Busulfan for lymphoma with CNS involvement

The prognosis of relapsed or refractory lymphoma with central nervous system (CNS) involvement remains poor because of the lack of anticancer drugs with sufficient CNS penetration. [Case 1] A 65-year-old man was diagnosed with Stage IV mantle cell lymphoma. After two courses of chemotherapy and autologous hematopoietic stem cell (HSC) collection, urinary retention with fever developed. Cerebrospinal fluid analysis revealed leptomeningeal involvement, which was refractory to high-dose methotrexate therapy. Autologous peripheral blood stem cell transplantation (ASCT) was performed, followed by intravenous busulfan (ivBU), cyclophosphamide, and etoposide ; thereafter, no relapse has been detected for over six years. [Case 2] A 40-year-old woman with right lower hemiplegia was diagnosed with primary CNS lymphoma. Although four courses of high-dose methotrexate therapy were administered, the cerebral tumor increased in size. HSCs were collected after methotrexate therapy, and ASCT was performed in addition to conditioning using ivBU, cyclophosphamide, and etoposide, followed by whole-brain and local boost irradiation. She achieved complete remission, but relapsed two years after ASCT. High-dose ivBU-containing conditioning regimens with ASCT may be useful for refractory B-cell lymphoma with CNS involvement

Novel antimyeloma therapeutic option with inhibition of the HDAC1-IRF4 axis and PIM kinase

Multiple myeloma (MM) preferentially expands and acquires drug resistance in the bone marrow (BM). We herein examined the role of histone deacetylase 1 (HDAC1) in the constitutive activation of the master transcription factor IRF4 and the prosurvival mediator PIM2 kinase in MM cells. The knockdown or inhibition of HDAC1 by the class I HDAC inhibitor MS-275 reduced the basal expression of IRF4 and PIM2 in MM cells. Mechanistically, the inhibition of HDAC1 decreased IRF4 transcription through histone hyperacetylation and inhibiting the recruitment of RNA polymerase II at the IRF4 locus, thereby reducing IRF4-targeting genes, including PIM2. In addition to the transcriptional regulation of PIM2 by the HDAC1-IRF4 axis, PIM2 was markedly upregulated by external stimuli from BM stromal cells and interleukin-6 (IL-6). Upregulated PIM2 contributed to the attenuation of the cytotoxic effects of MS-275. Class I HDAC and PIM kinase inhibitors cooperatively suppressed MM cell growth in the presence of IL-6 and in vivo. Therefore, the present results demonstrate the potential of the simultaneous targeting of the intrinsic HDAC1-IRF4 axis plus externally activated PIM2 as an efficient therapeutic option for MM fostered in the BM

TAK1 inhibition in myeloma

Along with the tumor progression, the bone marrow microenvironment is skewed in multiple myeloma (MM), which underlies the unique pathophysiology of MM and confers aggressiveness and drug resistance in MM cells. TGF-β-activated kinase-1 (TAK1) mediates a wide range of intracellular signaling pathways. We demonstrate here that TAK1 is constitutively overexpressed and phosphorylated in MM cells, and that TAK1 inhibition suppresses the activation of NF-κB, p38MAPK, ERK and STAT3 in order to decrease the expression of critical mediators for MM growth and survival, including PIM2, MYC, Mcl-1, IRF4, and Sp1, along with a substantial reduction in the angiogenic factor VEGF in MM cells. Intriguingly, TAK1 phosphorylation was also induced along with upregulation of vascular cell adhesion molecule-1 (VCAM-1) in bone marrow stromal cells (BMSC) in cocultures with MM cells, which facilitated MM cell-BMSC adhesion while inducing IL-6 production and receptor activator of nuclear factor κ-Β ligand (RANKL) expression by BMSC. TAK1 inhibition effectively impaired MM cell adhesion to BMSC to disrupt the support of MM cell growth and survival by BMSC. Furthermore, TAK1 inhibition suppressed osteoclastogenesis enhanced by RANKL in cocultures of bone marrow cells with MM cells, and restored osteoblastic differentiation suppressed by MM cells or inhibitory factors for osteoblastogenesis overproduced in MM. Finally, treatment with the TAK1 inhibitor LLZ1640-2 markedly suppressed MM tumor growth and prevented bone destruction and loss in mouse MM models. Therefore, TAK1 inhibition may be a promising therapeutic option targeting not only MM cells but also the skewed bone marrow microenvironment in MM

キサンチンオキシダーゼ阻害薬febuxostatはNrf2を活性化し脂肪細胞分化を抑制する

Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in purine catabolism that acts as a novel regulator of adipogenesis. In pathological states, xanthine oxidoreductase activity increases to produce excess reactive oxygen species (ROS). The nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical inducer of antioxidants, which is bound and repressed by a kelch-like ECH-associated protein 1 (Keap1) in the cytoplasm. The Keap1-Nrf2 axis appears to be a major mechanism for robust inducible antioxidant defenses. Here, we demonstrate that febuxostat, a xanthine oxidase inhibitor, alleviates the increase in adipose tissue mass in obese mouse models with a high-fat diet or ovariectomy. Febuxostat disrupts in vitro adipocytic differentiation in adipogenic media. Adipocytes appeared at day 7 in absence or presence of febuxostat were 160.8 ± 21.2 vs. 52.5 ± 12.7 (p < 0.01) in 3T3–L1 cells, and 126.0 ± 18.7 vs. 55.3 ± 13.4 (p < 0.01) in 10T1/2 cells, respectively. Adipocyte differentiation was further enhanced by the addition of hydrogen peroxide, which was also suppressed by febuxostat. Interestingly, febuxostat, but not allopurinol (another xanthine oxidase inhibitor), rapidly induced the nuclear translocation of Nrf2 and facilitated the degradation of Keap1, similar to the electrophilic Nrf2 activator omaveloxolone. These results suggest that febuxostat alleviates adipogenesis under oxidative conditions, at least in part by suppressing ROS production and Nrf2 activation. Regulation of adipocytic differentiation by febuxostat is expected to inhibit obesity due to menopause or overeating

臍帯血移植が奏効した肝脾型T細胞リンパ腫

Cord blood for transplant is collected from the umbilical cord and donated cord blood is tested, frozen and stored for future use. Cord blood stem cell transplantation（CBT）do not have to be as closely matched as bone marrow or peripheral blood stem cell transplantations, therefore we are able to perform CBT for refractory patients at optimal timing. Here, we report a ３３ years old woman with refractory hepatosplenic T-cell lymphoma（HSTL）who achieved complete response ; CR after unrelated CBT. She complained of fever and abdominal pain, she was diagnosed with HSTL. She was refractory to several chemotherapy regimens, we planned to allogenic transplantation for her. However, she had no HLA-matched sibling donors and we were not able to find favorable unrelated donors from Japan Marrow Donor Program. Therefore, we decided to perform CBT for her. We used fludarabine（１８０mg/m2）, busulfan（１２．８mg/kg）and melphalan（８０mg/m2） as conditioning regimens and we chose tacrolimus and MMF for graft versus host disease（GVHD） prophylaxis. On day ２２ after transplantation, her neutrophil count engrafted, she suffered from acute GVHD（skin, gastrointestinal tract, grade２）, she was improved by medical treatment. She achieved CR her disease status maintained over two years after CBT. HSTL is often refractory to chemotherapy, the clinical efficacy of hematopoietic stem cell transplantation may be expected. Our case suggests that CBT may be effective and feasible option for refractory HSTL who has no favorable HLA-matched donors

LL-Z1640-2 for rheumatoid arthritis

Objectives: Aberrant NLRP3 inflammasome activation has been demonstrated in rheumatoid arthritis (RA), which may contribute to debilitating inflammation and bone destruction. Here, we explored the efficacy of the potent TGF-β-activated kinase-1 (TAK1) inhibitor LL-Z1640-2 (LLZ) on joint inflammation and bone destruction in collagen-induced arthritis (CIA). Methods: LL-Z1640-2 was administered every other day in CIA mice. Clinical and histological evaluation was performed. Priming and activation of NLRP3 inflammasome and osteoclastogenic activity were assessed. Results: NLRP3 inflammasome formation was observed in synovial macrophages and osteoclasts (OCs) in CIA mice. TACE and RANKL were also overexpressed in synovial macrophages and fibroblasts, respectively, in the CIA joints. Treatment with LLZ mitigated all the above changes. As a result, LLZ markedly suppressed synovial hypertrophy and pannus formation to alleviate pain and inflammation in CIA mice. LLZ could block the priming and activation of NLRP3 inflammasome in RAW264.7 macrophage cell line, primary bone marrow macrophages and OCs upon treatment with LPS followed by ATP, thereby suppressing their IL-1β production. LLZ also suppressed LPS-induced production of TACE and TNF-α in bone marrow macrophages and abolished IL-1β-induced production of MMP-3, IL-6 and RANKL in synovial fibroblasts. In addition, LLZ directly inhibits RANKL-mediated OC formation and activation. Conclusion: TAK1 inhibition with LLZ may become a novel treatment strategy to effectively alleviate inflammasome-mediated inflammation and RANKL-induced osteoclastic bone destruction in joints alongside its potent suppression of TNF-α and IL-6 production and proteinase-mediated pathological processes in RA

RANKLが誘導する破骨細胞分化におけるROSの役割と、Febuxostatによる破骨細胞分化抑制効果

Receptor activator of NF-κB ligand (RANKL), a critical mediator of osteoclastogenesis, is upregulated in multiple myeloma (MM). The xanthine oxidase inhibitor febuxostat, clinically used for prevention of tumor lysis syndrome, has been demonstrated to effectively inhibit not only the generation of uric acid but also the formation of reactive oxygen species (ROS). ROS has been demonstrated to mediate RANKL-mediated osteoclastogenesis. In the present study, we therefore explored the role of cancer-treatment-induced ROS in RANKL-mediated osteoclastogenesis and the suppressive effects of febuxostat on ROS generation and osteoclastogenesis. RANKL dose-dependently induced ROS production in RAW264.7 preosteoclastic cells; however, febuxostat inhibited the RANKL-induced ROS production and osteoclast (OC) formation. Interestingly, doxorubicin (Dox) further enhanced RANKL-induced osteoclastogenesis through upregulation of ROS production, which was mostly abolished by addition of febuxostat. Febuxostat also inhibited osteoclastogenesis enhanced in cocultures of bone marrow cells with MM cells. Importantly, febuxostat rather suppressed MM cell viability and did not compromise Dox’s anti-MM activity. In addition, febuxostat was able to alleviate pathological osteoclastic activity and bone loss in ovariectomized mice. Collectively, these results suggest that excessive ROS production by aberrant RANKL overexpression and/or anticancer treatment disadvantageously impacts bone, and that febuxostat can prevent the ROS-mediated osteoclastic bone damage

同種移植後のHBV再活性化の後方視的検討

Reactivation of hepatitis B has been recognized as a careful adverse event after chemotherapies or immunosuppressive therapies because chronic hepatitis B leads to carcinoma and/or liver cirrhosis. Allogenic hematopoietic stem cell transplantation（allo-HSCT）against hematological diseases induces severe immunosuppression including reconstitution of naïve donor immunity against HBV-infected hepatocytes and we therefore need to follow-up HBV testing for a long term. In order to establish how to follow-up HBV-infected patients with receiving allo-HSCT, we retrospectively studied HBV serological markers and HBV-DNA in the HBV-infected patients, who received allo-HSCT and followed-up more than １ year in our single center. We detected ７ HBV-infected and allo-HSCT-received patients, and HBV reactivation was occurred in ３ patients with detecting HBV-DNA. No patients were died due to HBV reactivation. The HBV reactivation period after receiving allo-HSCT was １６，２０，７９ months, respectively. All the ３ patients received nucleoside analogues（NUCs）; however, the appearance of viral mutation was occurred in one patient who received lamivudine and already detected HBs-Ag before allo-HSCT. The HBV reactivation was controlled with addition of adefovir. Others were due to discontinuation of entecavir, which reason was poor medication-adherence after stopping immunosuppressive therapies. These two patients received tenofovir alafenamide in addition or retreated with entecavir, respectively, leading to disappearing of HBV-DNA. HBs-Ab were disappeared in ３１ months after allo-HSCT in one patient, and then the Ab was detected after occurring HBV reactivation, suggesting reconstitution of donor immunity. Taken together, our findings suggest that we need to follow-up immune-reconstitution and regularly evaluate HBV serological markers and HBV-DNA, in addition to maintain medication-adherence