Immunohistochemical evaluation of epidermis overlying basal cell carcinomas

GLI Transcriptional Targets S100A7 and KRT16 Show Upregulated Expression Patterns in Epidermis Overlying the Tumor Mass in Melanoma Samples

Although not completely understood, the role of the Hedgehog-GLI (HH-GLI) signaling pathway in melanoma and epithelial skin tumors has been reported before. In this study, we confirmed in various melanoma cell line models that keratin 16 (KRT16) and S100 Calcium-Binding Protein A7 (S100A7) are transcriptional targets of GLI Family Zinc Finger (GLI) proteins. Besides their important role in protecting and maintaining the epidermal barrier, keratins are somehow tightly connected with the S100 family of proteins. We found that stronger expression of KRT16 indeed corresponds to stronger expression of S100A7 in our clinical melanoma samples. We also report a trend regarding staining of GLI1, which corresponds to stronger staining of GLI3, KRT16, and S100A7 proteins. The most interesting of our findings is that all the proteins are detected specifically in the epidermis overlying the tumor, but rarely in the tumor itself. The examined proteins were also not detected in the healthy epidermis at the edges of the sample, suggesting that the staining is specific to the epidermis overlaying the tumor mass. Of all proteins, only S100A7 demonstrated a statistically significant trend regarding tumor staging and staining intensity. Results from our clinical samples prove that immune infiltration is an important feature of melanoma. Pigmentophages and tumor-infiltrating lymphocytes (TIL) demonstrate a significant association with tumor stage, while mononuclear cells are equally present in all stages. For S100A7, we found an association between the number of TILs and staining intensity. Considering these new findings presented in our study, we suggest a more detailed examination of the possible role of the S100A7 protein as a biomarker in melanoma.

Adhesion Molecules in Non-melanoma Skin Cancers: A Comprehensive Review

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the most frequently diagnosed cancers, generating significant medical and financial problems. Cutaneous carcinogenesis is a very complex process characterized by genetic and molecular alterations, and mediated by various proteins and pathways. Cell adhesion molecules (CAMs) are transmembrane proteins responsible for cell-to-cell and cell-to-extracellular matrix adhesion, engaged in all steps of tumor progression. Based on their structures they are divided into five major groups: cadherins, integrins, selectins, immunoglobulins and CD44 family. Cadherins, integrins and CD44 are the most studied in the context of non-melanoma skin cancers. The differences in expression of adhesion molecules may be related to the invasiveness of these tumors, through the loss of tissue integrity, neovascularization and alterations in intercellular signaling processes. In this article, each group of CAMs is briefly described and the present knowledge on their role in the development of non-melanoma skin cancers is summarized.

Follicular induction overlying a dermatofibrosarcoma protuberans

The term "induction" has been used to describe epidermal changes overlying a dermatofibroma (DF). Follicular induction is most often associated with DF, but can be observed in other lesions, including focal mucinosis, nevus sebaceous, seborrheic keratosis, wart, neurofibroma, and scars. Dermatofibrosarcoma protuberans (DFSP) is a malignant fibrohistiocytic tumor that may be difficult to distinguish from DF. In contrast to DF, the epidermis overlying DFSP is usually attenuated or ulcerated. Here, we report a case of DFSP exhibiting follicular induction of the overlying epidermis. This epidermal change has been rarely reported in DFSP and may present a diagnostic pitfall in superficially sampled lesions.

The disintegrin-metalloproteinases ADAM 10, 12 and 17 are upregulated in invading peripheral tumor cells of basal cell carcinomas

BACKGROUND

Members of the a disintegrin and metalloproteinase (ADAM) family are expressed in malignant tumors and participate in the pathogenesis of cancer. However, the presence of ADAM 10, 12, 17 and their role in basal cell carcinoma (BCC) have not been described. The purpose of this study was to investigate expression of ADAM 10, 12 and 17 in BCC.

METHODS

Expression of ADAM 10, 12 and 17 was analyzed by immunohistochemistry in skin tissues obtained from 25 patients with different types of BCC.

RESULTS

Immunoreactivity of ADAM 10, 12 and 17 was increased at the peripheral tumor margin compared with central areas of BCC tumor cell nests. Immunoreactivity of ADAM 10 and 12 was increased in the deep margin of invading tumor cell nests in mixed BCC. Focally increased expression of ADAM 12 was detected in squamous differentiated tumor cells of nodular BCC. In addition, immunoreactivity of ADAM 17 was increased in superficial BCC.

CONCLUSIONS

ADAM 10, 12 and 17 showed different expression pattern in BCC histologic subtypes, indicating their different role in the BCC pathogenesis. Overexpression of ADAM 10, 12 and 17 immunoreactivity in deep invasion area of BCC indicates that these three proteases may play an important role in the locally invasive and highly destructive growth behavior of BCC. Additionally, we suggest that ADAM 17 may play an important role in early development of BCC.

Differential ErbB1 signaling in squamous cell versus basal cell carcinoma of the skin

In this study, we examined ErbB1 signaling in human basal and squamous cell carcinomas (BCC and SCC) of the skin in vivo. We used enzyme-linked immunosorbent assay, laser capture microdissection-coupled real-time reverse transcriptase-polymerase chain reaction, and immunohistochemistry to assess expression and activation levels of ErbB1 protein, ligands, and potential downstream effectors, in BCC and SCC tumors, stroma, and adjacent epidermis. Although total ErbB1 protein and mRNA were similar in cancerous and normal skin, we found that ErbB1 activation (phospho-Tyr(1068)) was greater in bulk SCC versus BCC or normal skin. In addition, three ErbB1 ligand transcripts (amphiregulin, heparin-binding epidermal growth factor-like growth factor, and transforming growth factor-alpha) were up-regulated in tumor cells of SCC but not BCC. Expression of these ligands was also increased in asymptomatic epidermis adjacent to both SCC and BCC, relative to normal skin. Interestingly, betacellulin transcript levels were inversely regulated compared with the other ligands. Consistently, downstream ErbB1 effectors (Erk1/2 and Akt) were activated in tumor cells of SCC but not of BCC and in adjacent epidermis of both BCC and SCC. These results demonstrate that ErbB1 signaling is hyperactive in tumor cells of SCC but not of BCC and in nearby asymptomatic epidermis of both tumor types. Our results suggest that targeting ErbB1 signaling might be of benefit in the treatment of SCC.

Genetic mosaicism in basal cell carcinoma

Human basal cell cancer (BCC) shows unique growth characteristics, including a virtual inability to metastasize, absence of a precursor stage and lack of tumour progression. The clonal nature of BCC has long been a subject for debate because of the tumour growth pattern. Despite a morphologically multifocal appearance, genetic analysis and three-dimensional reconstructions of tumours have favoured a unicellular origin. We have utilized the X-chromosome inactivation assay in order to examine clonality in 13 cases of BCC. Four parts of each individual tumour plus isolated samples of stroma were analysed following laser-assisted microdissection. In 12/13 tumours, the epithelial component of the tumour showed a monoclonal pattern suggesting a unicellular origin. Surprisingly, one tumour showed evidence of being composed of at least two non-related monoclonal clones. This finding was supported by the analysis of the ptch and p53 gene. Clonality analysis of tumour stroma showed both mono- and polyclonal patterns. A prerequisite for this assay is that the extent of skewing is determined and compensated for in each case. Owing to the mosaic pattern of normal human epidermis, accurate coefficients are difficult to obtain; we, therefore, performed all analyses both with and without considering skewing. This study concludes that BCC are monoclonal neoplastic growths of epithelial cells, embedded in a connective tissue stroma at least in part of polyclonal origin. The study results show that what appears to be one tumour may occasionally constitute two or more independent tumours intermingled or adjacent to each other, possibly reflecting a local predisposition to malignant transformation.

Cytokeratin contents of basal cell carcinoma, epidermis overlying tumour, and associated stromal amyloidosis: an immunohistochemical study

Cytokeratins (CKs) are expressed specifically in the cytoplasm of epithelial cells. We investigated the expression of CKs immunohistochemically in basal cell carcinomas (BCCs), epidermis overlying tumour, and skin tumor-associated amyloidosis (STA). Twenty cases of BCC, 11 of which had STA were included to the study. The primary antibodies of CK1-8 (AE3), CK10 (DEK-10), CK14 (LL002), CK17 (E3), CK18 (DC10), CK19 (KS19.1), CK 5/6/18 (LP34), CK8/18 (5D3) were applied to the section immunohistochemically. In BCCs without STA, CK1-8, CK14 and CK17 antibodies were expressed by tumour tissue in all biopsy specimens. In the BCCs with STA, tumour tissue was immunoreactive always with CK1-8 and CK17 antibodies, and commonly immunoreactive with anti-CK 14 antibody. In the epidermis overlying tumour tissue, there was positive immunoreactivity with anti-CK 1-8, CK 5/6/18, CK 10 and CK 14 antibodies in all biopsy specimens. Anti-CK 17 antibody was also positive in 17 biopsy specimens. STA is immunoreactive with anti-CK1-8 in all specimens. There was mild staining with anti-CK5/6/18 and with anti-CK19 whereas no immunoreactivity with anti-CK10 and CK18 antibodies was found. In conclusion, we could not find a significant CK expression difference between BCCs with and without STA. Weak positivity and a few number of CKs were shown in STA when compared with those of BCC and epidermis overlying tumour tissue expressing the more variable CKs. Interestingly, although CKs coexpressed in pairs consisting of one basic and one acidic CK, we detected predominantly basic CKs in STA.

Proliferation and differentiation of the keratinocytes in hyperplastic epidermis overlying dermatofibroma: immunohistochemical characterization

Epidermal changes overlying dermatofibromas (DFs) have been described as ranging from psoriasiform simple hyperplasia to basaloid hyperplasia sometimes morphologically indistinguishable from superficial basal cell carcinoma (BCC). To characterize epidermal hyperplasia overlying DFs and to determine its association with the disease process, we examined 30 cases of DF showing hyperplastic epidermis. We used nine immunohistochemical markers associated with keratinocyte proliferation or differentiation. In DFs, the dermal metallothionein (MT) expression and immunophenotypic changes with regard to epidermal differentiation varied depending on the stage of lesional evolution of the DFs. Immunostaining for epidermal growth factor receptor (EGFR), MT, and keratin 6 (K6) increased in simple hyperplastic epidermis (SHE) overlying DFs (n = 11), whereas it gradually diminished in basaloid hyperplastic epidermis (BHE) overlying DFs (n = 19). In SHE, there was a significant increase in K14 expression. Among 19 BHE cases, 12 showed premature expression of involucrin and delayed appearance of K1 along with aberrant expression of K14. Conversely, the remaining 7 BHE cases showed a pattern of involucrin and K1 similar to that of normal skin coinciding with decreased or absent dermal MT expression. Loricrin and filaggrin expression in all DFs was the same as that of normal skin. Based on the sparse positivity of Ki-67 in the hyperplastic epidermis overlying DFs, we found that the biologic ability of BHE and SHE was not apparent in the hyperproliferative state observed in psoriasis and BCC. These results suggest that the dermal fibrohistiocytic process may trigger the induction of SHE overlying DFs by an unknown mechanism and then mediate both the abnormal keratinocyte differentiation and the transformation of SHE to BHE through the evolution of the dermal lesions.

Pseudocarcinomatous change in lymphomatoid papulosis and primary cutaneous CD30+ lymphoma: a clinicopathologic and immunohistochemical study of 6 patients

We report 6 cases of pseudoepitheliomatous hyperplasia (PEH) mimicking squamous cell carcinoma in association with an atypical CD30+ dermal infiltrate. Three patients had lymphomatoid papulosis type A, and 3 patients had cutaneous CD30+ lymphoma. All 6 cases showed histologic evidence of PEH with keratinocyte atypia. In 4 cases there was significant atypia to prompt a diagnosis of squamous cell carcinoma. Three of these received treatment with wide local excision and 2 had been engrafted. Immunohistochemical staining for epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha) showed similar expression in lesional and perilesional skin. Epidermal growth factor receptor (EGFR) expression by the proliferating epithelium was similar to that of the suprabasal adjacent normal epidermis. There was no aberrant expression of EGF, TGF-alpha, and EGFR by atypical lymphocytes. These cases demonstrate that PEH associated with CD30+ lymphoproliferative disease may closely resemble squamous cell carcinoma, thereby leading to inappropriate diagnosis and treatment.

Interferon-gamma-induced ICAM-1 and CD40 expression, complete lack of HLA-DR and CD80 (B7.1), and inconsistent HLA-ABC expression in basal cell carcinoma: a possible role for interleukin-10?

Basal cell carcinomas (BCCs) of the skin show varying degrees of peritumoural inflammatory infiltrate consisting mainly of T cells, but lack an effective T-cell-mediated immune response. This may be caused by the absence of the major histocompatibility complex (MHC) class I and II antigens, intercellular adhesion molecule-1 (ICAM-1), CD40 and CD80 (B7.1). Interferon-gamma (IFN-gamma) is known to induce or up-regulate their expression on epithelial cells, whereas interleukin-10 (IL-10) down-regulates their expression. The induction and up-regulation of HLA-ABC, HLA-DR, ICAM-1, CD40, and CD80 in BCC and normal skin from BCC patients were investigated in a culture system using recombinant human IFN-gamma (rHuIFN-gamma). The levels of IL-10 were determined in the supernatants after culture. The results showed that only ICAM-1 expression was significantly up-regulated on BCC cells. However, in the normal epidermis of BCC patients and in the epidermis overlying the tumour nests, significant up-regulation of ICAM-1, and CD40, and CD80 and slight up-regulation of HLA-DR were observed. No changes in HLA-ABC expression were observed in either normal skin or BCC. High levels of IL-10 were present in the supernatants of BCC biopsies after culture. It may be concluded that it is highly likely that the presence of IL-10 in BCC is directly or indirectly responsible for the complete lack of expression of HLA-DR, ICAM-1, CD40 and CD80 and the inconsistent expression of HLA-ABC on BCC cells in situ and may be a way of escaping immune survillance.

In situ hybridization analysis of the expression of human telomerase RNA in normal and pathologic conditions of the skin

Human telomerase RNA (hTER) expression in skin was examined by in situ hybridization analysis. All newborn foreskins examined (n = 5) expressed hTER in epidermal basal cells at moderate levels. Telomerase RNA was not detectable in most adult specimens from sun protected areas (six of seven), whereas all samples obtained from sun exposed areas (n = 8) showed moderate hTER signals in epidermal basal cells. Telomerase RNA was also detected at moderate to strong levels in basal cells of psoriasis, contact dermatitis, and the proliferative cells of the anagen hair bulb. Basal cell carcinoma samples (14 of 15) had moderate to high hTER expression throughout the entire tumor, whereas squamous cell carcinomas (seven of eight) showed variable intensities of hTER expression but only in the cells at the periphery of tumor nests. All melanomas examined (n = 5) had moderate hTER expression in all tumor cells. The hTER signal intensities in skin tumors did not correlate with the age or sex of the donors, the clinical history of the lesions, or the histologic subtypes. To address whether hTER expression correlated with the proliferative state, sequential sections were stained with anti-Ki-67 antibody, a proliferation marker. In newborn foreskins, squamous cell carcinomas, and basal cell carcinomas, the distributions of hTER and Ki-67 were similar but not always identical. Telomerase RNA was more abundant than Ki-67 in the basal and suprabasal layer of newborn foreskins, suggesting that hTER expression is present both in actively cycling and in resting cells.

Expression of interferon-gamma receptors and interferon-gamma-induced up-regulation of intercellular adhesion molecule-1 in basal cell carcinoma; decreased expression of IFN-gamma R and shedding of ICAM-1 as a means to escape immune surveillance

The peritumoural inflammatory infiltrate in basal cell carcinoma (BCC) of the skin consists mainly of T lymphocytes which hardly invade the tumour nests. The absence of intercellular adhesion molecule-1 (ICAM-1) on BCC cells may explain the lack of tumour-infiltrating cells and the lack of an active cell-mediated immune response in this tumour. In this study, the induction of ICAM-1 was investigated in BCC biopsies using recombinant human interferon-gamma (rHuIFN-gamma). The expression of interferon-gamma receptors (IFN-gamma R) in the biopsies was also investigated. The results showed that BCC cells expressed ICAM-1 after incubation with rHuIFN-gamma, but to a lesser degree than normal epidermal cells. The levels of shed ICAM-1 were significantly increased in the culture supernatants of tumour biopsies compared with those from normal skin biopsies, after culturing in the presence of rHuIFN-gamma. The expression of IFN-gamma R was significantly decreased on the tumour cells compared with the overlying epidermis. The decreased expression of IFN-gamma R on the tumour cells and the shedding of ICAM-1 into the peritumoural stroma may be a plausible mechanism by which the tumour cells are protected against an active cell-mediated immune response.

Epithelial induction in dermatofibroma: a role for the epidermal growth factor (EGF) receptor

Dermatofibroma (DF) refers to a spectrum of firm, nodular, nonencapsulated lesions that occur commonly on the extremities. Histologically, DF is composed of spindle cells with variable differentiation toward histiocytic and vascular elements, often associated with epithelial hyperplasia and basilar keratinocyte pigmentation that histologically may simulate basal cell carcinoma (BCC). The characteristic epithelial changes are likely to be mesenchyma-mediated and probably represent a host reparative response otherwise known as the inductive phenomenon. Epidermal-mesenchymal cellular interactions, including induction, occur in various stages of embryonic skin development and in response to injury with tissue repair. Cellular interaction is mediated by direct apposition of cells or by soluble protein hormones produced directly by the cell (autocrine effect) or adjacent cells (paracrine effect). Among the important soluble mediators are epidermal growth factor (EGF), which is known to stimulate the proliferation and differentiation of a variety of transformed and benign tissues. We investigated the possible etiologic association between EGF receptor (EGF-R) expression and epithelial induction in a prospective series of 20 cases of DF compared to entities such as granular cell tumor, scar tissue, and nevus sebaceus similarly showing epithelial hyperplasia. Immunohistochemical staining for EGF-R showed strong dermal staining of dendritic spindle cells and overlying hyperplastic keratinocytes in each of the DF cases. Immunohistochemical staining for EGF-R was absent within all dermal loci of granular cell tumor (n = 3), nevus sebaceus (n = 6), and scar tissue (n = 12).

Proliferation of epithelia of noninvolved mucosa in patients with head and neck cancer

BACKGROUND

Morphologically noninvolved mucosa in patients with head and neck cancer is altered by carcinogens. These alterations may include chromosome alterations, gene mutations, and other molecular abnormalities which may explain very high incidence of second tumors in this group of patients. The purpose of this study was to investigate the in vivo proliferative characteristics in epithelial tissues adjacent to the tumor in a series of patients with head and neck cancer.

METHODS

Twenty-one patients with head and neck tumors received IV infusions of iododeoxyuridine (IdUrd) and/or bromodeoxyuridine (BrdUrd). Surgical specimens containing normal-appearing epithelium adjacent to the tumor were selected and stained with the respective monoclonal antibody. The percentage of S-phase cells (labeling index, LI) was counted in the basal and suprabasal layers of the epithelium.

RESULTS

In 27 samples of oral epithelium obtained from 14 previously untreated patients, labeled (S-phase) cells were predominantly located in suprabasal layers with LI 31.6 +/- 3.1% (range 13.5-73.2%). In contrast, the LI of the basal layer was very low: 1.6 +/- 0.2% (range 0.5%-8.8%). There was no statistically significant difference between normal appearing and dysplastic samples (p > 0.05). In 10 samples obtained from 7 patients whose biopsies were studied 2 days to 2 month after concomitant radiation and chemotherapy, the LI of the oral mucosa basal layer was significantly higher (21.0 +/- 4.1%, range 6.3-39.2%). The LI of the suprabasal layer in treated patients was 14.3 +/- 2.4% (range 5.9-31.1%). The LI of nasal pseudostratified epithelium (4 samples) was 11.2%. The average LI of "basal" cells was 8.3% (range 5.9-11.9%) and that of "suprabasal" cells was 13.8% range (3.2-29.5%). The basal layer of the skin (5 samples) contained 9.3% labeled cells (range 3.3-16.3%); the LI of suprabasal layers of skin was 21.3% (range 7.8-33.2%).

CONCLUSION

Both the frequency and the spatial distribution of S-phase cells are disordered in noninvolved epithelia in patients with head and neck tumors. These observations suggest that disordered proliferation may be an early consequence of field cancerization, a consequence that occurs prior to appearance of morphologically apparent hyperplasia or dysplasia.

Differential patterns of placental and epithelial cadherin expression in basal cell carcinoma and in the epidermis overlying tumours

P-cadherin (P-CD) and E-cadherin (E-CD) are expressed by keratinocytes and play an important role in skin morphogenesis. P-CD expression is restricted to the basal layer of normal epidermis, whereas E-CD is expressed in all the living layers. We have previously reported a reduced expression of E-CD in most cases of infiltrative basal cell carcinoma (BCC). In the present work we have investigated by immunohistochemistry the expression of both P-CD and E-CD in a new series of 32 patients with BCC. Most cases of superficial multicentric BCC and some nodular tumours had preserved expression of both cadherins in all tumour cells. The majority of nodular BCCs had partially reduced expression of one or both cadherins with an ordered distribution of cells showing different cadherin staining throughout the tumour mass. A severe reduction of E-CD expression with a disordered distribution of cells with different immunostaining intensity was observed in most specimens of infiltrative BCC. In contrast, P-CD expression was preserved in all cases of infiltrative BCC. These results suggest that P-CD and E-CD play different roles in the growth pattern of BCC. In addition, both anomalous P-CD expression and reduced E-CD expression were frequently observed in the spinous layer of epidermis overlying tumours. This phenomenon was significantly associated with the presence of keratinocytic atypia, which suggests that disturbed cadherin expression could be a marker of premalignant changes and/or hyperproliferative activity in human epidermis.