Mechanosensitive hormone signaling promotes mammary progenitor expansion and breast cancer risk.

Tissue stem-progenitor cell frequency has been implicated in tumor risk and progression, but tissue-specific factors linking these associations remain ill-defined. We observed that stiff breast tissue from women with high mammographic density, who exhibit increased lifetime risk for breast cancer, associates with abundant stem-progenitor epithelial cells. Using genetically engineered mouse models of elevated integrin mechanosignaling and collagen density, syngeneic manipulations, and spheroid models, we determined that a stiff matrix and high mechanosignaling increase mammary epithelial stem-progenitor cell frequency and enhance tumor initiation in vivo. Augmented tissue mechanics expand stemness by potentiating extracellular signal-related kinase (ERK) activity to foster progesterone receptor-dependent RANK signaling. Consistently, we detected elevated phosphorylated ERK and progesterone receptors and increased levels of RANK signaling in stiff breast tissue from women with high mammographic density. The findings link fibrosis and mechanosignaling to stem-progenitor cell frequency and breast cancer risk and causally implicate epidermal growth factor receptor-ERK-dependent hormone signaling in this phenotype.

Genetic characterization of a novel organoid from human malignant giant-cell tumor.

Malignant giant-cell tumors are extremely rare bone sarcomas that transform from conventional giant-cell tumors during long periods of treatment. Owing to their rarity, no further analysis of their molecular pathogenesis exists, and thus, no standard treatment has been established. Recently, organoid culture methods have been highlighted for recapturing the tumor microenvironment, and we have applied the culture methods and succeeded in establishing patient-derived organoids (PDO) of rare sarcomas. This study aimed to investigate the genomic characteristics of our established novel organoids from human malignant giant-cell tumors. At our institute, we treated a patient with malignant giant-cell tumor. The remaining sarcoma specimens after surgical resection were cultured according to the air-liquid interface organoid-culture method. Organoids were xenografted into NOD-scid IL2Rgnull mice. The developed tumors were histologically and genomically analyzed to compare their characteristics with those of the original tumors. Genetic changes over time throughout treatment were analyzed, and the genomic status of the established organoid was confirmed. Organoids from malignant giant-cell tumors could be serially maintained using air-liquid interface organoid-culture methods. The tumors developed in xenografted NOD-scid IL2Rgnull mice. After several repetitions of the process, a patient-derived organoid line from the malignant giant-cell tumor was established. Immunohistochemical analyses and next-generation sequencing revealed that the established organoids lacked the H3-3A G34W mutation. The xenografted organoids of the malignant giant-cell tumor had phenotypes histologically and genetically similar to those of the original tumor. The established organoids were confirmed to be derived from human malignant giant-cell tumors. In summary, the present study demonstrated a novel organoid model of a malignant giant-cell tumor that was genetically confirmed to be a malignant transformed tumor. Our organoid model could be used to elucidate the molecular pathogenesis of a malignant giant-cell tumor and develop novel treatment modalities.

Establishment of Organoids From Human Epithelioid Sarcoma With the Air-Liquid Interface Organoid Cultures.

Background: Although biological resources are essential for basic and preclinical research in the oncological field, those of sarcoma are not sufficient for rapid development of the treatment. So far, some sarcoma cell lines have been established, however, the success rate was low and the established sarcoma types were frequently biased. Therefore, an efficient culture method is needed to determine the various types of sarcomas. Organoid culture is a 3-dimentional culture method that enables the recapitulation of the tumor microenvironment and the success rate reported is higher than the 2-dimentional culture. The purpose of this study was to report our newly established organoids from human epithelioid sarcoma using the air-liquid interface organoid culture method. Methods: We treated 2 patients with epithelioid sarcoma in our institute. The remaining sarcoma specimens after surgical resection were embedded in collagen type 1 gels according to the air-liquid interface organoid culture method. After serial passages, we xenografted the organoids to NOD-scid IL2Rgnull (NSG) mice. Using the developed tumors, we performed histological and genomic analyses to compare the similarities and differences with the original epithelioid sarcoma from the patient. Results: Organoids from the epithelioid sarcoma could be serially cultured and maintained in collagen type 1 gels for more than 3 passages. Developed orthotopic tumor xenografts were detected in the NSG mice. After the process was repeated severally, the patient derived organoid lines from the epithelioid sarcoma were established. The established organoids showed loss of integrase interactor 1 expression with polymerase chain reaction and immunohistochemical analyses. The xenografted organoids of the epithelioid sarcoma had histologically similar phenotypes with the original tumor and genetically resembled it to some degree. Conclusions: The present study demonstrated 2 novel established organoid models of epithelioid sarcoma, and our organoid models could be used to investigate the molecular pathogenesis and develop a novel treatment.

Lung fibrosis is a novel therapeutic target to suppress lung metastasis of osteosarcoma.

The prognosis of patients with metastatic and recurrent osteosarcoma has not improved over the last 30 years because no effective treatment strategy has been established for lung metastases. Although molecular-targeted drugs that modify the extracellular environment, such as antifibrotic agents, have been developed for cancer treatment, the suppressive effects of antifibrotic agents on osteosarcoma lung metastasis are unclear. Osteosarcomas need to adapt to considerable changes with respect to the stiffness of the environment and fibrosis during lung metastasis and may thus be vulnerable to fibrotic suppression as they originate at the site of a stiff bone with considerable fibrosis. In our study, we investigated whether fibrosis was a therapeutic target for suppressing osteosarcoma metastasis. Lung tissue samples from patients and a mouse model (LM8-Dunn model) showed that lung metastatic colonization of osteosarcoma cells proceeded with massive lung fibrosis. Metastatic osteosarcoma LM8 cells proliferated in a scaffold-dependent manner; the proliferation was less dependent on YAP-mediated mechanotransduction on soft polyacrylamide gels. The antifibrotic agents pirfenidone and nintedanib suppressed lung metastasis in the LM8-Dunn model. The osteosarcoma cells did not show increased proliferation, as reported in breast cancer, after continuous culture in a soft environment. We speculated that the antifibrotic agents were effective because the osteosarcoma cells remained scaffold-dependent in the soft tissue environment. Thus, antifibrotic strategies may be useful in suppressing lung metastasis of bone and soft tissue tumors with stiff primary sites such as those in osteosarcoma.

Molecular evidence of IGFBP-3 dependent and independent VD3 action and its nonlinear response on IGFBP-3 induction in prostate cancer cells.

BACKGROUND: Clinical trials have been conducted to clarify the beneficial effects of VD3 (1α,25-dihydroxy vitamin D3, also known as calcitriol) treatment in prostate cancer. However, the molecular mechanisms underlying these effects are not fully understood. Recent studies on IGFBP-3 have indicated its intracellular functions in cell growth and apoptosis. The aim of this study was to confirm the benefits of low-dose VD3 treatment and clarify the molecular mechanisms underlying these beneficial effects in prostate cancer cells. METHODS: The molecular effects of simultaneous treatment of LNCaP cells and their genetically modified cell lines with low concentration of docetaxel and VD3 were biologically and biochemically analyzed. To further determine the effects of VD3 treatment on IGFBP-3 induction system, cells were temporarily treated with VD3 in combination with a transcriptional inhibitor or protein synthesis inhibitor. Bcl-2 protein and its mRNA behavior were also observed in Igfbp-3 expression-modified LNCaP cells to determine the involvement of IGFBP-3 in the suppression of Bcl-2 by VD3 treatment. RESULTS: Changes in IGFBP-3 expression levels in LNCaP cells indicated that it mediated the inhibition of cell growth induced by VD3 treatment. IGFBP-3 was also found to be a mediator of the enhanced cytotoxicity of prostate cancer cells to VD3 in combination with the anti-cancer drug. We further identified the distinct property of the IGFBP-3 induction system, wherein temporal VD3 stimulation-induced prolonged IGFBP-3 expression and VD3 treatment-induced increase in IGFBP-3 expression were optimized based on the protein concentration rather than the mRNA concentration. Meanwhile, Bcl-2 expression was down-regulated by VD3 treatment in an IGFBP-3-independent manner. CONCLUSION: These findings indicate the molecular mechanisms of IGFBP-3 induction stimulated by VD3 and IGFBP-3 independent Bcl-2 suppression by VD3 treatment in prostate cancer cells. The results could prompt a re-evaluation of VD3 usage in therapy for patients with prostate cancer.

Low-dose eribulin reduces lung metastasis of osteosarcoma in vitro and in vivo.

Lung metastasis markedly reduces the prognosis of osteosarcoma. Moreover, there is no effective treatment for lung metastasis, and a new treatment strategy for the treatment of osteosarcoma lung metastasis is required. Therefore, in this study, we investigated the suppressive effect of the microtubule inhibitor eribulin mesylate (eribulin) on lung metastasis of osteosarcoma. At concentrations >proliferation IC50, eribulin induced cell cycle arrest and apoptosis in a metastatic osteosarcoma cell line, LM8. However, at concentrations

Evidence for intrathecal sodium butyrate as a novel option for leptomeningeal metastasis.

INTRODUCTION: The prognosis for leptomeningeal metastasis (LM) remains extremely poor regardless of intrathecal chemotherapy with various drugs, and thus, new treatments are necessary. Butyrate is an endogenous 4-carbon saturated fatty acid, has been investigated as an anti-tumor agent because of its multiple suppressive effects on several tumors. In this study, we investigated the cellular basis of sodium butyrate (SB), a sodium salt compound of butyrate, in vitro and evaluated the clinical potential of intrathecal SB administration for LM in vivo. METHODS: We examined SB's effects on Walker 256 rat mammary tumor cells with regard to cytotoxicity, cell morphology, colony formation, migration, and invasion. We also examined SB's neurotoxicity for primary neurons and primary astrocytes. We finally evaluated the potency of continuous intrathecal SB administration in rats with intrathecally transplanted breast tumors as an LM model. RESULTS: Physiological SB concentrations (2-4 mM) induced growth suppression, morphological changes, and inhibition of migration and invasion, but did not exhibit neurotoxic effects on primary neurons and astrocytes. Continuous intrathecal SB administration in a rat LM model significantly increased survival periods with little neurotoxicity. CONCLUSIONS: Continuous intrathecal SB administration significantly improved prognoses in a rat LM model, which suggests that SB is a promising therapy for LM.

Force engages vinculin and promotes tumor progression by enhancing PI3K activation of phosphatidylinositol (3,4,5)-triphosphate.

Extracellular matrix (ECM) stiffness induces focal adhesion assembly to drive malignant transformation and tumor metastasis. Nevertheless, how force alters focal adhesions to promote tumor progression remains unclear. Here, we explored the role of the focal adhesion protein vinculin, a force-activated mechanotransducer, in mammary epithelial tissue transformation and invasion. We found that ECM stiffness stabilizes the assembly of a vinculin-talin-actin scaffolding complex that facilitates PI3K-mediated phosphatidylinositol (3,4,5)-triphosphate phosphorylation. Using defined two- and three-dimensional matrices, a mouse model of mammary tumorigenesis with vinculin mutants, and a novel super resolution imaging approach, we established that ECM stiffness, per se, promotes the malignant progression of a mammary epithelium by activating and stabilizing vinculin and enhancing Akt signaling at focal adhesions. Our studies also revealed that vinculin strongly colocalizes with activated Akt at the invasive border of human breast tumors, where the ECM is stiffest, and we detected elevated mechanosignaling. Thus, ECM stiffness could induce tumor progression by promoting the assembly of signaling scaffolds, a conclusion underscored by the significant association we observed between highly expressed focal adhesion plaque proteins and malignant transformation across multiple types of solid cancer. See all articles in this Cancer Research section, "Physics in Cancer Research."

Tissue mechanics modulate microRNA-dependent PTEN expression to regulate malignant progression.

Tissue mechanics regulate development and homeostasis and are consistently modified in tumor progression. Nevertheless, the fundamental molecular mechanisms through which altered mechanics regulate tissue behavior and the clinical relevance of these changes remain unclear. We demonstrate that increased matrix stiffness modulates microRNA expression to drive tumor progression through integrin activation of ß-catenin and MYC. Specifically, in human and mouse tissue, increased matrix stiffness induced miR-18a to reduce levels of the tumor suppressor phosphatase and tensin homolog (PTEN), both directly and indirectly by decreasing levels of homeobox A9 (HOXA9). Clinically, extracellular matrix stiffness correlated directly and significantly with miR-18a expression in human breast tumor biopsies. miR-18a expression was highest in basal-like breast cancers in which PTEN and HOXA9 levels were lowest, and high miR-18a expression predicted poor prognosis in patients with luminal breast cancers. Our findings identify a mechanically regulated microRNA circuit that can promote malignancy and suggest potential prognostic roles for HOXA9 and miR-18a levels in stratifying patients with luminal breast cancers.

Dynamic analysis of lung metastasis by mouse osteosarcoma LM8: VEGF is a candidate for anti-metastasis therapy.

Osteosarcoma (OS) is the most common malignant bone tumor and the prognosis depends on pulmonary metastases, which arise from multi-step progression of malignant tumors. We herein aimed to clarify the critical step of pulmonary metastasis using the syngeneic mouse spontaneous highly metastatic OS LM8 and parental Dunn cell lines, to identify new candidate molecules to suppress pulmonary metastasis. We first investigated the chronological detection of circulating tumor cells (CTCs) from mice with either cell line. LM8 CTCs appeared faster, at a higher rate and with a greater number compared to Dunn CTCs. Cultured cells from CTCs of LM8 showed higher proliferative ability than cells from the primary site in suspension culture, which mimicked the environment of the bloodstream for CTCs. The proliferative ability of LM8 cells was also higher than that of Dunn cells in 3D collagen culture with low stiffness (-150 Pa; close to conditions in the lung). We next focused on the extravasation step. LM8 showed higher migration ability compared to Dunn with transendothelial migration assay. We also found a disruption in endothelial barrier function throughout co-culture with LM8 using time-lapse imaging. In addition, LM8 secreted high levels of vascular endothelial growth factor (VEGF), while VEGF signal inhibition with a small molecule tyrosine kinase inhibitor (pazopanib) decreased disruption of the vascular barrier and transendothelial migration of LM8. Finally, daily oral administration of pazopanib reduced the rate and size of pulmonary metastasis in vivo. Collectively, these results show anti-VEGF therapy as a candidate for pulmonary metastasis of OS.

Changes in cell migration of mesenchymal cells during osteogenic differentiation.

We showed that the migration, morphology and adhesiveness of undifferentiated mesenchymal cells dramatically changed during osteogenic differentiation. The migration of these cells was transiently upregulated early in osteogenic differentiation. At a later stage, migration was decreased but adhesiveness was increased. Furthermore, Cdc42 and Rac1 Rho-family small GTPases were activated at early stages of differentiation and the phosphorylation level of FAK decreased as differentiation progressed. We also showed cell migration was promoted by inhibition of the Rho-ROCK-myosin signaling. Finally, using a mouse model of ectopic bone formation, we confirmed that treatment with ROCK inhibitor, Y-27632 increased cell movement into bone formation sites, resulting in enhanced osteogenesis. These results provide a new insight into the link between cell migration and osteogenic differentiation.

Mesenchymal mode of migration participates in pulmonary metastasis of mouse osteosarcoma LM8.

The outcomes of osteosarcoma patients still remain poor because of intractable pulmonary metastasis. We previously established a highly metastatic osteosarcoma cell line, LM8 from Dunn mouse osteosarcoma by in vivo selection. We herein aimed to clarify the characteristic biological features related with high metastatic potential and new target molecules to suppress pulmonary metastasis of osteosarcoma, using this syngeneic spontaneous metastatic model. LM8 cells acquired fibroblastic morphology with striking filopodia on the cell surface. Immunostaining showed faint stress fiber formation and peripherally localized integrin ß1, and biochemical analyses showed the activated Cdc42 and autophosphorylation of focal adhesion kinase (FAK) in LM8 cells when compared to Dunn cells. LM8 cells had activated motility in single cell migration mode. LM8 migration was increased by a Rho-associated kinase (ROCK) inhibitor, Y-27632, while decreased by Cdc42 silencing using RNA interference system. We found that a clinically approved camptothecin analog, irinotecan suppressed the migration, Cdc42 activity, and autophosphorylation of FAK, and attenuated integrin ß1 distribution selectively in LM8 cells. Daily oral administration of irinotecan significantly reduced the rate and size of pulmonary metastasis in syngeneic C3H mice. The fibroblastic morphology and activated cell migration with the dependency on Cdc42 but not Rho-ROCK signaling pathway argued that LM8 moved in mesenchymal mode of cell migration. This activated mesenchymal migration was a key component of the pulmonary metastasis of LM8 cells. The inhibition of mesenchymal migration by irinotecan, in addition to its cytotoxic effects, might be effective in preventing pulmonary metastasis of osteosarcoma.

Prognostic significance of the BAALC isoform pattern and CEBPA mutations in pediatric acute myeloid leukemia with normal karyotype: a study by the Japanese Childhood AML Cooperative Study Group.

High BAALC (brain and acute leukemia, cytoplasmic) gene expression may indicate an adverse prognosis for adults who have acute myeloid leukemia (AML) and a normal karyotype, but its prognostic significance for pediatric AML cases is unclear. Whether different BAALC isoform patterns are of prognostic significance is also unclear. Newly diagnosed AML patients with normal karyotype who were treated by the Japanese Childhood AML Cooperative Treatment Protocol AML 99 were analyzed in terms of their BAALC expression levels (n = 29), BAALC isoforms (n = 29), and CEBPA mutations (n = 49). Eleven and 18 patients exhibited high and low BAALC expression, respectively, but these groups did not differ significantly in terms of overall survival (54.6 vs. 61.1%, P = 0.55) or event-free survival (61.4 vs. 50.0%, P = 0.82). Three of these 29 patients (10.3%) expressed the exon 1-5-6-8 BAALC isoform along with the expected 1-6-8 isoform and had adverse clinical outcomes. Novel CEBPA mutations were also identified in four of 49 patients (8.2%). All four patients have maintained complete remission for at least 5 years. Thus, 1-5-6-8 isoform expression may be associated with an adverse prognosis in pediatric AML with normal karyotype. CEBPA mutations may indicate a favorable prognosis.

Successful treatment of refractory donor lymphocyte infusion-induced immune-mediated pancytopenia with rituximab.

A 6-year-old male with chronic granulomatous disease, who was transplanted with bone marrow and exhibited increasing mixed chimerism, subsequently received two donor lymphocyte infusions (DLI). Two weeks after the second DLI, the patient developed acute graft-versus-host disease (GVHD) and progressive pancytopenia that was associated with autoantibody production. Conventional treatment did not improve the pancytopenia. However, administration of Rituximab (RTX) (375 mg/m(2)/week for four consecutive weeks) resulted in a rapid resolution of the pancytopenia. The patient achieved full donor chimerism without GVHD symptoms. RTX can be valuable for managing immune-mediated cytopenias that arise after DLI and are refractory to conventional therapies.

Granulocyte colony-stimulating factor protects cardiac mitochondria in the early phase of cardiac injury.

Although granulocyte colony-stimulating factor (G-CSF) reportedly plays a cardioprotective role in several models of cardiac injury, clinical use of this drug in cardiac patients has been controversial. Here, we tested, in vivo and in vitro, the effect of G-CSF on cardiac mitochondria, which play a key role in determining cardiac cellular fate and function. Mild stimulation of C57/BL6 mice with doxorubicin (Dox) did not induce cardiac apoptosis or fibrosis but did induce damage to mitochondrial organization of the myocardium as observed through an electron microscope. Cardiac catheterization and echocardiography revealed that Dox did not alter cardiac systolic function or left ventricular size but did reduce diastolic function, an early sign of cardiac damage. Treatment with G-CSF attenuated significantly the damage to mitochondrial organization and rescued diastolic function. In an in vitro model for rat neonatal cardiomyocytes, a subapoptotic dose of Dox induced severe mitochondrial damage, including marked swelling of the cardiac mitochondria and/or decreased mitochondrial membrane potential. These mitochondrial changes were completely blocked by pretreatment with G-CSF. In addition, G-CSF dramatically improved ATP generation, which rescued Dox-impaired mitochondrial electron transport and oxygen consumption mainly through complex IV. These findings clearly indicate that G-CSF protects cardiac mitochondria, which are key organelles in the determination of cardiac cellular fate, in the early phase of cardiac injury.

Involvement of extracellular signal-regulated kinase activation in human osteosarcoma cell resistance to the histone deacetylase inhibitor FK228 [(1S,4S,7Z,10S,16E,21R)-7-ethylidene-4,21-bis(propan-2-yl)-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone].

The histone deacetylase inhibitor depsipeptide [(1S,4S,7Z,10S, 16E,21R)-7-ethylidene-4,21-bis(propan-2-yl)-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8.7.6]tricos-16-ene-3,6,9,19, 22-pentone] (FK228) has attracted a great deal of interest because of its antiproliferative and apoptotic properties in various malignancies. Histone deacetylase inhibitors induce the expression of the multidrug resistance transporter P-glycoprotein (P-gp), and FK228 is a known P-gp substrate. Thus, FK228 seems to induce its own mechanism of drug resistance by up-regulating P-gp. The goal of this study was to establish human FK228-resistant osteosarcoma cell lines and to investigate whether there are mechanisms of FK228 resistance in addition to P-gp up-regulation. After 72 h in culture, the 50% inhibitory concentrations (IC(50)) of FK228 were 4.8 and 991 nM in HOS and HOS/FK8 cells, respectively, and 3.6 and 1420 nM in U2OS and U2OS/FK11 cells, respectively. Increased histone H3 acetylation was observed in FK228-resistant cell lines after a 1-h treatment with 10 nM FK228. Unlike in parental cells, significant P-gp overexpression was detected in FK228-resistant cells, and 10 nM FK228 treatment activated the mitogen-activated protein kinase (MAPK) pathway but did not induce Fas ligand (FasL) up-regulation or c-FLIP down-regulation. However, treatment of FK228-resistant cells with a combination of FK228 and mitogen-activated protein kinase kinase (MEK) inhibitors induced apoptosis, up-regulated FasL, and down-regulated c-FLIP. The expression and function of P-gp were unaltered by treatment with MEK inhibitors. These results indicate that the FK228 resistance of osteosarcoma cells is related to P-gp overexpression and MAPK pathway activation by FK228. MEK or P-gp inhibitors may be useful in overcoming this resistance.

Induction of autophagy in malignant rhabdoid tumor cells by the histone deacetylase inhibitor FK228 through AIF translocation.

Malignant rhabdoid tumors (MRT) exhibit a very poor prognosis because of their resistance to chemotherapeutic agents and new therapies are needed for the treatment of this cancer. Here, we show that the histone deacetylase (HDAC) inhibitor FK228 (depsipeptide) has an antitumor effect on MRT cells both in vitro and in vivo. FK228 is a unique cyclic peptide and is among the most potent inhibitors of both Class I and Class II HDACs. FK228 inhibited proliferation and induced apoptosis in all MRT cell lines tested. Preincubation with the pancaspase inhibitor zVAD-fmk did not completely rescue FK228-induced cell death, although it did inhibit apoptosis. Transmission electron microscopy (TEM) showed that FK228 could stimulate MRT cells to undergo apoptosis, necrosis or autophagy. FK228 converted unconjugated microtubule-associated protein light chain 3 (LC3-I) to conjugated light chain 3 (LC3-II) and induced localization of LC3 to autophagosomes. Apoptosis inducing factor (AIF), which plays a role in caspase-independent cell death, translocated to the nucleus in response to FK228 treatment. Moreover, small interfering RNA (siRNA) targeting of AIF prevented the morphological changes associated with autophagy and redistribution of LC3 to autophagosomes. Disrupting autophagy with chloroquine treatment enhanced FK228-induced cell death. In vivo, FK228 caused a reduction in tumor size and induced autophagy in tumor tissues. Using immunoelectron microscopy, we confirmed AIF translocation into the nucleus of FK228-induced autophagic cells in vivo. Thus, FK228 is a novel candidate for an antitumor agent for MRT cells.

Successful autologous peripheral blood stem cell transplantation with a double-conditioning regimen for recurrent hepatoblastoma after liver transplantation.

A four-yr-old boy developed a solitary metastasis nine months after living-related liver transplantation for unresectable hepatoblastoma. After resection of the metastatic lesion, he received an auto-PBSCT with a double-conditioning regimen consisting of melphalan and thiotepa. Auto-PBSCT could be safely performed without any serious regimen-related toxicity or infection. However, transient cessation of tacrolimus during myelosuppression resulted in graft rejection of the liver just after hematological engraftment, but rejection was resolved by tacrolimus and methylprednisolone. The patient is alive and free from disease two yr after auto-PBSCT without any signs of graft rejection. High-dose chemotherapy using this conditioning regimen may be feasible for recurrent hepatoblastoma after liver transplantation in terms of safety and anti-tumor activity.

[Continuous infusion of cyclosporine A and C3 monitoring in pediatric stem cell transplantation].

We performed an intravenous cyclosporine (CsA) drip infusion method for 3 hours and C3 monitoring in pediatric hematopoietic stem cell transplantation and examined the internal change and monitoring method of CsA. A total of six cases comprised five cord blood transplantations and one related allogeneic bone marrow transplantation. We started CsA 1.5 mg/kg at the day before transplantation by intravenous drip infusion (twice a day) for three hours. We controlled the dose so that the optimal peak value of C3 reached 800-1000 ng/ml. We recognized the C3 peak occurred three hours after initiation of infusion, and the blood CsA concentration was restored to the baseline value (C0) to (C12) 12 hours after that. We found a strong correlation between the C3 value (r = 0.90), and AUC(0-12). Two patients had grade II acute graft-versus-host disease (GVHD), but one needed no treatment, and the other recovered with short-term dosage of prednisolone. Apart from these instances, no serious complication occurred. In pediatric hematopoietic stem cell transplantation, it seems that regulation of the appropriate blood CsA concentration is enabled by using C3 monitoring at around 3 hours after commencing the intravenous drip infusion method for CsA.

A pediatric case of transfusion-related acute lung injury following bone marrow infusion.

TRALI is a rare but serious complication associated with transfusion, and known to occur following infusion of all types of plasma-containing blood products. However, only one adult case of TRALI after allogenic marrow graft has been reported. In this study, we present a pediatric case possibly associated with allogenic marrow infusion. A 10-yr-old girl was referred to our hospital for the treatment of acute myeloid leukemia. She underwent allogenic bone marrow transplantation from her HLA-2-loci-mismatched mother. During conditioning, she suffered from bacterial sepsis, but it had improved with antibiotics until day 0 of transplantation. Two h after starting the marrow infusion, she developed severe hypoxia. We discontinued the infusion and started steroids, which improved her respiratory condition. However, she developed respiratory failure again after resuming infusion of the graft. Despite intensive care with mechanical ventilation, the patient died of endotoxin shock five days after transplantation. Although we could not identify the antibody which might have been involved in the respiratory distress, the clear temporal relationship between marrow infusion and respiratory distress suggested that similar acute lung injury to TRALI might have occurred following allogenic marrow infusion in the present case.