Expression and glycosylation of MUC1 in epidermolysis bullosa-associated and sporadic cutaneous squamous cell carcinomas

BACKGROUND: Cutaneous squamous cell carcinoma (SCC) is particularly problematic in certain patient groups, including patients with dystrophic or junctional epidermolysis bullosa (DEB/JEB). Theoretically, vaccination against a cell surface antigen which is expressed on this type of tumour could prevent SCC development, as well as treat primary and metastatic disease in this patient group. Preliminary studies have suggested that MUC1, a transmembrane glycoprotein, is overexpressed in sporadic cutaneous SCCs, and MUC1 has been used with some success as a target antigen for vaccine development in breast cancer, where it is expressed on > 50% of neoplastic cells in approximately 50-80% of tumours. Furthermore, aberrant glycosylation of MUC1 has been detected in this and other cancer types; however, the glycosylation status of MUC1 in cutaneous SCC is not known. OBJECTIVES: To investigate the expression and glycosylation status of MUC1 in SCCs arising in patients with DEB and JEB, and for comparison in sporadic SCCs and sporadic Bowen's disease. METHODS: Immunohistochemical analysis of MUC1 in 30 SCCs from subjects with DEB/JEB, 55 sporadic SCCs and 30 sporadic lesions of Bowen's disease was carried out using four separate monoclonal antibodies which recognize different isoforms of MUC1. RESULTS: Expression of MUC1 was detected in 100% of SCCs arising in patients with DEB and JEB; > 50% of neoplastic cells stained positive for MUC1 in 57% of DEB/JEB SCCs, with over 95% of tumour cells immunopositive in 33% of cases. MUC1 expression was also observed in 95% of sporadic SCCs and 97% of Bowen's disease, with 36% of sporadic SCCs immunopositive for MUC1 in > 50% of tumour cells. Investigation of the glycosylation status showed that MUC1 was predominantly hyperglycosylated in the DEB/JEB and sporadic tumours. CONCLUSIONS: The results demonstrate that a significant proportion of DEB/JEB and sporadic SCCs express MUC1 in > 50% of tumour cells. Therefore, MUC1 may be a suitable candidate antigen against which to develop a tumour vaccine for these patient groups.     

Expression of matrix metalloproteinase (MMP)-7 and MMP-13 and loss of MMP-19 and p16 are associated with malignant progression in chronic wounds

BACKGROUND: The risk of squamous cell carcinoma (SCC) is significantly increased in chronic leg ulcers. Very little is known about the molecular pathogenesis of these tumours, which are often undiagnosed for a long time. As matrix metalloproteinases (MMPs) are implicated at all stages of tumorigenesis, we investigated whether the pattern of epithelial MMP expression can predict development of SCC from pseudoepitheliomatous hyperplasia of chronic wounds. METHODS: Samples from nine patients with SCCs that had arisen in chronic wounds and 31 with venous leg ulcers were studied using immunohistochemistry for MMP-7, MMP-8, MMP-9, MMP-13, MMP-19 and the tumour suppressor p16. In situ hybridization was performed for MMP-1, MMP-3, MMP-7, MMP-12 and MMP-13. RESULTS: MMP-7 was expressed by malignantly transformed epithelium, while it was absent from chronic wounds. MMP-9 was detected in the epithelium in both SCCs and chronic wounds. Epithelial MMP-13 expression was strong in SCC, but was absent in chronic wounds. MMP-12 was expressed in the epithelium in two SCCs, while macrophages were positive in chronic wounds. MMP-19 was induced in proliferating epithelium of wounds, but was absent from invasive areas of SCC. p16 was expressed by keratinocytes in half of the chronic wounds and at superficial margins of SCCs, while invasive areas were negative. CONCLUSIONS: Our results suggest that epithelial expression of MMP-7, MMP-12 and MMP-13, but not that of MMP-1, MMP-3, MMP-8, MMP-9 and MMP-10, in chronic wounds provides a diagnostic clue for distinguishing SCCs from nonmalignant wounds. The loss of MMP-19 and p16 from the epithelium could aid in making the differential diagnosis between well-differentiated SCCs and nonmalignant chronic wounds.     

Matrix metalloproteinases in keratinocyte carcinomas

The incidence of cutaneous keratinocyte‐derived cancers is increasing globally. Basal cell carcinoma (BCC) is the most common malignancy worldwide, and cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer. BCC can be classified into subtypes based on the histology, and these subtypes are classified further into low‐ and high‐risk tumors. There is an increasing need to identify new therapeutic strategies for the treatment of unresectable and metastatic cSCC, and for aggressive BCC variants such as infiltrating, basosquamous or morpheaform BCCs. The most important risk factor for BCC and cSCC is solar UV radiation, which causes genetic and epigenetic alterations in keratinocytes. Similar gene mutations are noted already in sun‐exposed normal skin emphasizing the role of the alterations in the tumor microenvironment in the progression of cSCC. Early events in cSCC progression are alterations in the composition of basement membrane and dermal extracellular matrix induced by influx of microbes, inflammatory cells and activated stromal fibroblasts. Activated fibroblasts promote inflammation and produce growth factors and proteolytic enzymes, including matrix metalloproteinases (MMPs). Transforming growth factor‐β produced by tumor cells and fibroblasts induces the expression of MMPs by cSCC cells and promotes their invasion. Fibroblast‐derived keratinocyte growth factor suppresses the malignant phenotype of cSCC cells by inhibiting the expression of several MMPs. These findings emphasize the importance of interplay of tumor and stromal cells in the progression of cSCC and BCC and suggest tumor microenvironment as a therapeutic target in cSCC and aggressive subtypes of BCC.     

Significance of sentinel node biopsy in the management of squamous cell carcinoma arising from recessive dystrophic epidermolysis bullosa

The most life-threatening complication developing in patients with recessive dystrophic epidermolysis bullosa (RDEB) is squamous cell carcinoma (SCC). To improve patient prognosis, early detection of regional lymph node metastasis is required. Herein, we report a patient diagnosed with non-Hallopeau-Siemens RDEB who developed SCC on the left foot with inguinal lymph node swelling. Use of the sentinel node biopsy (SNB) technique favorably minimized defective damage to the inguinal region in this case. Genetic analysis identified one novel COL7A1 mutation, a maternal c.238G > C (p.A80P) and one previously reported mutation, a paternal c.3631C > T (p.Q1211X). A published work review demonstrated that no COL7A1 mutations specific for SCC development in RDEB have previously been identified. It remains unclear if SNB in combination with gene diagnosis is beneficial for the management of SCC in RDEB patients, however, because of the limited number of case reports. To address this issue, COL7A1 mutational analysis should be performed in as many cases of RDEB as possible.     

Squamous cell carcinoma in a family with dominant dystrophic epidermolysis bullosa: a molecular genetic study

Squamous cell carcinoma in a family with dominant dystrophic epidermolysis bullosa: a molecular genetic study Squamous cell carcinoma (SCC) is a frequent complication in the severe, recessively inherited forms of dystrophic epidermolysis bullosa (RDEB), however, only rarely reported in dominant DEB. Although the SCCs in RDEB are frequently well-differentiated by histopathology, they often have a poor prognosis due to multicentricity, rapid invasiveness, and development of distant metastases. In this study, we sought to determine the molecular basis of DDEB in a family with the unusual occurrence of SCCs. Specifically, a large DDEB family with 2 individuals being affected with SCC was analyzed for potential mutations in the type VII collagen gene (COL7A1) by heteroduplex scanning and direct nucleotide sequencing of PCR amplified segments of the gene. This mutation detection strategy disclosed a G-->A transition at nucleotide position 6,235 which resulted in substitution of a glycine by arginine within the collagenous region of COL7A1. This study establishes, for the first time, the molecular basis in a family with DDEB/SCC. Clinically, this study reemphasizes the importance of vigilance in surveying DEB patients, not only those with recessive but also with dominant inheritance, for SCC.     

Matrix metalloproteinase‐7 activates heparin‐binding epidermal growth factor‐like growth factor in cutaneous squamous cell carcinoma

Background Tumour‐specific expression of matrix metalloproteinase (MMP)‐7 has been noted in cutaneous squamous cell carcinomas (SCCs) in patients with recessive dystrophic epidermolysis bullosa (RDEB). Objectives To examine the potential role of MMP‐7 in shedding of heparin‐binding epidermal growth factor‐like growth factor (HB‐EGF) in RDEB‐associated and sporadic SCCs. Methods Tissue microarrays of RDEB‐associated SCC (n = 20), non‐EB SCC (n = 60) and Bowen disease (n = 28) were immunostained for MMP‐7, CD44 variant 3 (CD44v3) and HB‐EGF. Shedding of HB‐EGF was studied in vitro using two cutaneous SCC cell lines. Results Immunohistochemical analysis showed that HB‐EGF was absent in tumour cells when MMP‐7 and CD44v3 colocalized, and that the absence of HB‐EGF was more pronounced in RDEB‐associated SCCs than in non‐EB SCCs. The loss of HB‐EGF in MMP‐7–CD44v3 double‐positive areas was interpreted to indicate shedding and activation of HB‐EGF; this was also detected in Bowen disease indicating its importance in the early phase of SCC development. Specific knockdown of MMP‐7 expression in human cutaneous SCC cells by small interfering RNA inhibited shedding of HB‐EGF and resulted in diminished activation of the EGF receptor (EGFR) and ERK1/2, and in reduced proliferation of SCC cells. Conclusions These findings provide evidence for the role of MMP‐7 in promoting the growth of cutaneous SCCs by shedding HB‐EGF, and identify EGFR signalling as a potential therapeutic target in RDEB‐associated SCC and unresectable sporadic cutaneous SCC.     

上皮型钙黏附素和基质金属蛋白酶-9在皮肤鳞状细胞癌中的表达及其意义

目的：探讨上皮型钙黏附素（E—cadhenn）和基质金属蛋白酶（MMP）-9在皮肤鳞状细胞癌（CSCC）中的表达及与CSCC转移的关系。方法：应用免疫组化SP法检测E—cadherin和MMP-9在10例正常皮肤组织和43例CSCC组织中的表达。结果：E—cadherin在43例CSCC中有30例（69．7％）表达减弱或表达缺失,31例无淋巴结转移的CSCC组织中19例（61．3％）表达减弱或缺失,12例有淋巴结转移的CSCC组织中11例（91．7％）表达减弱或缺失。MMP-9在43例CSCC中有34例（79．1％）有阳性表达,31例无淋巴结转移的CSCC组织中23例（74．2％）有阳性表达,12例有淋巴结转移的CSCC组织中11例（91．7％）有阳性表达。MMP-9的表达升高和E—cadherin的表达缺失呈显著负相关r=-0．315,P=0．04）。结论：E—cadherin表达下调和MMP-9表达升高可能与CSCC的浸润和转移有关。     

Epidermal aspects of type VII collagen: Implications for dystrophic epidermolysis bullosa and epidermolysis bullosa acquisita

Type VII collagen (COL7), a major component of anchoring fibrils in the epidermal basement membrane zone, has been characterized as a defective protein in dystrophic epidermolysis bullosa and as an autoantigen in epidermolysis bullosa acquisita. Although COL7 is produced and secreted by both epidermal keratinocytes and dermal fibroblasts, the role of COL7 with regard to the epidermis is rarely discussed. This review focuses on COL7 physiology and pathology as it pertains to epidermal keratinocytes. We summarize the current knowledge of COL7 production and trafficking, its involvement in keratinocyte dynamics, and epidermal carcinogenesis in COL7 deficiency and propose possible solutions to unsolved issues in this field.     

Anchorless keratinocyte survival: an emerging pathogenic mechanism for squamous cell carcinoma in recessive dystrophic epidermolysis bullosa

Squamous cell carcinomas in patients suffering from recessive dystrophic epidermolysis bullosa are highly invasive and frequently metastatic. Expression of a collagen VII fragment (NC1) has been described as a prerequisite for the development of this tumor form. This commentary focuses on potential molecular mechanisms by which expression of the NC1 fragment may augment anchorage-independent growth and survival of malignant keratinocytes.     

Squamous cell carcinoma developing in a 12-year-old boy with nonHallopeau-Siemens recessive dystrophic epidermolysis bullosa

We report a 12-year-old boy with nonHallopeau-Siemens recessive dystrophic epidermolysis bullosa (nHS-RDEB) who developed two skin lesions of squamous cell carcinoma (SCC) on the left foot. The incidence of SCC in nHS-RDEB is much lower than in the HS-RDEB subtype. Furthermore, this boy is the youngest among 92 previously described patients with DEB to develop SCC. This study emphasizes the importance of vigilance in monitoring the possible development of SCC in DEB patients regardless of age or clinical severity.     

Cutaneous undifferentiated small (Merkel) cell carcinoma,that developed synchronously with multiple actinic keratoses,squamous cell carcinomas and basal cell carcinoma

Merkel Cell Carcinoma (MCC) is an uncommon undifferentiated neuroendocrine tumor, arising in skin mainly on sun-exposed areas. We present an unusual case of primary cutaneous undifferentiated small cell carcinoma that co-existed with six other lesions; 2 actinic keratoses, 3 squamous-cell carcinomas and a basal-cell carcinoma. HE stained sections revealed MCC located in the mid-dermis, co-existing with severe actinic keratosis. Immunohistochemically, the tumor cells reacted to cytokeratin 20, epithelial membrane antigen, chromogranin and neuron specific enolase. This is an unusual case of cutaneous MCC co-existing with six other different lesions. The concurrent development of MCC, squamous-cell and basal-cell carcinoma in the same patient indicates the pluripotent epidermal stem cell origin of these tumors. Further research is needed to enlighten the factors inducing this divergent differentiation.     

Dominant dystrophic epidermolysis bullosa caused by a novel G2037R mutation and by a known G2028R mutation in the type VII collagen gene (COL7A1)

An autosomal dystrophic epidermolysis bullosa (DDEB) is a hereditary mechanobullous disease characterized by blistering of the skin and the mucous membrane. DDEB is caused by a heterozygous mutation in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils, and phenotypically classified into several types. We experienced two boys with DDEB and examined the mutation analyses of the COL7A1 genes of the two patients and their fathers to clarify the relationship between the genotypes and phenotypes, that is, the mutation sites of COL7A1 gene and the clinical types of DDEB. The case 1 and 2 patients and their fathers revealed a heterozygous nucleotide G to A transition at position 6109 and 6082 in 73 exon of COL7A1, which resulted in a glycine to arginine substitution (G2037R and G2028R), respectively. G2037R found in the case 1 patient was a novel mutation. There was no clear relationship recognized between the two mutation sites in the COL7A1 gene and the clinical variations.     

Increased Fas ligand expression by T cells and tumour cells in the progression of actinic keratosis to squamous cell carcinoma

BACKGROUND: In the counterattack model of tumorigenesis, it has been proposed that tumours develop resistance to attack from Fas ligand (FasL)-expressing cytotoxic T cells by downregulating Fas (immune escape), while at the same time upregulating FasL expression to induce apoptosis in Fas-expressing T cells (counterattack). OBJECTIVES: The aim of this study was to examine Fas and FasL expression on tumour cells and infiltrating T cells during the progression of actinic keratoses (AK), the benign precursor lesion, to squamous cell carcinoma (SCC). PATIENTS AND METHODS: Samples of AK (n = 20) and SCC (n = 20) were collected from immunocompetent patients attending dermatology clinics. Double-label immunohistochemistry was performed on frozen sections using mouse monoclonal antibodies to Fas or FasL, simultaneously with a rabbit polyclonal antibody to either CD3 or cytokeratin, markers of T cells and keratinocytes, respectively. Cell densities and the optical density of tumour Fas expression were measured using image analysis. RESULTS: FasL-expressing T cells were observed in nine of 19 SCCs, compared with three of 20 AKs (P < 0.05). FasL-expressing tumour cells were found in nine of 18 SCCs, compared with only one of 20 AK specimens (P < 0.005). There was no difference in the number of Fas-expressing T cells infiltrating AK and SCC. Fas expression by keratinocytes, measured by optical density, was lower in SCC (range 0.1-40, median 17) compared with AK (range 4-62, median 25) (P < 0.05). CONCLUSIONS: These results suggest that the greater numbers of FasL-expressing T cells infiltrating into SCC compared with AK are targeting Fas-expressing tumour cells. As AK cells progress to SCC, they subvert this T-cell-mediated killing of tumour cells by downregulating their Fas expression (immune escape). Furthermore, tumour cells upregulate their expression of FasL, possibly as a counterattack measure to induce apoptosis in the increased number of tumour-infiltrating T cells. Thus changes in Fas/FasL-mediated interactions between T cells and tumour cells occur during the progression of AK into SCC.     

Expression of apoptosis-inducing factor (AIF) in keratoacanthomas and squamous cell carcinomas of the skin

The complex biological trait 'susceptibility to apoptosis' is a nosological feature distinguishing squamous cell carcinomas (SCC) from keratoacanthomas (KA). The purpose of this study was to compare the expression of apoptosis-inducing factor (AIF), a major effector of the caspase-independent apoptosis pathway, in formalin-fixed SCC (N = 23) and KA (N = 29) resection specimens. SCC express statistically significant more AIF than KA both as proportion of AIF+ cells by immunohistochemistry (median: 54% vs 33%; P < 0.01) and as total AIF protein content by western blot quantification (six-fold increased; P < 0.01). However, the contribution of AIF to apoptosis, measured as fraction of apoptotic nuclei with overt DNA fragmentation by the TUNEL method that co-express AIF translocated to nucleus, is significantly less prevalent among SCC (median: 19% vs 48% in KA; P < 0.01). These findings indicate to a distinctive involvement of AIF in the progression of certain epithelial skin tumors that might be exploited as a promising treatment target.     

MicroRNA expression differs in cutaneous squamous cell carcinomas and healthy skin of immunocompetent individuals

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin cancers, but the influence of microRNA (miRNA) expression has only been sporadically analysed. We hypothesized that miRNAs are differentially expressed in cSCC and hence influence its development. We therefore isolated total miRNA from well‐differentiated cSCCs and from controls without SCC. Expression analyses of 12 miRNAs showed three significantly differentially expressed miRNAs. We identified a significant upregulation of the miR‐21 and the miR‐31, a proto‐oncogene like miR‐21. While the upregulated expression of miR‐21 has been known for some time, the increased expression of miR‐31 was never shown so clearly. Furthermore, we showed the upregulation of miRNA‐205, which has never been described before. The miR‐205 induces specific keratinocyte migration and could be a characteristic marker for cSCC. It has to be determined in following studies whether these upregulated expressions are specific for cSCC and if so, for which cSCC stages.