Cytokeratins and dermatology

Clinical, Dermoscopic, and Molecular Features of Acantholytic Squamous Cell Carcinoma: A Systematic Review

INTRODUCTION

Acantholytic squamous cell carcinoma (aSCC) is a rare clinicopathological subtype of cutaneous squamous cell carcinoma, accounting for approximately 4.9% of all SCC cases. However, there are currently no standardized criteria for the diagnosis of aSCC. This systematic review is the first to summarize the clinical and molecular features of aSCC.

METHODS

A systematic search of Medline, Embase, Scopus, and PubMed was performed. All articles in English or French were included, with no restriction of publication date. All articles with original data pertaining to clinical or molecular characteristics of aSCC were included. Two reviewers screened articles and resolved conflicts.

RESULTS

Our systematic review included 52 studies on the clinical and molecular features of aSCC, including a total of 482 patients (76% male, mean age at diagnosis 68.9 years): 430 cases assessed clinical features, while 149 cases assessed molecular features. The most common location of aSCC was the head and neck (n = 329/430; 76.5%). In terms of morphology, most lesions were described as nodules (n = 93/430, 21.6%), with common surface changes being hyperkeratosis (n = 6), erosion (n = 6), ulceration (n = 5), and crusting (n = 3). With regard to dermoscopy, only six cases were noted in the literature, including findings such as ulceration (n = 3), keratin clots (n = 2), and erosions (n = 2). Thirty-four studies discussed the molecular markers of aSCC, with the most prevalent markers being cytokeratins. CD15 negativity was noted in 23 cases, while common endothelial vascular markers such as CD34 (n = 16), CD31 (n = 15), factor VIII-related antigen (n = 10), and ERG (n = 1) were often not expressed. Finally, expression of intracellular adhesion molecules (i.e., E-cadherin, CD138) was markedly decreased compared to non-acantholytic invasive SCC.

CONCLUSIONS

This systematic review summarizes the clinical characteristics and molecular features of aSCC. As clinical differentiation can be difficult, clinicopathological correlation with molecular markers may help ensure proper diagnosis.

Evaluation of cytokeratin 19 as a prognostic tumoral and metastatic marker with focus on improved detection methods

In the last few years, there has been a growing interest in Cytokeratin 19 (CK19) studies in the cancer research field. CK19 belongs to the Type I CKs, serves as a useful research tool in prognosis, diagnosis, and management of the tumors. In this paper, we dissect the metastatic potential of CK19, its relation with cancer stem cells and retinal epithelial cells behavior, its application as a tumor marker and its role among 30 cancers such as thyroid, thoracic, lung, pancreatic, cervical, colorectal, and so forth. CK19 expressed in several cancer types because of its metastatic potential. This paper also presents modified detection methods of CK19 in disseminated tumor cells.

Epithelial and stromal developmental patterns in a novel substitute of the human skin generated with fibrin-agarose biomaterials

Development of human skin substitutes by tissue engineering may offer new therapeutic alternatives to the use of autologous tissue grafts. For that reason, it is necessary to investigate and develop new biocompatible biomaterials that support the generation of a proper human skin construct. In this study, we generated a novel model of bioengineered human skin substitute using human cells obtained from skin biopsies and fibrin-agarose biomaterials and we evaluated this model both at the ex vivo and the in vivo levels. Once the dermal fibroblasts and the epithelial keratinocytes were isolated and expanded in culture, we used fibrin-agarose scaffolds for the development of a full-thickness human skin construct, which was evaluated after 1, 2, 3 and 4 weeks of development ex vivo. The skin substitutes were then grafted onto immune-deficient nude mice and analyzed at days 10, 20, 30 and 40 postimplantation using transmission electron microscopy, histochemistry and immunofluorescence. The results demonstrated that the fibrin-agarose artificial skin had adequate biocompatibility and proper biomechanical properties. A proper development of both the bioengineered dermis and epidermis was found after 30 days in vivo, although the tissues kept ex vivo and those implanted in the animal model for 10 or 20 days showed lower levels of differentiation. In summary, our model of fibrin-agarose skin equivalent was able to reproduce the structure and histological architecture of the native human skin, especially after long-term in vivo implantation, suggesting that these tissues could reproduce the native skin.

Expression of cytokeratins 10, 13, 14 and 19 in oral lichen planus

OLP is a chronic inflammatory disease of unknown etiology that may develop into squamous-cell carcinoma. Cytokeratins, which are important components of the cytoskeleton, are excellent epithelial differentiation markers used to study neoplastic and inflammatory diseases. To study the profile of cytokeratins in OLP and their possible association with dysplastic alterations, monoclonal antibodies were used for cytokeratins 10, 13, 14 and 19, in 26 samples of OLP. The streptavidin-biotin technique was employed in paraffin-embedded tissue sections. Sample analysis revealed suprabasal expression of cytokeratin 10 in 16/17 samples, 14 of them with reduced expression; suprabasal expression of cytokeratin 13 in 18/23, 16 of them with delay; basal and suprabasal expression of cytokeratin 14 in all samples; and focal basal expression of cytokeratin 19 in 4/21. Expression of cytokeratins 10, 13 and 14 was altered in OLP lesions. The inflammatory process and hyperkeratosis or parakeratosis seem to have interfered with the expression of these CKs. Cytokeratin 19 was expressed in the lesions, in a pattern similar to that mentioned in the literature for the non-keratinized oral mucosa. The presence of mild dysplasia did not change the expression of the cytokeratins studied. No differences in pattern of expression were observed between keratinized and non-keratinized areas in the lesions caused by OLP.

Cytokeratin-related loss of cellular integrity is not a major driving force of human intrinsic skin aging

The contribution of extracellular matrix components to intrinsic skin aging has been investigated thoroughly, however, there is little information as to the role of the cytoskeletal proteins in this process. Therefore, we compared the expression of the constituents of the cytoskeleton, keratins 1-23 (K1-K23) as well as junction-plakoglobin (JUP), alpha-tubulin (TUBA), and beta-actin (ACTB) in human foreskins of both young (mean 6.4 years) and aged (mean 54.3 years) individuals. By applying RNA expression analysis to intrinsically aged human skin, we demonstrated that the mRNA levels of the genes for K1, K3, K4, K9, K13, K15, K18, K19 and K20 are downregulated in aged skin, K5 and K14 are unchanged, and K2, K16 and K17 are upregulated in aged skin. The mRNA data were confirmed on the protein level. This diverse picture is in contrast to other cytoskeletal proteins including components of the desmosome (JUP), microtubuli (TUBA) and microfilaments (ACTB) - often regarded as house-keeping genes - that were all reduced in aged skin. These cytoskeletal features of intrinsic aging highlight the importance of the cellular compartment in this process and demonstrate that special attention has to be given to RNA as well as protein normalization in aging studies.