Cutaneous T-cell lymphoma (CTCL) is the most common type of primary cutaneous lymphoma. Here we report that CTCL patients show increased interleukin-15 (IL-15) in a clinical stage-dependent manner. Mechanistically, we show that Zeb1 is a transcriptional repressor of IL-15 in T-cells and that hypermethylation of the Zeb1 binding region within the IL-15 promoter, as seen in CTCL patients, prevents Zeb1 binding and causes increased transcription of IL-15. Using a transgenic mouse model of IL-15, we provide evidence that overexpression of IL-15 induces a spontaneous CTCL that mimics the human neoplasm. Excessive autocrine production of IL-15 in T-cells inhibits an HDAC1-mediated negative autoregulatory loop, resulting in the upregulation of HDAC1 and HDAC6, and transcriptional induction of the onco-miR-21. Interruption of IL-15 downstream signaling with isotype-specific HDAC inhibitors halts (HDAC1) or significantly delays (HDAC6) the progression of CTCL in vivo and provides pre-clinical evidence supporting a hierarchical model of oncogenic signaling in CTCL.

The effects of pertussis toxin and cholera toxin on early events of T lymphocyte activation were examined in the T lymphocyte cell line, Jurkat. Pertussis toxin treatment of these T cells increased inositol phosphates production and led to increases in intracellular free calcium concentration. These effects were produced by the isolated B (binding) subunit of pertussis toxin, alone. Inositol phosphates production resulting from perturbation of the T cell antigen receptor-CD3 complex by MAb was not affected by pertussis toxin treatment but was markedly inhibited by cholera toxin. This effect of cholera toxin paralleled elevations in cAMP content. However, forskolin, in concentrations equipotent for cAMP production, was a weaker inhibitor of inositol phosphates production. Cholera toxin inhibition of inositol phosphates production did not result from inhibition of baseline incorporation of inositol into phosphoinositide substrates of phospholipase C. These studies underline the complexity of toxin effects on cellular systems and suggest that other approaches will be required to implicate guanine nucleotide-binding regulatory proteins in control of the early events of T lymphocyte activation. However, the data presented here provide a molecular basis for the clinical observations of lymphocytosis and the in vitro observations of lymphocyte mitogenesis after pertussis toxin stimulation.

Murine models of disease are vital to the understanding of pathogenesis and the development of novel therapeutics. We have previously established interleukin (IL)-15 transgenic (tg) mice that demonstrate rapid proliferation of natural killer (NK) and T cells, followed by spontaneous transformation to lethal leukemia. Herein, we have characterized this model, which has many features in common with the aggressive variants of NK and T large granular lymphocyte leukemia (LGLL) in humans. The LGLL blasts are cytolytic and produce IFN-γ ex vivo. Cytogenetic analysis revealed trisomy of chromosome 17 and/or 15. This model should provide opportunities to develop effective standard therapies for this fatal disease.

Objectives In addition to hysterectomy and bilateral salpingo-oophorectomy, comprehensive surgical staging for endometrial cancer includes pelvic and para-aortic lymphadenectomy. Clarifying and addressing the morbidity from these surgical procedures is imperative. The goal of this study was to assess the prevalence of lower extremity swelling following surgery for endometrial cancer. Methods/materials We performed a descriptive, cross-sectional survey study of women who underwent surgery for endometrial cancer at our institution from 2006–2008. Survey information included symptoms, management, and education regarding lymphedema. Demographic information such as race and education was collected in addition to clinical data such as body mass index (BMI) and age. Results Of the 482 patients identified, 440 were determined eligible and 305 (69.3%) responded to the survey with information on lower limb swelling (LLS). Of the 108 (35%) responders who reported swelling, only 68 (22%) participants reported a diagnosis of lower limb lymphedema (LLL). The most commonly experienced symptoms among those who reported LLS were tightness, pain/tenderness and heaviness. Among those with a diagnosis of LLL, a majority (60%) stated it affected their daily activities and noted exacerbating factors such as prolonged standing, heat, and walking. The most common therapies utilized to reduce symptoms included leg elevation (96%), compression stockings (65%), diuretics (46%), massage therapy (35%), and bandaging (25%). There was no association between LLS or LLL diagnosis and BMI, age, race, tobacco use. Only 8% of responders reported receiving preoperative education regarding risks for LLS and a desire for more comprehensive education was frequently noted. Conclusions The patient-reported incidence of LLS occurred in approximately 35% of survey participants who underwent surgery for endometrial cancer. However, only 22% reported a diagnosis of LLL. Efforts to obtain the true incidence of LLL and to develop effective educational materials and programs to improve the management of lymphedema are warranted.