A systems approach points to a therapeutic role for retinoids in asparaginase-associated pancreatitis.

Among drug-induced adverse events, pancreatitis is life-threatening and results in substantial morbidity. A prototype example is the pancreatitis caused by asparaginase, a crucial drug used to treat acute lymphoblastic leukemia (ALL). Here, we used a systems approach to identify the factors affecting asparaginase-associated pancreatitis (AAP). Connectivity Map analysis of the transcriptomic data showed that asparaginase-induced gene signatures were potentially reversed by retinoids (vitamin A and its analogs). Analysis of a large electronic health record database (TriNetX) and the U.S. Federal Drug Administration Adverse Events Reporting System demonstrated a reduction in AAP risk with concomitant exposure to vitamin A. Furthermore, we performed a global metabolomic screening of plasma samples from 24 individuals with ALL who developed pancreatitis (cases) and 26 individuals with ALL who did not develop pancreatitis (controls), before and after a single exposure to asparaginase. Screening from this discovery cohort revealed that plasma carotenoids were lower in the cases than in controls. This finding was validated in a larger external cohort. A 30-day dietary recall showed that the cases received less dietary vitamin A than the controls did. In mice, asparaginase administration alone was sufficient to reduce circulating and hepatic retinol. Based on these data, we propose that circulating retinoids protect against pancreatic inflammation and that asparaginase reduces circulating retinoids. Moreover, we show that AAP is more likely to develop with reduced dietary vitamin A intake. The systems approach taken for AAP provides an impetus to examine the role of dietary vitamin A supplementation in preventing or treating AAP.

A systematic review of oral retinoids for treatment of acneiform eruptions induced by epidermal growth factor receptor inhibitors.

Epidermal growth factor receptor inhibitors (EGFRi) are now standard of care in patients with EGFR mutations in non-small cell lung cancer (NSCLC) and are increasingly being used in other EGFR mutated cancers, including gastrointestinal, and head and neck. However, EGFRi are well known to cause acneiform eruptions, which are shown to positively correlate with tumor response to treatment, but may be severe enough to cause interruption of their treatment. Although most guidelines call for the use of tetracyclines to treat these acneiform eruptions, there is mounting evidence for the use of systemic retinoids instead. The objective of this review is to summarize available data on the use of systemic retinoids for management of acneiform eruptions on EGFRi. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE and EMBASE were searched from database inception until December 10th, 2021. All articles were screened and relevant data extracted independently in duplicate by two reviewers. In total, 16 case reports, case series and retrospective reviews were included. Forty-three patients were treated with retinoids for their acneiform eruption due to EGFRi. The majority (77%) noted moderate to significant improvement after treatment initiation with minimal adverse events (16%). The findings of this systematic review suggest that systemic retinoids are a safe and effective therapy for the management of acneiform eruptions induced by EGFRi.

A2E-induced inflammation and angiogenesis in RPE cells in vitro are modulated by PPAR-α, -ß/δ, -γ, and RXR antagonists and by norbixin.

N-retinylidene-N-retinylethanolamine (A2E) plays a central role in age-related macular degeneration (AMD) by inducing angiogenesis and inflammation. A2E effects are mediated at least partly via the retinoic acid receptor (RAR)-α. Here we show that A2E binds and transactivates also peroxisome proliferator-activated receptors (PPAR) and retinoid X receptors (RXR). 9'-cis-norbixin, a di-apocarotenoid is also a ligand of these nuclear receptors (NR). Norbixin inhibits PPAR and RXR transactivation induced by A2E. Moreover, norbixin reduces protein kinase B (AKT) phosphorylation, NF-κB and AP-1 transactivation and mRNA expression of the inflammatory interleukins (IL) -6 and -8 and of vascular endothelial growth factor (VEGF) enhanced by A2E. By contrast, norbixin increases matrix metalloproteinase 9 (MMP9) and C-C motif chemokine ligand 2 (CCL2) mRNA expression in response to A2E. Selective PPAR-α, -ß/δ and -γ antagonists inhibit the expression of IL-6 and IL-8 while only the antagonist of PPAR-γ inhibits the transactivation of NF-κB following A2E exposure. In addition, a cocktail of all three PPARs antagonists and also HX531, an antagonist of RXR reproduce norbixin effects on inflammation. Altogether, A2E's deleterious biological effects could be inhibited through PPAR and RXR regulation. Moreover, the modulation of these NR by norbixin may open new avenues for the treatment of AMD.

Topical and systemic retinoids for the treatment of cutaneous viral warts: A systematic review and meta-analysis.

Cutaneous viral warts (CVW), caused by human papillomavirus, often have a self-limited course. However, some patients experience a recalcitrant disease despite treatment. Retinoids are considered the mainstay of therapy in many dermatologic diseases. Data on their use for viral warts are limited. To systematically review the published evidence on the efficacy and safety of retinoids for the treatment of CVW. A systematic review and meta-analysis of topical or systemic retinoid treatment for CVW was performed in accordance with the PRISMA statement. The primary outcome was clinical response; secondary outcomes were recurrence rate and adverse events. Fourteen publications including 399 patients treated exclusively with retinoids (65% topical, 35% systemic) were evaluated. The complete response rate was 64% (95% CI, 46-78%; I2 =80%) for topical treatment and 61% (95% CI, 44-76%; I2 =69%) for systemic treatment. The most common side effects were irritant contact dermatitis and cheilitis, respectively. Relapse rates were 6% and 17%, respectively. The reviewed studies were considerably heterogenous and most lacked a control group. Both topical and systemic retinoids are effective and safe as monotherapy for CVW. Further studies are required to determine their exact role in this setting.

Suppressive Effect of Arctium Lappa L. Leaves on Retinal Damage Against A2E-Induced ARPE-19 Cells and Mice.

Age-related macular degeneration (AMD) is a major cause of irreversible loss of vision with 80-90% of patients demonstrating dry type AMD. Dry AMD could possibly be prevented by polyphenol-rich medicinal foods by the inhibition of N-retinylidene-N-retinylethanolamine (A2E)-induced oxidative stress and cell damage. Arctium lappa L. (AL) leaves are medicinal and have antioxidant activity. The purpose of this study was to elucidate the protective effects of the extract of AL leaves (ALE) on dry AMD models, including in vitro A2E-induced damage in ARPE-19 cells, a human retinal pigment epithelial cell line, and in vivo light-induced retinal damage in BALB/c mice. According to the total phenolic contents (TPCs), total flavonoid contents (TFCs) and antioxidant activities, ALE was rich in polyphenols and had antioxidant efficacies on 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and 2',7'-dichlorofluorescin diacetate (DCFDA) assays. The effects of ALE on A2E accumulation and A2E-induced cell death were also monitored. Despite continued exposure to A2E (10 µM), ALE attenuated A2E accumulation in APRE-19 cells with levels similar to lutein. A2E-induced cell death at high concentration (25 µM) was also suppressed by ALE by inhibiting the apoptotic signaling pathway. Furthermore, ALE could protect the outer nuclear layer (ONL) in the retina from light-induced AMD in BALB/c mice. In conclusion, ALE could be considered a potentially valuable medicinal food for dry AMD.

Physiological and pathological implications of retinoid action in the endometrium.

Retinol (vitamin A) and its derivatives, collectively known as retinoids, are required for maintaining vision, immunity, barrier function, reproduction, embryogenesis and cell proliferation and differentiation. Despite the fact that most events in the endometrium are predominantly regulated by steroid hormones (estrogens and progesterone), accumulating evidence shows that retinoid signaling is also involved in the development and maintenance of the endometrium, stromal decidualization and blastocyst implantation. Moreover, aberrant retinoid metabolism seems to be a critical factor in the development of endometriosis, a common gynecological disease, which affects up to 10% of reproductive age women and is characterized by the ectopic localization of endometrial-like tissue in the pelvic cavity. This review summarizes recent advances in research on the mechanisms and molecular actions of retinoids in normal endometrial development and physiological function. The potential roles of abnormal retinoid signaling in endometriosis are also discussed. The objectives are to identify limitations in current knowledge regarding the molecular actions of retinoids in endometrial biology and to stimulate new investigations toward the development potential therapeutics to ameliorate or prevent endometriosis symptoms.

Clinical, Diagnostic, and Therapeutic Implications in Psoriasis Associated With Cardiovascular Disease. / Implicaciones clínicas, diagnósticas y terapéuticas de la psoriasis y enfermedad cardiovascular.

In recent years the concept of psoriasis as a systemic disease has gained acceptance due to its association with numerous comorbid conditions, particularly atherosclerosis and cardiovascular disease. Several studies have shown that patients with psoriasis, especially younger patients and those with more severe forms of psoriasis or with psoriatic arthritis, have a higher prevalence of risk factors and metabolic syndrome, as well as an increased risk of major cardiovascular events such as myocardial infarction, cerebrovascular disease, and peripheral arterial disease. Furthermore, it remains unclear which of the current treatments might be more effective in reducing cardiovascular risk in these patients. It is therefore important for dermatologists to be aware of this increased risk, to be able to detect modifiable risk factors early and, when appropriate, refer patients to other specialists for the prevention of major cardiovascular events.

Peretinoin as an adjuvant therapy for hepatocellular carcinoma.

INTRODUCTION: The current curative treatment modalities for hepatocellular carcinoma (HCC) are unfortunately fraught with high rates of HCC recurrence. Hence there is a need to prevent or reduce HCC recurrence after initial curative therapy. Peretinoin is a synthetic oral retinoid showing significant reduction in the incidence of recurrent or new HCC in patients who had received curative HCC therapy. Areas covered: Peretinoin is analysed against the background of molecular pathogenesis of the different causes of HCC. Publications related to peretinoin since 1996 are reviewed, covering clinical characteristics, safety and tolerance profile as well as the current status of clinical development. Expert commentary: Early phase studies are promising but we need to await the results of the ongoing phase III study of peretinoin in hepatitis C related HCC. Long term impact of peretinoin may be diminished by the foreseeable near eradication of hepatitis C by the direct acting antivirals.

Retinoids and rexinoids in cancer prevention: from laboratory to clinic.

Early in the age of modern medicine the consequences of vitamin A deficiency drew attention to the fundamental link between retinoid-dependent homeostatic regulation and malignant hyperproliferative diseases. The term "retinoid" includes a handful of endogenous and a large group of synthetic derivatives of vitamin A. These multifunctional lipid-soluble compounds directly regulate target genes of specific biological functions and critical signaling pathways to orchestrate complex functions from vision to development, metabolism, and inflammation. Many of the retinoid activities on the cellular level have been well characterized and translated to the regulation of processes like differentiation and cell death, which play critical roles in the outcome of malignant transformation of tissues. In fact, retinoid-based differentiation therapy of acute promyelocytic leukemia was one of the first successful examples of molecularly targeted treatment strategies. The selectivity, high receptor binding affinity and the ability of retinoids to directly modulate gene expression programs present a distinct pharmacological opportunity for cancer treatment and prevention. However, to fully exploit their potential, the adverse effects of retinoids must be averted. In this review we provide an overview of the biology of retinoid (activated by nuclear retinoic acid receptors [RARs]) and rexinoid (engaged by nuclear retinoid X receptors [RXRs]) action concluded from a long line of preclinical studies, in relation to normal and transformed states of cells. We will also discuss the past and current uses of retinoids in the treatment of malignancies, the potential of rexinoids in the cancer prevention setting, both as single agents and in combinations.

Polish Lymphoma Research Group Experience With Bexarotene in the Treatment of Cutaneous T-Cell Lymphoma.

Bexarotene, a synthetic retinoid licensed for the treatment of refractory cutaneous T-cell lymphoma (CTCL), has been used clinically in Poland since 2007 in 21 patients. The objective of our retrospective, multicenter study was to evaluate our experience with bexarotene therapy, including efficacy, safety, and survival outcomes. We retrospectively identified 21 adult patients who were treated with bexarotene between the years 2007 and 2012. Starting dose of bexarotene was 300 mg/m per day. The analysis included 3 patients with early-stage mycosis fungoides (MF), 16 patients with advanced-stage MF, and 2 patients with Sézary syndrome (SS). The mean duration of therapy with bexarotene was 14.5 months. Use of bexarotene resulted in an overall response rate of 81.0%, although the overall mortality rate was 52.8%. In our study, early-stage CTCL responded better than advanced-stage CTCL (100.0% vs. 77.8%, respectively). The mean time to observable response was 1.8 months, and the mean duration of the response was 16.4 months. Most significant side effects were hyperlipidemia, hypothyroidism, and a bleeding gastric ulcer. Based on the results of our analysis, bexarotene is a valuable tool in the treatment of refractory early-stage CTCL. Although a majority of patients initially responded to therapy, the high mortality rate in the advanced-stage group suggests that bexarotene does not completely resolve the therapeutic problems in all stages of CTCL. Patient stratification for bexarotene treatment may need a thorough reassessment, in that bexarotene may not be an effective drug in the very advanced stages of CTCL.

The neurotoxic effects of vitamin A and retinoids.

Vitamin A (retinol) and its congeners - the retinoids - participate in a panoply of biological events, as for instance cell differentiation, proliferation, survival, and death, necessary to maintain tissue homeostasis. Furthermore, such molecules may be applied as therapeutic agents in the case of some diseases, including dermatological disturbances, immunodeficiency, and cancer (mainly leukemia). In spite of this, there is a growing body of evidences showing that vitamin A doses exceeding the nutritional requirements may lead to negative consequences, including bioenergetics state dysfunction, redox impairment, altered cellular signaling, and cell death or proliferation, depending on the cell type. Neurotoxicity has long been demonstrated as a possible side effect of inadvertent consumption, or even under medical recommendation of vitamin A and retinoids at moderate to high doses. However, the exact mechanism by which such molecules exert a neurotoxic role is not clear yet. In this review, recent data are discussed regarding the molecular findings associated with the vitamin A-related neurotoxicity.

Tolerability of Topical Retinoids: Are There Clinically Meaningful Differences Among Topical Retinoids?

BACKGROUND: Topical retinoids are first-line treatment options for acne vulgaris. These drugs, however, produce varying degree of cutaneous irritation within the first few weeks of treatment. OBJECTIVE: Our purpose was to examine differences in tolerability of topical retinoids and assess whether these differences would be clinically meaningful. METHODS: A PubMed search was performed for sources on topical retinoids in acne vulgaris treatment. Thirty-four clinical studies were analyzed. RESULTS: Thirteen studies had statistically significant results on tolerability of retinoid based on retinoid, vehicle, concentration, or skin type. All studies classified most of skin reactions as mild-moderate. Large differences in the number of dropouts due to irritation were not identified. CONCLUSION: Irritation studies did not show a high frequency of clinically significant irritation with topical retinoids. We anticipate that the large variation in patient use of topical retinoids would likely account for more variation in response than differences between drug formulations.

Peretinoin after curative therapy of hepatitis C-related hepatocellular carcinoma: a randomized double-blind placebo-controlled study.

BACKGROUND: Effective prophylactic therapies have not been established for hepatocellular carcinoma recurrence. Peretinoin represents one novel option for patients with hepatitis C virus-related hepatocellular carcinoma (HCV-HCC), and it was tested in a multicenter, randomized, double-blind, placebo-controlled study. METHODS: Patients with curative therapy were assigned to one of the following regimens: peretinoin 600, 300 mg/day, or placebo for up to 96 weeks. The primary outcome was recurrence-free survival (RFS). RESULTS: Of the 401 patients initially enrolled, 377 patients were analyzed for efficacy. The RFS rates in the 600-mg group, the 300-mg group, and the placebo group were 71.9, 63.6, and 66.0 % at 1 year, and 43.7, 24.9, and 29.3 % at 3 years, respectively. The primary comparison of peretinoin (300 and 600-mg) with placebo was not significant (P = 0.434). The dose-response relationship based on the hypothesis that "efficacy begins to increase at 600 mg/day" was significant (P = 0.023, multiplicity-adjusted P = 0.048). The hazard ratios for RFS in the 600-mg group vs. the placebo group were 0.73 [95 % confidence interval (CI) 0.51-1.03] for the entire study period and 0.27 (95 % CI 0.07-0.96) after 2 years of the randomization. Common adverse events included ascites, increased blood pressure, headache, presence of urine albumin, and increased transaminases. CONCLUSIONS: Although the superiority of peretinoin to placebo could not be validated, 600 mg/day was shown to be the optimal dose, and treatment may possibly reduce the recurrence of HCV-HCC, particularly after 2 years. The efficacy and safety of peretinoin 600 mg/day should continue to be evaluated in further studies.

Both low-dose arotinoid ethylester and acitretin are effective in the treatment of familial erythrokeratodermia variabilis.

We previously reported a large Chinese pedigree of erythrokeratodermia variabilis (EKV). A unique feature was that some of the affected members experienced transitory pustules on the border of classic lesions. Here we prescribed oral arotinoid ethylester and acitretin to two of the affected members in the pedigree, at starting dosage of 0.03 mg/day for arotinoid ethylester and 30 mg/day for acitretin, maintenance dosage of 0.03 mg every other day and 20 mg/day, respectively. Both patients reached complete clearance of the lesions during the treatment period. Side effect was negligible for the case on arotinoid ethylester. The patient on acitretin experienced elevated level of serum triglyceride and alanine aminotransferase that restrained further use.

The spectrum of oculocutaneous disease: Part II. Neoplastic and drug-related causes of oculocutaneous disease.

There are a multitude of diseases that commonly affect both the skin and the eye. Part II of this 2-part series reviews the oculocutaneous manifestations of neoplasms, both benign and malignant, and adverse drug reactions affecting the skin and the eye. Though rare, a number of neoplasms that primarily involve the skin, such as melanoma and basal cell carcinoma, can metastasize to the eye, leading to permanent damage if not properly treated. In addition, periocular neoplasms can irritate the conjunctiva and lid, reducing a patient's ability to see clearly. Neoplastic diseases, such as xeroderma pigmentosum, Sturge-Weber syndrome, and multiple myeloma, can also lead to permanent changes in the eye if not discovered and managed promptly. Furthermore, there are a multitude of drugs, including those commonly used by dermatologists, which can result in permanent damage to the eye. With proper knowledge of the ocular manifestations and treatment recommendations described in this 2-part series, dermatologists with the assistance of their ophthalmology colleagues can help avoid the complications, including permanent blindness, associated with infectious, inflammatory, genetic, neoplastic, and drug-related conditions.