Expression of Heat Shock Protein 105 in Cutaneous Squamous Cell Carcinoma: Correlation with Clinicopathological Characteristics

Use of HSP105 in the Differential Diagnosis of Basaloid Skin Tumors: A Study of 73 Cases

BACKGROUND

Basaloid skin tumors include subtypes of basal cell carcinoma (BCC) and the basaloid variant of squamous cell carcinoma (SCC). Due to their similarity in pathology and clinical presentation, their diagnosis is not straightforward. The aim of this study was to analyze the immunohistochemical expression of HSP105 in basaloid skin tumors, which include BCC, basosquamous carcinoma (BSC), metatypical basal cell carcinoma (MBCC), basaloid squamous cell carcinoma (BSCC), BCC with squamous differentiation as well as conventional SCC.

METHODS

This retrospective study included 17 cases of BCC, 11 cases of BSC, 8 instances of MBCC, 10 cases of BCC with squamous differentiation, 8 cases of BSCC, and 19 cases of SCC. Their clinical characteristics were summarized, and the paraffin blocks of tumor biopsy specimens were collected for HSP105 immunostaining.

RESULTS

In contrast to the BCC group, which stained predominantly negative, SCC stained diffusely positive for HSP105. BSCs showed some areas of HSP105 positivity with a transitional expression signature. HSP105 was only weakly positive in a few cases of MBCC. Although BSCC was stained positive for HSP105, the HSCORE was significantly lower than that of the classic SCC. In BCC with squamous differentiation, focal staining for HSP105 was only seen in the area of squamous differentiation.

CONCLUSION

There was a difference in immunohistochemical staining of HSP105 in basaloid skin tumors which helps in differential diagnosis. Differentiation between BCC, SCC, BSCC, MBCC, and BCC with squamous differentiation can be aided by immunohistochemistry using HSP105.

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.

Identifying SCC Lesions Capable of Spontaneous Regression by Using Immunohistochemistry: A Systematic Review and Meta-Analysis

INTRODUCTION

Keratoacanthoma (KA) and squamous cell carcinoma (SCC) are two cutaneous conditions with morphological resemblance, which can complicate the diagnosis in some cases. Using immunohistochemistry staining of biomarkers could be beneficial in resolving this obstacle.

OBJECTIVES

We investigated a variety of biomarkers assessed in different studies in order to find the most important and helpful biomarkers for differentiation between SCC and lesions capable of spontaneous regression.

METHODS

MEDLINE via PubMed and Google Scholar database were used to identify relevant literature up to 15 June 2022. The aim of our analyses was to determine the capability of biomarkers to distinguish between SCC and lesions capable of spontaneous regression using calculated individual and pooled odds ratios (OR) and 95% confidence intervals (CI) and I2 tests.

RESULTS

Six potential biomarkers were CD10 with pooled OR= 0.006 (95% CI: 0.001-0.057) and I2=0%; COX-2 with pooled OR=0.089 (95% CI: 0.029-0.269) and I2=17.1%; elastic fibers with pooled OR= 6.69 (95% CI: 2.928-15.281) and I2=0%; IMP-3 with pooled OR=0.145 (95% CI: 0.021-1.001) and I2=44.5%; P53 with pooled OR=0.371 (95% CI: 0.188-0.733) and I2=55.9%; AT1R with OR=0.026 (95% CI: 0.006-0.107).

CONCLUSIONS

We suggest the utilization of the following IHC biomarkers for discrimination between lesions with spontaneous regression such as KA and SCC: CD10, COX-2, and elastic fibers.

HSP105 suppresses the progression of cutaneous squamous cell carcinoma by activating the P53 signaling pathway

Cutaneous squamous cell carcinoma (cSCC) is a common type of nonmelanoma skin cancer with a very high incidence. Heat shock proteins (HSPs) are involved in abnormal proliferation, invasion and apoptosis of tumor cells. Whether HSP105 acts as a promoter or inhibitor of cSCC remains to be further explored. This study investigated the biological role of HSP105 in the progression of cSCC. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of HSP105 in cSCC cell lines. Cell lines with overexpression and knockdown of HSP105 were established to analyze their cell cycle distribution, proliferation, apoptosis, migration, invasion and biological mechanisms. Finally, the proliferative effect of HSP105 in cSCC cells was verified in nude mice. We found that HSP105 expression was decreased in cSCC cell lines. Overexpression of HSP105 in A431 and SCL-1 cell lines induced cell cycle arrest and apoptosis, inhibited cell proliferation, reduced cell migration and invasion, and inhibited tumor growth in vivo. The opposite result was observed in the HSP105-silenced cell lines. Furthermore, HSP105 activated the P53 signaling pathway and exerted anticancer effects. Our findings provide new perspectives on the critical role and potential mechanisms of HSP105 in the development of cSCC, suggesting that HSP105 may be a novel therapeutic target for cSCC.

The Contributions of Cancer-Testis and Developmental Genes to the Pathogenesis of Keratinocyte Carcinomas

Simple Summary

In addition to mutations, ectopically-expressed genes are emerging as important contributors to cancer development. Efforts to characterize the expression patterns in cancers of gamete-restricted cancer-testis antigens and developmentally-restricted genes are underway, revealing these genes to be putative biomarkers and therapeutic targets for various malignancies. Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are two highly-prevalent non-melanoma skin cancers that result in considerable burden on patients and our health system. To optimize disease prognostication and treatment, it is necessary to further classify the molecular complexity of these malignancies. This review describes the expression patterns and functions of cancer-testis antigens and developmentally-restricted genes in BCC and cSCC tumors. A large number of cancer-testis antigens and developmental genes exhibit substantial expression levels in BCC and cSCC. These genes have been shown to contribute to several aspects of cancer biology, including tumorigenesis, differentiation, invasion and responses to anti-cancer therapy.

Abstract

Keratinocyte carcinomas are among the most prevalent malignancies worldwide. Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are the two cancers recognized as keratinocyte carcinomas. The standard of care for treating these cancers includes surgery and ablative therapies. However, in recent years, targeted therapies (e.g., cetuximab for cSCC and vismodegib/sonidegib for BCC) have been used to treat advanced disease as well as immunotherapy (e.g., cemiplimab). These treatments are expensive and have significant toxicities with objective response rates approaching ~50–65%. Hence, there is a need to dissect the molecular pathogenesis of these cancers to identify novel biomarkers and therapeutic targets to improve disease management. Several cancer-testis antigens (CTA) and developmental genes (including embryonic stem cell factors and fetal genes) are ectopically expressed in BCC and cSCC. When ectopically expressed in malignant tissues, functions of these genes may be recaptured to promote tumorigenesis. CTAs and developmental genes are emerging as important players in the pathogenesis of BCC and cSCC, positioning themselves as attractive candidate biomarkers and therapeutic targets requiring rigorous testing. Herein, we review the current research and offer perspectives on the contributions of CTAs and developmental genes to the pathogenesis of keratinocyte carcinomas.