A simple and rapid quantitative sweat test based on cobalt chloride color change

BACKGROUND

Existing sweat tests are either cumbersome, require dedicated technical equipment and/or do not give reliable quantitative results. The present study was performed to develop and describe a rapid and simple test for a practical and quantitative evaluation of sweating.

METHODS

Cobalt chloride patches were used to collect sweat during exercise and after application of aluminum hydrochloride. Color change from blue to red was recorded and quantified, and the amount of sweat was calculated from a standard curve.

RESULTS

Cobalt-chloride-containing patches evaluated with standard office equipment provide a rapid, simple and highly sensitive method for the quantitative measurement of sweating.

CONCLUSIONS

Possible applications that need to be evaluated in further studies are the diagnosis and monitoring of diseases associated with disordered sweat production and the evaluation of antiperspirants.

Correlation of serum procalcitonin with the severity of skin and skin structure infections - a pilot study

BACKGROUND

Procalcitonin (PCT) is a specific biomarker for early detection of bacterial infections. While the usefulness of procalcitonin in severe conditions such as sepsis is well established, its relevance in the diagnosis and prognosis of localized cutaneous bacterial infections is unknown. Our aim was to initially evaluate if PCT is a useful parameter for predicting the severity of skin and skin structure infections (SSSI). Furthermore, the correlation of PCT levels with C-reactive protein (CRP), leukocyte counts, erythrocyte sedimentation rate (ESR), and body temperature was investigated.

PATIENTS AND METHODS

Serum PCT, routine laboratory parameters, and body temperature were regularly examined in 50 consecutive patients with SSSI requiring inpatient intravenous antibiotic treatment. Patients were classified into 2 groups according to the guidelines developed by the FDA (U.S. Food and Drug Administration) as having either an uncomplicated (SSSI) or a complicated skin and skin structure infection (cSSSI).

RESULTS

No significant correlation could be detected between the length of inpatient antibiotic treatment and PCT on days 1, 2, 3, and the maximum value on these days. The same result was found when uncomplicated SSSI and complicated SSSI (cSSSI) were evaluated separately. However, PCT levels were significantly higher in the latter. Furthermore, PCT levels showed a significant correlation with CRP, leukocyte count, ESR, and body temperature.

CONCLUSION

PCT might be a useful additional tool for initial diagnosis and monitoring of patients with SSSI.

High expression of Dicer reveals a negative prognostic influence in certain subtypes of primary cutaneous T cell lymphomas

BACKGROUND

Aberrant expression of microRNAs (miRNAs) has been implicated in oncogenesis of various tumors and primary cutaneous T cell lymphomas. Dicer, a ribonuclease III-like enzyme is essential for miRNA processing.

OBJECTIVE

We initiated a retrospective study to characterize the alterations in the expression profile of Dicer in patients with primary cutaneous T cell lymphomas (CTCL).

METHODS

A total of 50 consecutive patients with primary CTCL were studied, with the majority having mycosis fungoides (n=34). Five patients had primary cutaneous CD 30+ anaplastic large cell lymphoma, four patients each had lymphomatoid papulosis and primary cutaneous CD4-positive small/medium T-cell lymphoma, one primary cutaneous γδ T cell lymphoma, one Sézary syndrome and another subcutaneous panniculitis-like T cell lymphoma of αβ-phenotype. Immunohistochemistry was performed on paraffin sections using a commercially available antibody against Dicer. Intensity of expression was correlated with clinical parameters including disease specific survival (DSS) and time to progression (TTP).

RESULTS

After a median follow-up of 74 months (range: 1-271), 12/50 patients (24%) have died. Univariate and multivariate analysis for disease-specific survival showed Dicer expression and stage as a negative predictive factor in the sole group of MF patients (n=34) as well as in the heterogeneous group of patients (n=50), but not gender, histological subtype, primary localization of disease, age and recurrence of lymphoma (p>0.05).

CONCLUSION

Our data suggest Dicer expression as a possible molecular marker in patients with MF and apparently indicate that miRNA(s) might be of clinical relevance in CTCL.

Phototherapy of mycosis fungoides

BACKGROUND/PURPOSE

Among the primary cutaneous T-cell lymphomas, mycosis fungoides (MF) is the most common disease entity. Recently, an improved understanding of the pathology, clinical presentation, and prognosis of MF has lead to the development of new and practically useful classification and staging systems. In most patients, MF presents with patches and plaques and remains confined to the skin for years and decades, making it an ideal target for phototherapy. However, treatment schedules vary widely and this review describes the current knowledge about phototherapy of MF focusing mainly on narrow- and broadband UVB and 8-methoxypsoralen plus UVA, its indications, practical aspects, and clinical outcome.

METHODS

Review and summary of the pertinent literature.

RESULTS AND CONCLUSIONS

Since 1976, when the first report on phototherapy for MF was published, sufficient evidence has accumulated to make narrowband UVB and PUVA safe and effective treatment options for early stages of the disease. In refractory cases or more advanced stages, combination of phototherapy with systemic treatments including mainly interferons and retinoids might be valuable. Additional research is required to further define the optimal treatment schedules and the role of maintenance.

EGCG-meditated cyto- and genotoxicity in HaCat keratinocytes is impaired by cell-mediated clearance of auto-oxidation-derived H2O2: an algorithm for experimental setting correction

Several lines of evidence suggest that besides antioxidant also prooxidant properties are crucially involved in cytotoxic and protective activities of the major green tea catechin epigallocatechin-3-gallate (EGCG) in vitro (Elbling et al., 2011). Furthermore recent data suggest that EGCG induces oxidative stress also in vivo (Li et al., 2010). Here we set out to identify factors modulating cellular effects of EGCG in vitro. Using the HaCat keratinocytes model, we demonstrate that the cytotoxic, genotoxic and signal-activating effects of EGCG are significantly dependent on the ratio of cell number to working volume. Treatment with identical EGCG concentrations at altered experimental settings resulted in IC(50) values differing up to orders of magnitude and could even exert contradictory effects. This effect was based on cell-mediated clearance of autooxidation-derived H(2)O(2) from the supernatant. In order to estimate EGCG/H(2)O(2) concentrations equally effective under different settings, we have rationally derived and experimentally verified a simple algorithm relating concentration, working volume, cell number and - indirectly - exposure time. Algorithm application resulted in similar H(2)O(2) clearance curves from cell supernatants as well as comparable EGCG/H(2)O(2) effects at different settings. Our results demonstrate the importance of standardized experimental settings when investigating cytotoxic and/or beneficial effects of autooxidizing compounds.

The hsp27kD heat shock protein and p38-MAPK signaling are required for regular epidermal differentiation

BACKGROUND

In human epidermal keratinocytes the expression of hsp27 is closely related to differentiation in vitro and in situ.

OBJECTIVE

We aimed to gain further insight into the role of hsp27 in epidermal differentiation by specific inhibition through siRNA and inhibition of p38-MAPK, the key enzyme of hsp27 phosphorylation.

METHODS

Normal human keratinocytes (KC) and organotypic skin cultures (SE-skin equivalents) were used. Expression and phosphorylation of hsp27 was inhibited in these models by siRNA and SB203580, a specific inhibitor of p38-MAPK, respectively. Modification of morphology and expression of hsp27 and other differentiation associated proteins was investigated by immunofluorescence, western blot, and RT-PCR.

RESULTS

Inhibition of p38-MAPK resulted in a downregulation of hsp27 in KC and SE. Additionally, in the presence of SB203580 Ca(2+) induced expression of pro-filaggrin and loricrin was inhibited at the protein level and expression of filaggrin, keratin 10, and transglutaminase 1 at the mRNA level. Addition of SB203580 to SE, as well as hsp27 knockdown in this model resulted in identical patterns of irregular differentiation, disturbance of epidermal layers, and delayed expression of K10.

CONCLUSION

These results provide evidence that the expression of hsp27 and its phosphorylation by p38-MAPK are required for keratinocyte differentiation and for the formation of a regularly stratified epidermis.

Significance of heat shock proteins in the skin upon UV exposure

The expression of heat shock proteins (Hsp) expression is induced in all cells by exposure to heat and other environmental stress and Hsp can protect cells from damage through further exposure. Hsp are highly conserved and it is likely that they are essential for survival in a potentially harmful environment. Most Hsp are molecular chaperones sensing unfolded proteins and mediating their re-folding, transport, and interaction. In human epidermis Hsp are associated with differentiation, photoprotection, and skin disease. Recent research has mainly focused on the 27kD and 72kD Hsp that are constitutively expressed in keratinocytes. Cell death induced by ultraviolet radiation (UV) can be inhibited by previous heat shock and UV itself can induce Hsp experimentally. Regulation of Hsp can be pharmacologically modified and topical and systemic inducers and inhibitors of Hsp expression are under development. Whether phototherapy exerts its clinical efficacy by modulation of Hsp has not been sufficiently studied. The UV-wavelength ranges, -intensities and -doses that are required to interfere with the heat shock response in the skin still remain to be elucidated.

Rituximab monotherapy for primary cutaneous B-cell lymphoma: response and follow-up in 16 patients

BACKGROUND

We have carried out a retrospective analysis to evaluate the therapeutic value of the anti-CD20 antibody rituximab in 16 consecutive patients with primary cutaneous CD20+ B-cell lymphomas.

PATIENTS AND METHODS

Sixteen patients (4 females, 12 males) with a median age of 54 years received systemic therapy with rituximab 375 mg/m(2) once weekly for four or six consecutive weeks. Eleven patients had primary cutaneous follicle center cell lymphoma and five patients had a primary cutaneous marginal zone B-cell lymphoma.

RESULTS

Of the 16 patients with PCBCL, 14 patients (87.5%) achieved complete remission (CR). In two patients, partial remission was obtained and additional focal radiotherapy was applied, which resulted in final CR. Five to 14 (35%) patients with CR relapsed, in an interval between 6 and 37 months. There were no severe side-effects.

CONCLUSIONS

On the basis of our results, single-agent treatment with i.v. rituximab appears to be feasible and safe and results in a high rate of durable remissions. Judging from our data, it appears to be an attractive treatment option and should be directly compared with local radiotherapy.

Down-modulation of CXCR3 surface expression and function in CD8+ T cells from cutaneous T cell lymphoma patients

Viruses can escape destruction by the immune system by exploitation of the chemokine-chemokine receptor system. It is less established whether human cancers can adopt similar strategies to evade immunologic control. In this study, we show that advanced cutaneous T cell lymphoma (CTCL) is associated with selective and efficient inactivation of CXCR3-dependent T cell migration. Our studies demonstrate that this alteration is at least in part due to CXCR3 down-regulation in vivo by elevated serum levels of CXCR3 ligands. The T cell population most affected by this down-regulatory mechanism are CD8+ cytotoxic effector T cells. In CTCL patients, cytotoxic effector T cells have strongly reduced surface CXCR3 expression, accumulate in peripheral blood, but are virtually absent from CTCL tumor lesions, indicating an inability to extravasate into lymphoma tissue. CTCL-associated inactivation of effector cell recruitment may be a paradigmatic example of a new type of immune escape mechanisms shielding the neoplasm from a tumoricidal attack.

Revisions to the staging and classification of mycosis fungoides and Sezary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (EORTC)

The ISCL/EORTC recommends revisions to the Mycosis Fungoides Cooperative Group classification and staging system for cutaneous T-cell lymphoma (CTCL). These revisions are made to incorporate advances related to tumor cell biology and diagnostic techniques as pertains to mycosis fungoides (MF) and Sézary syndrome (SS) since the 1979 publication of the original guidelines, to clarify certain variables that currently impede effective interinstitution and interinvestigator communication and/or the development of standardized clinical trials in MF and SS, and to provide a platform for tracking other variables of potential prognostic significance. Moreover, given the difference in prognosis and clinical characteristics of the non-MF/non-SS subtypes of cutaneous lymphoma, this revision pertains specifically to MF and SS. The evidence supporting the revisions is discussed as well as recommendations for evaluation and staging procedures based on these revisions.

Photodegradation of folic acid during extracorporeal photopheresis

BACKGROUND

Photodegradation of folic acid (FA) by ultraviolet (UV) radiation is a well-documented photochemical reaction, and decreased serum levels of FA have been found in patients receiving photochemotherapy (psoralen plus UVA). During extracorporeal photopheresis (ECP) leucocytes and plasma are subjected to 8-methoxypsoralen (8-MOP) plus UVA.

OBJECTIVES

To investigate whether ECP leads to the photodegradation of FA in the extracorporeal system.

METHODS

In 30 patients undergoing ECP on two consecutive days the FA levels were measured in the extracorporeal collected plasma prior to and after UVA exposure. Healthy donor plasma was exposed to 8-MOP and increasing doses of UVA in vitro. In five patients serum folate levels were determined before and after ECP.

RESULTS

We found a mean reduction of 44% and 46% on the first and second day of treatment, respectively. This effect could be reproduced in vitro: the irradiation of healthy donor plasma with UVA led to a dose-dependent reduction of FA of up to 54.75% at 16 J cm(-2). This was independent of the presence of 8-MOP and the base concentration of 5-methyltetrahydrofolate; minimal changes were observed for vitamin B(12) and homocysteine, not undergoing photodegradation. Serum folate levels did not change significantly before and after ECP.

CONCLUSIONS

We conclude that extracorporeal exposure of plasma to UVA during ECP leads to photodegradation of FA. Further investigations are required to determine the biological effects of folate photoproducts and whether clinically relevant loss of FA might be a consequence of ECP.

UV-B Irradiation Attenuates Dermal Effects of Botulinum Toxin A: A Randomized, Double-Blind, Placebo-Controlled Study

BACKGROUND

Botulinum toxin type A (BoNT/A) is frequently used for cosmetic indications and hyperhidrosis.

OBJECTIVES

We investigated whether UV-B irradiation alleviates the BoNT/A effect on local sudomotor activity.

MATERIALS AND METHODS

In a randomized, double-blinded trial, the anhidrotic areas after BoNT/A (100 mU) injection 48 hours before and 14 days after UV-B irradiation were compared in six healthy volunteers.

RESULTS

UV-B irradiation alleviated BoNT/A effect by approximately 30% (p=.0017). The UV-B-evoked reduction of anhidrotic areas was constant over the observation period of 14 weeks.

CONCLUSIONS

When BoNT/A is applied intradermally, excessive exposure to UV-B and sunburn should be reconsidered. The authors have indicated no significant interest with commercial supporters.

Molecular cytogenetic evidence of t(14;18)(IGH;BCL2) in a substantial proportion of primary cutaneous follicle center lymphomas

In contrast to nodal follicular lymphoma, limited data exist on genetic changes in primary cutaneous follicular lymphoma (primary cutaneous follicle center lymphoma according to WHO-EORTC). The detection rate of the BCL2 rearrangement, representing the characteristic t(14;18)(q32;q21) underlying follicular lymphoma, by polymerase chain reaction (PCR) has been reported to vary over a wide range (0%-41%), and only a few cases have been studied by molecular cytogenetic techniques such as fluorescence in situ hybridization (FISH). In this study, 27 primary cutaneous follicle center lymphomas were analyzed by FISH and the results compared with those obtained by PCR. FISH demonstrated translocations affecting the immunoglobulin heavy chain locus (IGH) in 14 of 27 cases (52%): a t(14;18)(q32;q21) involving BCL2 was found in 11 cases (41%), a t(3;14)(q27;q32) affecting BCL6 in 2 cases (7%), and in 1 case the partner gene of IGH could not be identified. Interestingly, PCR did not detect BCL2 rearrangement in any case. These data suggest that the t(14;18)(q32;q21) frequently occurs in primary cutaneous follicular lymphoma. The reason(s) why BCL2 rearrangements escape the detection by PCR is (are) not clear but could be due to BCL2 mutations, breakpoints outside the amplified DNA, or a high load of somatic mutations.

Induction of the 72-kilodalton heat shock protein and protection from ultraviolet B-induced cell death in human keratinocytes by repetitive exposure to heat shock or 15-deoxy-delta(12,14)-prostaglandin J2

It has been demonstrated that hyperthermia protects keratinocytes from ultraviolet B (UVB)-induced cell death in culture and in vivo. This effect is mediated by the antiapoptotic effect of heat shock proteins that are transiently induced after exposure to heat at sublethal temperatures. Consequently, induction of Hsp has been proposed as a novel means of photoprotection. However, in the face of daily UVB exposure of human skin in vivo, this approach would not be useful if keratinocytes become less sensitive to Hsp induction with repeated exposure to the inducing agent. The aim of this study was to investigate whether repeated exposure to hyperthermia or to the stress protein activating cyclopentenone prostaglandin 15-deoxy-delta(12,14)-prostaglandin J2 (15dPGJ2) leads to adaptation of the cells, attenuation of the heat shock response, and abrogation of the protective effect. Normal human epidermal keratinocytes (NHEK) and the carcinoma-derived cell line A431 were exposed to either 42 degrees C or to 15dPGJ2 for 4 hours at 24-hour intervals for 4 consecutive days. The intracellular level of the 72-kDa heat shock protein (Hsp72) was determined by enzyme-linked immunosorbent assay (ELISA). Cells were exposed to UVB from a metal halide source after the last heat or 15dPGJ2 treatment, and survival was determined 24 hours after exposure by a MTT assay. Our results demonstrate that (1) heat shock and 15dPGJ2 are potent inducers of Hsp72 expression and lead to increased resistance to UVB-induced cell death in human keratinocytes; (2) re-exposure to heat shock leads to a superinduction without attenuation of the absolute increase in Hsp72 and of its UVB-protective effect; (3) the UVB tolerance induced by 15dPGJ2 is enhanced by repeated exposure without a further increase of Hsp72; (4) repeated heat shock and 15dPGJ2 up to a concentration of 1 microg/mL have no influence on cell growth over a period of 4 days. We conclude that through repeated exposure to Hsp-inducing factors, stress tolerance can be maintained without additional toxicity in human keratinocytes. These results provide a basis for the development of nontoxic Hsp inducers that can be repeatedly applied without loss of effect.

EORTC consensus recommendations for the treatment of mycosis fungoides/Sézary syndrome

Several reviews and guidelines on the management of mycosis fungoides and Sézary syndrome (MF/SS) have been published; however, treatment strategies for patients with MF/SS vary from institution to institution and no European consensus has yet been established. There are few phase III trials to support treatment decisions for MF/SS and treatment is often determined by institutional experience. In order to summarise the available evidence and review 'best practices' from each national group, the European Organisation for Research and Treatment of Cancer (EORTC) Cutaneous Lymphoma Task Force met in September 2004 to establish European guidelines for the treatment of MF/SS. This article reviews the treatment regimens selected for inclusion in the guidelines and summarises the clinical data for treatments appropriate for each stage of MF/SS. Guideline recommendations are presented according to the quality of supporting data, as defined by the Oxford Centre for Evidence-Based Medicine. Skin-directed therapies are the most appropriate option for early-stage MF/SS and most patients can look forward to a normal life expectancy. Patients with advanced disease should be encouraged to participate in clinical trials and maintenance of quality of life should be paramount.

The course of anticoagulation after extracorporeal photochemotherapy

During extracorporeal photochemotherapy (ECP) heparin is added to the extracorporeal circulation to avoid clotting. It has not been investigated whether and to what extend this procedure influences coagulation in patients after ECP. In this study activated partial thrombaplastin time (aPTT) and anti-factor Xa were monitored for up to 4 h after ECP in 10 patients. We found that anticoagulation followed the typical course of intravenously applied heparin: immediately after reinfusion anti-Xa was high (>1 IU/ml) and aPTT was prolonged to more than 180 s followed by a rapid decline and reaching normal values within 3-4 h in all patients. We conclude that anticoagulation and increased risk of bleeding after ECP is confined to a short period immediately following treatment. Physicians using ECP should be aware of the course of anticoagulation associated with this treatment.

UVA-induced oxidative damage and cytotoxicity depend on the mode of exposure

The reciprocity rule (Bunsen-Roscoe law) states that a photochemical reaction is directly proportional to the total energy dose, irrespective of the dose distribution. In photomedicine the validity of this law is usually taken for granted, although the influence of radiation intensity and dose distribution are largely unknown. We have examined in a tissue culture model the effects of fractionated versus single dose exposure to UV from a metal halide source on survival, DNA synthesis, glutathione, and oxidative membrane damage. Exposure to fractionated UVA was followed by an increased rate of cell death compared to single dose exposure, when intervals between fractions where short (10-120 min). Longer intervals had the opposite effect. Corresponding results were obtained for DNA synthesis (BrdU incorporation). The increased cytotoxicity of dose fractionation with short intervals could not be abrogated by non-enzymatic antioxidants (astaxanthin, ascorbic acid, alpha-tocopherol). Fractionated irradiation with short intervals led to higher degree of depletion of glutathione (GSH) and to enhanced formation of thiobarbituric acid reactive substances (TBARS) in comparison to an identical single dose. Long intervals between fractions induced opposite effects. Taken together, these data indicate that immediately after UVA exposure cells are more sensitive to a further oxidative attack making repeated exposure with short intervals more cytotoxic than continuous single dose UVA. This might have implications also for responses to UVA in vivo and further studies will have to extend these findings to the situation in healthy and diseased human skin.

The expression of the 27-kd heat shock protein in keratinization disorders: an immunohistological study

In human skin, the 27-kd heat shock protein (hsp27), a member of the small hsp family, is expressed mainly in the upper epidermal layers. Hsp27 functions as a molecular chaperone and is involved in the regulation of cell growth and differentiation. According to experimental evidence, epidermal hsp27, through its chaperone function, might play a role in the assembly of keratin filaments and the cornified cell envelope. This study was conducted to assess the expression pattern of hsp27 in a panel of different ichthyoses. Twelve hereditary and acquired skin diseases associated with an ichthyotic phenotype and 2 corresponding mouse models were investigated by immunohistochemistry on formalin-fixed paraffin-embedded tissue, using a monoclonal antibody specific for hsp27. In ichthyosis vulgaris, lamellar ichthyosis, Sjögren-Larsson syndrome, Netherton syndrome, and acquired ichthyosiform skin condition, the pattern of hsp27 expression resembles healthy human skin. Hsp27 expression was reduced in bullous ichthyosiform erythroderma and annular epidermolytic ichthyosis, and absent in X-linked recessive ichthyosis (1/3 patients) and congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome (1/1). In X-linked dominant chondrodysplasia, 3 small samples are completely negative and 2 larger samples show a pattern resembling random X inactivation. In the mouse models, tattered and bare patches, representing the murine analogues to X-linked dominant chondrodysplasia and congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome, expression of hsp25 (the murine homologue of hsp27) also showed lyonization, demonstrating a clear-cut link between hsp27 expression and underlying molecular pathology. Our results show that loss of hsp27 is a rare event in human epidermis that is associated with specific genetic defects. Among the cases described here, these defects are either in suprabasal keratins or in enzymes involved in cholesterol biosynthesis. The expression and chaperone function of hsp27 might be modified by low/absent epidermal cholesterol and aberrant substrates (ie, keratins) resulting in protein misfolding, dyskeratosis, and thus contribute to the ichthyotic phenotype.

Variable frequencies of MALT lymphoma-associated genetic aberrations in MALT lymphomas of different sites

Although several recurrent genetic aberrations are known to occur in MALT lymphoma, no comprehensive study on the most prevalent MALT lymphoma-associated genetic aberrations is available. We therefore screened 252 primary MALT lymphomas for translocations t(11;18)(q21;q21), t(14;18)(q32;q21), and t(1;14)(p22;q32), and trisomies 3 and 18. The above-listed translocations occurred mutually exclusively and were detected overall in 13.5, 10.8, and 1.6% of the cases; trisomy 3 and/or 18 occurred in 42.1%. The frequency at which the translocations occurred varied markedly with the primary site of disease. The t(11;18)(q21;q21) was mainly detected in pulmonary and gastric tumors, whereas the t(14;18)(q32;q21) was most commonly found in lesions of the ocular adnexa/orbit, skin, and salivary glands. Trisomies 3 and 18 each occurred most frequently in intestinal and salivary gland MALT lymphomas. Our results demonstrate that the three translocations and trisomies 3 and 18 occur at markedly variable frequencies in MALT lymphoma of different sites.

UVA activated 8-MOP and chlorpromazine inhibit release of TNF-α by post-transcriptional regulation

There is evidence that regulation of inflammatory cytokines is among the immunomodulatory effects of photochemotherapy with 8-MOP and UVA. We have recently demonstrated that in the monocytoid cell line U937 incubation with 8-MOP and subsequent exposure to UVA is able to efficiently downregulate the release of TNF-alpha into the culture supernatant. Chlorpromazine, a well known photosensitising drug, was even more potent with regard to this effect. Based on these observations, in this study we further investigate the mechanisms of TNF-alpha inhibition by 8-MOP and CPZ photosensitization. For this purpose we determined intracellular protein levels and gene expression of TNF-alpha by western blot and quantitative real-time PCR, respectively. Our results indicate that the observed inhibition of TNF-alpha secretion after photochemotherapy is not due to downregulation of gene transcription but rather to a post-transcriptional mechanism. The observed decrease of intracellular TNF-alpha with CPZ and 8-MOP points to decreased protein synthesis or enhanced degradation. These findings demonstrate that posttranscriptional regulation of cytokine expression is a possible mechanism of action of photochemotherapy.

Definition of TCR epitopes for CTL-mediated attack of cutaneous T cell lymphoma

Therapeutic vaccination against cutaneous T cell lymphoma (CTCL) requires the characterization of cancer cell-specific CTL epitopes. Despite reported evidence for tumor-reactive cytotoxicity in CTCL patients, the nature of the recognized determinants remains elusive. The clonotypic TCR of CTCL cells is a promising candidate tumor-specific Ag. In this study, we report that the clonotypic and framework regions of the TCRs expressed in the malignant T cell clones of six CTCL patients contain multiple peptides with anchor residues fitting the patients' MHC class I molecules. We demonstrate that TCR peptide-specific T cells from the blood of healthy donors and patients can be induced to become cytotoxic effectors after repeated stimulation with 6 of 11 selected peptides with experimentally proven affinity for HLA-A*0201. Importantly, 4 of these 6 CTL lines reproducibly recognize and lyse autologous primary CTCL cells in MHC class I/CD8-dependent fashion. These tumoricidal CTL lines are directed against epitopes from V, hypervariable, and C regions of TCRalpha. We therefore conclude that recombined as well as V framework regions of the tumor cell TCRs contain predictable epitopes for CTL-mediated attack of CTCL cells. Our data further suggest that such peptides represent valuable tools for future anti-CTCL vaccination approaches.

Heat shock and UV-B-induced DNA damage and mutagenesis in skin

There is evidence that heat pre-treatment protects cultured human keratinocytes and normal murine and human skin from ultraviolet (UV) radiation-induced cell death. It has been suggested that heat-shock proteins (hsps), particularly hsp72, are involved in this effect. Hsps are expressed in response to various types of stress, such as UV radiation. Whether heat shock interferes with the repair of UV-induced DNA damage and whether this can be regarded as a protective mechanism is poorly understood and needs further experimental investigation. This review gives an overview of the current state of research in the area.

Overexpression of Hsp27 in a human melanoma cell line: regulation of E-cadherin, MUC18/MCAM, and plasminogen activator (PA) system

Hsp27 is considered a potential marker for cell differentiation in diverse tissues. Several aspects linked to the differentiation process and to the transition from high to low metastatic potential were analyzed in melanoma cells transfected with Hsp27. E-cadherin plays a central role in cell differentiation, migration, and normal development. Loss of expression or function of E-cadherin has been documented in a variety of human malignancies. We observed by fluorescence-activated cell sorter (FACS) as well as immunofluorescence (IF) analysis a pronounced expression of E-cadherin in Hsp27-transfected A375 melanoma cells compared with control melanoma cells. The expression of the adhesion molecule MUC18/MCAM correlates directly with the metastatic potential of melanoma cells. In contrast to wild-type and neotransfected melanoma cells, in Hsp27-transfected cells the expression of MUC18/MCAM could not be detected by FACS and IF analysis. The plasminogen activator (PA) system plays a central role in mediating extracellular proteolysis and also in nonproteolytic events such as cell adhesion, migration, and transmembrane signaling. Hsp27 transfectants revealed elevated messenger ribonucleic acid expression of the urokinase-type PA (uPA) and its inhibitor, PA inhibitor type 1, which might indicate a neutralization effect of the proteolytic activity of uPA. Control cells failed to express both these molecules. The influence of Hsp27 expression on uPA activity and the involvement of E-cadherin could be demonstrated by use of anti-E-cadherin-blocking antibody. Our data provide evidence for an inhibitory-regulatory role of Hsp27 in tumor progression as found in our system.

Complete remission of chronic plaque psoriasis and gastric marginal zone B-cell lymphoma of MALT type after treatment with 2-chlorodeoxyadenosine

A 58-year-old woman with a 15-year history of chronic plaque psoriasis was diagnosed with gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. Topical treatment and ultraviolet radiation for therapy of psoriasis had been of limited efficacy. The patient received intravenous treatment with 0.12 mg/kg per day of 2-chlorodeoxyadenosine (2-CDA) over 5 days for management of MALT lymphoma, as it was resistant to eradication of Helicobacter pylori. A total of six cycles were administered from June 1999 until November 1999 (cumulative dose 244.8 mg 2-CDA). After 2 months of 2-CDA administration, psoriatic skin lesions improved significantly, and after 3 months, complete remission of skin lesions was observed. Ongoing complete remission of the MALT lymphoma could be achieved after six cycles of 2-CDA administration. After a follow-up period of 34 months, no recurrence of psoriatic lesions has occurred. The patient is at present free of psoriatic plaques and gastric MALT lymphoma. The course of disease in our patient provides evidence for sustained therapeutic efficacy of 2-CDA in chronic plaque psoriasis in the absence of severe side effects except asymptomatic lymphopenia.

Total skin electron radiation in the management of mycosis fungoides: Consensus of the European Organization for Research and Treatment of Cancer (EORTC) Cutaneous Lymphoma Project Group

Radiotherapy has been successfully implemented in the treatment of mycosis fungoides (MF) for almost a century. With the development of the modern linear accelerator, it has become possible to treat extended areas of the skin with accelerated electrons. Total skin electron beam radiation (TSEB) has been in use for several decades, and a number of technical modifications have been made with the goals of optimizing dose distribution and improving clinical outcome. Emerging evidence from recent studies suggests an association between TSEB techniques and efficacy in the treatment of MF. Based on this evidence, the European Organization for Research and Treatment of Cancer Cutaneous Lymphoma Project Group, in association with experts from radiotherapy centers in North America, has reached a consensus on acceptable methods and clinical indications for TSEB in the treatment of MF. The aims of this report are to enhance accessibility of this highly efficacious treatment modality to patients with MF and to provide a point of reference for further clinical research.

Subcorneal colocalization of the small heat shock protein, hsp27, with keratins and proteins of the cornified cell envelope

BACKGROUND

hsp27 is a member of the small heat shock protein family. Its expression in epidermal keratinocytes in situ and in tissue culture correlates with differentiation. Experimental evidence points to the fact that hsp27 is a molecular chaperone and is involved in the regulation of cell growth and differentiation.

OBJECTIVES

To investigate whether epidermal hsp27 through its chaperone function plays a role in the assembly of keratin filaments and the cornified cell envelope.

METHODS

We performed double staining immunofluorescence and immunogold microscopy on normal human skin (n = 15). We analysed the colocalization of hsp27 with actin, keratins and proteins of the cornified cell envelope (loricrin, filaggrin, transglutaminase 1).

RESULTS

Actin staining did not reveal detectable colocalization with hsp27. For keratins, transglutaminase, loricrin and filaggrin colocalization was found in more than 60% of the samples. Colocalization was confined to a narrow subcorneal layer with varying patterns of expression. Electron microscopy revealed that loricrin and filaggrin colocalize with hsp27 indirectly through binding to intermediate filaments.

CONCLUSIONS

These results provide morphological evidence that in normal human skin hsp27 might act as a chaperone of cornification. Investigations of the molecular hsp27 interactions with the proteins of the cornified cell envelope are necessary to gain further insight into terminal keratinocyte differentiation and disorders of keratinization.

Differential expression of a novel gene in response to hsp27 and cell differentiation in human keratinocytes

The 27 kDa heat shock protein (hsp27) is expressed in keratinocytes in a differentiation-related pattern. Keratinocyte differentiation involves a coordinated program of expression and interaction of specific differentiation-related genes and proteins. To investigate the functional role of hsp27 in these processes we used a differential display approach to identify genes that might be regulated by the expression of hsp27 in human keratinocytes. mRNA was extracted from the human squamous carcinoma cell line A431 and a subclone stably transfected with human hsp27. Reverse transcriptase differential display polymerase chain reaction was performed using one base anchored oligo-dT and arbitrary primers. Differentially expressed genes were confirmed by northern blot analysis and further characterized by sequencing. Their expression in human skin and other tissues was investigated by northern blot and in situ hybridization. Out of five fragments detected with the initial reverse transcriptase differential display polymerase chain reaction screen one could be confirmed by northern blot to be downregulated in hsp27-overexpressing A431. This mRNA (G24) is not only downregulated by overexpression of hsp27 in A431 but also during differentiation in normal human keratinocytes in culture and in situ, situations where hsp27 is known to be induced. According to sequence analysis G24 represents a novel gene that does not code for a protein and thus might belong to the growing family of noncoding RNAs. These results not only demonstrate for the first time that overexpression of hsp27 by gene transfer is associated with regulation of gene expression but also reveal a novel differentiation-associated gene in human keratinocytes.

Characterization of proteins associated with heat shock protein hsp27 in the squamous cell carcinoma cell line A431

Heat shock protein hsp27 is a molecular chaperone and identification of hsp27-binding proteins might help to elucidate its functional role in keratinocyte biology. In the present investigation we used a human epidermal cell carcinoma cell line (A431) transfected with hsp27 (A431/16) to study interference between hsp27 protein and other proteins. Immunoprecipitation experiments with anti-hsp27 antibody revealed a multicomponent complex when analysed by silver staining. By immunoblotting analysis we could demonstrate that hsp27 associates with actin, the mutant form of p53, hsp70 and hsp90. Immunofluorescence analysis showed a co-localization between hsp27 and p53, hsp70 and hsp90. To control for the specificity of the observed interactions, immuno-precipitations with antibodies to actin, p53, hsp70 and hsp90 respectively, were performed. All of the tested proteins demonstrated a coimmunoprecipitation with hsp27. We conclude that hsp27, like the other heat shock proteins, is part of a complex system of molecular chaperones in epidermal keratinocytes.

Overexpression of Hsp27 affects the metastatic phenotype of human melanoma cells in vitro

Overexpression of the small heat shock protein Hsp27 has been shown by us to inhibit the in vitro proliferation rate and to delay tumor development of a human melanoma cell line (A375) in nude mice. We hypothesized that Hsp27 may influence the neoplastic phenotype. In the present study Hsp27 transfectants from this cell line were analyzed for various cellular aspects associated with the metastatic process. We found that Hsp27-overexpressing clones exhibited an altered cellular morphology as compared with control transfected cells. The Hsp27-positive cells tended to develop an epithelial-like phenotype growing in clusters and were characterized by a loss of transcytoplasmic stressfibers. In parallel, Hsp27-expressing cells lost the ability to form colonies in soft agar. The invasive potential was studied in vitro by the use of a reconstituted extracellular matrix-coated filter (Matrigel). Compared with controls, Hsp27-overexpressing cells showed decreased cell invasiveness through Matrigel. A correlation between invasion and activation of matrix metalloproteinases (MMPs) has been shown in several cell models. Secretion of MMPs (MMP-2 and MMP-9) was studied by gelatin-substrate zymogram analysis, as well as by a sensitive gelatinase activity assay. The Hsp27-transfected A375 melanoma cell line showed decreased secretion of MMP-2 and MMP-9 as compared with the control transfected cells. Integrins are adhesion receptors and function in cell invasion by mediating cell movement on matrix molecules and by regulating the expression of MMPs. Both fluorescence-activated cell sorter analysis and immunofluorescence analysis revealed a loss of alpha(v)beta3 integrin in Hsp27-transfected cell colonies. Our results demonstrate that Hsp27 overexpression has a profound impact on several parameters regulating the invasive and metastatic potential of melanoma cells in vitro.

Overexpression of Hsp25 in K1735 murine melanoma cells enhances susceptibility to natural killer cytotoxicity

In the present study we used a murine melanoma model to investigate the effect of the 25-kDa heat shock protein (Hsp25) on natural killer (NK) cytotoxicity. The melanoma lines K1735-C123 (low metastatic potential) and K1735-M2 (high metastatic potential) were transfected with hsp25 and a control plasmid. Highly purified interleukin (IL)-2-stimulated DX-5+ NK cells showed enhanced lysis of Hsp25-overexpressing K1735-C123 targets in comparison with controls. In contrast, there was no difference in susceptibility to lysis by purified IL-2-stimulated DX-5+ NK cells between Hsp25-overexpressing and control-transfected K1735-M2 targets. Fluorescence-activated cell sorter analysis revealed that Hsp25 is displayed on the cell surface independently of Hsp25 overexpression and metastatic phenotype. Thus, surface localization of Hsp25 does not correlate with the target cell susceptibility to killing. To sum up, a cytoplasmic overexpression of Hsp25 is associated with an increased susceptibility to lysis by DX-5+ NK cells in the low-metastatic murine melanoma model investigated.

Heat shock proteins in the photobiology of human skin

All organisms respond to sudden environmental changes with the increased transcription of genes belonging to the family of heat shock proteins (hsps). Hsp-inducing stress factors include elevated temperatures, alcohol, heavy metals, oxidants, and agents leading to protein denaturation. The induction of heat shock proteins is followed by a transient state of increased resistance to further stress and the heat shock response is generally thought to represent an evolutionary conserved adaptive mechanism to cope with hostile environmental conditions. Since the skin as a barrier organ has to cope with the potentially harmful consequences of exposure to ultraviolet radiation (UV), it appears reasonable to question whether hsps constitute a natural defence mechanism against UV. Hsps have been detected in resting as well as in stressed epidermal and dermal cells and overexpression of hsps is associated with increased resistance to UV-induced cell death. Furthermore, UV itself is able to induce the expression of specific hsps. Thus, hsps might provide an adaptive cellular response to increasing UV and enhancing the expression of hsps might turn out as a new way to deal with the immediate and long-term consequences of UV exposure. Prerequisite for the utilization of this concept is the development of non-toxic heat shock inducers and their evaluation for clinical efficacy and safety.

Mechanisms of photodamage of the skin and its functional consequences for skin ageing

Chronic photodamage of the skin manifests itself as extrinsic skin ageing (photoageing) and photocarcinogenesis. DNA photodamage and UV-generated reactive oxygen species are the initial molecular events that lead to most of the typical histological and clinical manifestations of chronic photodamage of the skin. Knowledge of the UV-absorbing chromophores in the skin and of the molecular mechanisms leading to the unwanted effects of sun exposure provide a basis for the development of novel strategies for the prevention and repair of photoageing. This review provides an overview of the photochemistry of the major skin chromophores and their relationship to chronic photodamage.