Naoya Taira

Dose-intensified chemotherapy alone or in combination with mogamulizumab in newly diagnosed aggressive adult T-cell leukaemia-lymphoma: a randomized phase II study

This multicentre, randomized, phase II study was conducted to examine whether the addition of mogamulizumab, a humanized anti‐CC chemokine receptor 4 antibody, to mLSG15, a dose‐intensified chemotherapy, further increases efficacy without compromising safety of patients with newly diagnosed aggressive adult T‐cell leukaemia‐lymphoma (ATL). Patients were assigned 1:1 to receive mLSG15 plus mogamulizumab or mLSG15 alone. The primary endpoint was the complete response rate (%CR); secondary endpoints included the overall response rate (ORR) and safety. The %CR and ORR in the mLSG15‐plus‐mogamulizumab arm (n = 29) were 52% [95% confidence interval (CI), 33–71%] and 86%, respectively; the corresponding values in the mLSG15 arm (n = 24) were 33% (95% CI, 16–55%) and 75%, respectively. Grade ≥ 3 treatment‐emergent adverse events, including anaemia, thrombocytopenia, lymphopenia, leucopenia and decreased appetite, were observed more frequently (≥10% difference) in the mLSG15‐plus‐mogamulizumab arm. Several adverse events, including skin disorders, cytomegalovirus infection, pyrexia, hyperglycaemia and interstitial lung disease, were observed only in the mLSG15‐plus‐mogamulizumab arm. Although the combination strategy showed a potentially less favourable safety profile, a higher %CR was achieved, providing the basis for further investigation of this novel treatment for newly diagnosed aggressive ATL. This study was registered at ClinicalTrials.gov, identifier: NCT01173887.

Antiadult T‐cell leukemia effects of brown algae fucoxanthin and its deacetylated product, fucoxanthinol

Adult T‐cell leukemia (ATL) is a fatal malignancy of T lymphocytes caused by human T‐cell leukemia virus type 1 (HTLV‐1) infection and remains incurable. Carotenoids are a family of natural pigments and have several biological functions. Among carotenoids, fucoxanthin is known to have antitumorigenic activity, but the precise mechanism of action is not elucidated. We evaluated the anti‐ATL effects of fucoxanthin and its metabolite, fucoxanthinol. Both carotenoids inhibited cell viability of HTLV‐1‐infected T‐cell lines and ATL cells, and fucoxanthinol was approximately twice more potent than fucoxanthin. In contrast, other carotenoids, β‐carotene and astaxanthin, had mild inhibitory effects on HTLV‐1‐infected T‐cell lines. Importantly, uninfected cell lines and normal peripheral blood mononuclear cells were resistant to fucoxanthin and fucoxanthinol. Both carotenoids induced cell cycle arrest during G1 phase by reducing the expression of cyclin D1, cyclin D2, CDK4 and CDK6, and inducing the expression of GADD45α, and induced apoptosis by reducing the expression of Bcl‐2, XIAP, cIAP2 and survivin. The induced apoptosis was associated with activation of caspase‐3, ‐8 and ‐9. Fucoxanthin and fucoxanthinol also suppressed IκBα phosphorylation and JunD expression, resulting in inactivation of nuclear factor‐κB and activator protein‐1. Mice with severe combined immunodeficiency harboring tumors induced by inoculation of HTLV‐1‐infected T cells responded to treatment with fucoxanthinol with suppression of tumor growth, showed extensive tissue distribution of fucoxanthinol, and the presence of therapeutically effective serum concentrations of fucoxanthinol. Our preclinical data suggest that fucoxanthin and fucoxanthinol could be potentially useful therapeutic agents for patients with ATL.

Activation of hypoxia-inducible factor 1 in human T-cell leukaemia virus type 1-infected cell lines and primary adult T-cell leukaemia cells.

HTLV-1 (human T-cell leukaemia virus type 1) is the causative agent for ATL (adult T-cell leukaemia). HTLV-1 Tax can activate the PI3K (phosphoinositide 3-kinase)/Akt signalling pathway, which is responsible for survival of HTLV-1-infected T-cells. HIFs (hypoxia-inducible factors) are transcriptional regulators that play a central role in the response to hypoxia. Overexpression of HIF-1alpha in many cancers is associated with a poor response to treatment and increased patient mortality. Our objectives in the present study were to investigate whether HIF-1 was activated in HTLV-1-infected T-cells and to elucidate the molecular mechanisms of HIF-1 activation by focusing on the PI3K/Akt signalling pathway. We detected a potent pathway that activated HIF-1 in the HTLV-1-infected T-cells under a normal oxygen concentration. Enhanced HIF-1alpha protein expression and HIF-1 DNA-binding activity were exhibited in HTLV-1-infected T-cell lines. Knockdown of HIF-1alpha by siRNA (small interfering RNA) suppressed the growth and VEGF (vascular endothelial growth factor) expression of the HTLV-1-infected T-cell line. HIF-1 protein accumulation and transcriptional activity were enhanced by Tax, which was inhibited by dominant-negative Akt. Importantly, mutant forms of Tax that are defective in activation of the PI3K/Akt pathway failed to induce HIF-1 transcriptional activity. The PI3K inhibitor LY294002 suppressed HIF-1alpha protein expression, HIF-1 DNA-binding and HIF-1 transcriptional activity in HTLV-1-infected T-cell lines. In primary ATL cells, HIF-1alpha protein levels were strongly correlated with levels of phosphorylated Akt. The results of the present study suggest that PI3K/Akt activation induced by Tax leads to activation of HIF-1. As HIF-1 plays a major role in tumour progression, it may represent a molecular target for the development of novel ATL therapeutics.

Clonal evolution of adult T-cell leukemia/lymphoma takes place in the lymph nodes

Adult T-cell leukemia/lymphoma (ATLL) is the neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). We performed oligo-array comparative genomic hybridization (CGH) against paired samples comprising peripheral blood (PB) and lymph node (LN) samples from 13 patients with acute ATLL. We found that the genome profiles of the PB frequently differed from those of the LN samples. The results showed that 9 of 13 cases investigated had a log2 ratio imbalance among chromosomes, and that chromosome imbalances were more frequent in LN samples. Detailed analysis revealed that the imbalances were likely caused by the presence of multiple subclones in the LN samples. Five of 13 cases showed homozygous loss regions in PB samples, which were not found in the LN samples, indicating that tumors in the PB were derived from LN subclones in most cases. Southern blot analysis of TCRγ showed that these multiple subclones originated from a common clone. We concluded that in many ATLL cases, multiple subclones in the LNs originate from a common clone, and that a selected subclone among the LN subclones appears in the PB.

Childhood blastic NK cell leukemia successfully treated with L-asparagenase and allogeneic bone marrow transplantation

Blastic NK cell lymphoma/leukemia is a rare and highly malignant neoplasia in both adults and children. It is characterized by lymphoblastoid morphology without cytoplasmic granules and immature NK cell immunophenotypes (CD56+, CD57−, CD16−). It has predilection for extranodal organ involvement, and the prognosis of affected patients is extremely poor under the current chemotherapy. We present a 14‐year‐old girl who was diagnosed as having blastic NK cell leukemia with mediastinal, pleural, and pericardial involvement. Immunophenotyping of her leukemic cells showed positive for CD2, CD5, CD7, CD34, CD56, HLA‐DR, and cytoplasmic CD3. T cell receptor (TCR) and Immunoglobulin heavy chain genes were not rearranged. She received chemotherapy for acute lymphoblastic leukemia incorporating L‐asparaginase (L‐asp) which successfully induced complete remission. Bone marrow transplantation (BMT) from her HLA‐identical sibling was conducted after two courses of consolidation therapy. Expression of aspargine synthetase (AS) protein in the leukemic cells at diagnosis was examined by an immunocytochemical method. She remains in hematological remission for over 36 months after BMT. The expression of AS protein was negative, suggesting that the leukemic cells were sensitive to L‐asp. Induction and consolidation therapy incorporating L‐asp followed by allo‐BMT might be a promising treatment for child hood blastic NK cell leukemia, but more samples of the rare leukemia need to be studied before any definitive conclusions can be drawn.

A modified version of galectin-9 suppresses cell growth and induces apoptosis of human T-cell leukemia virus type I-infected T-cell lines.

Retraction: The following article has been retracted through agreement between the first author and several coauthors, the journal Editor‐in‐Chief, Peter Lichter, and John Wiley & Sons, Ltd.: Okudaira T, Hirashima M, Ishikawa C, Makishi S, Tomita M, Matsuda T, Kawakami H, Taira N, Ohshiro K, Masuda M, Takasu N, Mori N. (2007). A modified version of galectin‐9 suppresses cell growth and induces apoptosis of human T‐cell leukemia virus type I‐infected T‐cell lines. Int J Cancer; 120 (May (10)): 2251‐2261, published online on 2 FEB 2007 in Wiley Online Library (www.onlinelibrary.wiley.com). After an investigation the retraction has been agreed due to inappropriate duplication of images and overlap with other published work.

Multicenter Phase II Study of Lenalidomide in Relapsed or Recurrent Adult T-Cell Leukemia/Lymphoma: ATLL-002.

Purpose Few treatment options exist for adult T-cell leukemia/lymphoma (ATL), and the prognosis for this disease is poor. A phase I study of lenalidomide demonstrated preliminary antitumor activity in patients with relapsed ATL. The current phase II study evaluated the efficacy and safety of lenalidomide monotherapy in patients with relapsed or recurrent ATL. Patients and Methods Patients 20 years of age or older with acute, lymphoma, or unfavorable chronic subtype ATL, who had received one or more prior anti-ATL systemic chemotherapy and achieved stable disease or better on their last anti-ATL therapy with subsequent relapse or recurrence, were eligible. Patients received oral lenalidomide 25 mg/d continuously until disease progression or unacceptable toxicity. The primary end point was overall response rate; secondary end points included safety, tumor control rate (stable disease or better), time to response, duration of response, time to progression, progression-free survival, and overall survival. Results Objective responses were noted in 11 of 26 patients (overall response rate, 42%; 95% CI, 23% to 63%), including four complete responses and one unconfirmed complete response. The tumor control rate was 73%. The median time to response and duration of response were 1.9 months and not estimable, respectively, and the median time to progression was 3.8 months. The median progression-free survival and overall survival were 3.8 and 20.3 months, respectively. The most frequent grade ≥ 3 adverse events were neutropenia (65%), leukopenia (38%), lymphopenia (38%), and thrombocytopenia (23%), which were all manageable and reversible. Conclusion Lenalidomide demonstrated clinically meaningful antitumor activity and an acceptable toxicity profile in patients with relapsed or recurrent aggressive ATL, hinting at its potential to become a treatment option. Further investigations of lenalidomide in ATL and other mature T-cell neoplasms are warranted.

Inhibition of heat shock protein-90 modulates multiple functions required for survival of human T-cell leukemia virus type I-infected T-cell lines and adult T-cell leukemia cells.

Retraction: The following article has been retracted through agreement between the first author and several coauthors, the journal Editor‐in‐Chief, Peter Lichter, and John Wiley & Sons, Ltd.: Kawakami H, Tomita M, Okudaira T, Ishikawa C, Matsuda T, Tanaka Y, Nakazato T, Taira N, Ohshiro K, Mori N. (2007). Inhibition of heat shock protein‐90 modulates multiple functions required for survival of human T‐cell leukemia virus type I‐infected T‐cell lines and adult T‐cell leukemia cells. Int J Cancer; 120 (April (8)): 1811‐1820, published online on 17 JAN 2007 in Wiley Online Library (www.onlinelibrary.wiley.com). After an investigation the retraction has been agreed due to inappropriate duplication of images and overlap with other published work.

Molecular Characterization of Chronic-type Adult T-cell Leukemia/Lymphoma

Adult T-cell leukemia/lymphoma (ATL) is a human T-cell leukemia virus type-1-induced neoplasm with four clinical subtypes: acute, lymphoma, chronic, and smoldering. Although the chronic type is regarded as indolent ATL, about half of the cases progress to acute-type ATL. The molecular pathogenesis of acute transformation in chronic-type ATL is only partially understood. In an effort to determine the molecular pathogeneses of ATL, and especially the molecular mechanism of acute transformation, oligo-array comparative genomic hybridization and comprehensive gene expression profiling were applied to 27 and 35 cases of chronic and acute type ATL, respectively. The genomic profile of the chronic type was nearly identical to that of acute-type ATL, although more genomic alterations characteristic of acute-type ATL were observed. Among the genomic alterations frequently observed in acute-type ATL, the loss of CDKN2A, which is involved in cell-cycle deregulation, was especially characteristic of acute-type ATL compared with chronic-type ATL. Furthermore, we found that genomic alteration of CD58, which is implicated in escape from the immunosurveillance mechanism, is more frequently observed in acute-type ATL than in the chronic-type. Interestingly, the chronic-type cases with cell-cycle deregulation and disruption of immunosurveillance mechanism were associated with earlier progression to acute-type ATL. These findings suggested that cell-cycle deregulation and the immune escape mechanism play important roles in acute transformation of the chronic type and indicated that these alterations are good predictive markers for chronic-type ATL.

Anti-adult T-cell leukemia/lymphoma effects of indole-3-carbinol

BackgroundAdult T-cell leukemia/lymphoma (ATLL) is a malignancy derived from T cells infected with human T-cell leukemia virus type 1 (HTLV-1), and it is known to be resistant to standard anticancer therapies. Indole-3-carbinol (I3C), a naturally occurring component of Brassica vegetables such as cabbage, broccoli and Brussels sprout, is a promising chemopreventive agent as it is reported to possess antimutagenic, antitumorigenic and antiestrogenic properties in experimental studies. The aim of this study was to determine the potential anti-ATLL effects of I3C both in vitro and in vivo.ResultsIn the in vitro study, I3C inhibited cell viability of HTLV-1-infected T-cell lines and ATLL cells in a dose-dependent manner. Importantly, I3C did not exert any inhibitory effect on uninfected T-cell lines and normal peripheral blood mononuclear cells. I3C prevented the G1/S transition by reducing the expression of cyclin D1, cyclin D2, Cdk4 and Cdk6, and induced apoptosis by reducing the expression of XIAP, survivin and Bcl-2, and by upregulating the expression of Bak. The induced apoptosis was associated with activation of caspase-3, -8 and -9, and poly(ADP-ribose) polymerase cleavage. I3C also suppressed IκBα phosphorylation and JunD expression, resulting in inactivation of NF-κB and AP-1. Inoculation of HTLV-1-infected T cells in mice with severe combined immunodeficiency resulted in tumor growth. The latter was inhibited by treatment with I3C (50 mg/kg/day orally), but not the vehicle control.ConclusionOur preclinical data suggest that I3C could be potentially a useful chemotherapeutic agent for patients with ATLL.