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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: 277; Downloads: 86
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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: 412; Downloads: 109
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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: 260; Downloads: 140
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Abstract: Extracellular vesicle-bound DNA (evDNA) is an understudied extracellular vesicle (EV) cargo, particularly in cancer-unrelated research. Although evDNA has been detected in urine, little is known about its characteristics, localization, and biomarker potential for kidney pathologies. To address this, we enriched EVs from urine of well-characterized kidney transplant recipients undergoing allograft biopsy, characterized their evDNA and its association to allograft injury. The SEC-based method enriched pure EVs from urine of kidney transplant recipients, regardless of the allograft injury. Urinary evDNA represented up to 29.2 ± 8% (mean ± SD) of cell-free DNA (cfDNA) and correlated with cfDNA in several characteristics but was less fragmented (P < 0.001). Importantly, using DNase treatment and immunogold labelling TEM, we demonstrated that evDNA was bound to the surface of urinary EVs. Normalised evDNA yield (P = 0.042) and evDNA copy number (P = 0.027) significantly differed between patients with normal histology, rejection injury and non-rejection injury, the later groups having significantly larger uEVs (mean diameter, P = 0.045) and more DNA bound per uEV. ddDNA is detectable in uEV samples of kidney allograft recipients, but its quantity is highly variable. In a proof-of-principle study, several evDNA characteristics correlated with clinical and histological parameters (P = 0.040), supporting that the potential of evDNA as a biomarker for kidney allograft injury should be further investigated.
Keywords: DNA, donor-derived DNA, extracellular vesicles
Published in DiRROS: 26.02.2025; Views: 758; Downloads: 600
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Abstract: Background. Tramadol is an opioid analgesic often used for pain management after breast cancer surgery. Its anal-gesic activity is due to the activation of the μ-opioid receptor, encoded by the OPRM1 gene. This study investigated the association of genetic variability in OPRM1 and its regulatory miRNA genes with outcomes of tramadol/paraceta-mol treatment after breast cancer surgery with axillary lymphadenectomy.Patients and methods. The study included 113 breast cancer patients after breast cancer surgery with axillary lymphadenectomy treated with either 75/650 mg or 37.5/325 mg of tramadol with paracetamol for pain relief within the randomized clinical trial KCT 04/2015-DORETAonko/si at the Institute of Oncology Ljubljana. All patients were geno-typed for OPRM1 rs1799971 and rs677830, MIR23B rs1011784, and MIR107 rs2296616 using competitive allele-specific PCR. The association of genetic factors with acute and chronic pain as well as adverse effects of tramadol treatment was evaluated using logistic regression, Fisher’s exact test, and Mann-Whitney test.Results.The investigated OPRM1 related polymorphisms were not associated with acute pain assessed with the VAS scale within four weeks after surgery (all P > 0.05). Carriers of at least one polymorphic OPRM1 rs1799971 allele had a higher risk of constipation in the first four weeks after surgery compared to non-carriers (OR = 4.5, 95% CI = 1.6–12.64, P = 0.004). Carriers of at least one polymorphic OPRM1 rs677830 allele had a higher risk of constipation after third week of tramadol treatment (OR = 3.11, 95% CI = 1.08–8.89, P = 0.035). Furthermore, carriers of two polymorphic MIR23Brs1011784 alleles had a higher risk of nausea after 28 days of tramadol treatment (OR = 7.35, 95% CI = 1.27–42.6, P = 0.026), while heterozygotes for MIR107 rs2296616 allele had a lower risk of nausea after 21 days of tramadol treatment (OR = 0.21, 95% CI = 0.05–0.87, P = 0.031). In carriers of two polymorphic MIR107 rs2296616 alleles, chronic pain was significantly more common than in carriers of two wild-type alleles (P = 0.004). Carriers of at least one polymorphic MIR23B rs1011784 allele experienced more neuropathic pain after adjustment for tramadol dose (OR = 2.85, 95% CI = 1.07–7.59, P = 0.036), while carriers of at least one polymorphic OPRM1 rs677830 allele experienced less neuropathic pain compared to carriers of two wild-type alleles (OR = 0.38, 95% CI = 0.15–0.99, P = 0.047).Conclusions.Genetic variability of OPRM1 and genes coding for miRNAs that could affect OPRM1 expression may be associated with adverse effects of tramadol/paracetamol treatment as well as with chronic and neuropathic pain after breast cancer surgery with axillary lymphadenectomy.
Keywords: operacija raka na dojki, zdravljenje bolečine, tramadol
Published in DiRROS: 25.07.2024; Views: 1639; Downloads: 639
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