Treatment of cutaneous T-cell lymphoma with retinoids

CDK9 recruits HUWE1 to degrade RARα and offers therapeutic opportunities for cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous non-Hodgkin lymphoma originating in the skin and invading the systemic hematopoietic system. Current treatments, including chemotherapy and monoclonal antibodies yielded limited responses with high incidence of side effects, highlighting the need for targeted therapy. Screening with small inhibitors library, herein we identify cyclin dependent kinase 9 (CDK9) as a driver of CTCL growth. Single-cell RNA-seq analysis reveals a CDK9high malignant T cell cluster with a unique actively proliferating feature. Inhibition, depletion or proteolysis targeting chimera (PROTAC)-mediated degradation of CDK9 significantly reduces CTCL cell growth in vitro and in murine models. CDK9 also promotes degradation of retinoic acid receptor α (RARα) via recruiting the E3 ligase HUWE1. Co-administration of CDK9-PROTAC (GT-02897) with all-trans retinoic acid (ATRA) leads to synergistic attenuation of tumor growth in vitro and in xenograft models, providing a potential translational treatment for complete eradication of CTCL.

EORTC consensus recommendations for the treatment of mycosis fungoides/Sézary syndrome - Update 2023

On behalf of the EORTC Cutaneous Lymphoma Tumours Group (EORTC-CLTG) and following up on earlier versions published in 2006 and 2017 this document provides an updated standard for the treatment of mycosis fungoides and Sézary syndrome (MF/SS). It considers recent relevant publications and treatment options introduced into clinical practice after 2017. Consensus was established among the authors through a series of consecutive consultations in writing and a round of discussion. Treatment options are assigned to each disease stage and, whenever possible and clinically useful, separated into first- and second line options annotated with levels of evidence. Major changes to the previous version include the incorporation of chlormethine, brentuximab vedotin, and mogamulizumab, recommendations on the use of pegylated interferon α (after withdrawal of recombinant unpegylated interferons), and the addition of paragraphs on supportive therapy and on the care of older patients. Still, skin-directed therapies are the most appropriate option for early-stage MF and most patients have a normal life expectancy but may suffer morbidity and impaired quality of life. In advanced disease treatment options have expanded recently. Most patients receive multiple consecutive therapies with treatments often having a relatively short duration of response. For those patients prognosis is still poor and only for a highly selected subset long term remission can be achieved with allogeneic stem cell transplantation. Understanding of the disease, its epidemiology and clinical course, and its most appropriate management are gradually advancing, and there is well-founded hope that this will lead to further improvements in the care of patients with MF/SS.

Suggested Guidelines for the Treatment of Mycosis Fungoides in Countries with Limited Resources

The treatment options for mycosis fungoides (MF) have been expanding but unfortunately many of the currently used treatment modalities are unavailable in Egypt and other African/Arab countries. In addition, there is a lack of consensus on the treatment of hypopigmented MF (HMF), which is a frequently encountered variant in our population. We aimed to develop regional treatment guidelines based on the international guidelines but modified to encompass the restricted treatment availability and our institutional experience. Special attention was also given to studies conducted on patients with skin phototype (III-IV). Treatment algorithm was formulated at Ain-Shams cutaneous lymphoma clinic through the collaboration of dermatologists, haematologists, and oncologists. Level of evidence is specified for each treatment option. For HMF, phototherapy is recommended as a first line treatment, while low-dose methotrexate is considered a second line. For early classical MF, we recommend Psoralen-ultraviolet A (PUVA), which is a well-tolerated treatment option in dark phenotype. Addition of either retinoic acid receptor (RAR) agonist and/or methotrexate is recommended as a second line. Total skin electron beam (TSEB) is considered a third-line option. For advanced stage, PUVA plus RAR agonist and/or methotrexate is recommended as first line, TSEB or monochemotherapy is considered a second line option. Polychemotherapy is regarded as a final option. All patients with complete response (CR) enter a maintenance and follow-up schedule. We suggest a practical algorithm for the treatment of MF for patients with dark phenotype living in countries with limited resources.

Phototherapy combined with systemic agents for mycosis fungoides

The choice of tactics for managing a patient with mycosis fungoides is determined by the stage of the disease. In the early stages of mycosis fungoides, a treatment approach using external therapy and various ultraviolet irradiation spectra (UVB-311 nm and PUVA therapy) is preferable. With insufficient efficiency and / or short remissions in some patients, it is possible to use combined methods in the early stages: PUVA therapy or UVB-311 nm therapy. in combination with systemic therapy, including interferon (IFN) 2b preparations, methotrexate and retinoids. The results of original studies demonstrate an increase in the overall response rate when combining PUVA therapy with IFN- or retinoids in patients with stages IB-IIB. The effectiveness of combined treatment regimens using UVB-311 nm remains insufficiently studied.

The Use of Retinoids for the Prevention and Treatment of Skin Cancers: An Updated Review

Retinoids are natural and synthetic vitamin A derivatives that are effective for the prevention and the treatment of non-melanoma skin cancers (NMSC). NMSCs constitute a heterogenous group of non-melanocyte-derived skin cancers that impose substantial burdens on patients and healthcare systems. They include entities such as basal cell carcinoma and cutaneous squamous cell carcinoma (collectively called keratinocyte carcinomas), cutaneous lymphomas and Kaposi’s sarcoma among others. The retinoid signaling pathway plays influential roles in skin physiology and pathology. These compounds regulate diverse biological processes within the skin, including proliferation, differentiation, angiogenesis and immune regulation. Collectively, retinoids can suppress skin carcinogenesis. Both topical and systemic retinoids have been investigated in clinical trials as NMSC prophylactics and treatments. Desirable efficacy and tolerability in clinical trials have prompted health regulatory bodies to approve the use of retinoids for NMSC management. Acceptable off-label uses of these compounds as drugs for skin cancers are also described. This review is a comprehensive outline on the biochemistry of retinoids, their activities in the skin, their effects on cancer cells and their adoption in clinical practice.

How to Sequence Therapies in Mycosis Fungoides

OPINION STATEMENT

Choice of therapy in mycosis fungoides is based on both patient- and lymphoma-specific factors, such as disease characteristics, comorbidities, symptoms and effect on quality of life, potential associated toxicities of therapy, response and tolerance to prior lines of therapy, and convenience and practicality. Generally, we sequence therapies from least toxic, targeted, nonimmunosuppressive to more toxic, immunosuppressive and from single agent to multiple agents, as necessary. If more toxic, immunosuppressive agents are required to alleviate disease burden or symptoms, we generally use them just long enough to control the disease, then transition to a maintenance regimen with less toxic, less immunosuppressive agents.

Oral isotretinoin for the treatment of dermatologic conditions other than acne: a systematic review and discussion of future directions

While isotretinoin has been the gold-standard of therapy for severe acne since its approval in 1982, its anti-inflammatory properties makes it a potentially applicable and versatile therapy for a wide variety of dermatologic conditions yet to be explored. This systematic review comprehensively recounts the success of oral isotretinoin in non-acne cutaneous diseases and provide insight into future directions of isotretinoin utility. A systematic literature review was performed using PubMed. Search terms included "isotretinoin" OR "accutane" AND "skin" OR "dermatology" OR "hair" OR "nails" OR "rosacea" OR "psoriasis" OR "pityriasis rubra pilaris" OR "condyloma acuminata" OR "granuloma annulare" OR "darier's disease" OR "non-melanoma skin cancer" OR "frontal fibrosing alopecia" OR "cutaneous lupus erythematosus" OR "hidradenitis suppurativa" OR "photodamaged skin" OR "skin aging" OR "wart" OR "flat warts" OR "plane warts" OR "lichen planus" OR "dissecting cellulitis" OR "folliculitis decalvans" OR "sebaceous hyperplasia" OR "cutaneous t-cell lymphoma" OR "mycosis fungoides." A total of 169 studies discuss the use of oral isotretinoin for 16 non-acne dermatologic conditions, the most common being non-melanoma skin cancers (0.2-8.2 mg/kg/day), cutaneous T-cell lymphomas (0.5-2 mg/kg/day), and rosacea (0.22-1 mg/kg/day). Inflammatory conditions such as rosacea, granuloma annulare, and hidradenitis suppurativa benefit from lower oral isotretinoin dosage of 0.3-1 mg/kg/day, whereas, hyperkeratotic diseases such as psoriasis and pityriasis rubra pilaris, consistently respond better to higher dosages of up to 2-4 mg/kg/day for lesion clearance. Recurrence of disease following discontinuation of isotretinoin have been reported for rosacea, psoriasis, granuloma annulare, Darier's disease, dissecting cellulitis, and non-melanoma skin cancers. Disease exacerbation was reported in some patients with hidradenitis suppurativa. Off-label isotretinoin is an effective treatment choice for dermatological conditions beyond acne. Further prospective, randomized human trials are needed to clarify when and how to prescribe off-label isotretinoin for maximum efficacy and safety.

How do we treat cutaneous T-cell lymphoma?

Cutaneous T-cell lymphomas are a heterogeneous group of non-Hodgkin lymphomas which are based on the malignant proliferation of skin-related T lymphocytes. The clinical appearance, as well as the course and the associated therapeutic approach, are sometimes very different between the different subtypes. Since allogeneic stem cell transplantation is currently the only curative option, and the morbidity and mortality are not insignificant, a therapy concept should be developed that considers its often rather indolent but chronic course. This concept should enable a good disease control with as few side effects as possible and preserve or improve the quality of life. In the early stages of the disease, skin-oriented therapies are generally used first before systemic and increasingly aggressive therapeutic agents are used as the disease progresses. Considering the current guidelines, literature and subjective experience, we summarize in this review how we treat cutaneous T-cell lymphomas.

Monotherapy and combination therapy with acitretin for mycosis fungoides: results of a retrospective, multicentre study

BACKGROUND

Retinoids have long been used in the treatment of cutaneous T-cell lymphomas. However, data on acitretin use for mycosis fungoides (MF) are very limited.

OBJECTIVES

To evaluate treatment outcomes of acitretin in patients with MF attending three academic referral centres in different regions of Greece.

METHODS

Data on effectiveness, safety and drug survival of acitretin as monotherapy or as adjuvant regimen were collected in a multicentre, register-based, retrospective study.

RESULTS

Overall, 128 patients (64.8% male; mean age at MF diagnosis 59.7 years) were included. Folliculotropic MF was present in 24 (18.8%) cases. Most patients (n = 118; 92.2%) had early-stage disease (≤IIA) at acitretin initiation. In all, 28 (21.9%) patients received acitretin monotherapy, while 100 (78.1%) subjects on acitretin concomitantly received phototherapy (n = 65; 50.8%) or topical steroids (n = 27; 21.1%). Acitretin was given as a first-line agent in 73 (57%) cases. A 77.3% overall response rate was noted: 44.5% and 32.8% for complete and partial responses, respectively. Acitretin was more effective as first-line than as a subsequent agent (P = 0.008). A trend towards better response was observed in the combination arm compared to patients receiving acitretin alone (P = 0.056). Median time to best response was 6.9 months (IQR 4.4-9.4); median duration of response was 23.7 months (IQR 11.9-35.4). Overall, the mean length of all treatment patterns was 569 days (SD 718.8). Therapy was discontinued in 5 (3.9%) cases due to drug intolerance. Adverse effects were recorded in 62 (48.4%) cases with dyslipidaemia (n = 31; 24.2%), xerosis (n = 24; 18.6%) and hair loss (n = 10; 7.8%) being the most commonly recorded.

CONCLUSIONS

Acitretin, either alone or as adjuvant, showed a stable long-term effectiveness in this cohort, especially when used in the first-line setting. This RAR-selective agonist may serve as an attractive option for treatment of MF and should be further evaluated.

Alzheimer's Disease, a Lipid Story: Involvement of Peroxisome Proliferator-Activated Receptor α

Alzheimer's disease (AD) is the leading cause of dementia in the elderly. Mutations in genes encoding proteins involved in amyloid-β peptide (Aβ) production are responsible for inherited AD cases. The amyloid cascade hypothesis was proposed to explain the pathogeny. Despite the fact that Aβ is considered as the main culprit of the pathology, most clinical trials focusing on Aβ failed and suggested that earlier interventions are needed to influence the course of AD. Therefore, identifying risk factors that predispose to AD is crucial. Among them, the epsilon 4 allele of the apolipoprotein E gene that encodes the major brain lipid carrier and metabolic disorders such as obesity and type 2 diabetes were identified as AD risk factors, suggesting that abnormal lipid metabolism could influence the progression of the disease. Among lipids, fatty acids (FAs) play a fundamental role in proper brain function, including memory. Peroxisome proliferator-activated receptor α (PPARα) is a master metabolic regulator that regulates the catabolism of FA. Several studies report an essential role of PPARα in neuronal function governing synaptic plasticity and cognition. In this review, we explore the implication of lipid metabolism in AD, with a special focus on PPARα and its potential role in AD therapy.

Combination therapy versus monotherapy in the treatment of recalcitrant warts: A clinical and immunological study

BACKGROUND

Treatment of recalcitrant warts represents a continuing therapeutic challenge. Combination therapies can help improve treatment response, decrease adverse effects, and reduce recurrence.

OBJECTIVE

To compare the efficacy, safety and immunological effects of a combined acitretin-intralesional Candida antigen against acitretin alone and Candida antigen alone for intractable warts.

METHODS

Sixty adult patients with intractable warts were included in this study. Patients were subdivided into three groups, each containing 20 patients. Acitretin alone was taken by patients of group I, Candida antigen alone was injected in patients of group II, and group III received a combination of intralesional Candida antigen and acitretin. Serum cytokine levels of IL-10 and IFN-γ were measured before and after therapy in the studied groups.

RESULTS

Total resolution of warts was achieved in 8 patients (40%) of the acitretin alone group, 9 patients (45%) of the Candida antigen alone group and 15 patients (75%) of the combination therapy group. The therapeutic response was statistically higher in the combined acitretin-Candida antigen group as compared with either agent alone. Adverse effects were non-significant in the three groups. There were no statistically significant differences in the serum levels of IFN-γ and IL-10 between responders and non-responders after therapy in the three studied groups.

CONCLUSION

The combination therapy of acitretin + Candida antigen is superior to either agent alone. Serum cytokine levels of IL-10 and IFN-γ were not associated with clearance or persistence of warts in any of the studied groups.

The immunomodulatory potential of natural compounds in tumor-bearing mice and humans

Cancer is considered a fetal disease caused by uncontrolled proliferation and progression of abnormal cells. The most efficient cancer therapies suppress tumor growth, prevent progression and metastasis, and are minimally toxic to normal cells. Natural compounds have shown a variety of chemo-protective effects alone or in combination with standard cancer therapies. Along with better understanding of the dynamic interactions between our immune system and cancer development, nutritional immunology-the use of natural compounds as immunomodulators in cancer patients-has begun to emerge. Cancer cells evolve strategies that target many aspects of the immune system to escape or even edit immune surveillance. Therefore, the immunesuppressive tumor microenvironment is a major obstacle in the development of cancer therapies. Because interaction between the tumor microenvironment and the immune system is a complex topic, this review focuses mainly on human clinical trials and animal studies, and it highlights specific immune cells and their cytokines that have been modulated by natural compounds, including carotenoids, curcumin, resveratrol, EGCG, and β-glucans. These natural compounds have shown promising immune-modulating effects, such as inhibiting myeloid-derived suppressor cells and enhancing natural killer and cytolytic T cells, in tumor-bearing animal models, but their efficacy in cancer patients remains to be determined.

Phototherapy of cutaneous T-cell lymphomas

Cutaneous T-cell lymphomas (CTCL) are a heterogenous group of non-Hodgkin lymphomas arising in the skin. Mycosis fungoides (MF), the most common variant, is characterised by clonal proliferation of skin residing malignant T-cells. Initially appearing with erythematous patches and plaques it follows a chronic course with progression to cutaneous tumours and extracutaneous involvement in some patients. Phototherapy with ultraviolet A radiation combined with 8-methoxypsoralen (PUVA) and with narrow-band ultraviolet B radiation (NB-UVB) are among the first line options for the treatment of MF and can induce remission in most patients. Sézary syndrome (SS) is a rare and more aggressive CTCL variant with generalized skin involvement. Patients with SS and with erythroderma from MF can benefit from treatment with extracorporeal photochemotherapy (ECP) where peripheral blood is exposed to PUVA. Phototherapy can be safely combined with systemic agents, most notably interferon-alpha and retinoids. Another photoresponsive CTCL variant is lymphomatoid papulosis (LP), a CD30+ lymphoproliferative disease characterised by chronically recurring papules. The disease responds favourably to PUVA but low dose methotrexate might be preferred for long term disease control. Recently updated treatment guidelines have been published to provide evidence-based algorithms for the stage-oriented treatment of MF, SS and LP. Areas of uncertainty are treatment schedules that are currently not optimised for CTCL, the use of phototherapy for maintenance, and the value of ultraviolet A1 radiation, excimer lasers, and photodynamic therapy.

Management of Lymphomas: Consensus Document 2018 by an Indian Expert Group

The clinical course of lymphoma depends on the indolent or aggressive nature of the disease. Hence, the optimal management of lymphoma needs a correct diagnosis and classification as B cell, T-cell or natural killer (NK)/T-cell as well as indolent or high-grade type lymphoma. The current consensus statement, developed by experts in the field across India, is intended to help healthcare professionals manage lymphomas in adults over 18 years of age. However, it should be noted that the information provided may not be appropriate to all patients and individual patient circumstances may dictate alternative approaches. The consensus statement discusses the diagnosis, staging and prognosis applicable to all subtypes of lymphoma, and detailed treatment regimens for specific entities of lymphoma including diffuse large B-cell lymphoma, Hodgkin's lymphoma, follicular lymphoma, T-cell lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, Burkitt's lymphoma, and anaplastic large cell lymphoma.

Biocompatible Gold Nanoparticles Ameliorate Retinoic Acid-Induced Cell Death and Induce Differentiation in F9 Teratocarcinoma Stem Cells

The unique properties of gold nanoparticles (AuNPs) have attracted much interest for a range of applications, including biomedical applications in the cosmetic industry. The current study assessed the anti-oxidative effect of AuNPs against retinoic acid (RA)-induced loss of cell viability; cell proliferation; expression of oxidative and anti-oxidative stress markers, pro- and anti-apoptotic genes, and differentiation markers; and mitochondrial dysfunction in F9 teratocarcinoma stem cells. AuNPs were prepared by reduction of gold salts using luteolin as a reducing and stabilizing agent. The prepared AuNPs were spherical in shape with an average diameter of 18 nm. F9 cells exposed to various concentrations of these AuNPs were not harmed, whereas cells exposed to RA exhibited a dose-dependent change in cell viability and cell proliferation. The RA-mediated toxicity was associated with increased leakage of lactate dehydrogenase, reactive oxygen species, increased levels of malondialdehyde and nitric oxide, loss of mitochondrial membrane potential, and a reduced level of ATP. Finally, RA increased the level of pro-apoptotic gene expression and decreased the expression of anti-apoptotic genes. Interestingly, the toxic effect of RA appeared to be decreased in cells treated with RA in the presence of AuNPs, which was coincident with the increased levels of anti-oxidant markers including thioredoxin, glutathione peroxidases, glutathione, glutathione disulfide, catalase, and superoxide dismutase. Concomitantly, AuNPs ameliorated the apoptotic response by decreasing the mRNA expression of p53, p21, Bax, Bak, caspase-3, caspase-9, and increasing the expressions of Bcl-2 and Bcl-Xl. Interestingly, AuNPs not only ameliorated oxidative stress but also induced differentiation in F9 cells by increasing the expression of differentiation markers including retinoic acid binding protein, laminin 1, collagen type IV, and Gata 6 and decreasing the expressions of markers of stem cell pluripotency including Nanog, Rex1, octamer-binding transcription factor 4, and Sox-2. These consistent cellular and biochemical data suggest that AuNPs could ameliorate RA-induced cell death and facilitate F9 cell differentiation. AuNPs could be suitable therapeutic agents for the treatment of oxidative stress-related diseases such as atherosclerosis, cancer, diabetes, rheumatoid arthritis, and neurodegenerative diseases.

RARα/RXR synergism potentiates retinoid responsiveness in cutaneous T-cell lymphoma cell lines

Retinoids, natural and synthetic derivatives of vitamin A, induce cellular changes by activating nuclear retinoic acid receptors (RAR) and retinoid X receptors (RXR). Although the ability of retinoids to govern gene expression is exploited clinically for cancer therapeutics, the full benefit of retinoid-based strategies is unrealized due to detrimental side effects. Delineating the receptors that prompt cellular outcomes is critical to advancing retinoid-based approaches. Here, we identify the receptors that evoke multiple responses in cutaneous T-cell lymphoma (CTCL). The data demonstrate that RARα drives integrin β7-dependent adhesion and CCR9-mediated chemotaxis in CTCL cells. Of note, concomitant activation of RARα and RXR nuclear receptors yielded synergistic increases in adhesion and migration at concentrations where single agents were ineffective. As the established paradigm of retinoid action in CTCL is apoptosis and growth arrest, the role of RARα/RXR in these events was studied. As with adhesion and migration, RARα/RXR synergism prompted apoptosis and dampened CTCL cell proliferation. Strikingly, RARα/RXR synergism induced responses from CTCL cell lines previously reported to be unresponsive to retinoids. These data provide a novel framework that may further refine a proven CTCL therapy.

Retinoic Acid Negatively Impacts Proliferation and MCTC Specific Attributes of Human Skin Derived Mast Cells, but Reinforces Allergic Stimulability

The Vitamin-A-metabolite retinoic acid (RA) acts as a master regulator of cellular programs. Mast cells (MCs) are primary effector cells of type-I-allergic reactions. We recently uncovered that human cutaneous MCs are enriched with RA network components over other skin cells. Yet, direct experimental evidence on the significance of the RA-MC axis is limited. Here, skin-derived cultured MCs were exposed to RA for seven days and investigated by flow-cytometry (BrdU incorporation, Annexin/PI, FcεRI), microscopy, RT-qPCR, histamine quantitation, protease activity, and degranulation assays. We found that while MC size and granularity remained unchanged, RA potently interfered with MC proliferation. Conversely, a modest survival-promoting effect from RA was noted. The granule constituents, histamine and tryptase, remained unaffected, while RA had a striking impact on MC chymase, whose expression dropped by gene and by peptidase activity. The newly uncovered MRGPRX2 performed similarly to chymase. Intriguingly, RA fostered allergic MC degranulation, in a way completely uncoupled from FcεRI expression, but it simultaneously restricted MRGPRX2-triggered histamine release in agreement with the reduced receptor expression. Vitamin-A-derived hormones thus re-shape skin-derived MCs numerically, phenotypically, and functionally. A general theme emerges, implying RA to skew MCs towards processes associated with (allergic) inflammation, while driving them away from the skin-imprinted MC_TC (“MCs containing tryptase and chymase”) signature (chymase, MRGPRX2). Collectively, MCs are substantial targets of the skin retinoid network.

Neurological and Neuropsychiatric Adverse Effects of Dermatologic Medications

Severe, recalcitrant dermatologic conditions often require systemic treatment. Although efficacious, these medications have been associated with wide-ranging adverse reactions. Some are reversible, predictable, and either dose-dependent or treatment length-dependent, while others are unpredictable, irreversible, and potentially fatal. This review examines the neuropsychiatric adverse effects associated with US FDA-approved medications for treatment of the following dermatologic pathologies that typically require systemic therapy: autoimmune dermatoses, acne, psoriasis, and melanoma. A search of the literature was performed, with adverse effects ranging from mild headaches and neuropathy to severe encephalopathies. The medications associated with the most serious reactions were those used to treat psoriasis, especially the older non-biologic medications such as cyclosporine A and methotrexate. Given the importance of these systemic dermatologic therapies in treating severe, recalcitrant conditions, and the wide variety of potentially serious neuropsychiatric adverse effects of these medications, neurologists, psychiatrists, dermatologists, oncologists, and primary care providers must be aware of the potential for these neuropsychiatric adverse reactions to allow for appropriate counseling, management, and medication withdrawal.

Targretin Improves Cognitive and Biological Markers in a Patient with Alzheimer's Disease

We present the effects of Targretin® (bexarotene) on cognition and biomarkers in a patient with mild Alzheimer's disease (AD). Targretin® is a Retinoic X Receptor (RXR) agonist shown to improve synaptic and cognitive functions in animal models of AD by increasing neuronal cholesterol efflux. After 6 months of treatment with Targretin® 300 mg/day, memory improved by about 40% and the tau protein in the cerebrospinal fluid decreased by about 20% . No significant side effects were noticed. This observation in a single patient indicates that Targretin® may improve memory performance and biological markers at an early stage of AD.

Bexarotene protects against traumatic brain injury in mice partially through apolipoprotein E

Bexarotene has been proved to have neuroprotective effects in many animal models of neurological diseases. However, its neuroprotection in traumatic brain injury (TBI) is still unknown. This study aims to explore the neuroprotective effects of bexarotene on TBI and its possible mechanism. Controlled cortical impact (CCI) model was used to simulate TBI in C57BL/6 mice as well as APOE gene knockout (APOE-KO) mice. After CCI, mice were daily dosed with bexarotene or vehicle solution intraperitoneally. The motor function, learning and memory, inflammatory factors, microglia amount, apoptosis condition around injury site and main side-effects were all measured. The results showed that, after CCI, bexarotene treatment markedly improved the motor function and spatial memory in C57BL/6 compare to APOE-KO mice which showed no improvement. The inflammatory cytokines, microglia amount, cell apoptosis rate, and protein of cleaved caspase-3 around the injury site were markedly upregulated after TBI in both C57BL/6 and APOE-KO mice, and all these upregulation were significantly mitigated by bexarotene treatment in C57BL/6 mice, but not in APOE-KO mice. No side-effects were detected after consecutive administration. Taken together, bexarotene inhibits the inflammatory response as well as cell apoptosis and improves the neurological function of mice after TBI partially through apolipoprotein E. This may make it a promising candidate for the therapeutic treatment after TBI.

The Role of Systemic Retinoids in the Treatment of Cutaneous T-Cell Lymphoma

Retinoids are natural and synthetic vitamin A analogs with effects on cell proliferation, differentiation, and apoptosis. They have significant activity in hematologic malignancies and have been studied extensively in cutaneous T-cell lymphoma. Retinoids bind to nuclear receptors and exert their effects through moderation of gene expression. Retinoic acid receptor and retinoic X receptor exert regulatory activity in vivo, binding to distinct ligands. Studies investigating systemic retinoids as monotherapy and in combination with other agents active against cutaneous lymphoma are reviewed. Side effects associated with retinoids include teratogenicity, dyslipidemias, and hypothyroidism, which should be carefully monitored in patients receiving treatment.

Retinoids Bias Integrin Expression and Function in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of malignancies characterized by accumulation of malignant T-cells within the skin. Retinoids, metabolic derivatives, and synthetic analogs of vitamin A embody an effective CTCL therapy with over three decades of clinical use. The established mechanism of action is induction of growth arrest and apoptosis. However, the natural role of retinoids in T-cell biology is imprinting gut-homing properties by inducing integrin α4β7 expression. How the natural role of retinoids relates to therapeutic effectiveness in CTCL has not been addressed and merits investigation. Here we provide evidence that retinoids, including Bexarotene, selectively induce CTCL lineages to increase integrin β7 expression and function prior to growth arrest and apoptosis. Interestingly, augmented CTCL cell adhesion obtained with retinoid exposure was potently attenuated by 1,25-dihydroxyvitamin D3, a metabolic vitamin derivative involved in prompting immune cell skin homing. The integrin-dependent adhesion changes in CTCL cells occurred through synergistic activation of RAR and RXR nuclear receptors. These data explore the early cellular changes induced by retinoids that may be pivotal to sensitizing CTCL cells to growth arrest and apoptosis.

Retinoic acid potentiates inflammatory cytokines in human mast cells: identification of mast cells as prominent constituents of the skin retinoid network

Retinoic acid (RA), the active vitamin-A-metabolite, has well-established functions in skin homeostasis and in the immune system. Skin mast cells (MCs) combine traits of both structures, being of hematopoietic origin, but functional in the skin environment. It remains largely unknown whether mature MCs are targeted by the retinoid network. Here, we demonstrate that human skin MCs display substantial susceptibility to RA by which they are instructed to increase pro-inflammatory mediators (IL-1β, IL-8, TNF-α) but not histamine release. The effects are observed at physiological RA levels, in different microenvironments, and are largely donor-independent. RA susceptibility is owed to the cells' abundant expression of RARA, the receptor mediating MC cytokine responses. Unexpectedly, bioinformatics calculations on the FANTOM5 expression atlas revealed general enrichment of retinoid network components in MCs against other skin cells, and MCs rapidly upregulated RA responsive genes. In conclusion, MCs are important yet hitherto overlooked retinoid targets in the skin.

Retinoic acid receptors: from molecular mechanisms to cancer therapy

Retinoic acid (RA), the major bioactive metabolite of retinol or vitamin A, induces a spectrum of pleiotropic effects in cell growth and differentiation that are relevant for embryonic development and adult physiology. The RA activity is mediated primarily by members of the retinoic acid receptor (RAR) subfamily, namely RARα, RARβ and RARγ, which belong to the nuclear receptor (NR) superfamily of transcription factors. RARs form heterodimers with members of the retinoid X receptor (RXR) subfamily and act as ligand-regulated transcription factors through binding specific RA response elements (RAREs) located in target genes promoters. RARs also have non-genomic effects and activate kinase signaling pathways, which fine-tune the transcription of the RA target genes. The disruption of RA signaling pathways is thought to underlie the etiology of a number of hematological and non-hematological malignancies, including leukemias, skin cancer, head/neck cancer, lung cancer, breast cancer, ovarian cancer, prostate cancer, renal cell carcinoma, pancreatic cancer, liver cancer, glioblastoma and neuroblastoma. Of note, RA and its derivatives (retinoids) are employed as potential chemotherapeutic or chemopreventive agents because of their differentiation, anti-proliferative, pro-apoptotic, and anti-oxidant effects. In humans, retinoids reverse premalignant epithelial lesions, induce the differentiation of myeloid normal and leukemic cells, and prevent lung, liver, and breast cancer. Here, we provide an overview of the biochemical and molecular mechanisms that regulate the RA and retinoid signaling pathways. Moreover, mechanisms through which deregulation of RA signaling pathways ultimately impact on cancer are examined. Finally, the therapeutic effects of retinoids are reported.

The current management of mycosis fungoides and Sézary syndrome and the role of radiotherapy: Principles and indications

AIM

To evaluate the current treatment of mycosis fungoides (MF) and Sézary syndrome (SS) focusing on the role of radiotherapy (RT), its principles and indications, and the perspectives of the novel irradiation technologies.

BACKGROUND

MF and SS are rare lymphoproliferative diseases whose incidence is increasing. For a long time RT has been used as a single modality or in integrated treatment programs for these diseases.

MATERIALS AND METHODS

The latest systematic reviews, primary studies and new diagnostic and treatment guidelines on MF and SS were analyzed. Clinical outcomes together with the technical aspects and the role of RT were also evaluated.

RESULTS

New data are available on pathogenesis, diagnostic criteria, classification and staging procedures for MF and SS and several local and systemic therapies are proposed. Localized RT can cure "minimal stage" MF while total skin electron beam irradiation (TSEI) may cure initial-stage disease and may offer important symptom relief (itch, erythroderma) in a more advanced setting. Despite its efficacy, RT is not largely used, mainly because of some technical difficulties but new RT technologies may be proposed to treat large skin surfaces.

CONCLUSIONS

New treatment programs offer good results, with median survival of more than 12 years in early-stage MF, but the median survival of 2.5 years or less in advanced stages is still a challenge. RT remains an option for all stages with a good cost/effectiveness ratio in a curative or palliative setting. New RT technologies can overcome some technical problems of treating large skin surfaces.

Role of bexarotene in the treatment of cutaneous T-cell lymphoma: the clinical and immunological sides

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of lymphoid neoplasms. The incidence of CTCLs has risen over the last three decades. The most common CTCLs are mycosis fungoides and Sèzary syndrome. Therapies for CTCLs are various and range from skin-directed therapy to chemotherapy. Retinoids have been used in CTCL treatment since the 1980s with good results. Bexarotene is the first retinoid approved by the US FDA for CTCL therapy. Since then, numerous experiences of both its efficacy and mechanism of action have been reported. The aim of this paper is to review bexarotene action on CTCLs, as well as to highlight its immunological targets.

Panobinostat activity in both bexarotene-exposed and -naïve patients with refractory cutaneous T-cell lymphoma: results of a phase II trial

BACKGROUND

Panobinostat is a potent, oral pan-deacetylase inhibitor (pan-DACi) that increases the acetylation of proteins involved in multiple oncogenic pathways. Here, panobinostat is studied in bexarotene-exposed and -naïve patients with refractory cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

Patients with CTCL subtypes mycosis fungoides and Sézary syndrome who received ⩾2 prior systemic therapy regimens received panobinostat (20mg) three times every week. The primary objective was overall response rate (ORR) as determined by a combined evaluation of skin disease and involvement of lymph node and viscera. Disease progression was defined as an unconfirmed, ⩾25% increase in modified Severity Weighted Assessment Tool (mSWAT) compared with nadir.

RESULTS

Seventy-nine bexarotene-exposed and 60 bexarotene-naïve patients were enrolled. Reductions in baseline mSWAT scores were observed in 103 patients (74.1%). The ORR was 17.3% in all patients in the primary analysis (15.2% and 20.0% in the bexarotene-exposed and -naïve groups, respectively). The median progression-free survival was 4.2 and 3.7 months in the bexarotene-exposed and -naïve groups, respectively. The median duration of response was 5.6 months in the bexarotene-exposed patients and was not reached at data cutoff in the bexarotene-naïve patients. Additional responses were observed when less-stringent progression criteria were used. The most common adverse events were thrombocytopenia, diarrhoea, fatigue and nausea. Thrombocytopenia and neutropenia were the only grade 3/4 adverse events in >5% of patients and were manageable.

CONCLUSION

Despite a very conservative definition of disease progression, panobinostat demonstrated activity with a manageable safety profile in bexarotene-exposed and -naïve CTCL patients. ClinicalTrials.gov Identifier: NCT00425555.

Retinoic acid-induced differentiation increases the rate of oxygen consumption and enhances the spare respiratory capacity of mitochondria in SH-SY5Y cells

Retinoic acid (RA) is used in differentiation therapy to treat a variety of cancers including neuroblastoma. The contributing factors for its therapeutic efficacy are poorly understood. However, mitochondria (MT) have been implicated as key effectors in RA-mediated differentiation process. Here we utilize the SH-SY5Y human neuroblastoma cell line as a model to examine how RA influences MT during the differentiation process. We find that RA confers an approximately sixfold increase in the oxygen consumption rate while the rate of glycolysis modestly increases. RA treatment does not increase the number of MT or cause measurable changes in the composition of the electron transport chain. Rather, RA treatment significantly increases the mitochondrial spare respiratory capacity. We propose a competition model for the therapeutic effects of RA. Specifically, the high metabolic rate in differentiated cells limits the availability of metabolic nutrients for use by the undifferentiated cells and suppresses their growth. Thus, RA treatment provides a selective advantage for the differentiated state.

The use of growth factors to modulate the activities of antigen-specific CD8+ T cells in vitro

RATIONALE

Adoptive T cell therapy depends on the harvesting of the cells from the host, their activation in vitro, and their infusion back to the same host. The way of activating the T cells in vitro is a critical factor for their homing, survival and function in vivo. Sustaining T cell homing molecules, particularly CD62L, is benefic for the trafficking of the adoptive transferred cells.

OBJECTIVE

The aim of the present study is to test whether insulin-like growth factor-1 (IGF-1), thymosin- α1 (T-α1) as well as all-trans retinoid acid (ATRA) alone or in combination with IL-2, IL-12, IL-15 can enhance the activation and survival phenotypes of antigen-activated T cells in vitro.

METHODS & RESULTS

To this end, OT-1 transgenic T cells were used as a model. These CD8+ T cells recognize OVA peptide presented by MHC class-I. The results showed that antigen stimulation of OT1 cells resulted in their activation as evidenced by the decrease in surface expression of CD62L, analyzed for 3 days after antigen stimulation and was more pronounced on day 5. The addition of IL-12 or IGF-1 alone but not of IL-2, IL-15 augmented OT-1 cell activation measured on day 5. Interestingly, the combination of IL-12 with IGF-1 sustained the expression of CD62L on OT1 cells. Although the addition of ATRA alone or in combination with IL-12 resulted in decreases in CD62L expression on day 3, they showed a dose-dependent effect on the restoration of CD62L expression on day 5. The analysis of the activation-induced cell death (apoptosis) of OT1 cells showed an increased rate of death on day 5 than on day 3-post antigen stimulation. The addition of only IL-12 or IGF-1 alone, but not of IL-2, IL-15 or T- α1, decreased OT1 cell apoptosis on day 3. These anti-apoptotic effects of IL-12 and IGF- 1, however, were recovered on day 5-post stimulation.

DISCUSSION

In conclusion, these results indicate that the activation phenotype and the survival of antigen-specific T cells can be differently modulated by immunomodulatory factors, where, interleukin-12 and IGF-1 induced the favorable effect. These results have a significant implication for T cell adoptive immunotherapy in different settings.

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.

Erythroderma as a paraneoplastic cutaneous disorder in systemic anaplastic large cell lymphoma

BACKGROUND

  Paraneoplastic cutaneous disorders (PCDs) or dermadromes are skin conditions that have an association with internal malignancies but are not themselves malignant. We report the first two cases of systemic anaplastic large cell lymphoma (s-ALCL) accompanied by erythroderma and multiple leg ulcers as PCDs. CASE 1:  A 52-year-old Japanese man presented with disseminated itchy papular erythemas which he had over his entire body for the preceding 5 years that later exacerbated to erythroderma. Multiple punched-out ulcers also developed on his lower legs. Superficial lymph nodes (LNs) were swollen, and a left axillary LN biopsy demonstrated dense CD30(+) atypical large cell (ALC) infiltration. By contrast, lymphocytes infiltrating into the erythroderma and leg ulcers were CD30(-) , and T-cell receptor β (TCRβ) chain gene rearrangement was negative in skin biopsy specimens. Thus, he was diagnosed with s-ALCL. Not only his s-ALCL but also his erythroderma and leg ulcers responded well to chemotherapy. CASE 2:  A 71-year-old Japanese woman presented with erythroderma that persisted for approximately 20 years after mastectomy. At her initial hospital visit, she was diagnosed with s-ALCL by biopsy of swollen left inguinal LNs. Similar to Case 1, CD30(+) ALCs were negative in skin samples with normal TCRβ chain gene rearrangement. As the erythrodermic skin lesion responded well to chemotherapy for s-ALCL, it was considered a PCD.

CONCLUSION

  s-ALCL development may be predicted by the precedence and concurrence of intractable paraneoplastic erythrodermic and ulcerative skin lesions, as reported in our two cases.

Neuromuscular adverse effects associated with systemic retinoid dermatotherapy: monitoring and treatment algorithm for clinicians

Although neuromuscular adverse effects represent significant clinical manifestations of hypervitaminosis A syndrome, surprisingly little attention has been paid to the potential neuromuscular toxicity of vitamin A derivatives (retinoids). Since isotretinoin and acitretin are currently the two most commonly used oral retinoids in systemic dermatotherapy, this review focuses exclusively on their neuromuscular adverse effects and proposes a neuromuscular algorithm for appropriate monitoring of patients treated with these two compounds. The most frequent CNS adverse effect associated with oral isotretinoin is headache, either as an independent adverse effect or as part of benign intracranial hypertension, which is additionally characterized by nausea and visual changes. Isolated cases of stiff-person-like syndrome, epileptic seizures and generalized muscle stiffness syndrome, possibly or probably related to oral treatment with isotretinoin, have also been reported. In addition, oral isotretinoin has reportedly been associated with muscular adverse effects that most frequently manifest as myalgia and stiffness and, in rare cases, as true myopathy or rhabdomyolysis. Creatine phosphokinase, a specific marker of muscle destruction, has been found to be elevated, occasionally by up to 100 times the normal value (with or without muscular symptoms and signs), in a variable percentage of patients receiving isotretinoin treatment and particularly in those undergoing vigorous physical exercise. Oral acitretin has been found to cause peripheral nerve dysfunction, particularly of sensory fibres, which in rare cases leads to clinically evident sensory disturbances. Less clear is the causal relationship between acitretin and benign intracranial hypertension or myopathy, whereas an isolated case of cranial nerve IV (oculomotor) palsy and a further case of thrombotic stroke during treatment with oral acitretin have been reported. Systemic diseases with involvement of nervous and/or muscle tissue and neuromuscular disorders should be regarded as exclusion criteria for initiation of oral retinoid therapy. Additionally, intense physical exercise and concurrent treatment with neurotoxic or myotoxic drugs should be avoided during treatment with oral retinoids. In order to minimize the potential risk of neuromuscular adverse effects, a neuromuscular algorithm is suggested that may be useful for monitoring patients taking oral retinoids.

Acitretin systemic and retinoic acid 0.1% cream supression of basal cell carcinoma

Retinoids have been used for years as monotherapy and/or in combination for treatment and suppression of cutaneous malignancies in patients with basal cell nevus syndrome, xeroderma pigmentosum, or cutaneous T-cell lymphoma (CTCL) basal cell carcinoma (BCC). We report 4 cases with BCC confirmed by histopathology who were treated by short-term systemic acitretin combined with retinoic acid 0.1% cream. The 4 cases with BCC showed good response to the treatment without severe adverse effects during treatment and follow-up. The finding suggests that acitretin may be an appropriate treatment option for elderly patients who require less invasive treatment for BCC.

Cutaneous T-cell lymphoma in skin of color

Over the past three decades, there has been a marked increase in the incidence of cutaneous T-cell lymphoma (CTCL), with significant differences in the rates of CTCL by race and ethnicity. The overall incidence of CTCL has been shown to be higher among blacks than among whites and other racial groups. In addition, CTCL is thought to follow a more aggressive course in black patients. This article highlights the differences in clinical appearance and response to therapy, and discusses the differential diagnosis of CTCL in skin of color in an attempt to ensure earlier diagnosis and better outcomes for these patients.

The estrogen-responsive B box protein (EBBP) restores retinoid sensitivity in retinoid-resistant cancer cells via effects on histone acetylation

Retinoids have significant clinical activity in several human cancers, yet the factors determining retinoid sensitivity in cancer cells are still unclear. Retinoid-induced expression of retinoic acid receptor (RAR) beta(2) is a necessary component of the retinoid anticancer signal in cancer cells. We have previously identified the Estrogen-responsive B Box Protein (EBBP), a member of the Tripartite Motif (TRIM) protein family, as a novel RARbeta2 transcriptional regulator in the retinoid signal. Here we examined the mechanism of the EBBP effect on the retinoid anticancer signal. We assessed retinoid-responsive RARbeta2 transcription in retinoid-resistant breast and lung cancer cells in the presence of chromatin modifying agents. A histone deacetylase (HDAC) inhibitor alone, or in combination with retinoid, was more effective than a demethylating agent in restoring RARbeta2 transcription in resistant cells. Overexpression of EBBP alone markedly increased histone acetylation. The effect of EBBP on retinoid-responsive transcription appeared to be limited to genes with the retinoic acid response element (betaRARE) regulatory sequence, such as CYP26A1. EBBP inhibited cell growth by effects on cyclin D1 and Phospho-Rb, and, reduced cell viability in retinoid-resistant cancer cells. The viability of non-cancer cells was unaffected by EBBP overexpression. Taken together our data suggests that EBBP acts to de-repress transcription of RARbeta2 and CYP26A1, by modifying histone acetylation in retinoid-resistant cancer cells, and, is an important target for drug discovery in retinoid-resistant cancers.

Systemic therapies for psoriasis: methotrexate, retinoids, and cyclosporine

Despite the current use and ongoing development of the biological therapies 'traditional' systemic agents will continue to form a key part of the therapeutic armamentarium for patients with severe psoriasis. Long-term maintenance therapy with retinoids and methotrexate is cost-effective and, for many patients with psoriasis, life changing. Regular monitoring is required for both treatments, particularly methotrexate to prevent significant bone marrow suppression and hepatotoxicity. Ideally, cyclosporine should be used for short courses of 3 to 4 months duration, within which it provides excellent disease control. Close assessment of renal function and blood pressure is essential.