Georgios Sotiropoulos

Prof. Dr. Georgios Sotiropoulos


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

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

Representative Publications

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27 August 2010 in Molecular Cancer
Verified
Journal Article
Open access
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QSQingli Shen
Qingli Shen
VCVito R Cicinnati
Vito R Cicinnati
XZXiaoyong Zhang
Xiaoyong Zhang
SISperanta Iacob
Speranta Iacob
FWFrank Weber
Frank Weber
SBSusanne Beckebaum
Susanne Beckebaum
Background: Micro-ribonucleic acid (miRNA)-199a-5p has been reported to be decreased in hepatocellular carcinoma (HCC) compared to normal tissue. Discoidin domain receptor-1 (DDR1) tyrosine kinase, involved in cell invasion-related signaling pathway, was predicted to be a potential target of miR-199a-5p by the use of miRNA target prediction algorithms. The aim of this study was to investigate the role of miR-199a-5p and DDR1 in HCC invasion. Methods: Mature miR-199a-5p and DDR1 expression were evaluated in tumor and adjacent non-tumor liver tissues from 23 patients with HCC undergoing liver resection and five hepatoma cell lines by the use of real-time quantitative RT-PCR (qRT-PCR) analysis. The effect of aberrant miR-199a-5p expression on cell invasion was assessed in vitro using HepG2 and SNU-182 hepatoma cell lines. Luciferase reporter assay was employed to validate DDR1 as a putative miR-199a-5p target gene. Regulation of DDR1 expression by miR-199a-5p was assessed by the use qRT-PCR and western blotting analysis. Results: A significant down-regulation of miR-199a-5p was observed in 65.2% of HCC tissues and in four of five cell lines. In contrast, DDR1 expression was significantly increased in 52.2% of HCC samples and in two of five cell lines. Increased DDR1 expression in HCC was associated with advanced tumor stage. DDR1 was shown to be a direct target of miR-199a-5p by luciferase reporter assay. Transfection of miR-199a-5p inhibited invasion of HepG2 but not SNU-182 hepatoma cells. Conclusions: Decreased expression of miR-199a-5p contributes to increased cell invasion by functional deregulation of DDR1 activity in HCC. However, the effect of miR-199a-5p on DDR1 varies among individuals and hepatoma cell lines. These findings may have significant translational relevance for development of new targeted therapies as well as prognostic prediction for patients with HCC.

27 November 2008 in BMC Cancer
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Journal Article
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VCVito R Cicinnati
Vito R Cicinnati
QSQingli Shen
Qingli Shen
GSGeorgios Sotiropoulos
Georgios Sotiropoulos
ARArnold Radtke
Arnold Radtke
GGGuido Gerken
Guido Gerken
SBSusanne Beckebaum
Susanne Beckebaum
Background: Reference genes, which are often referred to as housekeeping genes are frequently used to normalize mRNA levels between different samples in quantitative reverse transcription polymerase chain reaction (qRT-PCR). The selection of reference genes is critical for gene expression studies because the expression of these genes may vary among tissues or cells and may change under certain circumstances. Here, a systematic evaluation of six putative reference genes for gene expression studies in human hepatocellular carcinoma (HCC) is presented. Methods: Six genes, beta-2-microglobulin (B2M), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), hydroxymethyl-bilane synthase (HMBS), hypoxanthine phosphoribosyl-transferase 1 (HPRT1), succinate dehydrogenase complex, subunit A (SDHA) and ubiquitin C (UBC), with distinct functional characteristics and expression patterns were evaluated by qRT-PCR. Inhibitory substances in RNA samples were quantitatively assessed and controlled using an external RNA control. The stability of selected reference genes was analyzed using both geNorm and NormFinder software. Results: HMBS and GAPDH were identified as the optimal reference genes for normalizing gene expression data between paired tumoral and adjacent non-tumoral tissues derived from patients with HCC. HMBS, GAPDH and UBC were identified to be suitable for the normalization of gene expression data among tumor tissues; whereas the combination of HMBS, B2M, SDHA and GAPDH was suitable for normalizing gene expression data among five liver cancer cell lines, namely Hep3B, HepG2, HuH7, SK-HEP-1 and SNU-182. The determined gene stability was increased after exclusion of RNA samples containing relatively higher inhibitory substances. Conclusion: Of six genes studied, HMBS was found to be the single best reference gene for gene expression studies in HCC. The appropriate choice of combination of more than one reference gene to improve qRT-PCR accuracy depends on the kind of liver tissues or cells under investigation. Quantitative assessment and control of qRT-PCR inhibitors using an external RNA control can reduce the variation of qRT-PCR assay and facilitate the evaluation of gene stability. Our results may facilitate the choice of reference genes for expression studies in HCC.

24 October 2021 in Journal of Clinical Medicine
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PDPanagiotis Dorovinis
Panagiotis Dorovinis
Nikolaos MachairasNikolaos Machairas
Nikolaos Machairas
Stylianos KykalosStylianos Kykalos
Stylianos Kykalos
PSParaskevas Stamopoulos
Paraskevas Stamopoulos
SVSpyridon Vernadakis
Spyridon Vernadakis
GSGeorgios Sotiropoulos
Georgios Sotiropoulos
Resection of the caudate lobe of the liver is considered a highly challenging type of liver resection due to the region’s intimacy with critical vascular structures and deep anatomic location inside the abdominal cavity. Laparoscopic resection of the caudate lobe is considered one of the most challenging laparoscopic liver procedures. The objective of our systematic review was to evaluate the safety, technical feasibility and main outcomes of laparoscopic caudate lobectomy LCL. A systematic review of the literature was undertaken for studies published until September 2021. A total of 20 studies comprising 221 patients were included. Of these subjects, 36% were women, whereas the vast majority of resections (66%) were performed for malignant tumors. Tumor size varied significantly between 2 and 160 mm in the largest diameter. The mean operative time was 210 min (range 60–740 min), and estimated blood loss was 173.6 mL (range 50–3600 mL). The median hospital length of stay LOS was 6.5 days (range 2–15 days). Seven cases of conversion to open were reported. The vast majority of patients (93.7%) underwent complete resection (R0) of their tumors. Thirty-six out of 221 patients developed postoperative complications, with 5.8% of all patients developing a major complication (Clavien–Dindo classification ≥ III).No perioperative deaths were reported by the included studies. LCL seems to be a safe and feasible alternative to open caudate lobectomy OCL in selected patients when undertaken in high-volume centers by experienced surgeons.

9 September 2022 in Cancers
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Journal Article
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GGGeorgios K. Glantzounis
Georgios K. Glantzounis
DKDimitris P. Korkolis
Dimitris P. Korkolis
GSGeorgios Sotiropoulos
Georgios Sotiropoulos
GTGeorge Tzimas
George Tzimas
AKANASTASIA Dimitrios KARAMPA
ANASTASIA Dimitrios KARAMPA
EFEVANGELOS FELEKOURAS
EVANGELOS FELEKOURAS
Background: Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the third leading cause of death worldwide. The management of HCC is complex, with surgical treatment providing long-term survival in eligible patients. This study aims to present the experience of aggressive surgical management of HCC in Greece. Methods: This is a retrospective multicentre clinical study with 242 patients. Results: Most patients were male (79%) and had a median age of 71 yrs. According to the most recent BCLC criteria, 172 patients (71.1%) were classified as BCLC 0-A stage, 33 patients (13.6%) were classified as BCLC B, and 37 (15.3%) were classified as BCLC C. A total of 54% of the patients underwent major hepatectomy. Major postoperative morbidity was 15.6%, and the 90-day postoperative mortality rate was 4.5%. The median follow-up was 33.5 months. Three- and five-year overall survival was 65% and 48%, respectively. The median overall survival was 55 months. Significantly, five-year survival was 55% for BCLC A, and 34% and 21% for BCLC B and C, respectively. In univariate analysis, cirrhosis, type of resection (R status), and BCLC stage were associated with overall survival. Multivariate analysis indicated that R1 and R2 resections compared to R0, and BCLC C compared to BCLC 0-A, were independently associated with increased mortality. Conclusions: Aggressive surgical treatment of HCC offers satisfactory long-term survival prospects. A significant percentage (29%) of HCCs that underwent liver resection were of the intermediate and advanced BCLC stage. The management of patients with HCC should be discussed in multidisciplinary tumour board meetings on a case-by-case basis to be more effective.

27 December 2025 in Cancers
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CTCharalampos Theocharopoulos
Charalampos Theocharopoulos
Nikolaos MachairasNikolaos Machairas
Nikolaos Machairas
IZIoannis A. Ziogas
Ioannis A. Ziogas
BMBenedetto Mungo
Benedetto Mungo
MCMarco Del Chiaro
Marco Del Chiaro
GSGeorgios Sotiropoulos
Georgios Sotiropoulos
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with poor long-term survival despite advances in surgical techniques, systemic therapies, and perioperative management. High rates of systemic recurrence following curative-intent resection suggest that many patients harbor minimal residual disease (MRD), microscopic tumor burden that persists postoperatively and remains undetectable by conventional diagnostic tools. Recent advances in liquid biopsy technologies, particularly circulating tumor DNA (ctDNA) analysis, alongside detailed characterization of the PDAC mutational landscape, offer a promising non-invasive approach for MRD detection. Emerging evidence indicates that MRD status can serve as a sensitive prognostic biomarker, identify patients at high risk of relapse, and guide personalized perioperative therapy, including optimization of adjuvant treatment. This review summarizes current knowledge on the biology and detection of MRD in PDAC, its implications for perioperative risk stratification and treatment decision-making, and discusses future directions for integrating MRD assessment into clinical practice to enable more precise, individualized patient management.

2 June 2026 in Gastroenterology Insights
Verified
Journal Article
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SRStefanos Raptis
Stefanos Raptis
CTCharalampos Theocharopoulos
Charalampos Theocharopoulos
ATAchilleas Theocharopoulos
Achilleas Theocharopoulos
GLGeorgios Levantis
Georgios Levantis
DVDimitrios Varvoglis
Dimitrios Varvoglis
Aristidis VrahatisAristidis Vrahatis
Aristidis Vrahatis
Background/Objectives: The global adoption of minimally invasive surgery has generated extensive video repositories, creating new opportunities for data-driven surgical education and quality assessment. Automated surgical phase recognition enables objective trainee evaluation, standardized competency assessment, and systematic procedural documentation. However, class imbalance in surgical workflows, where certain phases comprise 30–35% of frames while others represent only 5–10%, remains a significant challenge. This imbalance causes models to underperform on underrepresented yet clinically important phases. Methods: A retrospective analysis of laparoscopic cholecystectomy videos is performed with the implementation of a frame—based deep learning framework to develop and validate a surgical phase recognition pipeline based on ResNet-50 architecture with transfer learning. The model was designed to extract features from surgical video frames and classify them into seven distinct phases, without incorporating temporal context. We used the Cholec80 dataset and applied class balancing techniques to address inherent class imbalance. Results: The model achieved a mean balanced accuracy of 91.80% across five folds with consistent performance across all surgical phases. Per-phase F1-scores ranged from 0.89 to 0.95, demonstrating balanced classification without significant performance degradation on underrepresented phases. The confusion matrix revealed prediction errors primarily among adjacent or visually similar phases, reflecting the inherent ambiguity of surgical phase transitions. In practical terms, the model correctly identified the surgical phase in more than 9 out of 10 frames, enabling reliable automated segmentation of the operative workflow. Conclusions: This study demonstrates that artificial intelligence can reliably analyze surgical video data, achieving consistent and accurate phase recognition in laparoscopic cholecystectomy.