IkappaBalpha independent induction of NF-kappaB and its inhibition by DHMEQ in Hodgkin/Reed-Sternberg cells.

Constitutive nuclear factor kappaB (NF-kappaB) activation characterizes Hodgkin/Reed-Sternberg (H-RS) cells. Blocking constitutive NF-kappaB has been shown to be a potential strategy to treat Hodgkin lymphoma (HL). Here, for the first time we show that although constitutive NF-kappaB level of H-RS cell lines is very high, topoisomerase inhibitors further enhance NF-kappaB activation through IkappaB kinase activation in not only H-RS cell lines with wild-type IkappaBalpha, but also in those with IkappaBalpha mutations and lacking wild-type IkappaBalpha. Thus, both constitutive and inducible NF-kappaB are potential targets to treat HL. We also present the data that indicate the involvement of IkappaBbeta in NF-kappaB induction by topoisomerase inhibitors. A new NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ) inhibited constitutive NF-kappaB activity and induced apoptosis of H-RS cell lines. DHMEQ also inhibited the growth of H-RS cells without significant systemic toxicity in a NOD/SCID/gammac(null) (NOG) mice model. DHMEQ and topoisomerase inhibitors revealed enhancement of apoptosis of H-RS cells by blocking inducible NF-kappaB. Results of this study suggest that both constitutive and inducible NF-kappaB are molecular targets of DHMEQ in the treatment of HL. The results also indicate that IkappaBbeta is involved in NF-kappaB activation in H-RS cells and IkappaBbeta substitutes for IkappaBalpha in H-RS cells lacking wild-type IkappaBalpha.

[Successful radiotherapy for the thoracic cord infiltration of adult T-cell leukemia/lymphoma].

A-51-year-old woman with a sixteen-year history of mixed connective tissue disease was admitted to the Kitasato University Hospital because of hypogastric pain in September 1999. Colonofiberscopy and computed tomography in the abdomen demonstrated thickening of the intestinal wall with a hemorrhagic ulcer in the terminal ileum. The histopathologic findings of the lesion revealed diffuse infiltration of atypical T-lymphocytes. The titers of anti-HTLV-I antibody and serum soluble IL-2 receptor were elevated. The diagnosis of adult T-cell leukemia/lymphoma (ATLL) infiltrating the terminal ileum was made. Combination chemotherapy including VEPA-M was undertaken, and resulted in a partial response. ATLL became refractory about June 2000. Flaccid paralysis, dysesthesia in the left lower limb and bladder-bowel disturbance emerged in a few days, July 2000. T2-weighed MRCT images demonstrated that a lesion with a high intensity signal was present in the spinal cord around Th 7. Flower-like cells were detected in the cerebrospinal fluid. Infiltration of ATLL into the thoracic cord was diagnosed. Administration of intrathecal methotrexate and prednisolone, systemic dexamethasone and local irradiation of 30 Gy improved the paralysis and the abnormal MRCT findings. Rehabilitation restored the patient's ability to walk.

[Granulocytic sarcoma of the colon in chronic myelomonocytic leukemia].

A 59-year-old man with a six-month history of chronic myelomonocytic leukemia (CMML) was admitted to the Kitasato University Hospital because of melena in September 2000. Colonofiberscopy and barium enema demonstrated an ulcerated tumorous lesion in the transverse colon. The histopathologic findings of the ulcer bed revealed diffuse infiltration of granulocytes at each stage of differentiation. The diagnosis of granulocytic sarcoma (GS) was made. Surgical resection was not indicated, because thrombocytopenia was hardly improved enough to allow surgery despite repetitive transfusion of platelet concentrates. CMML developed to refractory anemia with excess of blast in transformation in February 2001. Two courses of low dose cytarabine plus aclarubicin were ineffective on the GS in spite of a decrease in the peripheral blood blasts. Progression to acute myeloid leukemia eventually broke out, in July 2001. The patient died of leukemia complicated with pneumonia and intestinal obstruction. At present, nine cases of GS in the colon have been reported. However, these cases did not include CMML. This is the first report describing GS in the colon associated with CMML.