Nikolaos Lefantzis

Oral squamous cell carcinoma (OSCC) is characterized by consistently high mortality rates (≤60%) despite therapeutic advances. This is attributable to diagnostic delays arising from the asymptomatic early stages and time-consuming protocols. Hence, the establishment of reliable biomarkers for the routine assessment of the oral mucosa is imperative. MicroRNAs (miRNAs), key epigenetic regulators of gene expression, represent ideal candidates given their characteristic dysregulation across different pathologies. Here, we aimed to identify novel OSCC-specific miRNAs for the saliva-based detection of OSCC from the presymptomatic stage of early invasion. Through a multistep bioinformatic workflow, four miRNAs (miR-20b-5p, miR-484, miR-185-5p and miR-181d-5p) were identified as disease-specific since they simultaneously regulated >65% of a panel encompassing the 15 primarily overexpressed oncogenes in OSCC and a stage-specific panel including the six upregulated genes that genetically define the malignant stages of sequential oral carcinogenesis. The salivary expression of the identified miRNAs was studied in 31 OSCC patients and 31 healthy controls, using quantitative real-time PCR, followed by statistical analysis and an evaluation of the diagnostic accuracy. All studied miRNAs were significantly downregulated in the saliva of OSCC patients compared to controls (miR-484, p < 0.001; miR-181d-5p, p < 0.001; miR-185, p = 0.008; miR-20b, p = 0.026) and exhibited combinatory diagnostic performance of 95.4% (p < 0.001) for OSCC detection. Their expression remained uninfluenced by lifestyle and clinicopathological parameters, including smoking/alcohol, tumor site, grade and disease stage. The proposed 4-miRNA panel exhibits high diagnostic performance for the early, saliva-based detection of OSCC, irrespective of histopathological and lifestyle confounders, highlighting its potential as a robust non-invasive screening tool.

Background: Oral squamous cell carcinoma (OSCC) is a highly aggressive neoplasm characterized by grim survival outcomes, despite significant therapeutic advances. Mortality rates (up to 70%) have remained unaltered for decades, predominantly due to profound diagnostic delays. These derive from the asymptomatic nature of the early stages of oral carcinogenesis and the emergence of dysplastic areas in previously benign lesions, acting as the bridge to malignant transformation. Hence, the establishment of reliable salivary biomarkers is crucial for non-invasive OSCC detection, even from the premalignant stage of dysplasia. Based on our previous bioinformatic research identifying stage-specific miRNAs throughout OSCC progression, which yielded miR-34a-5p as the most significant, we aimed to experimentally investigate its role in oral oncogenesis and explore its stage-reflecting biomarker potential for liquid biopsy. Methods: The expression of miR-34a was evaluated using quantitative real-time PCR in saliva samples from 9 patients with oral premalignant dysplastic lesions, 10 patients with OSCC and 10 healthy controls. The diagnostic accuracy of miR-34a expression profiles was assessed using ROC-curve analyses. Results: The expression of salivary miR-34a differed significantly across the studied groups, demonstrating a steep decrease in the presence of epithelial premalignant dysplasia, significant upregulation in OSCC and intermediate levels in normal oral mucosa (p < 0.001). The ROC results indicate strong diagnostic performance for the detection of oral dysplasia (AUC = 0.93; p < 0.001), OSCC (AUC = 0.77; p = 0.01) and excellent accuracy for the discrimination between premalignant and OSCC lesions (AUC = 0.98; p < 0.001). Conclusions: Our findings reveal a state-dependent dysregulation of miR-34a in oral carcinogenesis, suggesting its complex role as a pathogenetic agent that allows for malignant transformation through its diminished expression, and as a secondary reactive mechanism attempting to suppress tumor development. Salivary miR-34a holds great, stage-specific diagnostic potential, thereby reflecting the health state of oral mucosa in real time.

Cutaneous squamous cell carcinoma (cSCC) is a common and increasingly prevalent form of skin cancer, posing significant health challenges. Understanding the molecular mechanisms involved in cSCC progression is crucial for developing effective treatments. The primary aim of this research was to evaluate the activation of NOTCH1 and FGFR2 oncogenes in inducing skin cancer in FVB/N mice through a stepwise chemical process. Forty female FVB/N mice, aged four weeks, were randomly divided into a control group (n = 8) and two experimental groups (group A: n = 16, group B: n = 16). This study involved subjecting the groups to a two-stage carcinogenesis procedure. This included an initial application of 97.4 nmol DMBA on shaved skin on their backs, followed by applications of 32.4 nmol TPA after thirteen weeks for group A and after twenty weeks for group B. The control group did not receive any treatment. Their skin conditions were monitored weekly to detect tumor development. After the experiment, the animals were euthanized for further tissue sampling. The examination of skin lesions in the experimental groups showed a correlation with tumor progression, ranging from dysplasia to carcinoma. Tumor samples were assessed both histologically and immunohistochemically. Notably, FGFR2 expression was higher in benign, precancerous, and malignant tumors compared to normal tissue. NOTCH1 expression was only elevated in benign tumors compared to normal tissue. This study demonstrates a clear correlation of FGFR2 expression and the progression of cutaneous neoplasms, while NOTCH 1 expression is inversely correlated in FVB/N mice. This suggests an early involvement of these oncogenes in the development of skin tumors.

Background: The Mediterranean diet (MD) has been related with a decreased probability of overweight/obesity as well as central obesity at all stages of the human life, decreasing the risk of diverse disease states and improving quality of life. Over the last few years, the prevalence of childhood overweight/obesity and especially abdominal obesity has highly increased worldwide, being associated with a higher likelihood of overweight/obesity as well as central obesity at the next stages of the life during adulthood. The purpose of the present study was to explore the relationship of MD compliance with sociodemographic, anthropometry and lifestyle features in pre-school children aged 2–5 years old. Methods: This is a cross-sectional study, which includes 5188 pre-school children from diverse regions of Greece. Relevant questionnaires were applied to evaluate the sociodemographic features of the enrolled children. Anthropometric parameters were measured by relevant techniques. Qualified questionnaires were utilized for assessing several lifestyle factors such as physical activity, quality of life, breastfeeding practices, MD adherence, as well as the prevalence of childhood asthma and diabetes mellitus type I. Results: Of the enrolled children, 41.7% showed low MD compliance and 36.4% of them indicated moderated compliance, while only 21.9% of them showed a high MD adherence. Overweight/obesity was noted in 24.2% of the assigned children, while abdominal obesity was noticed in 18.2% of them. Higher MD compliance was related with an elevated prevalence of sex (boys, p = 0.0005), Greek nationality (p = 0.0088), rural type of residence (p = 0.0099), childhood overweight/obesity (p < 0.0001) and abdominal obesity (p < 0.0001), lower childbirth weight (p < 0.0001), increased physical activity (p = 0.0041), improved quality of life (p = 0.0008), exclusive breastfeeding (p < 0.0001), childhood asthma (p = 0.0001) and diabetes mellitus type 1 (p = 0.0002). Conclusions: A higher MD adherence is associated with specific sociodemographic, better anthropometric, and beneficial lifestyle factors in pre-school children. However, MD compliance remains low or moderate in the vast majority of children aged 2–5 years old. Thus, future public strategies and policies should be performed to inform parents of the potential beneficial effects of MD against obesity and related chronic diseases at the next stage of their children’s lives.