Genetic ablation of caspase-7 promotes solar-simulated light-induced mouse skin carcinogenesis: the involvement of keratin-17

iTRAQ-Based Proteomic Profiling of Potential Biomarkers in Rat Serum for Uranium Tailing Suspension Intratracheal Instillation

Protection against low-dose ionizing radiation is of great significance. Uranium tailings are formed as a byproduct of uranium mining and a potential risk to organisms. In this study, we identified potential biomarkers associated with exposure to low-dose radiation from uranium tailings. We established a Wistar rat model of low dose rate irradiation by intratracheal instillation of a uranium tailing suspension. We observed pathological changes in the liver, lung, and kidney tissues of the rats. Using isobaric tags for relative and absolute quantification, we screened 17 common differentially expressed proteins in three dose groups. We chose alpha-1 antiproteinase (Serpina1), keratin 17 (Krt17), and aldehyde dehydrogenase (Aldh3a1) for further investigation. Our data showed that expression of Serpina1, Krt17, and Aldh3a1 had changed after the intratracheal instillation in rats, which may be potential biomarkers for uranium tailing low-dose irradiation. However, the underlying mechanisms require further investigation.

Alternative Options for Skin Cancer Therapy via Regulation of AKT and Related Signaling Pathways

Global environmental pollution has led to human exposure to ultraviolet (UV) radiation due to the damaged ozone layer, thereby increasing the incidence and death rate of skin cancer including both melanoma and non-melanoma. Overexpression and activation of V-akt murine thymoma viral oncogene homolog (AKT, also known as protein kinase B) and related signaling pathways are major factors contributing to many cancers including lung cancer, esophageal squamous cell carcinoma and skin cancer. Although BRAF inhibitors are used to treat melanoma, further options are needed due to treatment resistance and poor efficacy. Depletion of AKT expression and activation, and related signaling cascades by its inhibitors, decreases the growth of skin cancer and metastasis. Here we have focused the effects of AKT and related signaling (PI3K/AKT/mTOR) pathways by regulators derived from plants and suggest the need for efficient treatment in skin cancer therapy.

Resatorvid-based Pharmacological Antagonism of Cutaneous TLR4 Blocks UV-induced NF-κB and AP-1 Signaling in Keratinocytes and Mouse Skin

Cutaneous exposure to solar ultraviolet (UV) radiation is a major causative factor in skin carcinogenesis, and improved molecular strategies for efficacious chemoprevention of nonmelanoma skin cancer (NMSC) are urgently needed. Toll-like receptor 4 (TLR4) signaling has been shown to drive skin inflammation, photoimmunosuppression, and chemical carcinogenesis. Here we have examined the feasibility of genetic and pharmacological antagonism targeting cutaneous TLR4 for the suppression of UV-induced NF-κB and AP-1 signaling in keratinocytes and mouse skin. Using immunohistochemical and proteomic microarray analysis of human skin, we demonstrate for the first time that a significant increase in expression of TLR4 occurs in keratinocytes during the progression from normal skin to actinic keratosis, also detectible during further progression to squamous cell carcinoma. Next, we demonstrate that siRNA-based genetic TLR4 inhibition blocks UV-induced stress signaling in cultured keratinocytes. Importantly, we observed that resatorvid (TAK-242), a molecularly targeted clinical TLR4 antagonist, blocks UV-induced NF-κB and MAP kinase/AP-1 activity and cytokine expression (Il-6, Il-8, and Il-10) in cultured keratinocytes and in topically treated murine skin. Taken together, our data reveal that pharmacological TLR4 antagonism can suppress UV-induced cutaneous signaling, and future experiments will explore the potential of TLR4-directed strategies for prevention of NMSC.