Chang-Yeol Yim

Clinical heterogeneity of extranodal NK/T-cell lymphoma, nasal type: a national survey of the Korean Cancer Study Group

BACKGROUND This national survey was undertaken to propose the classification of extranodal natural killer (NK)/T-cell lymphoma (NTCL) subtypes and to clarify a clinical heterogeneity. PATIENTS AND METHODS Two hundred and eighty patients newly diagnosed as NTCL were enrolled from 22 Korean medical centers. Two subsets were compared: one involving the upper aerodigestive tract (UAT) and another involving the non-upper aerodigestive tract (NUAT) region, which comprises the skin, gastrointestinal tract, and liver or soft tissues. Clinical prognostic factors, survival outcomes, and independent predictors for survival were compared between each subset. RESULTS NUAT-NTCL (59 patients) had significantly higher proportions of disseminated disease, aggressive biologic features, and unfavorable host reactions compared with UAT-NTCL (221 patients). NUAT-NTCL had shortened 5-year overall survival (OS) (22% versus 41%, P = 0.001). Ann Arbor staging, the International Prognostic Index, and the NTCL prognostic index failed to predict the OS of NUAT-NTCL, but did predict the OS in UAT-NTCL. Independent predictors for OS by multivariate analyses differed between each subset. In the NUAT subset, extranodal sites and regional nodes predicted the OS, while Ann Arbor staging, age, performance status, and lactate dehydrogenase level predicted the OS in the UAT subset. CONCLUSION NUAT-NTCL may represent a distinctive disease entity in terms of clinical factors, independent predictors, and survival outcomes.

Generation of Nicotinic Acid Adenine Dinucleotide Phosphate and Cyclic ADP-Ribose by Glucagon-Like Peptide-1 Evokes Ca2+ Signal That Is Essential for Insulin Secretion in Mouse Pancreatic Islets

OBJECTIVE—Glucagon-like peptide-1 (GLP-1) increases intracellular Ca2+ concentrations ([Ca2+]i), resulting in insulin secretion from pancreatic β-cells. The molecular mechanism(s) of the GLP-1–mediated regulation of [Ca2+]i was investigated. RESEARCH DESIGN AND METHODS—GLP-1–induced changes in [Ca2+]i were measured in β-cells isolated from Cd38+/+ and Cd38−/− mice. Calcium-mobilizing second messengers were identified by measuring levels of nicotinic acid adenine dinucleotide phosphate (NAADP) and cyclic ADP-ribose (ADPR), using a cyclic enzymatic assay. To locate NAADP- and cyclic ADPR–producing enzyme(s), cellular organelles were separated using the sucrose gradient method. RESULTS—A GLP-1–induced [Ca2+]i increase showed a cooperative Ca2+ signal, i.e., an initial [Ca2+]i rise mediated by the action of NAADP that was produced in acidic organelles and a subsequent long-lasting increase of [Ca2+]i by the action of cyclic ADPR that was produced in plasma membranes and secretory granules. GLP-1 sequentially stimulated production of NAADP and cyclic ADPR in the organelles through protein kinase A and cAMP-regulated guanine nucleotide exchange factor II. Furthermore, the results showed that NAADP production from acidic organelles governed overall Ca2+ signals, including insulin secretion by GLP-1, and that in addition to CD38, enzymes capable of synthesizing NAADP and/or cyclic ADPR were present in β-cells. These observations were supported by the study with Cd38−/− β-cells, demonstrating production of NAADP, cyclic ADPR, and Ca2+ signal with normal insulin secretion stimulated by GLP-1. CONCLUSIONS—Our findings demonstrate that the GLP-1–mediated Ca2+ signal for insulin secretion in pancreatic β-cells is a cooperative action of NAADP and cyclic ADPR spatiotemporally formed by multiple enzymes.

Prognostic impact of tumor infiltrating FOXP3 positive regulatory T cells in diffuse large B-cell lymphoma at diagnosis

Tumor-infiltrating immune cells perform a crucial function in host immune reactions against diffuse large B-cell lymphoma (DLBCL). In this study, we have identified a subset of tumor-infiltrating FOXP3-positive regulatory T cells (Tregs) in the initial DLBCL biopsy specimens, and have evaluated their prognostic significance. Ninety six patients with DLBCL were evaluated retrospectively. The pattern of FOXP3 protein expression was evaluated using standard immunohistochemistry in paraffin-embedded tissue samples. Sixty seven of all 96 specimens were stained with antibodies for CD-10, bcl-6 and MUM1 via tissue microarray (TMA) to classify the cases into a germinal center B-cell like (GCB) group and a non-GCB group. The median overall survival (OS) was 28 months. As compared with the others, the patients with higher percentages of FOXP3-positive Tregs on initial tumor biopsy evidenced a significantly longer OS (p = 0.003). Patients classified into the GCB group evidenced a significantly longer OS as compared with the non-GCB group (p = 0.008). When the prognostic factors were evaluated via a multivariate model, the international prognostic index and the percentage of infiltrating FOXP3-positive Tregs in the initial biopsy were identified as independent predictors of OS. In conclusion, the presence of an increased percentage of FOXP3-positive Tregs in DLBCL is predictive of better prognoses.

Interaction of two classes of ADP-ribose transfer reactions in immune signaling.

CD38 is a bifunctional ectoenzyme predominantly expressed on hematopoietic cells where its expression correlates with differentiation and proliferation. The two enzyme activities displayed by CD38 are an ADP-ribosyl cyclase and a cyclic adenosine diphosphate ribose (cADPR) hydrolase that catalyzes the synthesis and hydrolysis of cADPR. T lymphocytes can be induced to express CD38 when activated with antibodies against specific antigen receptors. If the activated T cells are then exposed with NAD, cell death by apoptosis occurs. During the exposure of activated T cells to NAD, the CD38 is modified by ecto-mono-ADP-ribosyltransferases (ecto-mono-ADPRTs) specific for cysteine and arginine residues. Arginine-ADP-ribosylation results in inactivation of both cyclase and hydrolase activities of CD38, whereas cysteine-ADP-ribosylation results only in the inhibition of the hydrolase activity. The arginine-ADP-ribosylation causes a decrease in intracellular cADPR and a subsequent decrease in Ca2+influx, resulting in apoptosis of the activated T cells. Our results suggest that the interaction of two classes of ecto-ADP-ribose transfer enzymes plays an important role in immune regulation by the selective induction of apoptosis in activated T cells and that cADPR mediated signaling is essential for the survival of activated T cells.

Imatinib mesylate discontinuation in patients with chronic myeloid leukemia who have received front-line imatinib mesylate therapy and achieved complete molecular response

The aims were to investigate the feasibility of imatinib mesylate (IM) discontinuation in chronic myeloid leukemia patients who were initially treated with IM and achieved complete molecular response (CMR). Fourteen patients were included. Ten were relapsed within 9.5 months after discontinuation of IM. All 7 patients with high Sokal risk were relapsed. The probability of CMR persistence at 1-year was 28.6%. All relapsed patients were still responsive to IM. A high Sokal risk and delayed acquisition of CMR were associated with relapse. IM discontinuation in patients achieved CMR after treatment with front-line IM might be feasible. Further studies are warranted.

The prognostic significance of tumor human papillomavirus status for patients with anal squamous cell carcinoma treated with combined chemoradiotherapy.

The prognostic relevance of tumor human papillomavirus (HPV) status in anal squamous cell carcinoma (SCC) had not been previously investigated, although its relevance to cervical, head and neck SCC is known. We retrospectively evaluated outcomes in 47 patients with anal SCC treated with combined chemoradiotherapy (CCRT) and determined tumor HPV status by HPV DNA chip method and p16 expression by immunohistochemistry (IHC) from paraffin‐embedded tumor tissues. The median age was 65 years (range, 44–90 years). Sixteen (34%) patients were diagnosed with T stage 3 to 4, and 18 (38%) patients had regional nodal disease (N‐positive). Thirty‐five (75%) patients were HPV positive, and 31 (66%) patients were genotype 16 (HPV16‐positive). Thirty‐nine (83.0%) patients were positive for p16. After median follow‐up of 51.7 months (range, 5.1–136.0 months), HPV16‐positive group had significantly better 4‐year progression‐free survival (PFS, 63.1% vs. 15.6%, p < 0.001) and overall survival (84.6% vs. 39.8%, p = 0.008) than HPV genotype 16 negative (HPV16‐negative) group. Patients with p16‐positive tumor also had a better 4‐year PFS (52.5% vs. 25.0%, p = 0.014) than those with p16‐negative tumor. In multivariate analysis for PFS, N‐positive and HPV16‐negative were independent prognostic factors for shorter PFS. Comparing patterns of failure, time to loco‐regional failure was statistically superior in HPV16‐positive over HPV16‐negative groups (p = 0.006), but time to systemic failure was not different (p = 0.098). Tumor HPV genotype 16 status is a prognostic and predictive factor in anal SCC treated with CCRT, and p16 expression determined by IHC might be advocated as a surrogate biomarker of HPV integration in anal SCC. Further studies are warranted.

Tumor necrosis factor-α enhances DMSO-induced differentiation of HL-60 cells through the activation of ERK/MAPK pathway

The differentiation of promyelocytic leukemic cells into mature cells is the major strategy for drug-based treatment of leukemia. Higher efficient methods to differentiate promyelocytic leukemic cells have been developed using various differentiation inducers including interferon-α, interleukin-4, tumor necrosis factor-α (TNF-α), and dimethyl sulfoxide (DMSO) as a single agent or in combination with each other. Here, we show that a combination of TNF-α with DMSO shows a synergic effect on HL-60 cell differentiation through the activation of ERK pathway. TNF-α enhanced CD11b expression and percent of cell population in the G1 phase induced by DMSO, which are hallmarks for HL-60 cell differentiation. Inhibition of ERK pathway abolished the synergic effect of TNF-α in combination with DMSO on HL-60 differentiation, but the inhibition NF-κB pathway did not. These results suggest that TNF-α synergistically increases DMSO-induced differentiation of HL-60 cells through the activation of ERK/MAPK-signaling pathway.

Use of curcumin to decrease nitric oxide production during the induction of antitumor responses by IL-2.

Nitric oxide (NO) synthesis is strongly induced during interleukin (IL)-2 treatment of mice and humans. Although this free radical can act as a cytotoxic effector molecule against cancer cells, immunosuppressive effects have also been suggested. We evaluated the effects of curcumin on IL-2-induced NO synthesis and IL-2-induced antitumor responses in a mouse ascites tumor model. Curcumin inhibited inducible nitric oxide synthase (iNOS) expression and NO production, and thereby enhanced the proliferation and cytotoxic activity of cocultured lymphocytes and macrophages during IL-2 stimulation which we earlier established as an in vitro model of IL-2-induced NO synthesis. Curcumin also decreased apoptosis of cocultured lymphocytes and macrophages during IL-2 stimulation. In contrast, the curcumin-induced changes in proliferation and apoptosis were not observed in cultures of lymphocytes alone, macrophages alone, and cocultured lymphocytes/iNOS-knock out macrophages, all of which produced little nitrite during IL-2 stimulation. In conjunction with IL-2 treatment, oral curcumin administration significantly inhibited IL-2 therapy-induced urinary nitrite/nitrate excretion and iNOS expression of tumor tissues, and further increased the IL-2 therapy-induced prolongation of survival in a murine Meth-A ascites tumor model. Curcumin may be useful as an adjunct to increase the antitumor activity of IL-2 therapy.

Usefulness of F-18 FDG PET/CT in subcutaneous panniculitis-like T cell lymphoma: disease extent and treatment response evaluation

Background. Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cutaneous lymphomas, accounting for less than 1% of cases of non-Hodgkin’s lymphoma. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positronemission tomography/computed tomography (PET/CT) findings of SPTCL before and after treatment were rarely reported. Case report. We report a case of SPTCL in which F-18 FDG PET/CT showed increased FDG accumulations in numerous subcutaneous nodules without extracutaneous disease. Contrast-enhanced CT during F-18 FDG PET/CT showed multiple minimally enhancing nodules with an infiltrative pattern in the subcutaneous layer throughout the body. Follow-up F-18 FDG PET/CT after three cycles of CHOP chemotherapy showed a complete metabolic remission of the lesions. Conclusions. F-18 FDG PET/CT is suggested to be useful in assessing the disease activity, extent and treatment response in SPTCL.

Cytokines secreted by IL-2-activated lymphocytes induce endogenous nitric oxide synthesis and apoptosis in macrophages

IL‐2‐activated killer (LAK) cells secrete inflammatory cytokines such as IFN‐γ and TNF‐α, which can induce NO synthesis (NOS). In this study, we investigated IL‐2‐activated lymphocyte‐mediated macrophage apoptosis via NOS. LAK cells and their culture supernatants induced NOS in murine macrophages. NOS was markedly inhibited by blocking antibodies to IFN‐γ and TNF‐α, suggesting the key role of these lymphocyte cytokines in mediating NOS. Endogenous NO production inhibited macrophage proliferation and induced apoptosis in concordance with p53 accumulation and caspase‐3 activation, processes that were inhibited by NG‐monomethyl‐l‐arginine (a NOS inhibitor) and 2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl 3‐oxide (a NO scavenger). Our study demonstrated a novel, noncontact‐dependent mechanism of macrophage suppression by IL‐2‐activated lymphocytes: induction of growth inhibition and apoptosis of macrophages as a result of endogenous NOS induced by cytokines secreted from IL‐2‐activated lymphocytes.