Biomarkers in Cutaneous Keratinocyte Carcinomas

Current and Emerging Insights into the Causes, Immunopathogenesis, and Treatment of Cutaneous Squamous Cell Carcinoma

The increasing incidence of cutaneous squamous cell carcinoma (cSCC), together with the ominous risks of metastasis and recurrence, underscores the importance of identifying novel therapies and validated biomarkers to augment patient management, particularly in the context of well-established and advanced disease. Following a brief overview of the well-recognized epidemiology, clinical features, and diagnosis of cSCC, the current review is focused on risk factors, most prominently excessive exposure to ultraviolet radiation (UVR) as a cause of persistent, pro-tumorigenic mutagenesis, and immune suppression. The next phase of the review encompasses an evaluation of the search for key driver mutations in the pathogenesis of cSCC, including the role of these and other mutations in the formation of immunologically reactive neoepitopes. With respect to additional mechanisms of tumorigenesis, immune evasion is prioritized, specifically the involvement of cell-free and infiltrating cellular mediators of immune suppression. Prominent amongst the former are the cytokine, transforming growth factor-β1 (TGF-β1), the prostanoid, prostaglandin E2, and the emerging immune suppressive nucleoside adenosine. In the case of the latter, tumor-infiltrating and circulating regulatory T cells have been implicated as being key players. The final sections of the review are focused on an update of the immunotherapy of established and advanced disease, as well as on the search for novel, reliable lesional and systemic biomarkers with the potential to guide patient management.

An epidermal serine sensing system for skin healthcare

Portable biosensors mainly focus on detecting biomarkers in biofluids but neglect the abundant skin biomarkers on the stratum corneum, which are associated with the functionality and integrity of the skin barrier. Here, we propose a sensing patch designed for direct sampling and in situ quantification of epidermal serine, an important biomarker for skin healthcare. The patch consists of a porous hydrogel for serine diffusion and ion conduction, and a molecular imprinted polymer-based electrochemical serine sensor. By integrating with a customized handheld serine tester, the serine sensing system enables in situ measurement of epidermal serine levels. We demonstrate the application of this serine sensing system in assessing the moisturizing effect of a skincare product and tracking the recovery progress of skin barrier function in a patient with atopic dermatitis. Our work opens up a potential application scenario for portable biosensors in personalized skin healthcare.

The diagnostic potential of Asprosin and Meteorin-like proteins in basal and squamous cell carcinomas

Non-melanoma skin cancer (NMSC) is the most prevalent malignancy worldwide, encompassing primarily BCC and SCC. Differentiating between these two carcinomas and distinguishing them from normal skin tissue can pose diagnostic challenges in certain cases. Adipokines, as regulators of various biological processes, have garnered attention for their potential roles in tumorigenesis. Asprosin (Asp) and Meteorin-like (Metrnl) are newly identified proteins implicated in several diseases, including cancer. Their potential contribution to the pathogenesis of skin cancers such as BCC and SCC remains underexplored. This study aimed to evaluate the expression profiles of Asp and Metrnl in BCC and SCC and to assess their potential utility as diagnostic biomarkers. The expression of Asp and Metrnl proteins was examined by immunohistochemical staining in biopsy samples from 60 control, 60 BCC, and 60 SCC cases obtained from the archive of the Pathology Laboratory of Malatya Turgut Ozal University Training and Research Hospital. Asp immunoreactivity was higher in BCC tissues compared to the other two groups, and it was statistically higher in SCC tissues compared to healthy control tissues. Metrnl immunoreactivity was also higher in BCC tissues compared to the other two groups, and statistically significant in SCC tissues when compared to healthy control tissues. The findings suggest that Asp and Metrnl proteins may serve as valuable biomarkers for distinguishing between BCC and SCC, the two most common non-melanoma skin cancers encountered in routine dermatopathology practice. These adipokines may also provide insights into the underlying pathophysiology of these malignancies, offering potential avenues for diagnostic and therapeutic advancements.