Sandra Zekic Tomas

Dr. Sandra Zekic Tomas


Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Journal Article
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JKJosipa Kokeza
Josipa Kokeza
ASAnte Strikic
Ante Strikic
MOMarin Ogorevc
Marin Ogorevc
Nela KelamNela Kelam
Nela Kelam
MVMartina Vukoja
Martina Vukoja
STSandra Zekic Tomas
Sandra Zekic Tomas
Lung cancer is the second-most-common cancer while being the leading cause of cancer deaths worldwide. It has been found that glucose transporter 1 (GLUT1) and hypoxia-inducible factor 1α (HIF-1α) are overexpressed in various malignancies and that they correlate with the maximum standard uptake values (SUVmax) on 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) and poor prognosis. In this study, we aim to evaluate the relationship between the SUVmax, GLUT1, and HIF-1α expression with primary tumor size, histological type, lymph node metastases, and patient survival. Of the 48 patients with non-small-cell lung cancer, those with squamous cell carcinomas (SCCs) had significantly higher GLUT1 and HIF-1α immunohistochemical expressions in comparison to adenocarcinomas (ACs), while there was no statistically significant difference in FDG accumulation between them. No significant correlation was noted between either GLUT1 or HIF-1α protein expression and FDG uptake and overall survival. However, an analysis of tumor transcriptomics showed a significant difference in overall survival depending on mRNA expression; patients with SCC and high HIF-1α levels survived longer compared to those with low HIF-1α levels, while patients with AC and low GLUT1 levels had a higher average survival time than those with high GLUT1 levels. Further studies are needed to determine the prognostic value of the expression of these factors depending on the histologic type.

15 February 2011 in The Journal of Maternal-Fetal & Neonatal Medicine
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DRDamir Roje
Damir Roje
STSandra Zekic Tomas
Sandra Zekic Tomas
IPIvana Kuzmic Prusac
Ivana Kuzmic Prusac
VCVesna Capkun
Vesna Capkun
ITIvica Tadin
Ivica Tadin
Objective. To investigate proliferative, apoptotic, and antiapoptotic activity of placental trophoblast in pregnancies complicated with idiopathic intrauterine growth retardation (IUGR). Methods. Study group included data and placentas from 52 normal singleton term pregnancies with idiopathic IUGR. Records and placentas from 69 singleton pregnancies with normal fetal growth served as a control group. IUGR was defined by birth weight less than 10th percentile of standard values. Children with congenital malformations and those born with the signs of hypoxia, laboratory or clinical signs of preeclampsia or infection, children born to anemic mothers and those born from pregnancies with an increased coagulation system activity were excluded. Results. There was no statistically significant difference in the cytotrophoblast proliferation index value (Z = 0.24; P = 0.553), trophoblast expression of the Bcl-2 antiapoptotic factor (Z = 0.47; P = 0.634), and trophoblast apoptotic index (Z = 0.51; P = 0.613) between the idiopathic IUGR and control group. Conclusion. The proliferative and apoptotic events in the trophoblast of placentas with idiopathic IUGR did not differ from physiologic ones. Study results suggest the IUGR syndrome to have no uniform etiology or even underlying pathophysiology that would determine the possible fetal risk and subsequent long-term consequences for fetal health and life. This imposes the need of a more precise definition and unambiguous distinction between the idiopathic and other forms of IUGR.

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DČDavor Čarić
Davor Čarić
STSandra Zekic Tomas
Sandra Zekic Tomas
NFNatalija Filipovic
Natalija Filipovic
VSVioleta Soljic
Violeta Soljic
BBBenjamin Benzon
Benjamin Benzon
Katarina VukojevicKatarina Vukojevic
Katarina Vukojevic
Hip osteoarthritis (HOA) is characterized by degradation of the cartilage and synovitis. However, the pathohistological effects of synovial tissue inflammation on HOA are not clear. The aim of this study was to evaluate the expression of iNOS, BCL-2 and MMP-9 markers in different synovial cell populations. A total of 32 patients were evaluated retrospectively. Age, sex, height, weight, body mass index were recorded and lymphocyte, fibrocytes and macrophages were analysed in tissue sections. Osteoarthritis cartilage histopathology assessment system (OARSI), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Krenn score, Harris Hip Score (HHS) and Kellgren–Lawrence (K-L) grading of the hip joints were performed. Total hip arthroplasty was performed on 32 patients and controls. Patients were divided into two groups according to their disease severity. The tissues were immunohistochemically analysed. K-L grade and Krenn score differ between all three groups, but also between moderate and severe OA. Synovial lining cell layer, resident cells in stroma and especially inflammatory infiltration were increasing with severity of OA. iNOS expression in both intima and subintima was positively correlated with Krenn score in moderate and severe osteoarthritis (OA) groups. Expression of BCL-2 in intima of severe OA patients was positively correlated with Krenn score. In conclusion, iNOS, BCL-2 and MMP-9 are involved in the regulation of HOA. Our study indicates a relationship between the pathohistological features, the synovial inflammation and the cartilage condition at the time of hip replacement due to OA or femoral neck fracture.

2 August 2021 in Biomedical Reports
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MOMarin Ogorevc
Marin Ogorevc
ASAnte Strikic
Ante Strikic
STSandra Zekic Tomas
Sandra Zekic Tomas
The aim of the present study was to compare the immunohistochemical expression of glucose transporter 1 (GLUT1) between the most common histological types of renal cell carcinoma (RCC), and to determine whether a correlation between GLUT1 expression and nuclear grade or tumor size exists. A total of 19 RCC samples were selected for the study, consisting of 8 clear cell (cc)RCC and 11 non‑ccRCC tissues. Immunohistochemistry for GLUT1 was performed on formalin‑fixed and paraffin‑embedded sections using GLUT1 antibodies. All data analyses were performed using the MedCalc software. There was a higher immunohistochemical expression of GLUT1 in the ccRCC group compared with the non‑cc group, but there was no difference in GLUT1 expression between groups of RCCs with differing nuclear grades. No significant correlation between GLUT1 expression and tumor size was found. The higher immunohistochemical expression of GLUT1 in ccRCC may be a contributing factor to the clinical characteristics and behavior of that group of carcinomas. These results suggest that GLUT1 expression cannot be used as a prognostic factor for RCC, but it may be used as a predictive factor in the future.

20 November 2023 in Frontiers in Oncology
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Journal Article
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ASAnte Strikic
Ante Strikic
JKJosipa Kokeza
Josipa Kokeza
MOMarin Ogorevc
Marin Ogorevc
NKNela Kelam
Nela Kelam
MVMartina Vukoja
Martina Vukoja
STSandra Zekic Tomas
Sandra Zekic Tomas
Renal cell carcinoma (RCC) represents around 3% of all cancers, with the most frequent histological types being clear-cell RCC (ccRCC), followed by papillary (pRCC) and chromophobe (chRCC). Hypoxia-inducible factors (HIFs), which promote the expression of various target genes, including vascular endothelial growth factor (VEGF) and the high- affinity glucose transporter 1, have an important role in the pathogenesis of RCC. This study investigated the immunohistochemical expression of HIF-1α and VEGF-A, showing significantly higher HIF-1α nuclear expression in pRCC compared to ccRCC, while there was no significant difference in VEGF-A protein expression between the analyzed histological RCC subtypes. The quantitative reverse transcription polymerase chain reaction for HIF1A showed no statistical difference between histological types. Data from publicly available RNA sequencing databases were analyzed and showed that, compared to healthy kidney tissue, VEGFA was significantly up-regulated in ccRCC and significantly down-regulated in pRCC. The comparison between histological subtypes of RCC revealed that VEGFA was significantly up-regulated in ccRCC compared to both pRCC and chRCC. There was no statistically significant difference in survival time between HIF1A high- and low-expression groups of patients. As for VEGFA expression, pRCC patients with low expression had a significantly higher survival rate compared to patients with high VEGFA expression.

2 April 2015 in The Journal of Maternal-Fetal & Neonatal Medicine
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Journal Article
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JKJasminka Rešić Karara
Jasminka Rešić Karara
STSandra Zekic Tomas
Sandra Zekic Tomas
JMJelena Marušić
Jelena Marušić
DRDamir Roje
Damir Roje
IPIvana Kuzmić Prusac
Ivana Kuzmić Prusac
To compare the level of Fas and FasL immunohistochemical expression in villous trophoblast (VT), extravillous trophoblast (EVT) cells, decidual cells (DC), endothelial cells (EC) of villous blood vessels and spiral arteries between the study groups of intrauterine growth retardation (IUGR) placentas with and without preeclampsia (PE).The study included 17 placentas from pregnancies complicated by IUGR + PE and 17 placentas from pregnancies complicated by idiopathic IUGR (I-IUGR). Seventeen placentas from normal pregnancies served as a control group. CD31 was used to detect endothelial cells (EC). Immunohistochemical expression of Fas and FasL was assessed in all examined parts of placenta using the semi-quantitative HSCORE method.FasL expression was significantly higher in all examined parts of placenta in I-IUGR as compared to IUGR + PE and control group. Placentas with IUGR + PE had the significantly lowest expression of FasL in VT and EC of villi vessels. Expression of Fas did not differ significantly between the study groups.Different expression of FasL in placentas from I-IUGR and IUGR + PE suggests that FasL probably has a different role in the etiology of these two syndromes.