A combination trial of human lymphoblastoid interferon and bestrabucil (KM2210) for adult T-cell leukemia-lymphoma

Mechanistic Insights into Effects of Different Dietary Polyphenol Supplements on Arsenic Bioavailability, Biotransformation, and Toxicity Based on a Mouse Model

Arsenic (As) exposure has been related to many diseases, including cancers. Given the antioxidant and anti-inflammatory properties, the dietary supplementation of polyphenols may alleviate As toxicity. Based on a mouse bioassay, this study investigated the effects of chlorogenic acid (CA), quercetin (QC), tannic acid (TA), resveratrol (Res), and epigallocatechin gallate (EGCG) on As bioavailability, biotransformation, and toxicity. Intake of CA, QC, and EGCG significantly (p < 0.05) increased total As concentrations in liver (0.48-0.58 vs 0.27 mg kg-1) and kidneys (0.72-0.93 vs 0.59 mg kg-1) compared to control mice. Upregulated intestinal expression of phosphate transporters with QC and EGCG and proliferation of Lactobacillus in the gut of mice treated with CA and QC were observed, facilitating iAsV absorption via phosphate transporters and intestinal As solubility via organic acid metabolites. Although As bioavailability was elevated, serum levels of alpha fetoprotein and carcinoembryonic antigen of mice treated with all five polyphenols were reduced by 13.1-16.1% and 9.83-17.5%, suggesting reduced cancer risk. This was mainly due to higher DMAV (52.1-67.6% vs 31.4%) and lower iAsV contribution (4.95-10.7% vs 27.9%) in liver of mice treated with polyphenols. This study helps us develop dietary strategies to lower As toxicity.

HIV vector-mediated targeted suicide gene therapy for adult T-cell leukemia

We investigated the potential efficacy of treating adult T-cell leukemia (ATL) using a gene therapeutic approach involving the use of a herpes simplex virus-thymidine kinase (HSV-TK)-mediated suicide system. Human immunodeficiency virus (HIV)-based vectors containing the HSV-TK gene were constructed to achieve targeted gene transfer into CD4-positive ATL cells, after which the transduced cells were selectively killed by treatment with ganciclovir (GCV). To examine the utility of HIV vectors in vivo, ATL-NOD-SCID mice were prepared by intraperitoneal injection of 1 x 10(7) MT2 cells into NK-depleted nonobese diabetic/severely compromised immunodeficient (NOD-SCID) mice. Thereafter, 1 ml of concentrated HIV vector expressing HSV-TK (HXCTKN) or GFP (HXGFP) stock was injected into the intraperitoneal cavity, and GCV was administered twice a day for 5 days. Fluorescence-activated cell sorting (FACS) analysis showed that 7-11% of MT2 or HUT102 cells recovered from the peritoneal cavity were transduced with the HXGFP. After 3 weeks, plasma sIL2-R alpha levels were significantly lower in mice administered HXCTKN than in those administered HXGFP. Moreover, HXCTKN-injected mice survived significantly longer than HXGFP-injected mice. Taken together, these findings suggest that HIV vectors could be used for in vivo targeted gene transfer into ATL cells and could thus serve as the basis for the development of effective new therapies for the treatment of ATL.

Natural history of adult T-cell leukemia/lymphoma and approaches to therapy

After cell-to-cell transmission, HTLV-I increases its viral genome by de novo infection and proliferation of infected cells. Proliferation of infected cells is clonal and persistent in vivo. During the carrier state, infected cells are selected in vivo by the host's immune system, the genetic and epigenetic environment of proviral integration sites, and other factors. In leukemic cells, tax gene expression is frequently impaired by genetic and epigenetic mechanisms. Such loss of Tax expression enables ATL cells to escape the host immune system. On the other hand, ATL cells acquire the ability to proliferate without Tax by intracellular genetic and epigenetic changes. Despite advances in support and the development of novel treatment agents, the prognosis for ATLL remains poor. A number of therapies, however, do appear to improve prognosis compared to CHOP (VEPA). These include interferon-alpha plus zidovudine (probably after 1-2 cycles of CHOP), intensive chemotherapy as in LSG-15 with G-CSF support and Allo-SCT (which includes the potential for cure). Emerging novel approaches include HDAC inhibitors, monoclonal antibodies, and proteasome inhibitors. Comparison between different therapeutic approaches is complicated by the range of natural history of ATLL, different recruitments of naïve-to-therapy, refractory or relapsed patients, and variations in the reporting of outcome that frequently excludes difficult-to-evaluate patients. Moreover, results from relatively small proof-of-principle studies have not been extended with randomized, controlled trials. As a result, currently, there is no clear evidence to support the value of any particular treatment approach over others. To avoid further unnecessary patient suffering and to identify optimal therapy as rapidly as possible, large randomized, controlled trials encompassing multicenter, international collaborations will be necessary.

Increase in gammadelta T cells in the blood of cattle persistently infected with bovine leukemia virus following administration of recombinant bovine IFN-gamma

To examine the effect of recombinant bovine interferon-gamma (rbIFN-gamma) on cattle persistently infected with bovine leukemia virus (BLV), BLV-infected cattle were inoculated intraperitoneally with IFN-gamma. All cattle were febrile after inoculation with IFN-gamma and then recovered within 48 h. Flow cytometric analysis showed that the numbers of CD4+ and CD8+ T cells were decreased for 2-3 days and then their numbers were recovered. The number of gammadelta T cells increased after the fever. In contrast, the number of IgM+ lymphocytes remained low for about 1 week. Moreover, the numbers of syncytia produced by peripheral blood lymphocytes decreased and remained low compared to that before IFN-gamma administration. These results suggest that IFN-gamma induces the up-regulation of gammadelta T cells, decreases the number of IgM+ lymphocytes and suppresses the growth of BLV in BLV-infected cattle in vivo.

Treatment of adult T-cell leukaemia/lymphoma: current strategy and future perspectives

Human T-cell leukaemia virus type I (HTLV-I) associated adult T-cell leukaemia/lymphoma (ATL) carries a very poor prognosis due to an intrinsic resistance of leukaemic cells to conventional or even high doses of chemotherapy and to an associated severe immunosuppression. Therefore, the potential role of conventional chemotherapy, high dose chemotherapy with autologous or allogeneic bone marrow transplantation remains to be defined. Important progress was achieved in the treatment of ATL with the combination of zidovudine (AZT) and interferon-alpha (IFN) which produces a high response rate in ATL patients with minimal side effects. This treatment seems to prolong the survival of patients much more than intensive chemotherapy. The success of this potentially anti-retroviral approach in the treatment of ATL suggests the existence of continuous HTLV-I replication in vivo. These encouraging results may be improved by the use of higher doses of AZT and IFN combined with other anti-retroviral agents. However, since cure seems still elusive, new therapeutic approaches or new combinations are required. For example, biological mediators such as retinoid acid, which induces apoptosis of ATL cells in vitro, may reduce drug resistance and stimulates immunity to restore anti-tumour activity against ATL cells. Alternatively, immunotherapy with anti-interleukin-2 receptor monoclonal antibodies or injection of cytotoxic T-cells directed against virus antigens could be interesting approaches which may merit further investigations in the near future. Finally, the recent demonstration that the combination of arsenic trioxide (As) and IFN induces a specific degradation of the viral transactivator Tax followed by cell cycle arrest and apoptosis of HTLV-I positive cells may constitute a valuable addition to ATL treatment.

Human T-cell lymphotropic-I-associated leukemia/lymphoma

Human T-cell lymphotropic virus-I (HTLV-I)-related adult T-cell leukemia/lymphoma (ATL) is a model disease for proof of viral oncogenesis. HTLV-I infection is endemic in southern Japan and the Caribbean basin, and occurs sporadically in Africa, Central and South America, the Middle East, and the southeastern United States. ATL occurs in only 2% to 4% of HTLV-I-infected people [1-3]. When it does occur, it is usually aggressive and difficult to treat; most people survive for less than 1 year [1-3]. Combination chemotherapy with cytotoxic agents has yielded complete response rates of 20% to 45%, but responses usually last only a few months [3]. Recently, novel treatments, such as monoclonal antibodies directed at the interleukin-2 receptor and the combination of interferon alfa and zidovudine, have been shown to be active in the treatment of patients with ATL. A small percentage of patients achieve long-lasting remissions [2,3].

Malignancy: Human T-Cell Lymphotropic Virus Type I and Adult T-Cell Leukaemia/Lymphoma

Adult T-cell leukaemia/lymphoma (ATLL) was first identified in Japan in 1977 [1,2]. The causative agent, the human T-lymphotropic virus type I (HTLV-I), was isolated 3 years later by Gallo's group from a patient initially diagnosed as having mycosis fungoides but subsequently reclassified as a case of ATLL [3]. Since this time, much has been discovered about the molecular pathogenesis of the disease. Despite this, treatment of ATLL remains disappointing and the prognosis of acute and lymphoma types poor. In the United Kingdom, cases of ATLL are mainly restricted to people of Afro-Caribbean descent but the disease is of general importance because ATLL has also been reported in non-endemic areas and may possibly spread into other populations via blood transfusion as blood donors in the UK are currently not screened for HTLV-I.

Lymphoblastoid interferon-alpha downregulates parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor expression in human osteoblastic cells (Saos-2)

Interferon-alpha (IFN-alpha) is a pleiotropic cytokine that modulates the cellular functions of both osteoblastic and osteoclastic lineages. It remains unclear whether IFN-alpha regulates the expression of parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor, which is a major target molecule regulating skeletal metabolism. In this study, we examined the effect of IFN-alpha on the expression of PTH/PTHrP receptor in human osteoblastic cells (Saos-2). IFN-alpha inhibited the expression of PTH/PTHrP receptor gene in both a time- and dose-dependent manner. The mRNA level was decreased to 61.1% of that of the untreated control by 48 h treatment with 6000 U/mL of IFN-alpha. IFN-alpha also decreased cAMP response to PTH(1-34) in a dose-dependent manner and significantly depressed expression of the receptor protein. However, IFN-alpha did not exert any effect on other osteoblastic markers, such as alkaline phosphatase (ALP) activity, cAMP response to prostaglandin E2 (PGE2), and secretion of bone gla-protein (BGP) and bone sialoprotein (BSP). Finally, IFN-alpha decreased PTH/PTHrP receptor mRNA to 60.7% that of control in the presence of actinomycin D. These data suggest that IFN-alpha downregulates the expression of PTH/PTHrP receptor and its signaling without affecting other osteoblastic markers, and that IFN-alpha regulates its gene expression mainly by decreasing the stability of its mRNA.

Adult T-cell leukemia/lymphoma in London: clinical experience of 21 cases

Adult T-cell leukemia/lymphoma (ATLL) is uncommon in the United Kingdom and has so far been restricted to people of Afro-Caribbean extraction. Between 1981 and 1995, 21 cases presented to 2 inner London teaching hospitals where 17% of the population are of Afro-Caribbean origin. Clinical presentations were similar to those of the disease in HTLV-I-endemic areas. Major responses (CR + PR) were obtained in 10/16 assessable patients (63%) treated with combination chemotherapy. However, median survival was only 5.5 months. Disease progression and opportunistic infection were the major causes of treatment failure and death. Three patients (14%) relapsed in the central nervous system (CNS). Our cases confirm the profound immunosuppression in ATLL. The poor prognosis of acute and lymphoma types of ATLL highlight the need for new approaches to treatment such as zidovudine and alpha-interferon, incorporating prophylaxis against CNS disease and opportunistic infections.

Arthritis syndromes associated with human T cell lymphotropic virus type I infection

Arthritis syndromes occur associated with HTLV-I infection both in the presence and in the absence of clinical ATL, and polyarthritis may be the presenting manifestation of HTLV-I-associated ATL. In both clinical settings, HTLV-I-infected T cells home to affected joints, and tax-transgenic mouse studies have suggested a pathogenic role for the HTLV-I tax gene in inducing synovial cell proliferation in HAA. Understanding the pathogenesis of rheumatoid arthritis-like arthritis syndromes that occur in the setting of HTLV-I infection should also provide insights into understanding of cellular and molecular mechanisms of synovial cell proliferation in HTLV-I-negative rheumatoid arthritis.

Treatment of adult T-cell leukemia/lymphoma with MST-16, a new oral antitumor drug and a derivative of bis(2,6-dioxopiperazine). The MST-16 Study Group

BACKGROUND

MST-16, a new orally administered bis(2,6-dioxopiperazine) analogue and an inhibitor of topoisomerase II, was given to 24 patients with adult T-cell leukemia-lymphoma (ATLL) in a Phase I-II multi-institutional cooperative study.

METHODS

MST-16 was administered orally daily for 7 days, with courses repeated at intervals of 2-3 weeks in 24 patients.

RESULTS

Two complete remissions (CR) and eight partial remissions (PR) were obtained in 23 evaluable patients who received 1200-2800 mg/day of MST-16. Among 13 acute-type ATLL, one CR and five PR were obtained. Among eight lymphoma-type ATLL, two PR were detected. Among two chronic-type ATLL, one CR and one PR occurred. Remissions were obtained at 7-232 days (median, 23 days) and lasted 43-374 days (median, 68 days). The major toxic effects were leukopenia (68%), anemia (52%), thrombocytopenia (35%), and gastrointestinal disorders (22%).

CONCLUSIONS

MST-16 was shown to be effective in ATLL, which has no standard therapy. This drug deserves further clinical trials because it shows little cross resistance to currently available antitumor drugs.

Adult T-cell leukemia developing during immunosuppressive treatment in a renal transplant recipient

We report a case of a 32-year-old male, an asymptomatic carrier of human T-cell leukemia virus type 1 (HTLV-1), who underwent a renal transplantation and developed adult T-cell leukemia (ATL) during the course of posttransplant immunosuppressive treatment. He was treated with combination chemotherapies consisting of cyclophosphamide, vincristine, doxorubicin, prednisolone, cisplatin, cytosine arabinoside, etoposide, and methyl-prednisolone, without any improvement. Bestrabucil (KM2210), a conjugate of chlorambucil and estradiol, was administered as an alternative therapy; this therapy successfully suppressed his leukemic cell growth, and partial remission was achieved. Posttransplant immunosuppressive therapy with prednisolone, mizoribine, and cyclosporin A might have been the predominant cause of the transition from an asymptomatic HTLV-1 infection to overt ATL. A careful approach is required with HTLV-1 asymptomatic carriers who need organ transplantation followed by immunosuppressive treatment.