Low-Molecular-Weight Hydrophilic and Lipophilic Antioxidants in Nonmelanoma Skin Carcinomas and Adjacent Normal-Looking Skin

Type I Diabetes Mellitus Suppresses Experimental Skin Carcinogenesis

This study explores the previously uncharted territory of the effects of ultraviolet (UV) radiation on diabetic skin, compared to its well-documented impact on normal skin, particularly focusing on carcinogenesis and aging. Employing hairless SKH-hr2, Type 1 and 2 diabetic, and nondiabetic male mice, the research subjected these to UV radiation thrice weekly for eight months. The investigation included comprehensive assessments of photoaging and photocarcinogenesis in diabetic versus normal skin, measuring factors such as hydration, trans-epidermal water loss, elasticity, skin thickness, melanin, sebum content, stratum corneum exfoliation and body weight, alongside photo documentation. Additionally, oxidative stress and the presence of hydrophilic antioxidants (uric acid and glutathione) in the stratum corneum were evaluated. Histopathological examination post-sacrifice provided insights into the morphological changes. Findings reveal that under UV exposure, Type 1 diabetic skin showed heightened dehydration, thinning, and signs of accelerated aging. Remarkably, Type 1 diabetic mice did not develop squamous cell carcinoma or pigmented nevi, contrary to normal and Type 2 diabetic skin. This unexpected resistance to UV-induced skin cancers in Type 1 diabetic skin prompts a crucial need for further research to uncover the underlying mechanisms providing this resistance.

Protective effect of phosphorylated Athyrium multidentatum (Doll.) Ching polysaccharide on vascular endothelial cells in vitro and in vivo

The purpose of this study was to prepare phosphorylated Athyrium multidentatum (Doll.) Ching polysaccharide (PPS) and investigate its protective effect on vascular endothelial cells (VECs) in vitro and in vivo and the underlying mechanisms. Sodium tripolyphosphate (STPP) and sodium trimetaphosphate (STMP) were used as phosphorylation reagents and PPS was characterized by Fourier transform infrared (FT-IR), 13 C nuclear magnetic resonance (13 C NMR) and 31 P nuclear magnetic resonance (31 P NMR) spectra. Chemical analysis demonstrated that PPS was composed of mannose, glucosamine, rhamnose, glucuronic acid, galacturonic acid, galactosamine, glucose, galactose, xylose, arabinose, and fucose with a molar ratio of 11.36:0.42:4.03:1.12:1.81:0.26:33.25:24.12:6.85:14.46:2.32 and a molecular weight of 28,837 Da. Results from in vitro and in vivo assays revealed that PPS protected human umbilical vein endothelial cells (HUVECs) against H2 O2 -induced oxidative injury and attenuated D-galactose-induced VECs damage in mice. RNA sequencing (RNA-seq) analysis identified 18 differentially expressed genes (DEGs) between D-galactose-treated and PPS-pretreated mice abdominal aorta. A deep analysis of these DEGs disclosed that PPS regulated the expression of genes involved in the functions of vascular endothelium repairment, cell growth and proliferation, cell survival and apoptosis, inflammation, angiogenesis and antioxidant, indicating that these biological processes might play crucial roles in the protective actions of PPS on VECs.

Approaches and Methods to Measure Oxidative Stress in Clinical Samples: Research Applications in the Cancer Field

Reactive oxygen species (ROS) are common by-products of normal aerobic cellular metabolism and play important physiological roles in intracellular cell signaling and homeostasis. The human body is equipped with antioxidant systems to regulate the levels of these free radicals and maintain proper physiological function. However, a condition known as oxidative stress (OS) occurs, when ROS overwhelm the body's ability to readily detoxify them. Excessive amounts of free radicals generated under OS conditions cause oxidative damage to proteins, lipids, and nucleic acids, severely compromising cell health and contributing to disease development, including cancer. Biomarkers of OS can therefore be exploited as important tools in the assessment of disease status in humans. In the present review, we discuss different approaches used for the evaluation of OS in clinical samples. The described methods are limited in their ability to reflect on OS only partially, revealing the need of more integrative approaches examining both pro- and antioxidant reactions with higher sensitivity to physiological/pathological alternations. We also provide an overview of recent findings of OS in patients with different types of cancer. Identification of OS biomarkers in clinical samples of cancer patients and defining their roles in carcinogenesis hold great promise in promoting the development of targeted therapeutic approaches and diagnostic strategies assessing disease status. However, considerable data variability across laboratories makes it difficult to draw general conclusions on the significance of these OS biomarkers. To our knowledge, no adequate comparison has yet been performed between different biomarkers and the methodologies used to measure them, making it difficult to conduct a meta-analysis of findings from different groups. A critical evaluation and adaptation of proposed methodologies available in the literature should therefore be undertaken, to enable the investigators to choose the most suitable procedure for each chosen biomarker.

Infrared and Raman Spectroscopic Studies of Molecular Disorders in Skin Cancer

AIM

To investigate the molecular structural disorders of cancerous skin.

MATERIALS AND METHODS

Human malignant melanoma and basal cell carcinoma biopsies were used for the investigation. Fourier transform infrared (FT-IR), Raman spectroscopy, and scanning electron microscopy were utilized. Spectral differences between healthy, basal cell carcinoma and melanoma tissues were recorded.

RESULTS

The FT-IR bands of vasCH2, vsCH2 and Raman vsCH3 of cell membrane lipids were increased in intensity in melanoma due to an increased lipophilic environment. The FT-IR band at 1,744 cm-1 assigned to malondialdehyde can be used as a band diagnostic of cancer progression. The amide I bands at 1,654 cm-1 and 1,650 cm-1 for Raman and FT-IR, respectively were broader in spectra from melanoma, reflecting changes of protein secondary structure from α-helix to β-sheet and random coil. The intensity of the FT-IR band at 1,046 cm-1 was increased in melanoma, suggesting glycosylation of the skin upon cancer development. Another band that might be considered as diagnostic was found at about 815 cm-1 in melanoma and was attributed to Z-DNA configuration. As far as we know, this is the first time that scanning electron microscopy revealed that metal components of titanium alloys from tooth implants were transferred to melanoma tissue taken from the back of one patient.

CONCLUSION

Vibrational spectroscopy highlighted increased glycosylation in melanoma.

Electron Spin Resonance (ESR) for the study of Reactive Oxygen Species (ROS) on the isolated frog skin (Pelophylax bergeri): A non-invasive method for environmental monitoring

BACKGROUND

Reactive oxygen species (ROS) in biological tissues of elected biosentinels represent an optimal biomarker for eco-monitoring of polluted areas. Electron spin resonance (ESR) is the most definitive method for detecting, quantifying and possibly identifying radicals in complex systems.

OBJECTIVE

A non-invasive method for monitoring polluted areas by the quantitative determination of ROS in frog skin biopsy is presented.

METHODS

We assessed by ESR spectroscopy the ROS level in adult male of Pelophylax bergeri, specie not a risk of extinction, collected from the polluted Sarno River (SA, Italy) basin. The spin-trap ESR method was validated by immunohistochemical analysis of the well-assessed pollution biomarkers cytochrome P450 aromatase 1A (CYP1A) and glutathione S-transferase (GST), and by determining the poly(ADPribose) polymerase (PARP) and GST enzymatic activity.

RESULTS

ROS concentration in skin samples from frogs collected in the polluted area is significantly higher than that determined for the unpolluted reference area. Immunohistochemical analysis of CYP1A and GST supported the reliability of our approach, even in the absence of evident morphological and ultrastructural differences. PARP activity assay, connected to possible oxidative DNA damage, and the detoxification index by GST enzymatic assay give statistically significant evidence that higher levels of ROS are associated to alterations of the different biomarkers.

CONCLUSIONS

ROS concentration, measured by ESR on isolated frog skin, through the presented non-lethal method, is a reliable biomarker for toxicity screening and represents a useful basic datum for future modelling studies on environmental monitoring and biodiversity loss prevention.

FT-IR Spectroscopy Study in Early Diagnosis of Skin Cancer

BACKGROUND/AIM

Mid-infrared spectroscopy (4000-500 cm^-1) was used to analyze the spectral changes and differences of the characteristic absorption bands of the skin components due to cancer development for early clinical diagnosis.

MATERIALS AND METHODS

Human biopsies from basal cell carcinoma, malignant melanoma, and nevus were used, while normal skin tissue served as a control.

RESULTS

The high quality of Fourier-transform infrared (FT-IR) spectra showed that upon cancer development the intensity of the absorption band at approximately 3062 cm^-1 was increased, indicating that most of the proteins had the configuration of amide B and the β-sheet protein structure predominated. The stretching vibration bands of vCH₂ in the region 2950-2850 cm^-1 were increased in melanoma and nevus, while were less pronounced in basal cell carcinoma due to the increased lipophilic environment. In addition, the intensity of a new band at 1744 cm^-1, which is assigned to aldehyde, was increased in melanoma and nevus and appeared as a shoulder in the spectra of normal skin. The absorption band of amide I at 1650 cm^-1 was split into two bands, at 1650 cm^-1 and 1633 cm^-1, due to the presence of both α-helix and random coil protein conformations for melanoma and nevus. This was confirmed from the amide II band at 1550 cm^-1, which shifted to lower frequencies at 1536 cm^-1 and 1540 cm^-1 for basal cell carcinoma and melanoma, respectively, indicating a damage of the native structure of proteins. The bands at 841 and 815 cm^-1, which are assigned to B-DNA and Z-DNA, respectively, indicated that only the bands of the cancerous Z-DNA form are pronounced in melanoma, while in BCC both the characteristic bands of B-DNA and Z-DNA forms are found.

CONCLUSION

It is proposed that the bands described above could be used as "diagnostic marker" bands for DNA forms, in the diagnosis of skin cancer.