1. Comprehensive phenotyping of extracellular vesicles in plasma of healthy humans - insights into cellular origin and biological variationMarija Holcar, Ivica Marić, Tobias Tertel, Katja Goričar, Urška Čegovnik Primožič, Darko Černe, Bernd Giebel, Metka Lenassi, 2025, original scientific article Abstract: Despite immense interest in biomarker applications of extracellular vesicles (EVs) from blood, our understanding of circulating EVs under physiological conditions in healthy humans remains limited. Using imaging and multiplex bead-based flow cytometry, we comprehensively quantified circulating EVs with respect to their cellular origin in a large cohort of healthy blood donors. We assessed coefficients of variations to characterize their biological variation and explored demographic, clinical, and lifestyle factors contributing to observed variation. Cell-specific circulating EV subsets show a wide range of concentrations that do not correlate with cell-of-origin concentrations in blood, suggesting steady-state EV subset concentrations are regulated by complex mechanisms, which differ even for EV subsets from the same cell type. Interestingly, tetraspanin+ circulating EVs largely originate from platelets and to a lesser extent from lymphocytes. Principal component analysis (PCA) and association analyses demonstrate high biological inter-individual variation in circulating EVs across healthy humans, which are only partly explained by the influence of sex, menopausal status, age and smoking on specific circulating EV and/or tetraspanin+ circulating EV subsets. No global influence of the explored subject's factors on circulating EVs was detected. Our findings provide the first comprehensive, quantitative data towards the cell-origin atlas of plasma EVs, with important implications in the clinical use of EVs as biomarkers.
Keywords: biological variation, blood, extracellular vesicles, helathy humans, plasma
Published in DiRROS: 15.04.2026; Views: 22; Downloads: 20
 Full text (2,92 MB)
This document has many files! More... |
2. Vnetni dejavniki kot označevalci odgovora na zdravljenje z obsevanjem pri duktalnem karcinomu in situTanja Marinko, Manca Pirc, Špela Plestenjak, Maja Marinčič, Vita Dolžan, Katja Goričar, 2025, published scientific conference contribution Keywords: rak dojke, obsevanje, vnetni dejavniki, radioterapija
Published in DiRROS: 11.03.2026; Views: 196; Downloads: 83
Full text (122,01 KB) |
3. |
4. Semaglutide delays 4-hour gastric emptying in women with PCOS and obesityMojca Jensterle Sever, Simona Ferjan, Luka Ležaič, Aljaž Sočan, Katja Goričar, Katja Zaletel, Andrej Janež, 2023, original scientific article Abstract: Context: Semaglutide could contribute to reduced energy intake and weight loss by delaying gastric emptying (GE). However, the evidence for notable effects of semaglutide is inconclusive and compromised by the use of indirect methodology. Objective: to evaluate the effect of once-weekly subcutaneous semaglutide 1.0 mg on late digestive period of GE after ingestion of a standardized solid test meal by using technetium scintigraphy, the reference method for this purpose. Design: We conducted single-blind, placebo-controlled trial with 20 obese women with PCOS (average age 35 (32.3-40.8) years), BMI 37 (30.7-39.8) kg/m2 ) randomized to s.c semaglutide 1.0 mg QW (S) or placebo (P) for 12 weeks. GE was assessed after ingestion of [99mT c] colloid in pancake labeled with radiopharmaceutical by scintigraphy using sequential static imaging and dynamic acquisition at baseline and at week 13. Estimation of GE was obtained by repeated imaging of remaining [99mT c] activity (RA) at fixed time intervals over 4 hours after ingestion. Results: From baseline to the study end, semaglutide increased the estimated retention of gastric contents by 3.5% at the 1st hour, 25.5% at 2nd , 38.0% at 3rd and 30.0% at the 4th hour after ingestion of the radioactively labeled solid meal. Four hours after ingestion, semaglutide retained 37% of solid meal in the stomach compared to no gastric retention in P group (p=0.002). Half time (T1/2 ) was significantly longer in S as compared to P (171 min vs 118 min, (p<0.001). Conclusion: Semaglutide markedly delayed 4-hour GE in women with PCOS and obesity. This article is protected by copyright. All rights reserved.
Keywords: PCOS, obesity, semaglutide
Published in DiRROS: 12.01.2026; Views: 330; Downloads: 208
Full text (1,41 MB)
This document has many files! More... |
5. Somatic mutation detection in tumor tissue and matched cell-free DNA using PCR-based methods in pancreatic cancer patients undergoing upfront resectionHana Zavrtanik, David Badovinac, Tanja Blagus, Katja Goričar, Branislava Ranković, Alenka Matjašič, Andrej Zupan, Aleš Tomažič, Vita Dolžan, 2025, original scientific article Abstract: Somatic mutations in KRAS and TP53 are among the most common genetic alterations in pancreatic ductal adenocarcinoma (PDAC). Advances in PCR-based technologies now enable the detection of these mutations in tumor tissue and cell-free DNA (cfDNA), providing a minimally invasive approach to assess tumor burden. However, in resectable PDAC, circulating tumor DNA (ctDNA) may represent less than 0.1% of total cfDNA, requiring highly sensitive detection methods. The aim of our study was to assess two PCR-based assays—competitive allele-specific PCR (castPCR) and digital PCR (dPCR)—for detecting selected somatic mutations in tumor tissue, cfDNA, and extracellular vesicle-associated DNA (EV-DNA) from plasma. Matched primary tumor and preoperative plasma samples were collected from 50 patients undergoing upfront resection for PDAC. CastPCR was used for detecting selected KRAS, TP53, SMAD4, and CDKN2A mutations in tumor DNA. Additionally, dPCR was used to analyze KRAS and TP53 mutations in tumor DNA as well as cfDNA and EV-DNA. The concordance between both platforms was 71.4% for KRAS p.G12D and 58.3% for the analysis of TP53 p.R273H mutations in tumor tissue. However, dPCR detected these mutations in an additional 28.6% and 39.6% of samples, respectively. In cfDNA, dPCR identified KRAS p.G12D in 10.2% and TP53 p.R273H in 2.0% of samples. Mutation detection in EV-DNA was limited by low DNA yield. Both platforms proved effective for tumor DNA analysis, with dPCR offering greater sensitivity. Somatic mutation detection from liquid biopsy using dPCR further supports its potential utility in the preoperative setting.
Keywords: somatic mutation detection, cell-free DNA, liquid biopsy, digital PCR, pancreatic cancer
Published in DiRROS: 08.01.2026; Views: 459; Downloads: 196
Full text (1,19 MB)
This document has many files! More... |
6. Genetic variability of HIF1A and response to treatment with cisplatin in combination with pemetrexed or gemcitabine in patients with malignant mesotheliomaMatic Šetina, Eva Šetina, Žiga Doljak, Katja Goričar, Vita Dolžan, Viljem Kovač, 2025, original scientific article Abstract: Background. Treatment of malignant mesothelioma (MM) still relies on chemotherapy with cisplatin in combination with pemetrexed or other drugs. Studies indicate that hypoxic conditions within tumour tissue may reduce responsiveness to cisplatin-based chemotherapy. Hypoxia-inducible factors (HIF) play an important role in regulation of cellular adaptation to hypoxia. The aim of our study was to investigate single nucleotide polymorphisms (SNPs) in the HIF1A gene coding for the regulatory alpha subunit (HIF-1A) and their role in the response to chemotherapy in patients with MM. Patients and methods. Our retrospective genetic association study included 234 patients with MM, who were treated with a combination of cisplatin/pemetrexed or cisplatin/gemcitabine at the Institute of Oncology Ljubljana between January 2001 and September 2018. Selected HIF1A SNPs (rs1154965, rs11549467, and rs2057482) were genotyped using the competitive allele-specific polymerase chain reaction (KASP). Additionally, we used a TaqMan assay for independent confirmation of rs11549465 genotyping results. The impact of the SNPs on response to chemotherapy was analysed using logistic regression. For survival analysis, we used the Kaplan-Meier method and Cox regression. Results. In heterozygotes with the HIF1A rs11549465 CT genotype, response to chemotherapy was significantly worse compared to homozygotes with the CC genotype, but only after adjustment for weight loss and CRP (ROadj = 0.37; 95% CI = 0.14–0.97; Padj = 0.044). HIF1A rs11549467 and rs2057482 were not associated with response to chemotherapy (all P > 0.05). None of the investigated SNPs were associated with progression-free survival or overall survival (all P > 0.05). Conclusions. Among the investigated HIF1A SNPs, only rs11549465 has showed association with a worse response to chemotherapy after the adjustment for clinical parameters. The findings of this study have improved our understanding of the role of HIF1A polymorphisms in MM and may offer valuable insights into their impact on other cancers as well.
Keywords: malignant mesothelioma, chemotherapy, polymorphism
Published in DiRROS: 10.12.2025; Views: 521; Downloads: 137
Full text (499,50 KB) |
7. Association of matrix metalloproteinases polymorphisms with glaucoma risk, glaucoma phenotype, and response to treatment with selective laser trabeculoplasty or latanoprostMakedonka Atanasovska Velkovska, Katja Goričar, Tanja Blagus, Vita Dolžan, Barbara Cvenkel, 2024, original scientific article Abstract: In open-angle glaucoma, the increase in intraocular pressure (IOP) is caused by an increased resistance to aqueous humour outflow in the trabecular meshwork. Since genetic variability of matrix metalloproteinase (MMP) genes may influence extracellular matrix remodelling, we investigated their association with glaucoma risk and/or response to treatment. The retrospective part of the study included patients with primary open-angle glaucoma and ocular hypertension (OHT); in the prospective part of the study, newly diagnosed patients with POAG or OHT were randomised to receive either latanoprost or selective laser trabeculoplasty (SLT) as the initial treatment. The reduction in IOP was measured 6 weeks after treatment. The following MMP single nucleotide polymorphisms were genotyped: MMP2 rs243865, rs243849, and rs7201; MMP3 rs3025058; MMP9 rs17576, rs17577, rs20544, and rs2250889; MMP14 rs1042704, rs1042704, and rs743257. Logistic regression was used to calculate odds ratios to assess the association between MMP polymorphism and risk of POAG or OHT, glaucoma phenotypes and response to treatment. Only carriers of the MMP3 rs3025058 TT genotype had a significantly higher risk of OHT, more advanced glaucoma, and a higher C/D ratio in the additive and dominant models. None of the investigated MMP polymorphisms were associated with response to treatment with latanoprost and SLT in our study population.
Keywords: glaucoma, latanoprost, matrix metalloproteinases, selective laser trabeculoplasty, single nucleotide polymorphisms
Published in DiRROS: 08.12.2025; Views: 526; Downloads: 207
Full text (235,20 KB)
This document has many files! More... |
8. Effect of tirzepatide-induced weight loss on adipose tissue in obesity : rationale and design of the randomized placebo-controlled Tirzepatide Brown and Beige Adipose Tissue Activation (TABFAT) trialRok Herman, Mojca Jensterle Sever, Simon Horvat, Luka Ležaič, Žiga Snoj, Igor Pušnik, Katja Goričar, Andrej Cör, Luka Pušnik, Vid Mlačnik, Lara Hanželič, Andrej Janež, 2025, original scientific article Abstract: Background Obesity is a complex disease marked by excessive, dysfunctional adipose tissue accumulation. Recent research underscores the pivotal role of brown adipose tissue (BAT) in metabolic health and its potential as a thera- peutic target for obesity management. Emerging preclinical and clinical evidence suggests that second-generation anti-obesity drugs, especially dual agonists such as tirzepatide, may enhance BAT activity. Additionally, beige adipose tissue, derived from white adipose tissue (WAT), may contribute significantly to whole-body thermogenesis, yet its role remains underexplored. Methods This investigator-initiated, randomized, placebo-controlled clinical trial aims to evaluate the effects of tirzepatide on BAT activity and WAT browning in premenopausal women with obesity. Thirty-four participants will be randomized 1:1 to receive either tirzepatide or a placebo for 24 weeks. Primary outcomes include changes in BAT volume and activity, assessed using 18F-FDG-PET/CT, MRI, and infrared thermography, as well as the induction of WAT browning, evaluated through changes in mRNA expression patterns and histomorphometric alterations in subcuta- neous adipose tissue samples. Secondary outcomes will involve the assessment of whole-body composition, resting energy expenditure, and various metabolic health markers, correlated with thermogenic adipose tissue changes. Comparative analysis of BAT assessment methods will refine protocols for research and clinical use. Discussion This study is the first to systematically explore the potential of pharmacological obesity management to enhance BAT activity and induce WAT browning. Results may establish thermogenic adipose tissue augmentation as a novel mechanism of action for second-generation anti-obesity medications.
Keywords: brown adipose tissue, beige adipose tissue, pancreas resection, tirzepatide, obesity
Published in DiRROS: 26.11.2025; Views: 379; Downloads: 220
Full text (1003,47 KB)
This document has many files! More... |
9. Genetic variability in sodium-glucose cotransporter 2 and glucagonlike peptide 1 receptor effect on glycemic and pressure control in type 2 diabetes patients treated with SGLT2 inhibitors and GLP-1RA in the everyday clinical practiceGašper Tonin, Katja Goričar, Tanja Blagus, Andrej Janež, Vita Dolžan, Jasna Klen, 2025, original scientific article Abstract: We investigated the impact of genetic polymorphisms in the GLP1R and SLC5A2 genes on the response to treatment with glucagon-like peptide-1 receptor (GLP-1R) agonists and sodium-glucose co-transporter-2 (SLGT2) inhibitors in patients with type 2 diabetes mellitus (T2DM) in everyday clinical practice.In our prospective interventional cohort open-label real-world genetic association study (DRKS-ID: DRKS00034478, https://drks.de/search/en/trial/DRKS00034478), we enrolled 161 clinically well-defined T2DM patients who received SGLT2 inhibitors and/or GLP-1R agonists alongside other medications for 3-6 months. The study's primary outcomes (HbA1c, body mass, and blood pressure) were measured before the treatment and at the follow-up at 3-6 months. GLP1R rs6923761, rs10305420, and SLC5A2 rs9934336 genotypes were determined by competitive allelespecific polymerase chain reaction. In patients receiving GLP-1R agonists, we analyzed the effect of GLP1R polymorphisms on the patients' response to treatment, while in patients receiving SGLT2 inhibitors, we analyzed the impact of the SLC5A2 polymorphism on the treatment effect.Treatment with prescribed antihyperglycemic drugs improved all primary outcomes (p < 0.050). The normal GLP1R rs6923761 G allele was associated with a greater reduction in HbA1c with GLP-1R agonists treatment than the polymorphic A allele in the dominant model (p = 0.029).The prevalent polymorphic A allele of GLP1R rs6923761 polymorphism was associated with the clinically relevant lower glycemic response to GLP-1R agonists. The described impact extends to everyday clinical practice, indicating that knowledge of these genetic polymorphisms could facilitate the development of targeted and personalized therapy in managing T2DM.
Keywords: polymorphism, type 2 diabetes, treatment response
Published in DiRROS: 17.11.2025; Views: 421; Downloads: 231
Full text (740,73 KB)
This document has many files! More... |
10. The association of KEAP1 and NFE2L2 polymorphisms with glycemic control and late complications in patients with type 2 diabetesZala Vraničar, Katja Goričar, Tanja Blagus, Vita Dolžan, Jasna Klen, 2025, original scientific article Abstract: To investigate the association of KEAP1 rs1048290, rs9676881 and NFE2L2 rs6706649, rs6721961, rs35652124 polymorphisms with glycemic control and development of late complications in patients with type 2 diabetes mellitus (T2DM), a total of 316 T2DM patients were included in the retrospective genetic association study. Genotyping was performed using competitive allele-specific PCR. Data on HbA1c levels as a measure of glycemic control, and information on late complications, including ischemic heart disease, retinopathy, and nephropathy, was obtained from the medical records. Logistic regression analysis was used to assess the association between selected genetic polymorphisms and patients outcomes. Significant associations were observed between KEAP1 rs9676881 (p < 0.001) and NFE2L2 rs6721961 (p = 0.006) polymorphisms and elevated HbA1c levels. Additionally, NFE2L2 rs35652124 polymorphism was linked to a nominally higher risk of late complications, including ischemic heart disease (p = 0.036), retinopathy (p = 0.032), and nephropathy (p = 0.026). Results indicate that polymorphisms in the KEAP1 and NFE2L2 genes may influence glycemic control and the development of late complications in T2DM patients. These findings provide valuable insights into the genetic factors underlying T2DM progression and its complications in European populations, highlighting the potential role of genetic markers in optimizing personalized treatment strategies.
Keywords: diabetes mellitus type 2, oxidative pathway, genetic polymorphism, microvascular complications, macrovascular complications, personalized medicine
Published in DiRROS: 11.11.2025; Views: 498; Downloads: 280
Full text (732,56 KB)
This document has many files! More... |
