Differentiating keratoacanthoma from squamous cell carcinoma by the use of apoptotic and cell adhesion markers

Gross, Histologic and Immunohistochemical Characteristics of Keratoacanthomas in Lizards

The present study describes the clinical behavior as well as the histopathologic and immunohistochemical characteristics of keratoacanthomas (Kas) in three different saurian species. While Kas presented as two dermal lesions in a bearded dragon (Pogona vitticeps), multicentric Kas were observed in three panther chameleons (Furcifer pardalis) and a veiled chameleon (Chamaeleo calyptratus). Macroscopically, Kas presented as dome-shaped skin tumors with a centralized keratinous pearl and a diameter ranging from 0.1-1.5 cm. In all lizards, Kas were predominantly located at the dorsolateral body wall, and KA of the eyelid was additionally observed in three out of four chameleons. Histologically, KAs presented as relatively well-defined, circumscribed epidermal proliferations that consisted of a crateriform lesion containing a central keratinous pearl with minimally infiltrating borders. In all KAs, a consistent immunohistochemical pattern was observed, with the expression of cyclooxygenase-2, E-cadherin, and pan-cytokeratin. A follow-up period of one to two years was established in all lizards. While no recurrence was observed in the panther chameleons, recurrence of a single keratoacanthoma was observed in the bearded dragon after one year, and in the veiled chameleon, multicentric keratoacanthomas reappeared during a follow-up period of two years. We describe KA as a previously unrecognized neoplastic entity in lizards that constitutes a low-grade, non-invasive but rapidly growing skin tumor that may show a multicentric appearance, especially in chameleons. As previously postulated for dermal squamous cell carcinomas (SCC), artificial ultraviolet lighting may play an important role in the oncogenesis of KAs in lizards. Although dermal SCCs in lizards show similar predilection sites and gross pathologic features, our results suggest that KA should be considered as a histologic variant of SCC that represents a rather benign squamous proliferation in comparison to conventional SCCs. Early diagnosis of KA and reliable discrimination from SCCs are essential for the prognosis of this neoplastic entity in lizards.

Keratoacanthoma in the External Auditory Canal

A 63-year-old male presented with a prolonged history of bilateral ear discharge, otalgia, and hearing loss. The patient required a significant number of investigations prior to obtaining a diagnosis. Subsequent investigations identified keratoacanthoma affecting the external ear canal (EAC). There has been no case report of keratoacanthoma within the EAC till now. The only risk factor identified for the development of keratoacanthoma, in this case, was the frequent use of earbuds and subsequent long-term trauma associated with a retained bud. The histology of keratoacanthoma is difficult to differentiate from that of squamous cell carcinoma but this is essential for the ear, nose, throat (ENT) multi-disciplinary team.

A clinical and biological review of keratoacanthoma

Keratoacanthoma (KA) is a common skin tumour that remains controversial regarding classification, epidemiology, diagnosis, prognosis and management. Classically, a KA manifests as a rapidly growing, well-differentiated, squamoid lesion with a predilection for sun-exposed sites in elderly people and a tendency to spontaneously regress. Historically, KAs have been considered a variant of cutaneous squamous cell carcinoma (cSCC) and are often reported as KA-type cSCC. However, the penchant for regression has led many to categorize KAs as biologically benign tumours with distinct pathophysiological mechanisms from malignant cSCC. The clinical and histopathological similarities between KA and cSCC, particularly the well-differentiated variant of cSCC, have made definitive differentiation difficult or impossible in many cases. The ambiguity between entities has led to the general recommendation for surgical excision of KAs to ensure a potentially malignant cSCC is not left untreated. This current standard creates unnecessary surgical morbidity and financial strain for patients, especially the at-risk elderly population. There have been no reports of death from a definitive KA to date, while cSCC has an approximate mortality rate of 1·5%. Reliably distinguishing cSCC from KA would shift management strategies for KAs towards less-invasive treatment modalities, prevent unnecessary surgical morbidity, and likely reduce associated healthcare costs. Herein, we review the pathophysiology and clinical characteristics of KA, and conclude on the balance of current evidence that KA is a benign lesion and distinct from cSCC.

The polarity protein PARD3 and cancer

Tissue disorganisation is one of the main hallmarks of cancer. Polarity proteins are responsible for the arrangement of cells within epithelial tissues through the asymmetric organisation of cellular components. Partition defective 3 (PARD3) is a master regulator of the Par polarity complex primarily due to its ability to form large complexes via its self-homologous binding domain. In addition to its role in polarity, PARD3 is a scaffolding protein that binds to intracellular signalling molecules, many of which are frequently deregulated in cancer. The role of PARD3 has been implicated in multiple solid cancers as either a tumour suppressor or promoter. This dual functionality is both physiologically and cell context dependent. In this review, we will discuss PARD3's role in tumourigenesis in both laboratory and clinical settings. We will also review several of the mechanisms underpinning PARD3's function including its association with intracellular signalling pathways and its role in the regulation of asymmetric cell division.

P2X7 in Cancer: From Molecular Mechanisms to Therapeutics

P2X7 is a transmembrane receptor expressed in multiple cell types including neurons, dendritic cells, macrophages, monocytes, B and T cells where it can drive a wide range of physiological responses from pain transduction to immune response. Upon activation by its main ligand, extracellular ATP, P2X7 can form a nonselective channel for cations to enter the cell. Prolonged activation of P2X7, via high levels of extracellular ATP over an extended time period can lead to the formation of a macropore, leading to depolarization of the plasma membrane and ultimately to cell death. Thus, dependent on its activation state, P2X7 can either drive cell survival and proliferation, or induce cell death. In cancer, P2X7 has been shown to have a broad range of functions, including playing key roles in the development and spread of tumor cells. It is therefore unsurprising that P2X7 has been reported to be upregulated in several malignancies. Critically, ATP is present at high extracellular concentrations in the tumor microenvironment (TME) compared to levels observed in normal tissues. These high levels of ATP should present a survival challenge for cancer cells, potentially leading to constitutive receptor activation, prolonged macropore formation and ultimately to cell death. Therefore, to deliver the proven advantages for P2X7 in driving tumor survival and metastatic potential, the P2X7 macropore must be tightly controlled while retaining other functions. Studies have shown that commonly expressed P2X7 splice variants, distinct SNPs and post-translational receptor modifications can impair the capacity of P2X7 to open the macropore. These receptor modifications and potentially others may ultimately protect cancer cells from the negative consequences associated with constitutive activation of P2X7. Significantly, the effects of both P2X7 agonists and antagonists in preclinical tumor models of cancer demonstrate the potential for agents modifying P2X7 function, to provide innovative cancer therapies. This review summarizes recent advances in understanding of the structure and functions of P2X7 and how these impact P2X7 roles in cancer progression. We also review potential therapeutic approaches directed against P2X7.

The role of p53, Ki-67 and laminin expression in the differential diagnosis of keratoacanthoma and well-differentiated SCC

Introduction

We have aimed to evaluate the difference between the expression of p53, Ki-67, and laminin in keratoacanthoma and well-differentiated SCC (SCC) and to determine its importance in differential diagnosis.

Methods

This study totally included 46 cases consisting of 23 cases with keratoacanthoma and 23 with SCC. As well as age, gender, localization, and diameter of the lesion, the expression of p53, Ki-67 and laminin was evaluated.

Results

No statistically significant difference was found between KA and well-differentiated SCC in terms of diameter, age, and localization. There was a statistically significant difference between KA and well-differentiated SCC in terms of p53 and Ki-67 staining (P < 0.001). Increased expression of p53 and Ki-67 was found in well-differentiated SCC. A statistically significant correlation was present between the expression of p53 and Ki-67 in KA. A statistically significant difference was detected between KA and well-differentiated SCC in terms of laminin staining (P = 0.018). Increased laminin expression was determined in well-differentiated SCC.

Conclusion

We have determined in this study that p53, Ki-67 and laminin may be used as adjuvant immunohistochemical markers in differential diagnosis of KA and well-differentiated SCC.

Keratoacanthoma of the lip: A case report with emphasis on histogenesis

Keratoacanthoma (KA) is a benign epithelial tumor which presents clinically as a proliferating dome-shaped keratin-filled crater. The lesion occurs predominantly upon sun-exposed areas of the body and is known to arise from hair follicle. Actinic rays are a major contributing factor in the etiology. It simulates grossly as well as microscopically a low-grade squamous cell carcinoma. KAs occur habitually on the mucous membrane as well, but their origin in these cases is debatable, owing to the lack of hair follicles in these sites. Our report is an attempt to demonstrate the cells that could be responsible for initiation of this lesion on the oral mucosa.

Keratoacanthoma (KA): An update and review

Keratoacanthoma (KA) is a common but underreported tumor of the skin. Two striking features of KA are its clinical behavior with spontaneous regression after rapid growth and its nosological position on the border between benignity and malignancy. We review current knowledge on the clinical, histopathological, and dermoscopic features of KA to ensure a proper diagnosis and describe its variants, including different types of multiple KAs. We highlight current concepts of KA ethiopathogenesis with special emphasis on the genetic background of multiple familial KA, the role of Wnt signaling pathway, and induction of KA by BRAF inhibitors and procedures of esthetic dermatology. Finally, treatment strategies are presented with surgical excision as a first option, followed by other modalities, including intralesional chemotherapy, topical and systemic agents, lasers, cryotherapy, and photodynamic therapy.

Keratoacanthoma and squamous cell carcinoma are distinct from a molecular perspective

Keratoacanthoma is a controversial entity. Some consider keratoacanthoma as a variant of squamous cell carcinoma, whereas others see it as a distinct self-resolving squamoproliferative lesion. Our objective is to examine the relationship of keratoacanthoma with squamous cell carcinoma and normal skin by using DNA microarrays. DNA microarray studies were performed on formalin-fixed and paraffin-embedded blocks from ten cases of actinic keratoacanthoma utilizing the U133plus2.0 array. These results were compared with our previously developed microarray database of ten squamous cell carcinoma and ten normal skin samples. Keratoacanthoma demonstrated 1449 differentially expressed genes in comparison with squamous cell carcinoma (>5-fold change: P<0.01) with 908 genes upregulated and 541 genes downregulated. Keratoacanthoma showed 2435 differentially expressed genes in comparison with normal skin (>5-fold change: P<0.01) with 1085 genes upregulated and 1350 genes downregulated. The most upregulated genes, comparing keratoacanthoma with normal skin included MALAT1, S100A8, CDR1, TPM4, and CALM1. The most downregulated genes included SCGB2A2, DCD, THRSP, ADIPOQ, adiponectin, and ADH1B. The molecular biological pathway analysis comparing keratoacanthoma with normal skin showed that cellular development, cellular growth and proliferation, cell death/apoptosis, and cell cycle pathways are prominently involved in the pathogenesis of keratoacanthoma. The most enriched canonical pathways were clathrin-mediated endocytosis signaling, molecular mechanisms of cancer and integrin signaling. The distinctive gene expression profile of keratoacanthoma reveals that it is molecularly distinct from squamous cell carcinoma. The molecular pathways and genes differentially expressed in comparing keratoacanthoma with normal skin suggest that keratoacanthoma is a neoplasm that can regress due to upregulation of the cell death/apoptosis pathway.

Pattern of TGFbeta receptor 1 expression differs between kras-mutated keratoacanthomas and squamous cell carcinomas of the skin

PURPOSE

Increasing evidence indicates that TGFbeta- and EGFR-signaling is involved in the pathogenesis of keratoacanthoma (KA) and squamous cell carcinoma (SCC) of the skin. We analyzed the expression pattern of TGFbeta-signaling components and screened for mutations in tgfbetaR1, egfr, kras and braf in KAs and SCCs.

METHODS

Immunohistochemical analysis of TGFbeta1, TGFbetaR1, TGFbetaR2 and phospho-SMAD2/3 was performed on skin tumors (29 KAs, 30 well and 31 moderately differentiated SCCs). Mutation screening in hotspot regions of tgfbetaR1, egfr, kras and braf was performed through pyrosequencing of tumor DNA.

FINDINGS

Expression of TGFbeta1, TGFbetaR1 and p-SMAD2/3 was increased in tumors as compared to surrounding skin. In KAs characteristic strong discontinuous membranous TGFbetaR1 expression pattern frequently associated with kras mutation was noted. SCCs showed continuous TGFbetaR1 expression, stronger p-SMAD2/3 expression and less frequent kras mutations. In tumors at sun-exposed sites stronger TGFbetaR1 expression was noted. One SCC showed tgfbetaR1 mutation, but no other mutations were found.

CONCLUSION

Although tgfbetaR1 germline mutations cause inherited KAs and our finding of strong discontinuous membranous expression in KAs suggests accumulation of functionally altered protein, we found no tgfbetaR1 mutations or influence on TGFbeta-signaling, but frequent kras mutations in this subgroup of KAs. Characteristic TGFbetaR1 expression pattern in KA can facilitate histopathologic distinction from SCC.

Histopathology of Keratoacanthoma Revisited

Background/Aims. Given the defining histopathologic architecture of keratoacanthoma (KA), the aim of this study was to measure the crateriform orifice (“orificial size”) in histopathologically crateriform lesions to ascertain its utility as an objective diagnostic histopathologic adjunct. Methods. This cross-sectional, retrospective study included 97 cases with a histopathologic diagnosis of KA. We measured the “orificial size” using the ocular micrometer in a BH-2 Olympus microscope at 4× magnification, in a blinded manner with respect to information. Frequency of histopathologic features observed was also recorded. Results. The average orificial size for different groups was as follows: 2.3 ± 0.2 mm for cases with a clinical presentation of KA/keratotic papule (KP) (n = 30) versus 2.9 ± 0.3 mm for other (n = 67), P = .18. Histopathologic findings in the 2 groups were as follows: crateriform architecture/epithelial lip and sharp demarcation of tumor from stroma (100% in both groups), fibrosis (29/30 vs 64/67), apoptotic keratinocytes (27/30 vs 56/67), dermal islands of “glassy” keratinocytes (26/30 vs 54/67), entrapped elastic fibers (26/30 vs 49/67), and neutrophilic abscesses (11/30 vs 21/670 [ P = not significant for all]. Conclusion. Our findings indicate that, in the appropriate clinical setting, a smaller orificial size, although predictive of a KA, in itself is not sufficient for a definitive diagnosis. Given that a major limitation is that this is a function of age of the lesion as orificial size depends on the evolution stage of the neoplasm with the largest diameter often evident in lesions at early stages of regression, for now correlation with histopathologic features such as presence of an epithelial lip, sharp demarcation of tumor from stroma, and fibrosis (present in >95% of cases of KAs) is required.

IMP-3 expression in keratoacanthomas and squamous cell carcinomas of the skin: an immunohistochemical study

The protein insulin-like growth factor II mRNA binding protein 3 (IMP-3) is an important factor for cell migration and adhesion in malignancies. Recent studies have shown a remarkable overexpression of IMP-3 in different human malignant neoplasms and also revealed it as an important prognostic marker in some tumor entities. The purpose of this study is to compare IMP-3 immunostaining in cutaneous squamous cell tumors and determine whether IMP-3 can aid in the differential diagnosis of these lesions. To our knowledge, IMP-3 expression has not been investigated in skin squamous cell proliferations thus far. Immunohi-stochemical staining for IMP-3 was performed on slides organized by samples from 67 patients, 34 with keratoacanthoma (KA) and 33 with primary cutaneous squamous cell carcinoma (SCC) (16 invasive and 17 in situ). Seventyfour percent of KAs (25/34) were negative for IMP-3 staining, while 57% of SCCs (19/33) were positive for IMP-3 staining. The percentage of IMP-3 positive cells increased significantly in the invasive SCC group (P=0.0111), and particularly in the SCC in situ group (P=0.0021) with respect to the KA group. IMP-3 intensity staining was significantly higher in invasive SCCs (P=0.0213), and particularly in SCCs in situ (P=0.008) with respect to KA. Our data show that IMP-3 expression is different in keratoacanthoma with respect to squamous cell carcinoma. IMP-3 assessment and staining pattern, together with a careful histological study, can be useful in the differential diagnosis between KA e SCC.

[The value of laminin-322 staining in distinguishing between keratoacanthoma, keratoacanthoma with areas of squamous cell carcinoma, and crateriform squamous cell carcinoma]

INTRODUCTION

Keratoacanthoma is a fast-growing crateriform skin tumor. Approximately 25% of such tumors undergo malignant transformation and develop areas of squamous cell carcinoma (SCC). The presence of laminin-322 has been associated with progression to invasive forms of SCC. The aim of this study was to determine whether or not immunohistochemical staining for laminin-322 would be of value in distinguishing between keratoacanthomas, keratoacanthomas with areas of squamous cell carcinoma, and SCCs.

MATERIAL AND METHODS

Seventy-four lesions were selected from the pathology archives of our hospital and divided into 4 groups: 20 keratoacanthomas without SCC, 20 keratoacanthomas with areas of squamous cell carcinoma, 20 invasive SCCs (8 with crateriform morphology) unrelated to keratoacanthoma, and 14 problem lesions (keratoacanthomas with areas suggestive of SCC). All 74 lesions were stained for laminin-322.

RESULTS

Laminin-322 staining was strongly positive both in areas of SCC in keratoacanthomas with malignant transformation and in invasive SCCs (mostly at the invasive front of the SCC). However, in benign keratoacanthomas, it was only weakly positive and furthermore it was confined to isolated cells or small groups of cells. The 14 problem lesions were reexamined after laminin-322 staining and 8 were diagnosed as keratoacanthomas with incipient SCC and 6 as keratoacanthomas without SCC.

CONCLUSIONS

Laminin-322 staining is different in keratoacanthomas and SCCs and would thus be a useful test for differentiating keratoacanthomas from both invasive SCCs and keratoacanthomas with areas of squamous cell carcinoma. It would also be of value in diagnosing keratoacanthomas with areas suggestive of SCC or with incipient SCC.

The nuclear factor kappa B p50 subunit and cortactin as markers to distinguish between keratoacanthoma and well-differentiated squamous cell carcinoma

BACKGROUND

Distinguishing keratoacanthoma (KA) from well-differentiated squamous cell carcinoma (SCC) is sometimes difficult. Recent evidence indicates that the nuclear factor kappa B p50 subunit (p50) and cortactin might be useful to distinguish between these two conditions.

AIM

To verify whether p50 and cortactin are useful differentiation markers to distinguish between subungual KA and well-differentiated SCC.

METHODS

Immunohistochemistry using p50, cortactin and Ki-67 was performed on 20 patients with KA and 20 patients with facial well-differentiated SC. Ki-67 staining was also evaluated and scored.

RESULTS

Both p50 and cortactin had higher levels of expression in KA than in SCC. Both were localized to the basal-cell layer of KA, whereas they were scattered without polarity throughout the SCC lesions. Although the Ki-67 index was not significantly different between KA and SCC, the staining pattern also showed loss of polarity in SCC.

CONCLUSION

p50 and cortactin might be useful makers to distinguish between KA and well-differentiated SCC.

Role of brush biopsy and DNA cytometry for prevention, diagnosis, therapy, and followup care of oral cancer

Late diagnosis resulting in late treatment and locoregional failure after surgery are the main causes of death in patients with oral squamous cell carcinomas (SCCs). Actually, exfoliative cytology is increasingly used for early detection of oral cancer and has been the subject of intense research over the last five years. Significant advances have been made both in relation to screening and evaluation of precursor lesions. As this noninvasive procedure is well tolerated by patients, more lesions may be screened and thus more oral cancers may be found in early, curable stages. Moreover, the additional use of DNA image cytometry is a reasonable tool for the assessment of the resection margins of SCC. DNA image cytometry could help to find the appropriate treatment option for the patients. Finally, diagnostic DNA image cytometry is an accurate method and has internationally been standardized. In conclusion, DNA image cytometry has increasing impact on the prevention, diagnostic, and therapeutical considerations in head and neck SCC.

Keratoacanthoma: facts and controversies

The keratoacanthoma and its variants are clinically and histologically heterogenous. Some consider the keratoacanthoma to be benign, whereas others classify it as a subtype of squamous cell carcinoma. The keratoacanthoma is generally treated rather than observed for spontaneous resolution. This hampers evaluation of the true natural history of lesions diagnosed as keratoacanthoma. In addition, studies have not found a reliable marker to differentiate keratoacanthoma from squamous cell carcinoma. It currently remains unclear how the keratoacanthoma relates to squamous cell carcinoma, and continued investigation is necessary.

PGP 9.5 and Cyclin D1 Coexpression in Cutaneous Squamous Cell Carcinomas

Background: squamous cell carcinoma (SCC) consists of altered keratinocytes, presents variable differentiation, inexorably progresses, and on occasion metastasizes. Objective: to investigate the biological activity of epidermal cells in SCCs by estimating the expression of PGP 9.5 and cyclin D1 using immunohistochemistry. Methods: the sample included 13 well-differentiated cases of cutaneous SCC (grade I), 12 moderately differentiated tumors (grade II), and 7 poorly differentiated lesions (grade III). Four cases belonged to the distinct entity of pseudoadenoid SCC. Results: PGP 9.5 expression was positively correlated with tumor stage ( P < .001) and potential perineural invasion ( P < .001), whereas cyclin D1 expression correlated inversely with the degree of cellular differentiation ( P < .001) and PGP 9.5 immunostaining ( P < .001). Conclusion: PGP 9.5 and cyclin D1 coexpression was closely associated with tumor aggressiveness and can be classified as a marker for predicting the outcome of resection-treated skin cancer patients.

Activation of P2X(7)-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice

BACKGROUND

The study tested the hypothesis that apoptosis can prevent and control growth of neoplastic cells. Previous studies in-vitro have shown that the pro-apoptotic P2X(7) receptor regulates growth of epithelial cells. The specific objective of the present study was to understand to what degree the P2X(7) system controls development and growth of skin cancer in vivo, and what cellular and molecular mechanisms are involved in the P2X(7) action.

METHODS

Skin neoplasias in mice (papillomas, followed by squamous spindle-cell carcinomas) were induced by local application of DMBA/TPA. Experiments in-vitro utilized cultured epidermal keratinocytes generated from wild-type or from P2X(7)-null mice. Assays involved protein immunostaining and Western blots; mRNA real-time qPCR; and apoptosis (evaluated in situ by TUNEL and quantified in cultured keratinocytes as solubilized DNA or by ELISA). Changes in cytosolic calcium or in ethidium bromide influx (P2X(7) pore formation) were determined by confocal laser microscopy.

RESULTS

(a) Co-application on the skin of the P2X7 specific agonist BzATP inhibited formation of DMBA/TPA-induced skin papillomas and carcinomas. At the completion of study (week 28) the proportion of living animals with cancers in the DMBA/TPA group was 100% compared to 43% in the DMBA/TPA+BzATP group. (b) In the normal skin BzATP affected mainly P2X(7)-receptor - expressing proliferating keratinocytes, where it augmented apoptosis without evoking inflammatory changes. (c) In BzATP-treated mice the degree of apoptosis was lesser in cancer than in normal or papilloma keratinocytes. (d) Levels of P2X(7) receptor, protein and mRNA were 4-5 fold lower in cancer tissues than in normal mouse tissues. (e) In cultured mouse keratinocytes BzATP induced apoptosis, formation of pores in the plasma membrane, and facilitated prolonged calcium influx. (f) The BzATP-induced apoptosis, pore-formation and augmented calcium influx had similar dose-dependence for BzATP. (g) Pore formation and the augmented calcium influx were depended on the expression of the P2X(7) receptor, while the BzATP-induced apoptosis depended on calcium influx. (h) The BzATP-induced apoptosis could be blocked by co-treatment with inhibitors of caspase-9 and caspase-3, but not of caspase-8.

CONCLUSION

(a) P2X(7)-dependent apoptosis is an important mechanism that controls the development and progression of epidermal neoplasia in the mouse. (b) The P2X(7)-dependent apoptosis is mediated by calcium influx via P2X(7) pores, and involves the caspase-9 (mitochondrial) pathway. (c) The diminished pro-apoptotic effect of BzATP in mouse cancer keratinocytes is possibly the result of low expression of the P2X(7) receptor. (d) Activation of P2X(7)-dependent apoptosis, e.g. with BzATP could be a novel chemotherapeutic growth-preventive modality for papillomas and epithelial cancers in vivo.

Expression of the P2X7 receptor increases the Ca2+ content of the endoplasmic reticulum, activates NFATc1, and protects from apoptosis

The P2X(7) receptor is known for the cytotoxic activity because of its ability to cause opening of non-selective pores in the plasma membrane and activate apoptotic caspases. A key factor of P2X(7)-dependent cytotoxicity is the massive intracellular Ca(2+) increase triggered by its activation. Here we show that P2X(7) transfection increased the ability of the endoplasmic reticulum to accumulate, store, and release Ca(2+). This caused a larger agonist-stimulated increase in cytosol and mitochondrial Ca(2+) in P2X(7) transfectants than in mock transfected cells. P2X(7) transfectants survived and even proliferated in serum-free conditions and were resistant to apoptosis triggered by ceramide, staurosporin, or intracellular Zn(2+) chelation. Finally, the nuclear factor of activated T cells complex 1 (NFATc1) was strongly activated in the P2X(7) transfectants. These observations support our previous finding that the P2X(7) receptor under tonic conditions of stimulation, i.e. those observed in response to basal ATP release, has an anti-apoptotic or even growth promoting rather than cytotoxic activity.

Additional use of DNA-image cytometry improves the assessment of resection margins

BACKGROUND

Despite the histopathologic findings of tumor-free margins, patients with oral squamous cell carcinoma (SCC) often suffer from local tumor relapse. The purpose of this study was to determine the prognostic value of DNA-image cytometry in the assessment of resection margins.

METHODS

DNA-image cytometry was performed in 40 SCC patients with histologically tumor-free resection margins. The follow-up period since the tumor resection was at least 3 years.

RESULTS

Twenty patients showed a locoregional relapse of the SCC. Fourteen of these patients had aneuploid cells in DNA-image cytometry. Two patients who were relapse-free revealed aneuploid cells too. The sensitivity of the adjuvant use of DNA-image cytometry was 70% and the positive predictive value was 87.5%.

CONCLUSIONS

The additional use of DNA-image cytometry is a reasonable tool for the assessment of the resection margins of SCCs. DNA-image cytometry could help to find the appropriate treatment option for the patients and thus might improve their prognosis.

Silver-stained nucleolar organizer regions and immunoglobulins in cutaneous squamocellular tumors

This study was conducted to elucidate the biological activity of epidermal cells in cutaneous squamocellular tumors by counting the number of silver-stained nucleolar organizer regions (AgNORs), to estimate the quantity of Ig-producing cells and the inflammatory cellular infiltrate (ICI), and to achieve a comparative evaluation. Twenty cases of actinic keratosis (AK), 20 in situ squamous cell carcinomas (ISC), and 20 invasive squamous cell carcinomas (SCCs) were assessed using a silver colloid technique. Ig-producing or binding cells and ICI were also investigated immunohistochemically. In all samples, AgNORs, Ig-producing cells, and ICI increased in proportion to the degree of malignancy. With regard to AgNORs values, a statistically significant difference was confirmed between AK and ISC (p<0.01), AK and SCC (p<0.001), and ISC and SCC (p<0.05). IgG-producing cells predominated in each case. Furthermore, a linear correlation was detected between ICI and AgNORs in AK and ISC. The significant difference in the number of AgNORs among the 3 stages of involution of SCC reinforces the value of AgNORs as a marker for malignant potential. Despite the absence of a correlation between AgNORs and the proportion of Ig-producing cells, the association between ICI and AgNORs in AK and ISC was obvious.