Browsing by Author "Leja, Mārcis"

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    Breath Fingerprint of Colorectal Cancer Patients Based on the Gas Chromatography–Mass Spectrometry Analysis
    (2024-02) Kononova, Elīna; Mežmale, Linda; Poļaka, Inese; Veliks, Viktors; Anarkulova, Linda; Vilkoite, Ilona; Tolmanis, Ivars; Ļeščinska, Anna Marija; Stonāns, Ilmārs; Pčolkins, Andrejs; Mochalski, Pawel; Leja, Mārcis; Department of Doctoral Studies; Faculty of Medicine
    The human body emits a multitude of volatile organic compounds (VOCs) via tissues and various bodily fluids or exhaled breath. These compounds collectively create a distinctive chemical profile, which can potentially be employed to identify changes in human metabolism associated with colorectal cancer (CRC) and, consequently, facilitate the diagnosis of this disease. The main goal of this study was to investigate and characterize the VOCs’ chemical patterns associated with the breath of CRC patients and controls and identify potential expiratory markers of this disease. For this purpose, gas chromatography–mass spectrometry was applied. Collectively, 1656 distinct compounds were identified in the breath samples provided by 152 subjects. Twenty-two statistically significant VOCs (p-xylene; hexanal; 2-methyl-1,3-dioxolane; 2,2,4-trimethyl-1,3-pentanediol diisobutyrate; hexadecane; nonane; ethylbenzene; cyclohexanone; diethyl phthalate; 6-methyl-5-hepten-2-one; tetrahydro-2H-pyran-2-one; 2-butanone; benzaldehyde; dodecanal; benzothiazole; tetradecane; 1-dodecanol; 1-benzene; 3-methylcyclopentyl acetate; 1-nonene; toluene) were observed at higher concentrations in the exhaled breath of the CRC group. The elevated levels of these VOCs in CRC patients’ breath suggest the potential for these compounds to serve as biomarkers for CRC.
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    Breath Volatile Organic Compounds in Surveillance of Gastric Cancer Patients following Radical Surgical Management
    (2023-05) Škapars, Roberts; Gašenko, Evita; Broza, Yoav Y.; Sīviņš, Armands; Poļaka, Inese; Bogdanova, Inga; Pčolkins, Andrejs; Veliks, Viktors; Folkmanis, Valdis; Lesčinska, Anna; Liepniece-Karele, Inta; Haick, Hossam; Rumba-Rozenfelde, Ingrīda; Leja, Mārcis
    As of today, there is a lack of a perfect non-invasive test for the surveillance of patients for potential relapse following curative treatment. Breath volatile organic compounds (VOCs) have been demonstrated to be an accurate diagnostic tool for gastric cancer (GC) detection; here, we aimed to prove the yield of the markers in surveillance, i.e., following curative surgical management. Patients were sampled in regular intervals before and within 3 years following curative surgery for GC; gas chromatography-mass spectrometry (GC-MS) and nanosensor technologies were used for the VOC assessment. GC-MS measurements revealed a single VOC (14b-Pregnane) that significantly decreased at 12 months, and three VOCs (Isochiapin B, Dotriacontane, Threitol, 2-O-octyl-) that decreased at 18 months following surgery. The nanomaterial-based sensors S9 and S14 revealed changes in the breath VOC content 9 months after surgery. Our study results confirm the cancer origin of the particular VOCs, as well as suggest the value of breath VOC testing for cancer patient surveillance, either during the treatment phase or thereafter, for potential relapse.
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    Comprehensive characterization of RNA cargo of extracellular vesicles in breast cancer patients undergoing neoadjuvant chemotherapy
    (2022-10-26) Sadovska, Lilite; Zayakin, Pawel; Eglītis, Kristaps; Endzeliņš, Edgars; Radoviča-Spalviņa, Ilze; Avotiņa, Elīza; Auders, Jānis; Keiša, Laura; Liepniece-Karele, Inta; Leja, Mārcis; Eglītis, Jānis; Linē, Aija; Department of Pathology
    Extracellular vesicles (EVs) are g7aining increased attention as carriers of cancer-derived molecules for liquid biopsies. Here, we studied the dynamics of EV levels in the plasma of breast cancer (BC) patients undergoing neoadjuvant chemotherapy (NAC) and explored the relevance of their RNA cargo for the prediction of patients’ response to the therapy. EVs were isolated from serial blood samples collected at the time of diagnosis, at the end of NAC, and 7 days, 6, and 12 months after the surgery from 32 patients with locally advanced BC, and 30 cancer-free healthy controls (HCs) and quantified by nanoparticle tracking analysis. The pre-treatment levels of EVs in BC patients were higher than in HCs, significantly increased during the NAC and surgery, and decreased to the levels found in HCs 6 months after surgery, thus showing that a substantial fraction of plasma EVs in BC patients are produced due to the disease processes and treatment. RNA sequencing analysis revealed that the changes in the EV levels were associated with the alterations in the proportions of various RNA biotypes in EVs. To search for RNA biomarkers that predict response to the NAC, patients were dichotomized as responders and non-responders based on Miller-Payne grades and differential expression analyses were carried out between responders and non-responders, and HCs. This resulted in the identification of 6 miRNAs, 4 lncRNAs, and 1 snoRNA that had significantly higher levels in EVs from non-responders than responders at the time of diagnosis and throughout the NAC, and significantly lower levels in HCs, thus representing biomarkers for the prediction of response to NAC at the time of diagnosis. In addition, we found 14 RNAs representing piRNA, miRNA, lncRNA, snoRNA, and snRNA biotypes that were induced by NAC in non-responders and 2 snoRNAs and 1 piRNA that were induced by NAC in patients with early disease progression, thus warranting further functional studies on their role in chemoresistance and metastasis.
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    The diagnostic value of anti-parietal cell and intrinsic factor antibodies, pepsinogens, and gastrin-17 in corpus-restricted atrophic gastritis
    (2022-11) Kriķe, Petra; Shums, Zakera; Polaka, Inese; Kikuste, Ilze; Vanags, Aigars; Tolmanis, Ivars; Isajevs, Sergejs; Liepniece-Karele, Inta; Santare, Daiga; Tzivian, Lilian; Rudzite, Dace; Song, Minkyo; Camargo, Maria Constanza; Norman, Gary; Leja, Mārcis; Department of Pathology
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