antibodies in the serum of adult healthy donors (N=24; age range 40-80) as well as patients with pancreatic cancer (N=31; age range 50-90). Importantly, all patient specimens were collected before any treatment. Reactivity to all adducts was analyzed using a random forest predictive model with 10,000 bootstrapped decision trees to distinguish between the two groups. Results revealed a distinctive anti-adduct IgG reactivity profile for pancreatic cancer patients when compared to controls. Applying feature selection using the Boruta algorithm identified a reduced set of 19 target adducts recognized by IgG that most efficiently discriminated between healthy donors and pancreatic cancer cases. All 19 adducts were confirmed as IgG targets in cancer patients using multiple unpaired t-tests (p≤0,05). Aside from their predictive value, we reasoned that the detection of adduct-specific antibodies in cancer patients reflected their accumulation in the tumor cells. To test this hypothesis, we assessed the level of two representative target adducts by immunofluorescence staining in tumor tissue compared to control adjacent non-tumoral tissue or healthy tonsil. Results unequivocally show higher levels of these two adducts in cancer cells compared to non-cancer cells. Taken together, these preliminary findings support our hypothesis of the development of anti-adduct antibodies in pancreatic cancer patients. Furthermore, the specific antibody signature detected in these patients is consistent with the abnormal presence of corresponding adducts in the transformed cells. Our findings pave the way for the development of diagnostic tests based on the detection of serum IgG specific to tumor-associated adducts. Citation Format: Talita Aguiar, Shunya Mashiko, Poulomi Roy, Max Dietzel, Kesava Asam, Bradley Aouizerat, Jeanine Genkinger, Helen Remotti, Emmanuel Zorn. Serological responses to tumor-associated adducts in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 601.

Validation of Aspartylglucosaminidase Activity Assay for Human Serum Samples: Establishment of a Biomarker for Diagnostics and Clinical Studies.

Novel treatment strategies are emerging for rare, genetic diseases, resulting in clinical trials that require adequate biomarkers for the assessment of the treatment effect. For enzyme defects, biomarkers that can be assessed from patient serum, such as enzyme activity, are highly useful, but the activity assays need to be properly validated to ensure a precise, quantitative measurement. Aspartylglucosaminuria (AGU) is a lysosomal storage disorder caused by the deficiency of the lysosomal hydrolase aspartylglucosaminidase (AGA). We have here established and validated a fluorometric AGA activity assay for human serum samples from healthy donors and AGU patients. We show that the validated AGA activity assay is suitable for the assessment of AGA activity in the serum of healthy donors and AGU patients, and it can be used for diagnostics of AGU and, potentially, for following a treatment effect.

Characteristics of circulating small noncoding RNAs in plasma and serum during human aging.

Aging is a complicated process that triggers age-related disease susceptibility through intercellular communication in the microenvironment. While the classic secretome of senescence-associated secretory phenotype (SASP) including soluble factors, growth factors, and extracellular matrix remodeling enzymes are known to impact tissue homeostasis during the aging process, the effects of novel SASP components, extracellular small noncoding RNAs (sncRNAs), on human aging are not well established. Here, by utilizing 446 small RNA-seq samples from plasma and serum of healthy donors found in the Extracellular RNA (exRNA) Atlas data repository, we correlated linear and nonlinear features between circulating sncRNAs expression and age by the maximal information coefficient (MIC) relationship determination. Age predictors were generated by ensemble machine learning methods (Adaptive Boosting, Gradient Boosting, and Random Forest) and core age-related sncRNAs were determined through weighted coefficients in machine learning models. Functional investigation was performed via target prediction of age-related miRNAs. We observed the number of highly expressed transfer RNAs (tRNAs) and microRNAs (miRNAs) showed positive and negative associations with age respectively. Two-variable (sncRNA expression and individual age) relationships were detected by MIC and sncRNAs-based age predictors were established, resulting in a forecast performance where all R 2 values were greater than 0.96 and root-mean-square errors (RMSE) were less than 3.7 years in three ensemble machine learning methods. Furthermore, important age-related sncRNAs were identified based on modeling and the biological pathways of age-related miRNAs were characterized by their predicted targets, including multiple pathways in intercellular communication, cancer and immune regulation. In summary, this study provides valuable insights into circulating sncRNAs expression dynamics during human aging and may lead to advanced understanding of age-related sncRNAs functions with further elucidation.

Особенности инфракрасных спектров сыворотки крови больных множественной миеломой

Comparative analysis of infrared (IR) spectra of blood serum of healthy donors and patients with multiple myeloma (MM) was performed. MM is characterized by hyperproduction of the paraprotein, which manifests itself in a change in the spectral pattern of mid-IR absorption spectra. It has been shown that the most significant deviations in the spectra were observed for samples of MM near the Amide I and Amide II´ bands. As a result of a comparative analysis of the IR spectra of blood serum in the region of 1700-1350 cm-1, nine parameters were established, the average values of which in the samples obtained from patients with a secretory form of MM differ significantly from similar indicators for the serum of healthy donors.

SPD-1/sPD-L1 proteins in non-small cell lung cancer and esophageal squamous cell carcinoma

Background. Implementation of immunotherapy in clinical oncological practice has significantly improved the results of cancer treatment. It resulted in the need for seeking new markers to assess the effectiveness of therapy and the disease prognosis.Aim. To analyze the content of soluble forms of PD-1 and PD-L1 immune checkpoint proteins in the blood serum of patients with non-small cell lung cancer and esophageal squamous cell carcinoma and their association with clinical and morphological characteristics of the disease and the disease prognosis.Materials and methods. The study included tumor samples obtained from 43 patients with non-small cell lung cancer and 21 patients with esophageal squamous cell carcinoma. The concentration of sPD-L1 and sPD-1 in the blood serum was determined using enzyme-linked immunosorbent assay (ELISA). The Mann – Whitney test was used to determine statistically significant differences in independent groups. A correlation analysis was performed using the Spearman’s rank correlation coefficient. Overall survival was analyzed by constructing survival curves using the Kaplan – Meier method and a Cox proportional hazards model. The differences were considered statistically significant at p &lt; 0.05.Results. The study showed that sPD-1 and sPD-L1 were found in the blood serum of both cancer patients and healthy donors, and their concentrations did not differ significantly. It was shown that the high concentration of sPD-L1 in the blood serum of patients with non-small cell lung cancer was significantly associated with the late stage of the disease and was an independent unfavorable prognostic factor. It should be noted that for patients with esophageal cancer, an unfavorable prognostic marker was the high concentration of the soluble form of PD-1 protein, and not PD-L1 ligand, as in case of lung cancer.Conclusion. The content of sPD-1 and sPD-L1 in the blood serum can have different prognostic significance for various types of cancer, and further studies are required to confirm their clinical usability.

Detection of unusual high molecular form of albumin in blood serum of COVID-19 patients

Blood sera of 12 severe Covid-19 patients and 14 healthy human donors were subjected to original TCA-extraction/acetone-precipitation followed by SDS-PAAG electrophoresis and mass-spectrometry. 76 kDa protein was detected as one of the differentially expressed proteins in the samples of Covid-19 patients. This 76 kDa protein was identified with mass-spectrometry as human serum albumin. Such molecular form of albumin was absent in blood serum of healthy human donors. The potential ways of generation of the unusual form of human serum albumin and its probable diagnostic value were discussed. Keywords: acetone-precipitation, biomarker proteins, COVID-19, electrophoresis, mass-spectrometry, TCA-extraction, unusual form of human serum albumin

Atomic Force Microscopy Application for the Measurement of Infliximab Concentration in Healthy Donors and Pediatric Patients with Inflammatory Bowel Disease.

The use of infliximab has completely changed the therapeutic landscape in inflammatory bowel disease. However, despite its proven efficacy to induce and maintain clinical remission, increasing evidence suggests that treatment failure may be associated with inadequate drug blood concentrations. The introduction of biosensors based on different nanostructured materials for the rapid quantification of drugs has been proposed for therapeutic drug monitoring. This study aimed to apply atomic force microscopy (AFM)-based nanoassay for the measurement of infliximab concentration in serum samples of healthy donors and pediatric IBD patients. This assay measured the height signal variation of a nanostructured gold surface covered with a self-assembled monolayer of alkanethiols. Inside this monolayer, we embedded the DNA conjugated with a tumor necrosis factor able to recognize the drug. The system was initially fine-tuned by testing known infliximab concentrations (0, 20, 30, 40, and 50 nM) in buffer and then spiking the same concentrations of infliximab into the sera of healthy donors, followed by testing pediatric IBD patients. A good correlation between height variation and drug concentration was found in the buffer in both healthy donors and pediatric IBD patients (p-value < 0.05), demonstrating the promising use of AFM nanoassay in TDM.