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

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

Overall survival in erythrodermic cutaneous T-cell lymphoma: an analysis of prognostic factors in a cohort of patients with erythrodermic cutaneous T-cell lymphoma

Background The most common cutaneous T‐cell lymphomas (CTCLs) are mycosis fungoides and Sézary syndrome. Aim To determine whether blood stage and other prognostic variables affect overall survival (OS) in CTCL. Methods We studied retrospectively 1197 CTCL patients seen at the M.D. Anderson Cancer Center since 1987. Results We identified 124 (10.3%) patients with erythrodermic CTCL (E‐CTCL), 63% of whom had positive gene rearrangements in skin and 19 of whom had no evidence of hematologic involvement. The median age at diagnosis was 63 years (range, 26–90 years); the male to female ratio was 1.3 : 1. OS curves were estimated by the Kaplan–Meier method and compared using log‐rank tests. The median OS in all 124 E‐CTCL patients was 5.1 years (range, 0.4–18.6 years) regardless of the cause of death or blood involvement. Patients were stratified by the H0–H4 staging system with manual or flow cytometric determination of Sézary cell counts (Russell‐Jones R, Whittaker SJ. Sézary syndrome: diagnostic criteria and therapeutic options. Semin Cutan Med Surg 2000; 19 : 100–108). The median OS was 7.6 years for H0–H2 (< 1000 Sézary cells/L) (n = 23), 5.4 years for H3 (≥ 1000 to ≤ 10,000 Sézary cells/L) (n = 79), and 2.4 years for H4 (≥ 10,000 Sézary cells/L) (n = 22) (P = 0.011). Treatment with systemic steroids, age, serum lactate dehydrogenase, and white blood cell count ≥ 20,000 µL were significant prognostic factors, but large cell transformation, T‐cell receptor gene rearrangement, tumor–node–metastasis stage, treatments, and CD4 : CD8 ratio were not. In multivariate analysis, advanced age and elevated lactate dehydrogenase were the strongest predictors of a poor prognosis. Conclusions Serum LDH and age were the strongest predictive factors for OS in E‐CTCL.     

Pilot study of denileukin diftitox alternate dosing regimen in patients with cutaneous peripheral T-cell lymphomas

PurposeTo evaluate the safety and efficacy of an alternate dosing regimen in rare primary cutaneous peripheral T-cell lymphoma variants.MethodsThis is a prospective, single center, pilot study of denileukin diftitox (Dd) in patients with persistent or recurrent cutaneous peripheral T-cell lymphomas and mycosis fungoides (MF) variants, excluding Sézary syndrome (SS). Dd was administered at 18 μg/kg per day for 5 days and once weekly for 24 weeks, with response by modified skin weighed assessment tool.ResultsEight patients, with a median age of 76 years (range, 44-88 years), were treated between December 2003 and July 2008. Five (62.5%) of 8 patients responded, including 3 patients with CD30⁺ anaplastic large-cell lymphoma (ALCL) with 2 complete responses, one ongoing at 8 years. One patient with CD8⁺ and 1 patient with natural killer T cell lymphoma (NK-T) had partial responses. Progressive disease occurred in 1 patient positive for human T-cell lymphotropic virus and 1 patient with ALCL. Vascular leak syndrome (VLS) occurred in 6 (75%) of 8 patients during or just after cycle 1. Three were grade 3, and 2 of these resulted in study withdrawal. Other adverse effects included nausea or vomiting (n = 3), fatigue (n = 1), back pain (n = 1), transaminase elevations (n = 3), and elevated creatinine (n = 1).ConclusionsDd with an alternate dosing schedule was active in this small study of primary cutaneous T-cell lymphomas.     

Treatment of mycosis fungoides with denileukin diftitox and oral bexarotene

Cutaneous T-cell lymphomas, including mycosis fungoides and Sezary syndrome, are often responsive to treatment, but current therapies have not been shown to increase survival, and in advanced stages, durable remissions are hard to achieve. We present a patient who was initially misdiagnosed with psoriasis and, 16 years later, was diagnosed with mycosis fungoides. Denileukin diftitox was used as a tumor debulking agent to give a partial response that was further improved with a combination of systemic interferon/oral bexarotene and skin-directed psorlen plus UV-A. The purpose of this case report is to show the value of sequential combination therapy for improving overall response.     

CD25 expression is correlated with histological grade and response to denileukin diftitox in cutaneous T-cell lymphoma

Denileukin diftitox (Ontak), a recombinant fusion protein of diphtheria toxin and ligand, IL-2, binds to the IL-2 receptor, is internalized, and causes cell death. Denileukin diftitox was approved for the treatment of cutaneous T-cell lymphomas (CTCLs) with CD25+ expression. We prospectively stained lesional skin biopsy specimens from 113 mycosis fungoides and Sézary Syndrome patients for activation markers CD25 and CD30 to correlate expression with clinical tumor-node metastasis (TNM) stage, histologic grade, and response to denileukin diftitox. High expression was defined as positivity of > or =20% of lesional T-cells using immunohistochemistry (IHC). CD25 and CD30 expression was more common in lesions from advanced patients (P = 0.04 and 0.002, respectively). Advanced TNM (T3 or T4) was significantly associated with intermediate-grade (P = 0.002) and large-cell transformation histology (P = 0.04). Of interest, clinical responses were observed in 78.5% of patients with high CD25 expression versus 20% with low to undetectable CD25 expression (P = 0.01) among 24 patients receiving standard 5-day infusions of denileukin diftitox at 18 microg/kg/day. These data suggest that high CD25 expression by IHC is associated with advanced CTCL and with clinical response to denileukin diftitox therapy.     

Increased serum immunoglobulin levels are common in mycosis fungoides and Sézary syndrome

BACKGROUND: Patients with cutaneous T-cell lymphoma (CTCL; mycosis fungoides [MF] and Sézary syndrome [SS]) acquire immunodeficiency and opportunistic infections. OBJECTIVE: We attempted to determine whether abnormalities of humoral immunoglobulin levels are present. METHODS: A retrospective analysis of serum immunoglobulin levels in patients with CTCL at baseline evaluation at a cancer center was compared to levels in patients with leukemias and levels in healthy control subjects. RESULTS: A total of 254 of 650 patients with CTCL evaluated between 1987 and 2001 had baseline quantitative immunoglobulin levels. Mean IgG, IgA, and IgM levels were similar among all MF/SS patients versus controls. The percentages of MF/SS patients with elevated levels of each immunoglobulin class were higher than percentages in healthy controls, and elevated IgA levels occurred among late versus early patients (P =.043). CONCLUSION: High immunoglobulin levels are more frequent in patients with MF and SS than in healthy controls, patients with chronic lymphocytic leukemia, and patients with hairy cell leukemia. High IgA levels are more frequent in late stage MF/SS.     

Long-term control of mycosis fungoides of the hands with topical bexarotene

BACKGROUND: Limited Stage IA mycosis fungoides (MF) is often treated with topical steroids, which can cause atrophy, or with nitrogen mustard, which imposes several limitations on the patient's lifestyle. Topical bexarotene is a novel synthetic rexinoid with few side-effects that has shown efficacy for treatment of mycosis fungoides skin lesions in recent Phase II-III clinical trials. The Phase I-II trial involving 67 stage IA-IIA MF patients demonstrated complete response (CR) in 21% and partial response (PR) in 42% of the patients. The median time to response was approximately 20 weeks. In the phase III trial of refractory stage IA, IB and IIA MF, the patients demonstrated a 44% response rate (8% CR). Patients with no prior therapy for mycosis fungoides responded at a higher rate (75%) than those with prior topical therapies. METHODS: Case report of a patient with MF limited to the hands treated with topical bexarotene 0.1% gel in a open label phase II clinical trial. RESULTS: Partial response occurred after 2 weeks of topical bexarotene therapy and the lesions were well controlled for 5 years using bexarotene monotherapy, with only occasional mild local irritation. CONCLUSIONS: Topical bexarotene is effective as long-term treatment monotherapy for limited MF lesions. To our knowledge this is the longest use of the drug by any individual.