Treatment outcome of elderly patients with aggressive adult T cell leukemia-lymphoma: Nagasaki University Hospital experience

VCAP (vincristine, cyclophosphamide, doxorubicin, and prednisone)-AMP (doxorubicin, ranimustine, and prednisone)-VECP (vindesine, etoposide, carboplatin, and prednisone) is a standard regimen for aggressive adult T cell leukemia-lymphoma (ATL). However, the efficacy of this regimen has not been fully elucidated for patients aged 70 years or older. Here, we retrospectively analyzed elderly patients with aggressive ATL at Nagasaki University Hospital between 1994 and 2010 to assess treatment outcomes. Of 148 evaluable patients, 54 were aged 70 years or older at diagnosis. The median survival time (MST) and overall survival (OS) at 2 years in elderly patients were 10.6 months and 22.1 %, respectively. Thirty-four patients received VCAP-AMP-VECP as the initial treatment, although the doses were reduced for most patients. In these patients, MST and OS at 2 years were 13.4 months and 26.6 %, respectively. Eleven of 34 patients (32 %) received maintenance oral chemotherapy after two or three cycles of VCAP-AMP-VECP, and MST and OS at 2 years were 16.7 months and 32.7 %, respectively. Our results suggest that the VCAP-AMP-VECP regimen may be effective and that maintenance oral chemotherapy may be considered as a therapeutic option for elderly patients with aggressive ATL

HTLV-1 Evades Type I Interferon Antiviral Signaling by Inducing the Suppressor of Cytokine Signaling 1 (SOCS1)

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of Adult T cell Leukemia (ATL) and the neurological disorder HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the majority of HTLV-1–infected individuals remain asymptomatic carriers (AC) during their lifetime, 2–5% will develop either ATL or HAM/TSP, but never both. To better understand the gene expression changes in HTLV-1-associated diseases, we examined the mRNA profiles of CD4+ T cells isolated from 7 ATL, 12 HAM/TSP, 11 AC and 8 non-infected controls. Using genomic approaches followed by bioinformatic analysis, we identified gene expression pattern characteristic of HTLV-1 infected individuals and particular disease states. Of particular interest, the suppressor of cytokine signaling 1—SOCS1—was upregulated in HAM/TSP and AC patients but not in ATL. Moreover, SOCS1 was positively correlated with the expression of HTLV-1 mRNA in HAM/TSP patient samples. In primary PBMCs transfected with a HTLV-1 proviral clone and in HTLV-1-transformed MT-2 cells, HTLV-1 replication correlated with induction of SOCS1 and inhibition of IFN-α/β and IFN-stimulated gene expression. Targeting SOCS1 with siRNA restored type I IFN production and reduced HTLV-1 replication in MT-2 cells. Conversely, exogenous expression of SOCS1 resulted in enhanced HTLV-1 mRNA synthesis. In addition to inhibiting signaling downstream of the IFN receptor, SOCS1 inhibited IFN-β production by targeting IRF3 for ubiquitination and proteasomal degradation. These observations identify a novel SOCS1 driven mechanism of evasion of the type I IFN antiviral response against HTLV-1

Little enhancement of meal-induced GLP-1 secretion in Japanese: Comparison of type 2 diabetes and healthy controls

Although glucose‐dependent insulinotropic polypeptide (GIP) levels have been characterized previously, GLP‐1 levels in Asians remain unclear. Here, we investigate total and intact levels of GLP‐1, as well as GIP during oral glucose and meal tolerance tests (OGTT and MTT) in Japanese patients with or without type 2 diabetes (T2DM). Seventeen Japanese healthy controls and 18 age‐matched and untreated patients with T2DM of short duration participated in the present study. Fasting levels of total GPL‐1 were similar between the two groups (approximately 15 pM), and intact GLP‐1 levels were considerably low in both groups (less than 1 pM). In both groups, total GLP‐1 reached a peak 30 min after glucose ingestion (30–40 pM), whereas intact GLP‐1 levels remained low with no significant peak. In MTT, total and intact GLP‐1 showed no obvious peak. The current data indicate that intact GLP‐1 levels are considerably low in the Japanese and that meal‐induced enhancement of GLP‐1 secretion is negligible in the Japanese. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00010.x, 2010

Abacavir, an anti-HIV-1 drug, targets TDP1-deficient adult T cell leukemia

抗HIV-1薬の新規抗癌作用の解明に成功 -難治性血液がんである成人T細胞白血病の新規治療に期待-. 京都大学プレスリリース. 2015-04-27.Adult T cell leukemia (ATL) is an aggressive T cell malignancy caused by human T cell leukemia virus type 1 (HTLV-1) and has a poor prognosis. We analyzed the cytotoxic effects of various nucleoside analog reverse transcriptase inhibitors (NRTIs) for HIV-1 on ATL cells and found that abacavir potently and selectively kills ATL cells. Although NRTIs have minimal genotoxicities on host cells, the therapeutic concentration of abacavir induced numerous DNA double-strand breaks (DSBs) in the chromosomal DNA of ATL cells. DSBs persisted over time in ATL cells but not in other cell lines, suggesting impaired DNA repair. We found that the reduced expression of tyrosyl-DNA phosphodiesterase 1 (TDP1), a repair enzyme, is attributable to the cytotoxic effect of abacavir on ATL cells. We also showed that TDP1 removes abacavir from DNA ends in vitro. These results suggest a model in which ATL cells with reduced TDP1 expression are unable to excise abacavir incorporated into genomic DNA, leading to irreparable DSBs. On the basis of the above mechanism, we propose abacavir as a promising chemotherapeutic agent for ATL