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Background: Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy of peripheral T-lymphocytes and its prognosis still remains very poor., Materials and Methods: The potential of combining the Bcl-2 homology 3 mimetic ABT-737, which blocks Bcl-2, Bcl-XL, and Bcl-w, with either the proteasome inhibitor bortezomib or histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) to inhibit the growth of human T-lymphotropic virus type-I (HTLV-1) infected T-cell lines and its mechanism was further evaluated., Results: ABT-737 synergistically induced apoptosis when combined with either bortezomib or SAHA in HTLV-1 infected T-cell lines and fresh ATL cells. Bortezomib increased the expression of Noxa, which subsequently enhanced the formation of Mcl-1-Noxa complexes, resulting in the functional neutralization of Mcl-1, an inducer of resistance to ABT-737. On the other hand, SAHA reduced the expression of survivin, an anti-apoptotic molecule that confers drug resistance on ATL cells., Conclusion: The combination of ABT-737 with bortezomib or SAHA is promising for the treatment of ATL., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

The therapeutic outcome for T-cell acute lymphoblastic leukemia (T-ALL) remains poor; thus, novel, targeted therapies are urgently needed. Recently, we showed that heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the EGF family, is a promising target for the treatment of various types of cancer. The aim of the present study was to investigate whether HB-EGF is a therapeutic target for T-ALL, and to further elucidate the antitumor effects of a specific inhibitor of HB-EGF, cross-reacting material 197 (CRM197). We elucidated the expression of HB-EGF in T-ALL cell lines, and evaluated the effect of CRM197 on these cells alone or in combination with anticancer agent. The expression of EGFR and EGFR ligands was determined by flow cytometry, RT-PCR and real-time quantitative PCR. Induction of apoptosis was assessed by TUNEL assay. HB-EGF was strongly expressed by T-ALL cell lines, and the expression of both HB-EGF and EGFR was enhanced by doxorubicin. CRM197 induced apoptosis, and furthermore, the combination of CRM197 plus doxorubicin enhanced cytotoxicity in a T-ALL cell line. These results suggest that HB-EGF is a promising therapeutic target for T-ALL.

A 72-year-old man with extranodal natural killer cell lymphoma (ENKL) presented with a painless swelling of the left forearm. He was initially diagnosed as having a bacterial cellulitis and received antimicrobial therapy. However, his left arm became increasingly swollen in association with fever and redness of the lesion. Therefore, he underwent focal dissection. Because of persistent swelling, the left arm was rebiopsied 9 months later, and a diagnosis of ENKL developing in the subcutis was established. He was treated with focal radiation therapy in combination with dexamethasone, etoposide, ifosfamide, methotrexate and L-asparaginase. The lesion was significantly reduced in size but did not disappear completely. Two months later the lesion became necrotic, although swelling of the forearm lesion, left axillary and cervical lymph nodes were kept under control. We then performed amputation of the left forearm since it could not be saved medically. The patient currently remains alive and well without progression 2 years after amputation. When evaluating panniculitis, which is difficult to cure, ENKL should be considered in the differential diagnosis and treated appropriately.