Naotaka Hayasaka

Activated p53 with Histone Deacetylase Inhibitor Enhances L-Fucose-Mediated Drug Delivery through Induction of Fucosyltransferase 8 Expression in Hepatocellular Carcinoma Cells.

Background The prognosis of advanced hepatocellular carcinoma (HCC) is dismal, underscoring the need for novel effective treatments. The α1,6-fucosyltransferase (fucosyltransferase 8, FUT8) has been reported to accelerate malignant potential in HCC. Our study aimed to investigate the regulation of FUT8 expression by p53 and develop a novel therapeutic strategy for targeting HCC cells using L-fucose-mediated drug delivery. Methods Binding sites for p53 were searched for within the FUT8 promoter region. FUT8 expression was assessed by immunoblotting. Chromatin immunoprecipitation (ChIP) assays were performed to analyze p53 binding to the FUT8 promoter. The delivery of Cy5.5-encapsulated L-fucose-liposomes (Fuc-Lip-Cy5.5) to a Lens Culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3)-expressing HCC cells was analyzed by flow cytometry. The induction of FUT8 by histone deacetylase inhibitor (HDACi) -inducing acetylated -p53 was evaluated by immunoblotting. Flow cytometric analysis was performed to assess whether the activation of p53 by HDACi affected the uptake of Fuc-Lip-Cy5.5 by HCC cells. The cytotoxicity of an L-fucose-bound liposome carrying sorafenib (Fuc-Lip-sorafenib) with HDACi was assessed in vivo and in vitro. Results The knock down of p53 with siRNA led to decreased FUT8 expression. ChIP assays revealed p53 binds to the FUT8 promoter region. Flow cytometric analyses demonstrated the specific uptake of Fuc-Lip-Cy5.5 into AFP-L3-expressing HCC cells in a p53- and FUT8-dependent manner. HDACi upregulated the uptake of Fuc-Lip-Cy5.5 by HCC cells by increasing FUT8 via acetylated -p53. The addition of a HDACi increased apoptosis induced by Fuc-Lip-sorafenib in HCC cells. Conclusions Our findings reveal that FUT8 is a p53 target gene and suggest that p53 activated by HDACi induces Fuc-Lip-sorafenib uptake by HCC cells, highlighting this pathway as a promising therapeutic intervention for HCC.

The iron chelator deferasirox induces apoptosis by targeting oncogenic Pyk2/β-catenin signaling in human multiple myeloma

Deregulated iron metabolism underlies the pathogenesis of many human cancers. Recently, low expression of ferroportin, which is the only identified non-heme iron exporter, has been associated with significantly reduced overall survival in multiple myeloma (MM); however, the altered iron metabolism in MM biology remains unclear. In this study we demonstrated, by live cell imaging, that MM cells have increased intracellular iron levels as compared with normal cells. In experiments to test the effect of iron chelation on the growth of MM cells, we found that deferasirox (DFX), an oral iron chelator used to treat iron overload in clinical practice, inhibits MM cell growth both in vivo and in vitro. Mechanistically, DFX was found to induce apoptosis of MM cells via the inhibition of proline-rich tyrosine kinase 2 (Pyk2), which is known to promote tumor growth in MM. Inhibition of Pyk2 is caused by the suppression of reactive oxygen species, and leads to downregulation of the Wnt/β-catenin signaling pathway. Taken together, our findings indicate that high levels of intracellular iron, which might be due to low ferroportin expression, play a role in MM pathophysiology. Therefore, DFX may provide a therapeutic option for MM that is driven by deregulated iron homeostasis and/or Pyk2/Wnt signaling.

Anti-erythropoietin receptor antibody-associated pure red cell aplasia accompanied by Coombs-negative autoimmune hemolytic anemia in a patient with T cell/histiocyte-rich large B cell lymphoma

A 79-year-old female diagnosed with T cell/histiocyte-rich large B cell lymphoma in complete remission after six cycles of rituximab-combined chemotherapy developed severe anemia, reticulocytopenia, and bone marrow erythroid hypoplasia. She was diagnosed with pure red cell aplasia (PRCA) accompanied by Coombs-negative autoimmune hemolytic anemia evidenced by a lack of glycophorin-A-positive cells in the bone marrow, haptoglobin under the detection level, and a high titer of RBC-bound IgG. Anti-erythropoietin receptor (EPOR) antibody was detected in the serum, and oligoclonal α/β and γ/δ T cells were also detected in her peripheral blood by Southern blotting analysis. Parvovirus B19 DNA was not detected by PCR. Although the treatment with rituximab had limited efficacy (specifically, only for hemolysis), subsequent cyclosporine therapy led to prompt recovery of erythropoiesis with the disappearance of anti-EPOR antibody and oligoclonal T cells. This is the first case report of anti-EPOR antibody-associated PRCA in a patient with malignant lymphoma treated successfully with cyclosporine.

Small molecule CP-31398 induces reactive oxygen species-dependent apoptosis in human multiple myeloma

Reactive oxygen species (ROS) are normal byproducts of a wide variety of cellular processes. ROS have dual functional roles in cancer cell pathophysiology. At low to moderate levels, ROS act as signaling transducers to activate cell proliferation, migration, invasion, and angiogenesis. In contrast, high levels of ROS induce cell death. In multiple myeloma (MM), ROS overproduction is the trigger for apoptosis induced by several anticancer compounds, including proteasome inhibitors. However, no drugs for which oxidative stress is the main mechanism of action are currently used for treatment of MM in clinical situations. In this study, we demonstrate that the p53-activating small molecule CP-31398 (CP) effectively inhibits the growth of MM cell lines and primary MM isolates from patients. CP also suppresses the growth of MM xenografts in mice. Mechanistically, CP was found to induce intrinsic apoptosis in MM cells via increasing ROS production. Interestingly, CP-induced apoptosis occurs regardless of the p53 status, suggesting that CP has additional mechanisms of action. Our findings thus indicate that CP could be an attractive candidate for treatment of MM patients harboring p53 abnormalities; this satisfies an unmet clinical need, as such individuals currently have a poor prognosis.Reactive oxygen species (ROS) are normal byproducts of a wide variety of cellular processes. ROS have dual functional roles in cancer cell pathophysiology. At low to moderate levels, ROS act as signaling transducers to activate cell proliferation, migration, invasion, and angiogenesis. In contrast, high levels of ROS induce cell death. In multiple myeloma (MM), ROS overproduction is the trigger for apoptosis induced by several anticancer compounds, including proteasome inhibitors. However, no drugs for which oxidative stress is the main mechanism of action are currently used for treatment of MM in clinical situations. In this study, we demonstrate that the p53-activating small molecule CP-31398 (CP) effectively inhibits the growth of MM cell lines and primary MM isolates from patients. CP also suppresses the growth of MM xenografts in mice. Mechanistically, CP was found to induce intrinsic apoptosis in MM cells via increasing ROS production. Interestingly, CP-induced apoptosis occurs regardless of the p53 status, suggesting that CP has additional mechanisms of action. Our findings thus indicate that CP could be an attractive candidate for treatment of MM patients harboring p53 abnormalities; this satisfies an unmet clinical need, as such individuals currently have a poor prognosis.

Thrombocytopenia and Anemia with Anti-c-Mpl antibodies Effectively Treated with Cyclosporine in a Patient with Rheumatoid Arthritis and Chronic Renal Failure.

A 61-year-old woman with rheumatoid arthritis who was undergoing hemodialysis for end-stage renal failure was transferred to our hospital due to severe thrombocytopenia and anemia. A bone marrow biopsy showed the complete absence of megakaryocytes and erythroblasts. Cyclosporine treatment resulted in the improvement of her megakaryocyte and erythroblast levels, and a decrease in her serum level of anti-c-Mpl (thrombopoietin receptor) antibodies. After this initial improvement, her anemia progressively worsened, despite the continuous administration of immunosuppressive therapy with cyclosporine. Her platelet and leukocyte counts remained stable. This is the first report of a probable case of anti-c-Mpl antibody-associated pure red cell aplasia and acquired amegakaryocytic thrombocytopenic purpura.

Neoadjuvant chemotherapy with docetaxel, nedaplatin, and fluorouracil for resectable esophageal cancer: A phase II study

Cisplatin plus 5‐fluorouracil is regarded as standard neoadjuvant chemotherapy for esophageal squamous cell carcinoma (ESCC) in Japan, but the prognosis remains poor. We have previously described how definitive chemoradiotherapy with docetaxel, nedaplatin, and 5‐fluorouracil (DNF) led to a very high response rate and promising survival times. We therefore undertook a phase II trial to evaluate the feasibility and efficacy of neoadjuvant DNF. The study included patients with clinical stage Ib‐III ESCC. Chemotherapy consisted of i.v. docetaxel (30 mg/m2) and nedaplatin (50 mg/m2) on days 1 and 8, and a continuous infusion of 5‐fluorouracil (400 mg/m2/day) on days 1‐5 and 8‐12, every 3 weeks. After three courses of chemotherapy, esophagectomy was carried out. The primary end‐point was the completion rate of the protocol treatment. Twenty‐eight patients were enrolled (cStage Ib/II/III, 2/3/23) and all received at least two cycles of chemotherapy. Twenty‐five patients underwent surgery, all of whom achieved an R0 resection, leading to a completion rate of 89.3%. The overall response rate was 87.0%. A pathological complete response was confirmed in eight (32.0%) cases. Grade 3/4 adverse events included leukopenia (32.1%), neutropenia (39.3%), febrile neutropenia (10.7%), thrombocytopenia (10.7%), and diarrhea (14.3%), but were manageable. Treatment‐related deaths and major surgical complications did not occur. Estimated 2‐year progression‐free and overall survival rates were 70.4% and 77.2%, respectively. Thus, DNF therapy was well tolerated and deemed feasible, with a strong tumor response in a neoadjuvant setting for ESCC. This trial is registered with the University Hospital Medical Information Network (UMIN ID: 000014305).

Abstract 2112: FoxO3a activation by HDAC class IIa inhibition induces cell cycle arrest in pancreatic cancer cells

Pancreatic cancer is highly chemo-resistant associated with oncogenic mutations such as KRAS and/or p53. The effect of conventional chemotherapy is not sufficient and new target and strategy is urgently needed. The forkhead box (Fox) proteins are multidirectional transcriptional factors strongly implicated in malignancies. Although Fox O (FoxO) protein, and particularly FoxO3a, works as negative regulator of cell proliferation by repressing cyclin proteins and inducing cell cycle inhibitors such as p21Waf1/Cip1, its expression is consistently suppressed by several oncogenic pathways including phosphatidylinositol-3 kinase (PI3K) / AKT pathway, constitutively activated in pancreatic cancer. Thus, upregulating FoxO3a activity could be a promising target of pancreatic cancer treatment without impact of underlying oncogenic mutations. Class IIa Histone deacetylase (HDAC) is a subgroup of HDAC. Though HDAC inhibitors (HDACi) have been extensively investigated as a cancer target, its action mechanism is considered due to histone modification by class I. Biological significance of class IIa HDACs which have minimal histone deacetylation activity have not been elucidated yet. Recent studies show class IIa HDACs act as a transcriptional regulator including FoxO3a. In this study, we investigate the biologic impact of HDAC class IIa inhibition on FoxO3a and anti-tumor effect against pancreatic cancer cell line using selective class IIa HDACi TMP269. TMP269 treatment showed increased FoxO3a expression in a dose dependent manner with immunoblotting and modest cell growth inhibition effect at 57.5 μM of IC50 dose for 48-hour treatment against AsPC-1 in MTT. G1/S arrest was observed with cell cycle assay. Upregulated p21Waf1/Cip1 and downregulated CDK2 and 4/6 and cyclin D1 and D2 expressions were further observed, consistent with inducing G1/S arrest and transcriptionally activated FoxO3a. Importantly, upregulated p21Waf1/Cip1 was observed in AsPC-1 p53 null cell line, suggesting independent with p53 pathway. These findings suggest upregulated FoxO3a induced by HDAC class IIa inhibition activated its transcription and resulted in cell growth inhibition. Because PI3K/AKT leads FoxO3a to the ubiquitylation-mediated proteasome degradation, we examined irreversible proteasome inhibitor carfilzomib (CFZ) combined with TMP269, aiming synergistic FoxO3a upregulating. As expected, FoxO3a expression was further increased in TMP269 combined with CFZ compared with TMP269 or CFZ alone. Following the activated FoxO3a, p21Waf1/Cip1 expression was upregulated and cell growth inhibition was dramatically enhanced. In conclusion, HDAC class IIa inhibition modified FoxO3a transcriptional activation and upregulating FoxO3 by dual inhibition of HDAC class IIa and proteasome is promising target against pancreas cancer. Citation Format: Makoto Usami, Shohei Kikuchi, Kohichi Takada, Yusuke Sugama, Yohei Arihara, Naotaka Hayasaka, Hajime Nakamura, Yuki Ikeda, Yusuke Kamihara, Masahiro Hirakawa, Makoto Yoshida, Masayoshi Kobune, Koji Miyanishi, Junji Kato. FoxO3a activation by HDAC class IIa inhibition induces cell cycle arrest in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2112. doi:10.1158/1538-7445.AM2017-2112

[Successful treatment with dose-adjusted EPOCH-R for triple-hit lymphoma having BCL2, BCL6 and MYC translocations].

Double- and triple-hit lymphomas (DHL/THL), high-grade B-cell lymphomas with an extremely poor prognosis, are defined by a chromosomal breakpoint affecting the MYC/8q24 locus in combination with another recurrent breakpoint. The successful use of dose-adjusted (DA) EPOCH-R in patients with MYC-positive lymphoma and Burkitt lymphoma (BL) was recently reported. A 74-year-old man with acute renal dysfunction and hyperkalemia was transferred to our emergency center by ambulance. PET-CT revealed a left renal hilar mass enveloping the abdominal para-aortic domain and bladder and hydronephrosis. High (18)F-FDG uptake revealed lymph node, peritoneum, and multiple bone metastases. Analysis of the bone marrow aspirate revealed abnormal lymphoid cells with deeply basophilic cytoplasm and numerous vacuoles resembling Burkitt cells. Chromosomal analysis revealed a complex chromosomal karyotype, including t(14;18)(q32;q21), and FISH analysis confirmed split BCL2, BCL6, and MYC signals. Bone marrow biopsy revealed diffusely infiltrating large abnormal lymphoid cells with a CD10⁺, CD20⁺, BCL2⁺, BCL6⁺, c-MYC⁺ and MUM1(-) immunophenotype. B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma and BL, was diagnosed. The patient achieved a partial response after eight courses of DA-EPOCH-R chemotherapy. Our experience suggests that DA-EPOCH-R may be an effective treatment for DHL/THL.