Inhibition of Integrin αVß3 Signaling Improves the Antineoplastic Effect of Bexarotene in Cutaneous T-Cell Lymphoma.

Bexarotene is a specific retinoid X receptor agonist that has been used for the treatment of cutaneous T-cell lymphoma (CTCL). Because bexarotene causes hypothyroidism, it requires the administration of levothyroxine. However, levothyroxine, in addition to its ubiquitous nuclear receptors, can activate the αVß3 integrin that is overexpressed in CTCL, potentially interfering the antineoplastic effect of bexarotene. We thus investigated the biological effect of levothyroxine in relation to bexarotene treatment. Although in isolated CTCL cells levothyroxine decreased, in an αVß3-dependent manner, the antineoplastic effect of bexarotene, levothyroxine supplementation in preclinical models was necessary to avoid suppression of lymphoma immunity. Accordingly, selective genetic and pharmacologic inhibition of integrin αVß3 improved the antineoplastic effect of bexarotene plus levothyroxine replacement while maintaining lymphoma immunity. Our results provide a mechanistic rationale for clinical testing of integrin αVß3 inhibitors as part of CTCL regimens based on bexarotene administration. TEASER: Inhibiting αVß3 integrin improves the antineoplastic effect of bexarotene while maintaining lymphoma immunity.

Anticancer activity and molecular mechanisms of α-conidendrin, a polyphenolic compound present in Taxus yunnanensis, on human breast cancer cell lines.

α-Conidendrin is a polyphenolic compound found mainly in Taxus yunnanensis, as the source of chemotherapy drug paclitaxel, which has been used in traditional medicine for treatment of cancer. This study aimed to investigate the anticancer activity and molecular mechanisms of α-conidendrin on breast cancer cell lines. The results of the present study show that α-conidendrin possesses potent antiproliferative effects on breast cancer cell lines MCF-7 and MDA-MB-231. α-Conidendrin significantly induced apoptosis in breast cancer cells via reactive oxygen species generation, upregulation of p53 and Bax, downregulation of Bcl-2, depolarization of mitochondrial membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspases-3 and -9. α-Conidendrin remarkably inhibited the proliferation of breast cancer cells through induction of cell cycle arrest by upregulating p53 and p21 and downregulating cyclin D1 and CDK4. Unlike breast cancer cells, the antiproliferative effect of α-conidendrin on human foreskin fibroblast cells (normal cells) was very small. In normal cells, reactive oxygen species levels, loss of MMP, release of cytochrome c, mRNA expression of p53, p21, cyclin D1, CDK4, Bax, and Bcl-2 as well as mRNA expression and activity of caspases-3 and -9 were significantly less affected by α-conidendrin compared with cancer cells. These results suggest that α-conidendrin can be a promising agent for treatment of breast cancer with little or no toxicity against normal cells.

Nirogacestat suppresses RANKL-Induced osteoclast formation in vitro and attenuates LPS-Induced bone resorption in vivo.

Bone resorption, initiated by osteoclasts (OCs), plays an essential role in bone homeostasis. The abnormalities of bone resorption may induce a series of diseases, including osteoarthritis, osteoporosis and aseptic peri-implant loosening. Nirogacestat (PF-03084014, PF), a novel gamma-secretase inhibitor, has been used in phase II clinical trial for treatment of desmoid tumor. However, whether it has the therapeutic effect on abnormal bone resorption remains to be evaluated. In this study, we investigated the role of PF in the regulation of receptor activator of nuclear factor-kB ligand (RANKL)-induced osteoclastogenesis in vitro, and the lipopolysaccharide (LPS)-induced bone resorption in vivo. It was found that PF could suppress the formation of osteoclasts from bone marrow macrophages (BMMs) without causing cytotoxicity, inhibit bone resorption and downregulate the mRNA level of osteoclast-specific markers, including calcitonin receptor (CTR), tartrate resistant acid phosphatase (TRAP), cathepsin K (CTSK), dendritic cell-specific transmembrane protein (Dc-stamp), Atp6v0d2 (V-ATPase d2) and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). Furthermore, Notch2 signaling, as well as RANKL-induced AKT signaling was significantly inhibited in BMMs. Consistent with in vitro observation, we found that PF greatly ameliorated LPS-induced bone resorption. Taken together, our study demonstrated that PF has a great potential to be used in management of osteolytic diseases.

Sigma-2 receptor/TMEM97 agonist PB221 as an alternative drug for brain tumor.

BACKGROUND: There are limited effective drugs that can reach the brain to target brain tumors, in particular glioblastoma, which is one of the most difficult cancers to be cured from. Because the overexpression of the sigma-2 receptor is frequently reported in glioma clinical samples and associated with poor prognosis and malignancy, we herein studied the anti-tumor effect of the sigma-2 receptor agonist PB221 (4-cyclohexyl-1-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl]piperidine) on an anaplastic astrocytoma tumor model based on previous encouraging results in pancreatic cancer and neuroblastoma SK-N-SH cells. METHODS: The expression of the sigma-2 receptor, transmembrane protein 97 (TMEM97), in ALTS1C1 and UN-KC6141 cell lines was measured by RT-PCR and quantitative RT-PCR. The binding of sigma-2 receptor fluorescent ligands PB385 (6-[5-[3-(4-cyclohexylpiperazin-1-yl)propyl]-5,6,7,8-tetrahydronaphthalen-5-yloxy]-N-(7-nitro-2,1,3-benzoxadiazol-4-yl)hexanamine) and NO1 (2-{6-[2-(3-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)propyl)-3,4-dihydroisoquinolin-1(2H)-one-5-yloxy]hexyl}-5-(dimethylamino)isoindoline-1,3-dione) was examined by flow cytometry and the fluorescent plate reader. The antitumor activity of PB221 was initially examined in the murine brain tumor cell line ALTS1C1 and then in the murine pancreatic cell line UN-KC6141. The potential therapeutic efficacy of PB221 for murine brain tumors was examined by in vitro migration and invasion assays and in vivo ectopic and orthotopic ALTS1C1 tumor models. RESULTS: The IC50 of PB221 for ALTS1C1 and UN-KC6141 cell lines was 10.61 ± 0.96 and 13.13 ± 1.15 µM, respectively. A low dose of PB221 (1 µM) significantly repressed the migration and invasion of ALTS1C1 cells, and a high dose of PB221 (20 µM) resulted in the apoptotic cell death of ALTS1C1 cells. These effects were reduced by the lipid antioxidant α-tocopherol, but not by the hydrophilic N-acetylcysteine, suggesting mitochondrial oxidative stress is involved. The in vivo study revealed that PB221 effectively retarded tumor growth to 36% of the control tumor volume in the ectopic intramuscular tumor model and increased the overall survival time by 20% (from 26 to 31 days) in the orthotopic intracerebral tumor model. CONCLUSIONS: This study demonstrates that the sigma-2 receptor agonist PB221 has the potential to be an alternative chemotherapeutic drug for brain tumors with comparable side effects as the current standard-of-care drug, temozolomide.

Management of treatment failure in restless legs syndrome (Willis-Ekbom disease).

Dopaminergic drugs have been widely used over the last decades for the treatment of restless legs syndrome (RLS)/Willis-Ekbom disease (WED). While the majority of studies show an initial improvement in symptoms, longer studies and clinical experience show that either treatment efficacy decreases with time, and/or augmentation develops: dopaminergic augmentation has been reported to be the main reason for treatment discontinuation and treatment failure in RLS/WED. The current review discusses the main reasons for treatment failure in RLS/WED and outlines the most recent expert-based strategies to prevent and manage it. The main strategy for preventing augmentation is to consider non-dopaminergic medications such as α2δ ligands for initial RLS/WED treatment; these effective drugs have been shown to have little risk of augmentation. Alternatively, should dopaminergic drugs be elected as initial treatment, then the daily dose should be kept low and not exceed maximum recommended doses, however, it should be kept in mind that even low dose dopaminergics can cause augmentation. Patients with low iron stores should be given appropriate iron supplementation. Daily treatment should start only when symptoms significantly impact quality of life in terms of frequency and severity; while intermittent treatment might be considered in intermediate cases. Treatment of existing augmentation should be initiated, where possible, with the elimination/correction of extrinsic exacerbating factors (iron levels, antidepressants, antihistamines, etc.). In cases of mild augmentation, dopamine agonist therapy can continue by dividing or advancing the dose, or increasing the dose if there are breakthrough nighttime symptoms. Alternatively, the patient can be switched to an α2δ ligand or rotigotine. For severe augmentation, the patient can be switched to an α2δ ligand or rotigotine, noting that rotigotine may produce augmentation at higher doses with long-term use. In more severe cases of augmentation an opioid may be considered, bypassing α2δ ligands and rotigotine.

Effects of rotigotine on clinical symptoms, quality of life and sleep hygiene adequacy in haemodialysis-associated restless legs syndrome. / Efectos de la rotigotina sobre la sintomatología, calidad de vida e higiene de sueño en el síndrome de piernas inquietas en hemodiálisis.

BACKGROUND: Restless legs syndrome (RLS) is a neurological disorder characterised by bothersome symptoms associated with impaired quality of life and sleep hygiene. Rotigotine is a novel therapeutic alternative, although few studies have been published in patients on haemodialysis (HD) with RLS treated with rotigotine. OBJECTIVES: 1.- To establish the prevalence of RLS in our HD unit. 2.- To evaluate the efficacy and safety profile of rotigotine and its effect on symptoms, quality of life and sleep hygiene in our HD population with RLS. MATERIAL AND METHODS: A single-centre, 12-week prospective study. Two stages (6 weeks): stage 1 (no treatment) and stage 2 (rotigotine). We analysed: 1.- Demographic data, biochemistry data, HD suitability parameters and RLS medical treatment data. 2.- Lower extremity symptoms questionnaire (QS). 3.- RLS severity symptoms scale (SRLSS). 4.- RLS Quality of life: John Hopkins RLS-QoL (JH-QoL). 5.- Sleep hygiene: SCOPA Scale. RESULTS: We included 66 HD patients, 14 with RLS; 44.4% male, 70.2±9.9 years and 111.1±160.8 months on HD. And 22.9% RLS. Exclusively in stage 2, a significant improvement for QS (10±2.4 vs. 5.7±1.0), SRLSS (21±4 vs. 5.7±4.6), JH-QoL (22.1±4.4 vs. 4.3±4.0) and SCOPA (16±5.3 vs. 6.7±1.9) were observed. A 77.7 and 11.1%, showed partial (> 20%) and complete (> 80%) remission, respectively, while 55.5% achieved «zero¼ symptoms. Only one patient had gastrointestinal intolerance and none experienced augmentation effect. No changes in biochemical data, suitability for dialysis or medical treatment were found. The inter-group analysis showed a significant improvement in relation to QS, SRLSS, JH-QoL and SCOPA in stage 2. CONCLUSIONS: RLS showed a considerable prevalence in our HD unit. Rotigotine improved clinical symptoms, quality of life and sleep hygiene in RLS patients on HD and was found to be a safe drug with minimal side effects and total therapeutic compliance. Nevertheless, future studies should be performed to confirm the benefits of rotigotine in RLS patients on haemodialysis.

Clinical management of restless legs syndrome in end-stage renal disease patients.

Restless legs syndrome (RLS) is a common neurological movement disorder, characterized by restless and unpleasant sensations in the deep inside of legs. The symptoms of RLS are less noticeable during daytime, but more prevalent at night. Therefore, the disorder can induce low quality of life, insomnia, and impairment of daytime activity. RLS in end-stage renal disease (ESRD) patients is especially problematic due to premature discontinuation of dialysis and increased mortality. The prevalence of RLS among dialysis patients is much higher compared to the prevalence of the same disorder in patients with normal renal functions. Even though there are recommended treatment guidelines for the general population established by Medical Advisory Board of the RLS foundation, which include the use of dopamine agonists, levodopa, gabapentin, benzodiazepines, and opioids, limited information is available on the effects of these therapies in ESRD patients. Since the existing clinical data were extrapolated from small sample sizes in short-term clinical trials, further clinical studies are still needed to better assess the efficacy, safety, and tolerability of these medications in patients with ESRD.

Practice guideline summary: Treatment of restless legs syndrome in adults: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology.

OBJECTIVE: To make evidence-based recommendations regarding restless legs syndrome (RLS) management in adults. METHODS: Articles were classified per the 2004 American Academy of Neurology evidence rating scheme. Recommendations were tied to evidence strength. RESULTS AND RECOMMENDATIONS: In moderate to severe primary RLS, clinicians should consider prescribing medication to reduce RLS symptoms. Strong evidence supports pramipexole, rotigotine, cabergoline, and gabapentin enacarbil use (Level A); moderate evidence supports ropinirole, pregabalin, and IV ferric carboxymaltose use (Level B). Clinicians may consider prescribing levodopa (Level C). Few head-to-head comparisons exist to suggest agents preferentially. Cabergoline is rarely used (cardiac valvulopathy risks). Augmentation risks with dopaminergic agents should be considered. When treating periodic limb movements of sleep, clinicians should consider prescribing ropinirole (Level A) or pramipexole, rotigotine, cabergoline, or pregabalin (Level B). For subjective sleep measures, clinicians should consider prescribing cabergoline or gabapentin enacarbil (Level A), or ropinirole, pramipexole, rotigotine, or pregabalin (Level B). For patients failing other treatments for RLS symptoms, clinicians may consider prescribing prolonged-release oxycodone/naloxone where available (Level C). In patients with RLS with ferritin ≤75 µg/L, clinicians should consider prescribing ferrous sulfate with vitamin C (Level B). When nonpharmacologic approaches are desired, clinicians should consider prescribing pneumatic compression (Level B) and may consider prescribing near-infrared spectroscopy or transcranial magnetic stimulation (Level C). Clinicians may consider prescribing vibrating pads to improve subjective sleep (Level C). In patients on hemodialysis with secondary RLS, clinicians should consider prescribing vitamin C and E supplementation (Level B) and may consider prescribing ropinirole, levodopa, or exercise (Level C).

Marked lowering of high-density lipoprotein cholesterol levels due to high dose bexarotene therapy.

CONTEXT: Bexarotene is a retinoid X receptor agonist, which is currently used for the treatment of cutaneous T-cell lymphoma (CTCL). It is known to induce central hypothyroidism as well as dyslipidemia including elevation of triglycerides (TG) and low-density lipoprotein cholesterol along with slight lowering of high-density lipoprotein cholesterol (HDL-C). Marked lowering of HDL-C has never been previously reported in bexarotene-treated patients and whether it is related to hypothyroidism remains unclear. CASE REPORT: A 49-year-old African female with a history of CTCL on treatment with bexarotene of 300 mg/d, presented with serum total cholesterol level of 249 mg/dL (6.4 mmol/L), TG level of 92 mg/dL (1.03 mmol/L), HDL-C level of 78 mg/dL (2.02 mmol/L), thyroid stimulating hormone (TSH) of 0.68 µIU/mL, and free thyroxine level of 0.5 ng/dL. Six months later, on increasing the bexarotene dose to 600 mg daily, serum TG increased to 310 mg/dL (3.5 mmol/L) and HDL-C dropped to 3 to 5 mg/dL (0.077-0.13 mmol/L), whereas the TSH was undetectable (0.01 µIU/mL). Despite adequate levothyroxine replacement to 225 µg daily resulting in free thyroxine levels up to 1.5 ng/dL, HDL-C remained extremely low of 4 to 9 mg/dL (0.103-0.233 mmol/L). Bexarotene was discontinued due to poor response of CTCL, 3 months after which her HDL-C levels returned to baseline of 80 to 90 mg/dL (2.07-2.33 mmol/L). CONCLUSIONS: High dose bexarotene can markedly lower HDL-C levels, which normalize on discontinuation of the drug. Lowering of HDL-C with bexarotene may be due to an increase in cholesterol ester transfer protein activity and appears to be independent of central hypothyroidism.

Trimodal Therapy: Combining Hyperthermia with Repurposed Bexarotene and Ultrasound for Treating Liver Cancer.

Repurposing of existing cancer drugs to overcome their physical limitations, such as insolubility, represents an attractive strategy to achieve enhanced therapeutic efficacy and broaden the range of clinical applications. Such an approach also promises to offer substantial cost savings in drug development efforts. Here we repurposed FDA-approved topical agent bexarotene (Targretin), currently in limited use for cutaneous manifestations of T-cell lymphomas, and re-engineer it for use in solid tumor applications by forming self-assembling nanobubbles. Physico-chemical characterization studies of the novel prodrug nanobubbles demonstrated their stability, enhanced target cell internalization capability, and highly controlled release profile in response to application of focused ultrasound energy. Using an in vitro model of hepatocellular carcinoma and an in vivo large animal model of liver ablation, we demonstrate the effectiveness of bexarotene prodrug nanobubbles when used in conjunction with catheter-based ultrasound, thereby highlighting the therapeutic promise of this trimodal approach.

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.

Papuloeritrodermia de Ofuji asociada a linfoma cutáneo de células T Cd3+, Cd4+, Cd8-y gammapatía monoclonal de significado incierto / Papuloerythroderma of Ofuji Associated With CD3, + CD4, + and CD8− Cutaneous T-Cell Lymphoma and Monoclonal Gammopathy of Undetermined Significance

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[Granulomatous mycosis fungoides: combination therapy with bexarotene and PUVA]. / Granulomatöse Mycosis fungoides : Kombinationstherapie mit Bexaroten und PUVA.

A 74-year-old male with granulomatous mycosis fungoides presented with multiple, red-brown macules and plaques up to 8 cm in diameter, just as in classical mycosis fungoides. Dermatohistopathologic findings showed extensive granulomatous infiltrates, in which clonality could be detected in various locations via T cell receptor rearrangement. Granulomatous mycosis fungoides is a very rare form of mycosis fungoides with histological resemblance to granulomatous slack skin. It shows a rather aggressive course and can be challenging to diagnose. In our case, combination treatment with bexarotene and bath PUVA, as recommended in guidelines, resulted in an impressive improvement of the skin lesions within ten weeks.

A case of idiopathic follicular mucinosis treated with bexarotene gel.

BACKGROUND: Topical bexarotene 1% gel is currently FDA-approved for early stage (IA and IB) persistent or refractory cutaneous T-cell lymphoma (CTCL). No uniformly effective therapy exists for follicular mucinosis, although several treatments are routinely used. There are no known reports of topical bexarotene being used in the treatment of idiopathic follicular mucinosis when there is no association with CTCL. This article reports the first case of bexarotene gel to successfully treat persistent idiopathic follicular mucinosis. MATERIALS AND METHODS: This study describes a 34-year-old Caucasian male with idiopathic follicular mucinosis. The patient had treatment failure with clobetasol 0.05% ointment and narrow-band UVB. Intralesional injections with triamcinolone 5 mg/ml were successful for treating the plaques in the beard area. The patient was treated with bexarotene 1% gel applied twice a day to the persistent plaques on the lower extremities. The patient reported significant improvement in hair growth after only six weeks of treatment. The treatment was decreased to once a day due to erythema, and he had complete hair regrowth at 26 weeks. DISCUSSION: Several treatments have been described in the literature, such as corticosteroids, psoralen plus ultraviolet A (PUVA) light therapy, topical nitrogen mustard, and radiation therapy. Isolated cases have documented the beneficial responses of pimecrolimus, dapsone, indomethacin, minocycline, isotretinoin, hydroxychloroquine and interferons. No single treatment has been shown to be consistently effective. CONCLUSION: Topical bexarotene 1% gel should be considered for patients with idiopathic follicular mucinosis resistant to standard treatment.

Effects of rotigotine on Parkinson's disease-related sleep disturbances.

INTRODUCTION: Sleep abnormalities are a frequent non-motor symptom and a prominent cause of disability in patients with Parkinson's disease (PD). AREAS COVERED: This review discusses what is currently known about the characteristics of sleep disturbances in PD patients and attempts to clarify the role of dopaminergic pathways in their pathogenesis as well as the beneficial effect of dopaminergic agents in their treatment. In particular, this review will focus on the effects of transdermal rotigotine on improving PD-related sleep disorders. EXPERT OPINION: Sleep disturbances are common in PD, and these disturbances can be reduced or resolved, in large part, by preventing or attenuating nocturnal and early morning motor and non-motor symptoms of PD. The studies discussed within this review suggest that sleep disorders are not just a consequence of motor impairment and dopaminergic therapy but are an integral part of the neurodegenerative process of PD. This is supported by the appearance of specific sleep disturbances, which are related to degeneration of the brainstem areas involved in the regulation of sleep/wake states in advance of typical PD symptoms. Development of more detailed diagnostic tools aimed at detecting sleep disturbances and at defining the main causative factors of sleep disturbances in PD will lead to improved treatment of these disturbances.

New hope from an old drug: fighting Alzheimer's disease with the cancer drug bexarotene (targretin)?

Despite decades of research, there is no cure for Alzheimer disease (AD), and current pharmacological treatments only partially mask the symptoms while the disease progresses within the brain. AD is associated with impaired clearance of ß-amyloid (Aß) from the brain, a process facilitated by apolipoprotein E (ApoE), whose expression is transcriptionally regulated by the ligand-activated nuclear receptors peroxisome proliferator-activated receptor-γ (PPARγ) and liver X receptor (LXR), in conjunction with retinoid X receptor (RXR). A very interesting study performed by G.E. Landreth's group in three murine models of AD has shown that the RXR agonist bexarotene (Targretin), Food and Drug Administration (FDA) approved and used since 1999 for the treatment of cutaneous T cell lymphoma, promotes a fast ApoE-dependent clearance of soluble Aß peptides from the brain, reduces Aß plaques, and stimulates the reversal of cognitive, social, and olfactory deficits. Four independent studies tried to replicate these observations; the clearance of soluble Aß peptides and the reversal of cognitive deficits were replicated in two studies, but all of the studies failed to replicate the reduction of Aß plaques. In a second report, G.E. Landreth's group formulates some hypotheses to explain these discrepancies. Although observations in mouse models of AD might not necessarily extrapolate to humans, bexarotene is a very interesting potential drug against AD; phase I and II clinical trials are under way.