p63 expression in normal human epidermis and epidermal appendages and their tumors

p63 immunoexpression in hair follicles of normal and alopecia X-affected skin of Pomeranian dogs

BACKGROUND

Alopecia X in Pomeranians is caused by a hair cycle deregulation, associated with downregulation of key regulatory genes of the Wnt and Shh pathways, and stem-cell markers. However, the pathogenesis remains unclear. p63 is an important transcription factor correlated with the aforementioned hair cycle modulating genes.

HYPOTHESIS/OBJECTIVES

The aim of this study was to highlight possible changes of p63 immunohistochemical expression within the hair follicles in canine alopecia X compared with normal skin.

ANIMALS

Skin biopsies from 19 alopecia X-affected and six control Pomeranians were analysed.

MATERIALS AND METHODS

Serial histological sections of skin biopsies harbouring anagen, telogen and kenogen hair follicles were immunohistochemically evaluated for differences in p63 expression in the affected and control samples.

RESULTS

Dogs with alopecia X had a significantly decreased immunoexpression of p63 in telogen and kenogen hair follicles.

CONCLUSIONS AND CLINICAL RELEVANCE

The decrease of p63 immunoexpression observed in canine alopecia X suggests an involvement of p63 in hair cycle.

P63 and Ki-67 expression in radicular cyst

Objectives

The aim of the current study was to identify the expression of P63 and its relation to odontogenic epithelial cell proliferation, severity of the inflammatory infiltrate and size of radicular cysts (RCs).

Methods

In this retrospective cross-sectional study, 30 cases of paraffin-embedded RCs were randomly selected from the archive. P63 and Ki-67 expression was assessed by immunohistochemistry.

Results

Epithelial P63 expression was absent in four (13.3%), weak in 10 (33.3%), and moderate in 16 (53.3%) cases. In the connective tissue wall of RC, P63 expression was absent in two (6.7%) cases, weak in 24 (80.0%) cases, and moderate in four (13.3%) cases. Ki-67 was found to be weakly expressed in 12 (40.0%) cases, moderately expressed in 13 (43.3%), and strongly expressed in five (16.7%) cases. No correlation was found between Ki-67 expression in odontogenic epithelium and P63 expression in the odontogenic epithelium (rho = 0.110, p = .563) or fibrous capsule (rho = 0.160, p = .399). Nevertheless, we found a positive correlation between Ki-67 expression in the odontogenic epithelium and the size of the RC (rho = 0.450, p = .013). The inflammatory infiltrate was negatively correlated with P63 expression in the odontogenic epithelium (rho = -0.428, p = .018), and with the size of cysts (rho = -0.728, p < .001).

Conclusions

There is a high expression of P63 throughout the odontogenic epithelium and connective tissue capsule of the RC. P63 expression in the odontogenic epithelium is negatively correlated with the degree of the inflammatory infiltrate but not with epithelial cell proliferation or the size of the cyst.

Differentiating pagetoid Bowen disease from Paget disease on the nipple-areola complex: Two unique, challenging cases

Pagetoid Bowen disease is a subtype of Bowen disease that accounts for 5% of Bowen disease. It is extremely rare for Bowen disease to appear on the nipple-areola complex, with only seven cases described in the previous literature. Of those seven cases, only one was of the pagetoid subtype. We report two cases of pagetoid Bowen disease on this location, one of them being the first case of pagetoid Bowen disease affecting the nipple reported to date. On this location, it is crucial to perform a meticulous differential diagnosis to rule out Paget disease, because of its contrasting therapeutic and prognostic implications. In order to do this, clinical and histopathological aspects must be considered. From a clinical point of view, previous literature has stated that nipple involvement can be a clue that points to Paget disease. However, one of our cases shows that this is not always true. Regarding histopathological analysis, a complete excision of the tumor might be necessary to observe clear features of Bowen disease, such as full-thickness atypia of the epidermis and intercellular bridges. An immunohistochemical panel comprising carcinoembryonic antigen, gross cystic disease fluid protein, epithelial membrane antigen, p63, CK34betaE12, periodic acid-Schiff, estrogen receptor, and progesterone receptor can be decisive in complicated cases.

Spiradenoma With Adenoid Cystic Carcinoma-Like Features

Spiradenoma is a benign cutaneous adnexal neoplasm that characteristically presents as a painful dermal nodule, often on the head or trunk. It has a distinct histologic phenotype and management involves surgical excision with low risk of recurrence. In comparison, adenoid cystic carcinoma (ACC) is a low-grade malignancy manifesting as an often painless subcutaneous mass with potential for local invasion, perineural extension, and high rates of recurrence after excision. We report the case of a 63-year-old male patient with a recurrent, painful hematoma-like cyst overlying the left lower extremity tibial tuberosity. A firm nodule was located at the base of the cyst, which was histologically consistent with spiradenoma. Interestingly, the lesion contained multifocal ACC-like components composed of epithelial basaloid cells surrounding pseudocystic structures filled with mucinous material. The ACC-like components did not demonstrate infiltration or perineural invasion. To the best of our knowledge, this is the second publication in the English literature regarding spiradenoma with an ACC-like pattern. Although a benign entity, knowledge of this morphological variant of spiradenoma is essential for diagnostic accuracy in these cases. If a limited biopsy captures only the ACC-like component of a spiradenoma, the lesion may be incorrectly diagnosed as ACC.

Expression of the epidermal stem cell marker p63/CK5 in cutaneous papillomas and cutaneous squamous cell carcinomas of dogs

Cutaneous papillomas (CPs) and cutaneous squamous cell carcinomas (CSCCs) are usual epidermal tumours in dogs. CPs and CSCCs probably arise from the neoplastic transformation of the keratinocytes within the stem cell compartment, since these cells are the only keratinocytes that would reside long enough to accumulate the number of molecular alterations to drive the progression towards a tumour cell phenotype. However, the role of these cells in common epidermal tumours in dogs is still unknown. Thus, the purpose of this study was to evaluate the immunohistochemical expression pattern of p63 together with CK5, molecular markers of epidermal stem cells, on sections of tissue microarrays constructed from canine samples of CP and CSCC to investigate the contribution of stem cells in those canine tumours. p63/CK5 coexpression was retained in most basal and some suprabasal cells in CPs and CSCCs. In addition, increased coexpression of these molecules was observed in a group of CPs and CSCCs, as a result of a higher p63 expression. These results suggest that the coexpression of p63/CK5 may mark epidermal keratinocytes that possess self-renewal capacity rather than only stem cells, and suggest that transit amplifying cells, and even differentiated keratinocytes, may also contribute to the pathogenesis of epidermal tumours in dogs.

Prognostic Role of Epithelial-Mesenchymal Transition Markers "E-Cadherin, β-Catenin, ZEB1, ZEB2 and p63" in Bladder Carcinoma

Background

This study aimed to investigate the expression of epithelial-mesenchymal markers’ E-cadherin, β-catenin, zinc-finger E-box-binding homeobox 1 (ZEB1), zinc-finger E-box-binding homeobox 2 (ZEB2) and p63 in transitional cell carcinoma (TCC) and squamous cell carcinoma (SCC) variants of bladder carcinoma (BC) and their correlation with clinicopathological parameters of prognostic importance.

Methods

In this retrospective study, 91 patients were enrolled (66 with TCC and 25 with SCC). All patients had full clinical and follow-up data and available paraffin blocks. Immunohistochemical analysis was performed and correlated with clinicopathological factors.

Results

In TCC cases, reduced E-cadherin, β-catenin positivity and p63 expression rate were evident in the sitting of increased expression of ZEB1 and ZEB2. Patients with ZEB2 positive tumors were more likely to die compared to those with negative ZEB2 (P = 0.024). Moreover, in patients with muscle-invasive BCs, an intense p63 expression was associated with poor overall survival (OS) (P < 0.001). For patients with SCC, there was a reduction in E-cadherin and β-catenin positivity with elevated p63 expression and concomitant increased ZEB1 and ZEB2 expression. Poor prognosis was evident in association with reduced E-cadherin, positive nuclear β-catenin/reduced membranous β-catenin, ZEB1 and ZEB2 positive cases as well patients with elevated p63 expression (P < 0.001). TCC and SCC cases showed similar poor prognosis in association with elevated p63 expression (P < 0.001).

Conclusions

In both TCC and SCC variants, epithelial-mesenchymal transition (EMT) process is evident; however, its molecular mechanism shows some variations, specifically this notably different p63 expression pattern among two carcinoma variants with the similar impact of elevated p63 expression pattern on prognosis.

p63 Is a Promising Marker in the Diagnosis of Unusual Skin Cancer

Skin cancer is the most common type of cancer worldwide. Ozone depletion and climate changes might cause a further increase in the incidence rate in the future. Although the early detection of skin cancer enables it to be treated successfully, some tumours can evolve and become more aggressive, especially in the case of melanoma. Therefore, good diagnostic and prognostic markers are needed to ensure correct detection and treatment. Transcription factor p63, a member of the p53 family of proteins, plays an essential role in the development of stratified epithelia such as skin. In this paper, we conduct a comprehensive review of p63 expression in different types of skin cancer and discuss its possible use in the diagnosis and prognosis of cutaneous tumours.

Sox10 and DOG1 Expression in Primary Adnexal Tumors of the Skin

Primary skin adnexal tumors can be challenging to classify and must be discerned from cutaneous adenocarcinoma metastases from various sites. We evaluated expression of Sox10 and DOG1 in normal cutaneous adnexa and in 194 primary skin adnexal tumors, and compared their performance in discriminating primary skin adnexal tumors from cutaneous metastatic adenocarcinomas with that of p40 and p63. In normal skin adnexa, we noted Sox10 expression in both the secretory and myoepithelial cells in eccrine glands, but only in myoepithelial cells in apocrine glands. DOG1 demonstrated canalicular expression in eccrine glands, and weak expression in myoepithelial cells of apocrine glands, germinative cells of sebaceous glands, and outer root sheath of follicular infundibulum. Sox10 was expressed in 100% of cylindromas and spiradenomas, and in variable frequency in other benign and malignant tumors of sweat glands. DOG1 was positive in most cylindromas (87.5%), in only 10.5% of spiradenomas, and was variably expressed in other benign and malignant tumors of sweat glands. All syringomas (n = 20) were negative for Sox10 and DOG1. One out of the 33 follicular neoplasms was positive for Sox10 and DOG1 (3%). All sebaceous neoplasms were negative for Sox10, and 28.1% of them were positive for DOG1. Sox10 was specific (91.9%) but not sensitive (28.4%) for primary skin origin, and was far less accurate (38.5%) than p63 or p40 (95.5% accuracy). Combining Sox10 with p63 or p40 showed only very minimal gain in accuracy (96%). DOG1 expression in tumors showed low sensitivity and specificity for skin adnexal origin.

p53: key conductor of all anti-acne therapies

This review based on translational research predicts that the transcription factor p53 is the key effector of all anti-acne therapies. All-trans retinoic acid (ATRA) and isotretinoin (13-cis retinoic acid) enhance p53 expression. Tetracyclines and macrolides via inhibiting p450 enzymes attenuate ATRA degradation, thereby increase p53. Benzoyl peroxide and hydrogen peroxide elicit oxidative stress, which upregulates p53. Azelaic acid leads to mitochondrial damage associated with increased release of reactive oxygen species inducing p53. p53 inhibits the expression of androgen receptor and IGF-1 receptor, and induces the expression of IGF binding protein 3. p53 induces FoxO1, FoxO3, p21 and sestrin 1, sestrin 2, and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), the key inducer of isotretinoin-mediated sebocyte apoptosis explaining isotretinoin's sebum-suppressive effect. Anti-androgens attenuate the expression of miRNA-125b, a key negative regulator of p53. It can thus be concluded that all anti-acne therapies have a common mode of action, i.e., upregulation of the guardian of the genome p53. Immortalized p53-inactivated sebocyte cultures are unfortunate models for studying acne pathogenesis and treatment.

Clinicopathological Features and Immunohistochemical Alterations of Keratinocyte Proliferation, Melanocyte Density, Smooth Muscle Hyperplasia and Nerve Fiber Distribution in Becker's Nevus

Background

Although Becker's nevus (BN) is a relatively common disease, the systematic studies of clinicopathological and immunohistochemical results are poorly reported.

Objective

To investigate the clinicopathological features and immunohistochemical alterations of keratinocyte proliferation, melanocyte density, smooth muscle hyperplasia and nerve fiber distribution in BN.

Methods

Clinical and pathological data were collected in 60 newly-diagnosed BN cases. Immunohistochemical stain of Ki-67, Melan-A, keratin 15, smooth muscle actin and protein gene product 9.5 was performed in 21 cases.

Results

The median diagnostic and onset age was 17 and 12 years, respectively. Skin lesions usually appeared on the upper trunk and upper limbs. The pathological features included the rete ridge elongation and fusion and basal hyperpigmentation. Epidermal Ki-67, Melan-A and keratin 15 expression and dermal nerve fiber length were significantly higher in lesional and perilesional skin than in normal skin (p<0.05~0.01), while smooth muscle actin expression was upregulated only in skin lesion (p<0.05).

Conclusion

Although the clinical diagnosis of BN is often straightforward, histopathology is helpful to differentiate from other pigmentary disorders. The hyperproliferation of keratinocytes, melanocytes, arrector pili muscle and dermal nerve fibers could be involved in the pathogenesis of BN.

Propionibacterium species and follicular keratinocyte activation in acneic and normal skin

BACKGROUND

The pathogenesis of acne vulgaris is multifactorial with increased sebum production, alteration in the quality of sebum lipids, dysregulation of the hormone microenvironment, follicular hyperkeratinization and Propionibacterium acnes-driven inflammation as major contributory factors. Hyperproliferation of keratinocytes is believed to contribute to hypercornification and eventually leads to comedone development. While the distribution of P. acnes is relatively well documented in acneic and healthy skin, little is known about P. granulosum and P. avidum.

OBJECTIVES

To visualize directly the three major Propionibacterium in 117 control and 26 acneic skin samples. In addition, keratinocyte proliferation was evaluated.

METHODS

Propionibacteria were visualized by immunofluorescence microscopy, and keratinocyte proliferation was assessed by Ki67, keratin (K) 16 and p63 immunochemistry.

RESULTS

P. acnes was identified in 68 samples (48%), while P. granulosum was identified in 12 (8%) samples; P. avidum was not detected at all. Unexpectedly, acne samples did not show higher keratinocyte proliferation than controls, nor was there any association between bacterial colonization and expression of Ki67/K16/p63.

CONCLUSIONS

Our findings do not support earlier notions of follicular keratinocyte hyperproliferation as a cause of ductal hypercornification in acneic facial skin. Further studies on the mechanisms underlying hypercornification in acne pathogenesis are needed.

Expression Patterns of Gli-1, Pleckstrin Homology-Like Domain, Family A, Member 1, Transforming Growth Factor-β1/β2, and p63 in Sebaceous and Follicular Tumors

Background

Certain epidermal appendage tumors, including hyperplasias (hamartomas), adenomas, benign epitheliomas, primordial epitheliomas, and malignant tumors, can exhibit any stage of differentiation. Several molecules associated with tumorigenesis, such as Gli-1, pleckstrin homology-like domain, family A, member 1 (PHLDA-1), transforming growth factor (TGF)-β1, TGF-β2, and p63, are associated with tumor grade and aggressive behavior in follicular and sebaceous tumors in ways that are not well understood.

Objective

The aim of this study was to elucidate the expression of Gli-1, PHLDA-1, TGF-β1/β2, and p63 in benign and malignant tumors of the hair and sebaceous glands and to determine their importance in the degree of tumor differentiation.

Methods

Immunohistochemistry was performed in follicular and sebaceous tumors using antibodies against Gli-1 (sebaceous tumor marker), PHLDA-1 (hair follicle outer root sheath [ORS] cell marker), p63, TGF-β1, and TGF-β2.

Results

Gli-1 was expressed in basaloid cells, sebocytes, and sebaceous carcinoma cells, and expression levels decreased as differentiation progressed. PHLDA-1 was expressed in ORS cells and some follicular tumor cells. Expression of p63 was observed in the nuclei of the outermost basaloid cells (seboblasts), poorly differentiated sebaceous carcinoma cells, and tumor cells toward the direction of the hair. Remarkably, TGF-β1 was expressed exclusively in the nuclei of benign and malignant follicular (hair) tumors, but not in sebaceous tumors, at levels that correlated with the degree of differentiation.

Conclusion

We propose that p63 and/or TGF-β1 are useful for predicting the degree of differentiation and malignant potential of sebaceous and follicular tumors and for distinguishing trichilemmal carcinoma from sebaceous carcinoma.

Clinicopathology significance of p53 and p63 expression in Indonesian cervical squamous cell carcinomas

BACKGROUND

Human papilloma virus infection is associated with genesis and malignant potential of cervical cancer. E6 and E7 oncogens are known to bind to p53 and retinoblastoma gene products, abrogating their functions as tumor suppressors, leading to an abnormal cell cycle machinery. Roles of the p53 homolog p63 have also been postulated, E6 expression leading to TAp63b degradation allowing anchorage independent growth. Molecular studies correlated with clinicopathological factors are important to determine prognosis and treatment strategies, but results have been controversial and need to be clarified.

AIM

To investigate expression of p53 and p63 in cervical squamous cell carcinomas in correlation with age, FIGO staging, morphology, and cancer cell proliferation.

MATERIALS AND METHODS

Expression of p53 and p63 immunohistochemical staining in a total of 56 paraffin-embedded tissues of cervical squamous cell carcinomas from Dr. Sardjito General Hospital Indonesia, was evaluated for correlation with clinicopathological parameters. The Mann-Whitney test was used to compare the percentage of p53 and p63 expression with patient age, FIGO staging and morphology and to compare mean p53 and p63 expression. The Spearman correlation test was applied to correlate p53 and p63 expression with that of Ki-67. A p-value of <0.05 was considered statistically significant.

RESULTS

There were significant associations between p53 expression with age (p=0.019) and FIGO staging (p=0.026), but not with with morphology or Ki-67 expression. There were no links between p63 expression and age, morphology, FIGO staging or Ki-67.

CONCLUSIONS

This study indicated that p53 has a prognostic value in cervical squamous cell carcinomas given the relation with FIGO staging.

Re-epithelialization of the Buccal Mucosa after Alkaline Chemical Injury

Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water and bicarbonate toothpaste. However, the effects of an alkaline pH on the oral mucosa had not been elucidated. The purpose of this study was to investigate how basal keratinocytes are actively involved in re-epithelialization after alkaline chemical injury. We generated epithelial defects in the oral mucosa of mice by applying an alkaline chemical, and the localization of cytokeratin 13, cytokeratin 14, PCNA and p63 was investigated during the re-epithelialization process. PCNA- and p63-positive staining was seen in basal cells covering the wound surface at 1 day after the chemical injury. Cytokeratin 14-positive and PCNA-negative basal keratinocytes were localized in a few layers of the wound epithelium during epithelial outgrowth. Cytokeratin 14-positive and PCNA-positive basal keratinocytes, indicating proliferation, were localized over the entire layer of the epithelium at the wound margin. These results imply that basal keratinocytes at the wound margin migrate to the wound surface, provoke differentiation and keratinization during epithelial outgrowth and that epithelial cells are supplied from the wound margin to the epithelial outgrowth after alkaline chemical injury.

A Rare Case of Aggressive Digital Adenocarcinoma of the Lower Extremity, Masquerading as an Ulcerative Lesion that Clinically Favored Benignancy

A rare case report of Aggressive Digital Adenocarcinoma (ADPCa) is presented complete with a literature review encompassing lesions that pose potential diagnostic challenges. Similarities between basal cell carcinoma (BCC), marjolin’s ulceration/squamous cell carcinoma (MSCC) and ADPCa are discussed. This article discusses potential treatment options for ADPCa and the need for early biopsy when faced with any challenging lesion. An algorithmic approach to ADPCa treatment based on the most current research is recommended.

The Expression of p63 during Epidermal Remodeling in Psoriasis

Psoriasis is a skin disorder of chronic keratinization characterized by epidermal hyperplasia, hyperkeratosis, and inflammation. However, little is known about the mechanism (s) underlying the hyperplasia with elongated rete ridges characteristic of psoriasis. The p63 transcription factor, a homologue of the p53 tumor suppressor, has been implicated in the maintenance of epidermal stem cells and the stratification of the epidermis. p63 is up-regulated in squamous cell carcinomas with anaplasia, suggesting that it is also associated with epidermal hyperplasia. In this study, we examined the expression of p63 in the remodeling of psoriatic epidermis. Lesional tissues from 17 psoriasis patients in various stages of plaque-type psoriasis and normal skin tissues from five healthy subjects were examined by immunohistochemistry using a monoclonal anti-p63 antibody. Normal epidermis stained positively for p63 in the basal cell layer and in 2 to 4 layers of the spinous cell layer. p63 was positive in the thickened rete ridges of the epidermis even in early psoriatic lesions. As the epidermis elongated, p63-positive cells moved down and were localized in the lower parts of the rete ridges where keratinocytes densely proliferated. From these results, we suggest that p63 may be involved in the early stage of the remodeling process of the psoriatic epidermis as well as in the elongation of the rete ridges.

PPARγ-mediated and arachidonic acid-dependent signaling is involved in differentiation and lipid production of human sebocytes

The transcriptional basis of sebocyte differentiation and lipid production is mostly unclear. Peroxisome proliferator-activated receptor gamma (PPARγ), a lipid-activated transcription factor, has been implicated in differentiation and lipid metabolism of various cell types. Here, we show that PPARγ is differentially expressed in normal and pathological human sebocytes and appears to have roles in their differentiation and lipid production. We used laser-microdissected normal and pathological human sebaceous glands (SGs) and SZ95 cells (immortalized sebocyte cell line) analyzed by real-time quantitative PCR and immunohistochemistry. Lipids were analyzed by quantitative fluorimetry- and mass spectrometry-based approaches. We have observed that PPARγ and its target genes, ADRP (adipose differentiation-related protein) and PGAR (PPARγ angiopoietin-related protein), are expressed in sebocytes and show association with their level of differentiation. Also, PPARγ is present in normal and hyperplastic SG, whereas its expression levels are decreased in SG adenoma and SG carcinoma cells, reflecting a maturation-linked expression pattern. Furthermore, in SZ95 sebocytes, naturally occurring lipids, including arachidonic acid and arachidonic acid keto-metabolites (e.g., 5-KETE (5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid), 12-KETE (12-oxo-5Z,8Z,10E,14Z-eicosatetraenoic acid)), appear to regulate PPARγ signaling pathways, which in turn modulate phospholipid biosynthesis and induce neutral lipid synthesis. Collectively, our findings highlight the importance of endogenous ligand-activated PPARγ signaling in human sebocyte biology and suggest that PPARγ might be a promising candidate for the clinical management of SG disorders.

Basal cell carcinoma: cell of origin, cancer stem cell hypothesis and stem cell markers

Cancer stem cells have recently been described in several high-grade neoplasms. It is still unclear if they also occur in cutaneous malignancies. Cancer stem cells are not identical with somatic stem cells. The presence of tumour stem cells in a neoplasm does not in itself equal that the tumour derives from a somatic stem cell. A cell originally lacking stem cell characteristics could also acquire those features during the course of carcinogenesis and then becomes the clonal founder cell of a tumour. Basal cell carcinoma (BCC) is the most common cutaneous malignancy. A plethora of various stem cell markers has been applied to study its cellular origin. Intriguingly, the anatomical origin of BCC is still uncertain. This review will discuss the various stem cell markers used in BCC and the cellular origin of this tumour, and touches briefly on the possibility of cancer stem cells in BCC. If BCC or other skin cancers harbour tumour stem cells, these cells could be specifically targeted, making use of specific cell surface molecules such as receptor proteins. Novel drugs directed against those receptor proteins could replace currently available shotgun approaches including imiquimod.

Stem cell markers (cytokeratin 15, cytokeratin 19 and p63) in in situ and invasive cutaneous epithelial lesions

The inherent longetivity of stem cells causes them to be susceptible to multiple genetic hits. Thus, it is not surprising that stem cells are implicated in the etiopathogenesis of select cutaneous neoplasms. However, most studies to date are restricted to the use of a single marker (p63, cytokeratin-15 or cytokeratin-19) and do not appear to compare distribution of stem cell markers in a spectrum of cutaneous in situ versus invasive epithelial malignancies. In this study, we evaluate expression of cytokeratin-15, cytokeratin-19, and p63 in a series of primary cutaneous epithelial lesions that include actinic keratosis (n=29), squamous cell carcinoma in situ (n=30), bowenoid papulosis (n=15) and squamous cell carcinoma, well differentiated (n=29) in order to evaluate the role of stem cell marker expression in the grading and development of in situ and invasive malignancies. For cytokeratin-15, expression was retained in actinic keratosis (38%), squamous cell carcinoma in situ (53%) and bowenoid papulosis (60%) but appeared to be lost in squamous cell carcinoma (3%) with statistically significant differences observed between groups that retained versus those that did not (P<0.05 for all three); for cytokeratin-19, patchy yet basal expression was noted in actinic keratosis (21%), patchy and suprabasal expression was noted in squamous cell carcinoma in situ (37%), bowenoid papulosis (13%) and squamous cell carcinoma (24%) with no statistically significant differences between groups; for p63, expression was retained in actinic keratosis (90%), squamous cell carcinoma in situ (87%), bowenoid papulosis (60%) and squamous cell carcinoma (100%) with no statistically significant differences between groups. In summary, our findings expand the neoplasms which involve stem cells to include cutaneous epithelial malignancies. Differential localization of each of these markers argues in favor of stem cell heterogeneity.

The diagnostic utility of immunohistochemistry in distinguishing primary skin adnexal carcinomas from metastatic adenocarcinoma to skin: an immunohistochemical reappraisal using cytokeratin 15, nestin, p63, D2-40, and calretinin

Often the distinction of primary adnexal carcinoma from metastatic adenocarcinoma to skin from breast, lung, and other sites can be a diagnostic dilemma. Current markers purportedly of utility as diagnostic adjuncts include p63 and D2-40; however, their expression has been demonstrated in 11-22% and 5% of metastatic cutaneous metastases, respectively. Both cytokeratin (CK) 15 and nestin have been reported as follicular stem cell markers. We performed CK15 and nestin, as well as previously reported stains (such as p63, D2-40, and calretinin) on 113 cases (59 primary adnexal carcinomas and 54 cutaneous metastases). Expressions of p63, CK15, nestin, D2-40, and calretinin were observed in 91, 40, 37, 44, and 14% of primary adnexal carcinoma, respectively, and in 8, 2, 8, 4, and 10% of cutaneous metastases, respectively. p63 appeared to be the most sensitive marker (with a sensitivity of 91%) in detecting primary adnexal carcinomas. CK15 appeared to be the most specific marker with a specificity of 98%. Using chi(2) analysis, statistically significant P-values (<0.05) were observed for p63, CK15, nestin, and D2-40 in the distinction of primary adnexal carcinoma versus cutaneous metastases. In logistic regression and stepwise selection for predicting a primary adnexal carcinoma, statistical significance was observed for p63, CK15, and D2-40 (P-values: <0.001, 0.0275, and 0.0298, respectively) but not for nestin (P-value=0.4573). Our study indicates that diagnostic sensitivity and specificity are significantly improved using a selected panel of immunohistochemical markers, including p63, CK15, and D2-40. Positive staining with all three markers argues in favor of a primary cutaneous adnexal neoplasm.

The expression of p63 and p53 in keratoacanthoma and intraepidermal and invasive neoplasms of the skin

p53 is a well-known tumor suppressor gene, and its mutation is a common event in intraepidermal and invasive neoplasms of the skin. p63 is a homologue of the tumor suppressor gene p53, which is expressed in human basal squamous epithelium, and despite its homology to p53, it is considered to act as an oncogene. We evaluated p63 and p53 expression in usual skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), keratoacanthoma (KA), and intraepidermal neoplasms, including Bowen's disease (BD), actinic keratosis (AK), malignant melanoma in situ (MM in situ), and Paget's disease (PD) to clarify the putative role of p63 and p53 in the development and differential diagnosis of these lesions. Seventeen SCC, 23 BCC, 16 KA, 26 AK, 22 BD, 7 MM in situ, and 6 PD were included in this study. We determined decreasing p63 staining in BD, AK, BCC, SCC, and KA, respectively. None of the MM in situ and PD was positive for p63. The mean p53 staining was highest in BD, followed by AK, SCC, PD, KA, BCC, and normal skin. There was no correlation between the groups in terms of p63 and p53 staining. Based on our findings, analysis of p63 expression may be helpful in the differential diagnosis of BD and AK versus MM in situ and PD, particularly in small biopsies.

Increased expression of p63 and survivin in cholesteatomas

CONCLUSION

This study showed increased expression of p63 and survivin in cholesteatoma. Our finding indicates a putative role of p63 and survivin in the development of certain cholesteatomas.

OBJECTIVES

Keratinocytes in cholesteatoma demonstrate uncoordinated hyperproliferation, migration, and invasion properties. p63 is a p53 homologue and a marker expressed in replicating keratinocytes. Survivin is an inhibitor of apoptosis protein that is abundantly expressed in most solid and hematologic malignancies. The purpose of this study was to investigate the differential expression of p63 and survivin in human middle ear cholesteatoma epithelium.

MATERIALS AND METHODS

The expression levels of p63 and survivin protein were examined by immunohistochemical analysis of 40 cholesteatomas and 5 skin tissues obtained from patients during ear surgery.

RESULTS

Expression of p63 protein was diffusely observed in entire samples of cholesteatoma, especially in acquired cholesteatoma, compared with the control group. Congenital cholesteatoma showed variable p63 reactivity in a basal cell-like pattern. Primary and recurrent cholesteatomas showed no significant difference in p63 expression. Survivin was detected in 31 of 40 cholesteatoma samples. Acquired cholesteatomas showed especially increased survivin expression compared with congenital cases. The expression of p63 was correlated with survivin expression.

A Case of Trichilemmal Carcinoma Treated with Mohs Micrographic Surgery

Trichilemmal carcinoma is a cutaneous adnexal tumor originating from the outer root sheath of hair follicle, and it was first described by Headington in 1976. Clinically, it usually occurs as an asymptomatic solitary papule, nodule or mass on the face or scalp. This neoplasm is a malignant counterpart of trichilemmoma, and it has been reported in the literature as trichilemmal carcinoma, tricholemmal carcinoma, malignant trichilemmoma, and tricholemmocarcinoma. Although histologically, trichilemmal carcinoma frequently has maliganant features, it has a relatively benign clinical behavior. We think Mohs micrographic surgery is a useful treatment modality in trichilemmal carcinoma because the final skin defect is smaller than a wide excision. We report a case of primary trichilemmal carcinoma which had developed on the face, treated with Mohs micrographic surgery.

Characterization of DeltaNp63 isoforms in normal cornea and telomerase-immortalized human corneal epithelial cells

Previous reports have suggested that specific isoforms of the potential stem cell marker p63 may regulate corneal epithelial homeostatic renewal through control of cell proliferation. In this study, we characterized the presence of DeltaNp63 isoforms in telomerase-immortalized human corneal epithelial cells (hTCEpi) in comparison to normal human corneal epithelium to validate the hTCEpi cell line as a viable model for the study of p63 isoforms. We further examined roles for DeltaNp63 in proliferation and differentiation. For in vitro studies, hTCEpi cells were cultured in serum-free culture media and grown under 0.15 mM calcium or sequential 1.15 mM calcium/air-lifted culture. Fresh donor human corneal tissue was used to assess expression and localization in situ. mRNA and protein levels were assessed by real-time PCR, Immunofluorescence (IF) and Western blotting (WB). DeltaNp63 expression levels throughout the cell cycle were assessed by double-labeling with DeltaNp63 and Ki-67. In situ, DeltaNp63 localized to nuclei throughout the human corneal epithelium and was lost only in superficial cells. WB confirmed the presence of all three DeltaNp63 isoforms in the central corneal epithelium and in hTCEpi cells. DeltaNp63 mRNA levels decreased when grown on collagen substrate and under increased calcium/air-lifted culture. mRNA and protein levels increased as cells approached confluence, with a significant decrease in post-confluent culture. DeltaNp63 expression levels did not vary with the cell cycle, as assessed by Ki-67 labeling. Collectively, the presence of all three DeltaNp63 isoforms in hTCEpi cells and in intact cornea validates the use of this cell line for the study of individual isoforms in the corneal epithelium; and these data suggest that expression of DeltaNp63 isoforms are not altered as a function of the cell cycle or cell division in subconfluent hTCEpi cells cultured in serum-free media, but demonstrate reduced expression upon contact-inhibited growth down-regulation and differentiation. Significantly, the localization of DeltaNp63 in central corneal epithelial cells with a loss of expression in superficial cells suggests that DeltaNp63 may play a role in mediating desquamative events at the ocular surface.

Distinct epidermal stem cell compartments are maintained by independent niche microenvironments

The mammalian epidermis is a stratified, multilayered epithelium, consisting of the interfollicular epidermis and associated appendages, which extend into the dermis and include hair follicles, sebaceous glands, and sweat glands. Stem cells are essential for the maintenance of this tissue and are also potential sources of multipotent adult precursor cells. Stem cell populations occupying specific locations or niches have been identified in the interfollicular epidermis, the hair follicle and the sebaceous gland. Recent research has focused on how the stem cell niches provide specific sites where stem cells can reside indefinitely and undergo self-renewal or differentiation into specific cell lineages, as required for epidermal replenishment or hair follicle growth.

Prognostic significance of p53 and p63 immunolocalisation in primary and matched lymph node metastasis in oral squamous cell carcinoma

This study evaluates the prognostic significance of p53 and p63 immunolocalisation in oral squamous cell carcinoma samples from 45 matched primary tumors (PT) and lymph node metastases (LNM). Data regarding patient age, gender, primary site, histological differentiation, metastasis, disease-free survival (DFS) and overall survival (OS) were available. p53 and p63 immunolabeling was detected in 17 (37.8%) and 23 (51.1%) of the PT, respectively. For LNM, there was p53 and p63 labeling in 23 (51.1%) and 26 (57.8%) cases, respectively. Most cases showed similar labeling in PT and the corresponding LNM (73.3% for p53 and 53.3% for p63, respectively). No statistically significant associations were found between p53 and p63 immunolabeling and histological differentiation; p63 positive tumors showed higher DFS (p=0.006) and OS (p=0.049); and p53-negative tumors had a higher DFS interval (p=0.009). Our findings suggest that initially p53-negative tumors and initially p63-positive tumors that retain this labeling pattern may follow less aggressive biological courses and present better prognoses.

Use of p63 expression in distinguishing primary and metastatic cutaneous adnexal neoplasms from metastatic adenocarcinoma to skin

p63, a recently identified homologue of the p53 gene, is mainly expressed by basal and myoepithelial cells in skin. Others and we have shown the value of p63 in distinguishing primary adnexal tumors from visceral adenocarcinomas metastatic to skin. We now investigate the pattern of p63 expression in metastases from skin adnexal carcinomas and their cognate primaries and evaluate p63 expression in a larger case series of malignant cutaneous adnexal neoplasms. Immunohistochemical analysis for p63 was performed on 13 metastases of adnexal carcinomas and their corresponding primary tumors. Twenty visceral metastatic adenocarcinomas to the skin and 7 primary mucinous carcinomas with cutaneous or visceral origin were compared. The majority (90.9%) of primary adnexal tumors strongly expressed p63 and their metastases labeled similar to their cognate primary tumors. With one exception, primary or metastatic mucinous carcinomas did not express p63. Metastases from two apocrine carcinomas lacked p63 expression. All other cutaneous metastases from internal adenocarcinomas were negative for p63. Analysis of p63 expression may assist in the differential diagnosis of primary adnexal carcinomas versus metastatic visceral adenocarcinomas to the skin. Metastases from adnexal carcinomas generally retain p63 expression similar to their associated primary tumors.

Hair follicle regeneration using grafted rodent and human cells

Hair follicle regeneration involves epithelial-mesenchymal interactions (EMIs) of follicular epithelial and dermal papilla (DP) cells. Co-grafting of those cellular components from mice allows complete hair reconstitution. However, regeneration of human hair in a similar manner has not been reported. Here, we investigated the possibility of cell-based hair generation from human cells. We found that DP-enriched cells (DPE) are more critical than epidermal cells in murine hair reconstitution on a cell number basis, and that murine DPE are also competent for hair regeneration with rat epidermal cells. Co-grafting of human keratinocytes derived from neonatal foreskins with murine DPE produced hair follicle-like structures consisting of multiple epidermal cell layers with a well-keratinized innermost region. Those structures expressed hair follicle-specific markers including hair keratin, and markers expressed during developmental stages. However, the lack of regular hair structures indicates abnormal folliculogenesis. Similar hair follicle-like structures were also generated with cultured human keratinocytes after the first passage, or with keratinocytes derived from adult foreskins, demonstrating that epidermal cells even at a mature stage can differentiate in response to inductive signals from DP cells. This study emphasizes the importance of EMI in follicular generation and the differentiation potential of epidermal keratinocytes.

P63 expression pattern during rat epidermis morphogenesis and the role of p63 as a marker for epidermal stem cells

BACKGROUND

Recent evidence has suggested that p63 plays a particular role in maintaining the population of epidermal stem cells (ESCs), but the expression pattern of p63 during normal rat epidermis development is still unknown. We investigated the expression of p63 during development and differentiation of rat epidermis and identified whether p63 is a specific marker of rat ESCs cultured in vitro.

METHODS

Skin biopsies were obtained from embryonic day (E) 12 rat embryo, newborn, and 4-week-old rats. Immunohistochemistry was used to monitor the expression profile of p63. ESCs were isolated from newborn rat epidermis by rapid adhesion to IV collagen and examined by immunofluorescence staining to detect p63 and k14 expression.

RESULTS

P63 expression was first observed at E12 when the epidermis was only a simple-layer surface ectoderm. P63 continued to be expressed as the epidermis matured but restricted to the basal layer. In adult trunk epidermis, p63 was expressed in both the hair follicle and the sebaceous glands. Immunofluorescence staining for ESCs was double positive for p63 and k14.

CONCLUSIONS

These expression data suggest a role of p63 in the development of rat epidermis. P63 transcription factor may be a specific marker of keratinocyte progenitor cells.

Cytokeratin, filaggrin, and p63 expression in reepithelialization during human cutaneous wound healing

Cytokeratin (CK), filaggrin (filament aggregating protein), and p63 expression and cellular distribution during reepithelialization has not been systemically studied in the healing stage of human cutaneous wounds. We examined these proteins by immunohistochemical methods in 12 cases of skin ulcer, using seven anti-keratin antibodies, anti-filaggrin, and anti-p63 antibody. At the edge of the wound in skin ulcers, CK1 and 10 expression was reduced, while CK14, 16, and 17 expression was raised. Beneath the wound bed, all layers of the epidermal tongue, deriving from sweat ducts, were positive for CK14 and 17. Both cytokeratins were also found in basal and luminal cells of the dermal duct. CK expression by epithelia continuous with hair follicles showed that, CK14, 16, and 17 were present, and CK1 and 10 were absent. Filaggrin expression was elevated in reepithelialized epithelium. Expression of p63 expression was verified in the suprabasal layer in reepithelialized epithelia. CK, filaggrin, and p63 expression in the reepithelialization stage at the wound edge and at epidermal appendages remaining in the wound bed is undifferentiated and hyperproliferative. The presence of CK14 and 17 in the remaining epidermal appendages in the pathological wound may be important in epidermal replacement.

Immunohistochemical expression of p16, p53, and p63 in colorectal adenomas and adenocarcinomas

PURPOSE

The aim of this study was to investigate the immunohistochemical expression of p16, p53, and p63 proteins according to some pathologic parameters related to colorectal adenomas and adenocarcinomas such as grade of dysplasia and histologic type.

METHODS

Immunohistochemistry with the antibodies p16, p53, and p63 was performed in tubular, tubular-villous, and villous adenomas (n = 30) and in well, moderately, and poorly differentiated adenocarcinomas (n = 30). The p63-positive cases were submitted to double immunolabeling with the cytokeratin 5 (CK5).

RESULTS

The p16 and p53 labelings were observed in some adenomas and adenocarcinomas but without any association with p63 expression, histologic type, or grade of differentiation of the neoplasm. P63 expression was found mainly in the villous adenomas and in the poorly differentiated adenocarcinomas. The poorly differentiated adenocarcinomas also exhibited coexpression of CK5 and p63.

CONCLUSIONS

Despite both p16 and p53 having been detected in colorectal neoplasms, they were not related to the different histologic variables nor to the expression of p63. However, p63 expression was closely associated with villous adenomas and poorly differentiated adenocarcinomas. Thus, p63 may represent a marker of poor differentiation in colorectal neoplasms. The coexpression of p63 and CK5 observed in this study could be related to divergent differentiation during the development of colorectal cancer, although further studies are warranted to refine the understanding of this process.

The expression of p63 in basal cell carcinomas and association with histological differentiation

BACKGROUND

We aim to examine p63 expression in basal cell carcinomas (BCCs) and to investigate association with their histopathological differentiation subtypes.

METHODS

Eighty-four BCCs were classified according to the histopathologic differentiation subtypes. Immunohistochemistry using monoclonal antibody against p63 was performed.

RESULTS

In nontumoral skin, p63 expression was consistently seen in basal/suprabasal cells of epidermis, hair matrix cells, and outer root sheath of the hair follicle. In BCCs, the cases were distributed as 47 undifferentiated, 28 differentiated (16 adenoid and 12 keratotic), and nine superficial. The nuclear p63 expression was negative in two cases, whereas 64 BCCs (76.2%) showed homogeneous p63 immunostaining. There was no statistically significant difference between p63 expression and histological differentiation subtypes (p > 0.05). The expression of p63 was found strongly and diffuse in 72.3% of solid undifferentiated and 82.1% differentiated and in 77.8% of superficial type BCCs.

CONCLUSIONS

p63 is consistently expressed in epidermal basal/suprabasal and adnexal basal cells. Most BCCs have higher homogeneous p63 expression than nontumoral epidermis, which is not changed according to histological differentiation subtypes. Thus, overexpression of p63 in all histological subtypes may confirm that basaloid progenitor cells are linked tumor-cell lineage and have a role in the tumorigenesis of BCC.

Giant vascular eccrine spiradenoma: report of a case with immunohistochemical study

We report a rare case of giant vascular eccrine spiradenoma (GVES) which developed in 56-yr-old Korean woman. It is a rare variant of eccrine spiradenoma (ES), which might be mistaken for angiomatous lesions in view of its florid vascularity and hemorrhagic features. Histogenesis of GVES is not clearly elucidated although it is known that ES presumably originates in the eccrine glands. To clarify the histogenesis of GVES, immunohistochemical stainings using various monoclonal antibodies were also performed. The tumor was composed of three types of cells, namely pale epithelial cells, small basal cells, and myoepithelial cells. Therefore, we conclude that GVES originated from eccrine gland and mainly differentiates toward secretory portion of secretory coil.

Characterization of a novel human type II epithelial keratin K1b, specifically expressed in eccrine sweat glands

In this study, we show that a novel human type II epithelial keratin, K1b, is exclusively expressed in luminal duct cells of eccrine sweat glands. Taking this luminal K1b expression as a reference, we have used antibodies against a plethora of epithelial keratins to systematically investigate their expression in the secretory globule and the two-layered sweat duct, which was divided into the intraglandular, intradermal, and intraepidermal (acrosyringium) segments, the latter being further subdivided into the sweat duct ridge and upper intraepidermal duct. We show that (i) each of the eccrine sweat gland tissue compartments expresses their own keratin patterns, (ii) the peripheral and luminal duct layers exhibit a sequential keratin expression, with both representing self-renewing cell layers, (iii) the intradermal duct and the sweat duct ridge display hitherto unknown length variations, and (iv) out of all cell layers, the luminal cell layer is the most robust layer and expresses the highest number of keratins, these being concentrated at the apical side of the cells to form the cuticle. We provide evidence that the cellular and intercellular properties of the peripheral and the luminal layers reflect adaptations to different functions.

p63 expression in odontogenic cysts

A total of 123 cases of odontogenic cysts, distributed as follows: 30 follicular (FC), 35 radicular (RC), 53 keratocysts, 1 glandular odontogenic and 4 calcifying odontogenic cysts, were analysed by immunohistochemistry for expression of p63, a component of p53 protein family. In RCs p63 positivity was not only in basal and parabasal layers but also in the intermediate layer and about 1/3 of cases displayed a percentage of stained cells comprised between 0 and <5%, and about 2/3 between >5% and <50%. In FCs positivity was confined to basal and parabasal layers of the epithelium and in the majority of FCs the stained cells were comprised between 0 and <5%. OKCs displayed the most intense and diffuse p63 labeling. In conclusion, these data suggest that p63 expression may be useful to identify cysts type with more aggressive and invasive phenotype supporting the hypothesis of a suprabasal proliferative compartment in OKCs.