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  • Author: Maja Milošević x
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TP53 and C-MYC Co-Alterations – A Hallmark of Oral Cancer Progression / SIMULTANA ALTERACIJA TP53 I C-MYC GENA – OBELEŽJE PROGRESIJE ORALNIH KARCINOMA

Summary

Background: Head and neck squamous cell carcinoma, including oral cancer, is the sixth most common cancer worldwide. Despite advances in surgery and treatment, the 5-year survival rate has not improved significantly. There- fore, reliable molecular markers for oral cancer progression are badly needed.

Methods: We conducted a copy number analysis to esti- mate amplification status of c-myc, cycD1 and EGFR onco- genes, mutational PCR-SSCP analysis to determine activa- tion of H-ras oncogene and inactivation of TP55 tumour suppressor gene and methylation specific PCR analysis to evaluate hypermethylation of p16 and MGMT genes.

Results: c-myc oncogene was amplified in 56.7%, cycD1 in 20% and EGFR in 16.7% of Oral Squamous Cell Carci- noma (OSCC) cases while H-ras was activated in 33.3% of samples. Amplification of c-myc was significantly associat- ed with the tumour grade 2. Interestingly, EGFR and H-ras alterations were mutually exclusive. p16 and MGMT were inactivated by hypermethylation in 30% and 13.3% of cases. Co-alteration of cycD1 and p16 were not observed in any of the analyzed samples. TP53 was inactivated in 56.7% of samples and was significantly associated with progression of OSCC, grade 2 and stage 2. Moreover, TP55 and c-myc oncogene were simultaneously altered in grade 2 OSCC.

Conclusions: The most promising marker of OSCC pro- gression remains the TP53 tumour suppressor, which is the most frequently mutated gene in oral cancers. Since there is synergism between TP55 and c-myc, it seems that co- alteration of these two genes could be also a good marker of OSCC progression from gradel to grade 2 tumours.

Open access
Morphofunctional Characteristics of Pituitary Adrenocorticotropes in An Animal Model of Heat Stress

Morphofunctional Characteristics of Pituitary Adrenocorticotropes in An Animal Model of Heat Stress

As a result of the global warming, the average ambient temperature during summertime has increased in regions with moderate continental cli mate. The effects of 24 h exposure to heat stress (35±1 °C) on the morphology and function of pituitary adrenocorticotropes were examined in adult male Wistar rats. Significant changes in the morphofunctional features of adrenocorticotropes were found after the heat stress, with no differences noted in the cell shape or localization, compared to controls. The adrenocorticotropes cell volume, as well as the volume density, were significantly decreased (p<0.05) by 12.3% and 26.7%, respectively, in comparison with controls. The concentration of plasma adrenocorticotropic hormone and serum corticosterone in the heat stressed group were significantly decreased (p<0.05) by 21.9% and 27.2%, respectively, compared to controls. These findings suggest that 24 h exposure of adult male rats to heat stress has an inhibitory effect on the morphofunctional characteristics of adrenocorticotropes.

Open access
Manufacturing of Biodegradable Scaffolds to Engineer Artificial Blood Vessel

Abstract

Blood vessels diseases such as cardiac infarction with coronary artery occlusion, peripheral arterial disorders, or stroke of carotid or cerebral arteries, are the leading causes of death in the world. One of medical procedures for clinical treatment of vascular diseases is the blood vessels grafting. As the autologous blood vessels, which are the “golden standard” for coronary grafting, are not always suitable for blood vessels grafting, there is a need to develop artificial blood vessels as a vascular prostheses, either from natural and synthetic materials, permanent synthetic or biodegradable scaffolds which would be suitable for vascular grafts. Considering this to be our study goal we made bilayered biodegradable polycaprolactone scaffolds with different properties and evaluated their morphological and biomechanical characteristics.

Open access
Cytotoxic Effects of Different Aromatic Plants Essential Oils on Oral Squamous Cell Carcinoma- an in vitro Study

Summary

Background/Aim: Current approaches in therapy of head and neck cancers are surgery, radiotherapy and chemotherapy. However, recurrence, development of multidrug resistance, side effects, and high costs of therapy are significant problems which point to the need for more efficient and less toxic drugs and interventions.

Material and Methods: Eight essential oils obtained from Thymus serpyllum, Mentha piperita, Juniperus communis, Rosmarinus officinalis, Melissa officinalis, Achillea millefolium, Zingiber officinale, and Helichrysum arenarium were tested for their anti-proliferative on oral squamous cell carcinoma (OSCC) culture and SCC-25 cell line. Cytotoxicity assays (MTT and Neutral red) were used to detect the effect of the mentioned essential oils.

Results: T. serpyllum, M. piperita, J. communis, and R. officinalis essential oils exhibited the best anti-proliferative effect, on both types of cells. M. piperita had the greatest effect on SCC-25 cell line (4,5% of viable cells) and OSCC cells (7,2% of viable cells). Overall, cytotoxicity was higher in OSCC than in SCC-25 cell line.

Conclusions: This study showed a clear anti-proliferative effect of four essential oils, in vitro making them novel potential antineoplastic agents.

Open access