Phototherapy for cutaneous T-cell lymphoma

Phototherapy for age-related brain diseases: Challenges, successes and future

Brain diseases present a significant obstacle to both global health and economic progress, owing to their elusive pathogenesis and the limited effectiveness of pharmaceutical interventions. Phototherapy has emerged as a promising non-invasive therapeutic modality for addressing age-related brain disorders, including stroke, Alzheimer's disease (AD), and Parkinson's disease (PD), among others. This review examines the recent progressions in phototherapeutic interventions. Firstly, the article elucidates the various wavelengths of visible light that possess the capability to penetrate the skin and skull, as well as the pathways of light stimulation, encompassing the eyes, skin, veins, and skull. Secondly, it deliberates on the molecular mechanisms of visible light on photosensitive proteins, within the context of brain disorders and other molecular pathways of light modulation. Lastly, the practical application of phototherapy in diverse clinical neurological disorders is indicated. Additionally, this review presents novel approaches that combine phototherapy and pharmacological interventions. Moreover, it outlines the limitations of phototherapeutics and proposes innovative strategies to improve the treatment of cerebral disorders.

A novel mouse model of cutaneous T-cell lymphoma revealed the combined effect of mogamulizumab with psoralen and ultraviolet a therapy

Mycosis fungoides (MF) is a subtype of cutaneous T-cell lymphoma (CTCL). Topical or systemic treatment with psoralen, such as 8-methoxypsoralen (8-MOP), followed by ultraviolet A (UVA) irradiation (PUVA therapy) is an effective phototherapy for early-stage MF. However, the efficacy of PUVA therapy for advanced-stage MF is not satisfactory, and the ideal combination partner for PUVA therapy has not yet been found. In this study, we developed a new mouse model of CTCL in which efficacy of PUVA was detected and further evaluated the efficacy of combination treatment of PUVA and mogamulizumab, an anti-CCR4 monoclonal antibody. Cytotoxicity of PUVA therapy against HH cells, a CTCL cell line, was observed in vitro. The cytotoxicity was dependent on both 8-MOP and UVA. Using HH cells, we developed a mouse model in which HH cells were subcutaneously inoculated in the ear. In this model, PUVA therapy suppressed tumour growth with statistical significance, while 8-MOP or UVA alone did not. Combination therapy of PUVA and mogamulizumab showed greater antitumor activity than either monotherapy with statistical significance. In the histological analysis of the tumour tissue, PUVA accelerated tumour necrosis and then induced the infiltration inflammatory cells in the necrotic area, suggesting that these cells served as effector cells for mogamulizumab. This combination therapy is expected to be a beneficial option for CTCL therapy.

Multi-responsive deep-ultraviolet emission in praseodymium-doped phosphors for microbial sterilization

Perusing multimode luminescent materials capable of being activated by diverse excitation sources and realizing multi-responsive emission in a single system remains a challenge. Herein, we utilize a heterovalent substituting strategy to realize multimode deep-ultraviolet (UV) emission in the defect-rich host Li₂CaGeO₄ (LCGO). Specifically, the Pr³⁺ substitution in LCGO is beneficial to activating defect site reconstruction including the generation of cation defects and the decrease of oxygen vacancies. Regulation of different traps in LCGO:Pr³⁺ presents persistent luminescence and photo-stimulated luminescence in a synergetic fashion. Moreover, the up-conversion luminescence appears with the aid of the 4f discrete energy levels of Pr³⁺ ions, wherein incident visible light is partially converted into germicidal deep-UV radiation. The multi-responsive character enables LCGO:Pr³⁺ to response to convenient light sources including X-ray tube, standard UV lamps, blue and near-infrared lasers. Thus, a dual-mode optical conversion strategy for inactivating bacteria is fabricated, and this multi-responsive deep-UV emitter offers new insights into developing UV light sources for sterilization applications. Heterovalent substituting in trap-mediated host lattice also provides a methodological basis for the construction of multi-mode luminescent materials.

Targeting Cutaneous T-Cell Lymphoma Cells by Ingenol Mebutate (PEP005) Correlates with PKCδ Activation, ROS Induction as Well as Downregulation of XIAP and c-FLIP

New therapeutic strategies are needed for cutaneous T-cell lymphoma (CTCL), and the plant extract ingenol mebutate (PEP005) may be considered. PEP005 has been approved for actinic keratosis, and proapoptotic activities were described in different cancer cells. Here, we aimed to investigate its efficacy in four CTCL cell lines and its mode of action. While HuT-78 and HH responded with induced apoptosis as well as with loss of cell viability and cell proliferation, MyLa and SeAx remained resistant. Interestingly, both sensitive and resistant cells showed caspase-8 activation and enhanced levels of reactive oxygen species (ROS), while final caspase-3 activation was restricted to sensitive cells. Apoptosis induction was prevented by the caspase inhibitor QVD-Oph as well as by the antioxidant vitamin E. Caspase activation by PEP005 may be explained to some extent by the downregulation of the caspase antagonistic proteins c-FLIP and XIAP in sensitive cells, whereas both proteins were strongly expressed in resistant cells. Finally, PEP005 resulted in the activation of proapoptotic PKCδ, and the PKC inhibitor bisindolylmaleimide I reduced apoptosis, caspase-3 processing and ROS production, as well as restored cell viability. In conclusion, PKCδ appeared as a central player in apoptosis regulation in CTCL cells, also suggesting its therapeutic targeting.

Light-controlled inhibition of BRAFV600E kinase

Metastatic melanoma is amongst the most difficult types of cancer to treat, with current therapies mainly relying on the inhibition of the BRAF^V600E mutant kinase. However, systemic inhibition of BRAF by small molecule drugs in cancer patients results - paradoxically - in increased wild-type BRAF activity in healthy tissue, causing side-effects and even the formation of new tumors. Here we show the development of BRAF^V600E kinase inhibitors of which the activity can be switched on and off reversibly with light, offering the possibility to overcome problems of systemic drug activity by selectively activating the drug at the desired site of action. Based on a known inhibitor, eight photoswitchable effectors containing an azobenzene photoswitch were designed, synthesized and evaluated. The most promising inhibitor showed an approximately 10-fold increase in activity upon light-activation. This research offers inspiration for the development of therapies for metastatic melanoma in which tumor tissue is treated with an active BRAF^V600E inhibitor with high spatial and temporal resolution, thus limiting the damage to other tissues.

Ultraviolet A1 Phototherapy for Fibrosing Conditions

In this article we describe efficacy and safety aspects of ultraviolet A1 (UV-A1) phototherapy in fibrosing conditions. UV-A1 is a specific phototherapeutic modality that is defined by a selective spectral range (340–400 nm). UV-A1 includes distinct modes of action qualifying this method for therapy of a variety of conditions, in particular fibrosing skin diseases. Concerning efficacy of UV-A1 phototherapy in fibrosing conditions, the best evidence obtained from randomized controlled trials exists for localized scleroderma. Moreover, fibrosing disorders such as lichen sclerosus and graft-vs.-host disease can be treated successfully by means of UV- A1. Regarding the optimal dosage regimen medium-dose UV-A1 seems to be linked to the best benefit/risk ratio. Possible acute adverse events of UV-A1 phototherapy include erythema and provocation of photodermatoses. Skin ageing and skin cancer formation belong to the chronic adverse events that may occur after long-term UV-A1 phototherapy.

Iron-based radiochromic systems for UV dosimetry applications

Phototherapy treatment using ultraviolet (UV) A and B light sources has long existed as a treatment option for various skin conditions. Quality control for phototherapy treatment recommended by the British Association of Dermatologists and British Photodermatology Group generally focused on instrumentation-based dosimetry measurements. The purpose of this study was to present an alternative, easily prepared dosimeter system for the measurement of UV dose and as a simple quality assurance technique for phototherapy treatments. Five different UVA-sensitive radiochromic dosimeter formulations were investigated and responded with a measurable and visible optical change both in solution and in gel form. Iron(III) reduction reaction formulations were found to be more sensitive to UVA compared to iron(II) oxidation formulations. One iron(III) reduction formulation was found to be especially promising due to its sensitivity to UVA dose, ease of production, and linear response up to a saturation point.

Photochemically Controlled Drug Dosing from a Polymeric Scaffold

Purpose

To develop the first photoactive biomaterial coating capable of controlled drug dosing via inclusion of synthesised drug-3,5-dimethoxybenzoin (DMB) conjugates in a poly(2-methyoxyethyl acrylate) (pMEA) scaffold.

Methods

Flurbiprofen- and naproxen-DMB conjugates were prepared via esterification and characterised via NMR spectroscopy and mass spectrometry following chromatographic purification. Conjugate photolysis was investigated in acetonitrile solution and within the pMEA matrix following exposure to low-power 365 nm irradiation. Photo-liberation of drug from pMEA into phosphate buffered saline was monitored using UV-vis spectroscopy.

Results

The synthetic procedures yielded the desired drug conjugates with full supporting characterisation. Drug regeneration through photolysis of the synthesised conjugates was successful in both acetonitrile solution and within the pMEA scaffold upon UV irradiation. Conjugates were retained within the pMEA scaffold with exclusive drug liberation following irradiation and increased drug dose with increasing exposure. Multi-dosing capacity was demonstrated though the ability of successive irradiation periods to generate further bursts of drug.

Conclusion

This study demonstrates the first application of photochemically controlled drug release from a biomaterial coating and the feasibility of using pMEA as a scaffold for housing the photoactive drug-DMB conjugates.

Guidelines for phototherapy of mycosis fungoides and Sézary syndrome: A consensus statement of the United States Cutaneous Lymphoma Consortium

BACKGROUND

Ultraviolet light (UVL) is a long established treatment for mycosis fungoides (MF) and Sézary syndrome (SS), subtypes of cutaneous T-cell lymphoma (CTCL). Treatments have traditionally included broadband, narrowband ultraviolet B light (UVB) and psoralen plus ultraviolet A light photochemotherapy (PUVA), but more recently, treatment options have expanded to include UVA1 and excimer laser. UVL is used either as monotherapy or as an adjuvant to systemic therapy, demonstrating efficacy in many cases that equal or surpass systemic medications. Despite its utility and duration of use, the current practice of using UVL guidelines for psoriasis to treat patients with MF/SS is problematic because the goals of prolonging survival and preventing disease progression are unique to CTCL compared to psoriasis.

OBJECTIVES

We sought to develop separate guidelines for phototherapy for MF/SS for both clinical practice and for clinical trials.

METHODS

Literature review and cutaneous lymphoma expert consensus group recommendations.

RESULTS

This paper reviews the published literature for UVB and UVA/PUVA in MF/SS and suggests practical standardized guidelines for their use.

LIMITATIONS

New standardization of phototherapy.

CONCLUSIONS

These guidelines should allow the comparison of results with phototherapy in MF/SS across different stages of patients, centers, and in combination with other agents in practice and in clinical trials.

Primary cutaneous T cell lymphomas: photochemotherapy immunomodulation with analysis of the inflammatory-expansive cellular dynamic

Primary cutaneous T cell lymphomas (CTCLs) are characterized by hyperproliferation of malignant CD4+ T cells with primary localization on the skin. The common characteristics are the migration of the malignant mature T-lymphocytes into the epidermis, with hyperproliferation of malignant CD4+ T cells and epidermotropism. Sézary syndrome (SS) is the leukemic variant. It was established that CTCLs arise from a clonal expansion of CD4+ T cells with an identical rearrangement of the T cell receptor. The purpose of this study was to evaluate the immunomodulation effect of photochemotherapy-A (psoralen plus ultraviolet A (PUVA)). Pre- and post-PUVA punch skin biopsies of nine patients were stained immunohistochemically for CD34+, CD8+, CD7+, CD16+, CD56+, CD1a+, Bcl2+, p53+, CD45RA+, and CD45RO+ cells. The results showed a pre-PUVA cells/mm(2) without significant difference among expansive or reactive cells. Post-PUVA analysis showed a significant decrease in the mean of expansive-reactive cells. PUVA immunomodulated decreasing cellular infiltrate. These findings could contribute to the comprehension of how PUVA acts. We achieved ectoscopic clearance of the lesions, although post-PUVA, there still was a mononuclear pathological infiltrate. This result demonstrates that the PUVA treatment should only be withheld when the histological analysis is normal.

Is PUVA maintenance therapy necessary in patients with early-stage mycosis fungoides? Evaluation of a treatment guideline over a 28-month follow-up

BACKGROUND

Cutaneous T-cell lymphoma is a rare condition that represents 2% of all lymphomas and 75-80% of primary cutaneous lymphomas. The objective of the present study is to evaluate a clinical practice guideline.

METHODS

This paper reports a prospective cohort study with a five-year follow-up. This is the second report to describe the analysis of data obtained during follow-up of 28 months. To date, 40 patients diagnosed with early-stage mycosis fungoides (stage IA, n = 20; stage IB, n = 20) have been enrolled. All patients have been treated with a minimum of 58 sessions of psoralen and long-wave ultraviolet radiation, with complete clinical and histological clearance of lesions. Variables considered include disease duration, treatment time, treatment dose, and history of relapse. Complete physical examinations and diverse complementary examinations were performed. A tumor-node-metastasis-blood staging system was applied. The population was divided into two groups according to results consisting, respectively, of those who relapsed during follow-up (n = 12) and those who did not (n = 28).

RESULTS

History of relapse was the variable most strongly associated with future relapse (relative risk = 10.38, 95% confidence interval 2.64-40.72). No statistically significant difference between the groups according to receipt of maintenance therapy was found (P = 0.161).

CONCLUSIONS

Our results strongly suggest that maintenance therapy does not prevent future relapse. However, history of relapse is a strong predictor for future relapse.

UVA1 phototherapy: a review of mechanism and therapeutic application

Ultraviolet radiation (UVR) phototherapy has been associated with both deleterious and beneficial effects to patients with both localized and systemic skin disorders. Phototherapy is advantageous in diseases of the epidermis and dermis, as it provides the most direct approach minimizing systemic side effects. Most recently, ultraviolet A1 (UVA1) phototherapy has emerged as a specific UVR phototherapeutic mechanism. It has shown to be therapeutic in a number of sclerosing skin conditions and other dermatitides, in many cases proving to be more effective than other phototherapy modalities. Treatment advantages of UVA1 phototherapy include the ability to penetrate into the deep layers of the skin to affect changes on disease-causing T cells, as well as activation of endothelial cells to promote neovascularization. UVA1 therapy also has been shown to be relatively free of side effects associated with other phototherapy regimens, including erythema and cellular transformation. These properties make UVA1 phototherapy an important treatment option for many debilitating skin conditions.

Repair of DNA interstrand cross-links during S phase of the mammalian cell cycle

DNA interstrand cross-linking (ICL) agents are widely used in anticancer chemotherapy regimens, yet our understanding of the DNA repair mechanisms by which these lesions are removed from the genome remains incomplete. This is at least in part due to the enormously complicated nature and variety of the biochemical pathways that operate on these complex lesions. In this review, we have focused specifically on the S-phase pathway of ICL repair in mammalian cells, which appears to be the major mechanism by which these lesions are removed in cycling cells. The various stages and components of this pathway are discussed, and a putative molecular model is presented. In addition, we propose an explanation as to how this pathway can lead to the observed high levels of sister chromatid exchanges known to be induced by ICLs.

Idiopathic guttate hypomelanosis-like lesions in patients with mycosis fungoides: a new adverse effect of phototherapy

BACKGROUND

Idiopathic guttate hypomelanosis (IGH) is a common pigmentary disorder, the aetiology and pathogenesis of which are largely unknown. The appearance of IGH-like lesions during phototherapy has been reported previously in only one patient.

OBJECTIVE

To describe the clinical and histological features of phototherapy-induced IGH-like lesions, their relation to ultraviolet dosimetry and the course of this eruption in patients with mycosis fungoides (MF).

METHODS

The files of all patients with MF who underwent phototherapy in our centre from 1992 to 2008 were searched to identify those in whom IGH-like lesions appeared during treatment. Results Among 87 patients with early-stage MF who underwent phototherapy, seven acquired IGH-like lesions during monotherapy with narrow-band ultraviolet B (NB-UVB; four patients) or psoralen and ultraviolet A (PUVA; three patients). All but one had a light complexion. The lesions appeared in areas exposed to ultraviolet light, and not exclusively on the skin previously involved by the disease. The mean number of exposures until appearance of the lesions was 92 for NB-UVB and 137 for PUVA. Biopsy study showed a decreased number of melanocytes. Phototherapy was discontinued in four patients, of whom three showed a partial or complete disappearance of the IGH-lesions. The other three patients are still receiving phototherapy, with no change in their IGH-like lesions.

CONCLUSIONS

Phototherapy may induce an eruption bearing similar clinical and histopathological features to IGH. The eruption is rare, appears to emerge only after prolonged therapy and seems to be reversible upon discontinuation of phototherapy. IGH-like eruption should be added to the list of side-effects of phototherapy.

An uncommon skin condition illustrates the need for caution when prescribing for friends

PURPOSE

A dual-focused case study written to discuss the legal and medical hazards of informally writing prescriptions for friends or family members and to provide knowledge of early-stage mycosis fungoides (MF), its course, and treatment.

DATA SOURCES

A review of the prescribing practices of clinicians, the cognitive processes needed in diagnosis and treatment, the current ethical guidelines, and a review of MF, its course, and treatments.

CONCLUSIONS

Treating acquaintances and family informally places clinicians at risk for liability and patients at risk for inaccurate diagnosis and treatment. This case illustrates the potential hazard of casually treating a friend for what looks like a benign condition. Resembling atopic dermatitis in its early stages, MF is the most common of a rare group of skin lymphomas. Early diagnosis and treatment are crucial for a better prognosis. Had this clinician complied with the request of her friend, his diagnosis would have been missed and timely treatment delayed.

IMPLICATIONS FOR PRACTICE

No matter what the prior relationship may have been, once a clinician treats a patient, a legally binding relationship begins, requiring the due standard of care. Nurse practitioners (NPs) need to be aware of the potential for error when treating acquaintances. Available NP standards of practice and ethical guidelines should address informal treatment situations.

Avicin D selectively induces apoptosis and downregulates p-STAT-3, bcl-2, and survivin in cutaneous T-cell lymphoma cells

Avicin D, a natural triterpenoid saponin, inhibits cell growth and induces apoptosis in transformed tumor cell lines in vitro and mouse skin carcinogenesis models in vivo. To investigate the anti-tumor effects of avicin D in cutaneous T-cell lymphomas (CTCL), we compared three CTCL cell lines and Sézary cells from three Sézary syndrome (SS) patients with normal CD4+ and activated CD4+ T cells from three healthy donors. Avicin D at 0.5-5 mug ml(-1) induced apoptosis in a time- and dose-dependent manner in three cell lines: MJ (-0.2 to 13% and 0.6-37%), Hut78 (2-39% and 3-53%), and HH (13-83% and 44-89%) at 24 and 48 hours, respectively. Avicin D at 0.5-5 microg ml(-1) for 48 hours caused more apoptosis in patients' Sézary cells than in healthy donors' CD4+ T cells and activated CD4+ T cells. The general caspase inhibitor Z-VAD-FMK and caspase-3 inhibitor Z-DEVD-FMK decreased avicin D-induced apoptosis in CTCL cells. Caspase-3 was activated and poly (ADP-ribose) polymerase was cleaved after avicin D treatment. Avicin D did not change the expression of signal transducer and activator of transcription-3 (STAT-3) but decreased phospho-signal transducer and activator of transcription-3 (p-STAT-3) protein levels in all three cell lines and two patients' Sézary cells. Avicin D also decreased expression of the inhibitor of apoptosis protein survivin, the anti-apoptotic protein bcl-2, but not the pro-apoptotic protein bax in these CTCL cells. In summary, avicin D selectively induced apoptosis, inhibited STAT-3 activation, and decreased apoptosis inhibitors (bcl-2 and survivin) in CTCL cell lines and SS patients' Sézary cells. Our findings underlie the therapeutic potential of avicin D in patients with SS.

Cutaneous T-cell lymphoma: overview and nursing perspectives

Cutaneous T-cell lymphoma (CTCL) is an uncommon and complex malignancy of the immune system with a wide range of clinical presentations primarily involving the skin. An extensive menu of skin-directed and/or systemic treatment options exists. Best practices in management involve multidisciplinary collaboration. Nursing care for patients who have CTCL is a critical component in the successful management of the disease and requires special attention to the patient's physical, emotional, and spiritual needs. Nurses can make a significant impact by being accessible, offering emotional support, demonstrating advocacy, and providing ongoing education for the patient and family.

Treatment of mycosis fungoides: overview

BACKGROUND

Mycosis fungoides (MF) is the most common clinicopathologic subtype of primary cutaneous T-cell lymphoma.

OBJECTIVE

The therapy of MF is highlighted in this overview.

RESULTS AND CONCLUSIONS

Skin-directed MF therapies include topical corticosteroids, nitrogen mustard, carmustine (BCNU), topical bexarotene gel, imiquimod cream, radiotherapy, total skin electron beam therapy, and phototherapy. Systemic therapies include extracorporeal photopheresis, interferon, oral bexarotene, denileukin diftitox, monoclonal antibodies and cytokine therapy, and other systemic chemotherapy. Finally, some investigative therapeutic modalities are presented.

Management of refractory early-stage cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of non-Hodgkin's lymphomas that manifest primarily in the skin. Mycosis fungoides is recognized as the most common type of CTCL. Patients with early-stage CTCL usually have a benign and chronic disease course. However, although there is a wide array of therapeutic options for early-stage CTCL, not all patients respond to these individual therapies, resulting in refractory cutaneous disease over time. Refractory early-stage CTCL poses an important therapeutic challenge, as one of the principal treatment goals is to keep the disease confined to the skin, thereby preventing disease progression. Much of the focus of current research has been on the evaluation of already available skin-directed therapies and biologic response modifiers and combination regimens thereof, such as the combination of psoralen and UVA (PUVA) with interferon-alpha or retinoids. Recent novel developments include oral bexarotene, a retinoid X receptor-selective retinoid that has activity in all stages of CTCL and has been shown to be effective in patients with refractory early-stage disease as well as advanced-stage disease. Likewise, the topical gel formulation of bexarotene has proved to be an important therapeutic option in patients with refractory or relapsed lesions. Oral bexarotene and topical bexarotene have been approved by the US FDA for the treatment of refractory CTCL. Systemic chemotherapy is typically reserved for advanced-stage CTCL and is usually not recommended for early-stage, skin-limited disease. However, recent exploratory studies indicate that low-dose methotrexate may represent an overall well tolerated therapy in a subset of patients with refractory early-stage CTCL, as may pegylated liposomal doxorubicin, which is currently being investigated in this specific clinical setting. Another recently FDA-approved therapy is the interleukin-2 fusion toxin denileukin diftitox, which is now well established to play a role in the treatment of refractory CTCL, including early-stage extensive plaque disease. The value of other agents, such as topical tazarotene, topical methotrexate, and topical imiquimod, and of novel immunomodulatory approaches including monoclonal antibodies, still needs to be assessed for refractory early-stage CTCL.

UVB in the management of early stage mycosis fungoides

BACKGROUND

Several options for treatment of early mycosis fungoides (MF) offer similar success rates. Previous small studies have shown UVB to be at least as effective as PUVA.

OBJECTIVE

To summarize our experience with UVB treatment of early MF.

METHODS

A retrospective analysis of early-stage MF patients treated by narrow band (NB) or broad band (BB) UVB in our institution between 1996 and 2002. Most patients achieving complete response (CR) were put on maintenance until natural sun exposure was possible and followed up every 3-6 months. The results were compared to those previously reported regarding PUVA.

RESULTS

Sixty-eight and 43 patients were treated by NB and BB UVB, respectively. Eighty-six per cent (84 and 89% in NB and BB UVB groups, respectively) of IA and 71% (78 and 44% in NB and BB UVB groups, respectively) of IB patients achieved CR within a mean of 12.8 and 10.6 weeks, respectively. When maintenance was stopped, 65 and 30% had not relapsed after an average follow up of 27 and 222 weeks, respectively. Non-relapse rate was 33 and 48% for those having had vs. those not having had maintenance, respectively.

CONCLUSIONS

Our results are comparable to all previously reported for skin-targeted treatments, including PUVA and, to our belief, reflect the nature of early MF, in which CR can probably be achieved in most of the patients. Among the responding patients there is no relapse during prolonged follow-up in about one third of the cases. Thus, we believe treatment should be stopped completely following first CR induction and maintenance treatment should be considered for relapsing patients only. Both broad and narrow UVB options are good and future choices should be made on the basis of short- and long-term side-effects.

Selective induction of apoptosis by histone deacetylase inhibitor SAHA in cutaneous T-cell lymphoma cells: relevance to mechanism of therapeutic action

Suberoylanilide hydroxamic acid (SAHA), an orally administered inhibitor of histone deacetylases, is currently in phase II clinical trials for cutaneous T cell lymphomas (CTCL), but the mechanism of SAHA action is unknown. In this study, we investigated the anti-tumor effects of SAHA in CTCL cell lines and freshly isolated peripheral blood lymphocytes (PBL) from CTCL patients with high percentage of circulating malignant T cells. Three cell lines (MJ, Hut78, and HH) and PBL from 11 patients and three healthy donors were treated with SAHA (1, 2.5, and 5 microM) for 24 and/or 48 h. Apoptosis was determined by flow cytometry analysis of sub-G1 hypodiploid nuclei and/or annexin V binding populations. Acetylated histones and apoptosis-associated proteins were detected by Western blotting. SAHA at 1-5 microM for 24 and 48 h induced apoptosis in a concentration- and time-dependent manner in three cell lines: MJ (0%-7% and 1%-32%), Hut78 (4%-36% and 5%-54%), and HH (4%-67% and 8%-81%). SAHA at 1-5 muM for 48 h also induced more apoptosis of patients' PBL than healthy donors' (15%-32%versus 6%-13%, p < 0.05). SAHA treatment caused an accumulation of acetylated histones (H2B, H3, and H4), an increase of p21(WAF1) and bax proteins, a decrease of Stat6 and phospho-Stat6 proteins, and activation of caspase-3 in CTCL cells. Our data suggest that selective induction of malignant T cell apoptosis and modulation of acetylated histones, p21(WAF1), bax, Stat6, and caspase-3 may underlie the therapeutic action of SAHA in CTCL patients.

Repair of genome destabilizing lesions

Living organisms are constantly exposed to detrimental agents both from the environment (e.g. ionizing radiation, ultraviolet light, natural and synthetic chemicals) and from endogenous metabolic processes (e.g. oxidative and hydrolytic reactions), resulting in modifications of proteins, lipids and DNA. Proteins and lipids are degraded and resynthesized, but the DNA is replicated only during cell division, when DNA damage may result in mutation fixation. Thus the DNA damage generated has the potential to lead to carcinogenesis, cell death, or other genetic disorders in the absence of efficient error-free repair. Because modifications in DNA sequence or structure may be incompatible with its essential role in preservation and transmission of genetic information from generation to generation, exquisitely sensitive DNA repair pathways have evolved to maintain genomic stability and cell viability. This review focuses on the repair and processing of genome destabilizing lesions and helical distortions that differ significantly from the canonical B-form DNA in mammalian cells. In particular, we discuss the introduction and processing of site-specific lesions in mammalian cells with an emphasis on psoralen interstrand crosslinks.

Idiopathic guttate hypomelanosis: idiopathic or ultraviolet induced?

Idiopathic guttate hypomelanosis (IGH) is a common but often unrecognized skin disease with obscure etiopathogenesis. As the lesions mostly develop on the exposed parts of the extremities, ultraviolet has been hypothesized to induce these lesions. However, previous statistical studies did not confirm any association between ultraviolet and IGH. We describe a 72-year-old woman with mycosis fungoides in whom widespread IGH occurred during narrow band ultraviolet B (UVB) therapy. The lesion development in the trunk following narrow band UVB therapy suggests that these lesions may not be idiopathic and they may be associated with UV exposure although controversy exist in the literature. This case is particular as it reveals strong evidence on this relationship.

Narrowband UVB phototherapy in skin conditions beyond psoriasis

BACKGROUND

Narrowband (NB) UVB phototherapy has been proven to be clearly more effective than broadband UVB and safer and/or more practicable than psoralen-UVA in the management of psoriasis. However, the role of NB UVB seems to be less clear in the management of skin conditions beyond psoriasis.

OBJECTIVES

We sought to give an update on clinical experiences in NB UVB of nonpsoriatic skin conditions, and to establish its current position within the spectrum of competing photo(chemo)therapeutic options.

METHODS

The computerized bibliographic database PubMed, without time limits, and other sources were screened for clinical trials on NB UVB. Included were research articles of randomized controlled trials, open prospective studies, and retrospective observations on NB UVB in skin disorders other than psoriasis.

RESULTS

A total of 28 articles met our eligibility criteria including 6 randomized controlled studies, 16 open prospective studies, and 6 retrospective observations. NB UVB is effective in patients with chronic atopic dermatitis (AD) (n = 719) and generalized vitiligo (n = 305) and appears to have some advantages over competing photo(chemo)therapeutic regimens. NB UVB also seems to be effective in patients with polymorphic light eruption (n = 25), early stages of cutaneous T-cell lymphoma (n = 108), chronic urticaria (n = 88), lichen planus (n = 15), pruritus associated with polycythemia vera (n = 10), seborrheic dermatitis (n = 18), actinic prurigo (n = 6), and acquired perforating dermatosis (n = 5). The quality of evidence determined for the aforementioned diagnoses ranged from high to moderate to very low.

CONCLUSIONS

The best currently available data on NB UVB in nonpsoriatic conditions exist for AD and generalized vitiligo. In view of its efficacy, benefit/risk profile, and costs, NB UVB may be considered the first-line photo(chemo)therapeutic option for moderately severe AD and widespread vitiligo. In the treatment of most other nonpsoriatic conditions, NB UVB appears to be effective, but current data allow no definitive conclusions as to whether NB UVB should be preferred to competing photo(chemo)therapeutic options such as UVA1 and psoralen-UVA regimens. Because NB UVB may have a wider indication spectrum, including AD, vitiligo, and early-stage T-cell lymphoma, and appears to be equally effective or even more effective than broadband UVB, a switch from broadband UVB to NB UVB seems to be justified.