Loss of CD26 protease activity in recipient mice during hematopoietic stem cell transplantation results in improved transplant efficiency.

BACKGROUND: A firm understanding of the biology of hematopoietic stem and progenitor cell (HSC/HPC) trafficking is critical to improve transplant efficiency and immune reconstitution during hematopoietic stem cell transplantation (HSCT). Our earlier findings suggested that suppression of CD26 (dipeptidyl peptidase IV) proteolytic activity in the donor cell population can be utilized as a method for increasing transplant efficiency. However, factors in the recipient should not be overlooked, given the potential for the bone marrow (BM) microenvironment to regulate HSCT. STUDY DESIGN AND METHODS: We first evaluated CD26 expression and then investigated the effects of the CD26 inhibitor diprotin A and the absence of CD26 (CD26-/-) in recipient mice on HSC/HPC homing and engraftment using an in vivo congenic mouse model of HSCT. RESULTS: A significant increase in donor cell engraftment into the peripheral blood (PB), and to a lesser extent homing into the BM, was observed in CD26-/- mice or CD26 inhibitor-treated mice. Increased PB engraftment of CD26-/- mice was significant at 3 and 6 months, but not 1 month, after transplant. It was noted that the increased homing was statistically greater with donor cell manipulation (CD26-/- donor cells) than with recipient manipulation (CD26-/- recipient mice). Conversely, donor and recipient manipulation both worked well to increase PB engraftment at 6 months. CONCLUSION: These results provide preclinical evidence of CD26, in the HSCT recipient, as a major regulator of HSC/HPC engraftment with minor effects on HSC/HPC homing and suggest the potential use of CD26 inhibitors in HSCT patients to improve transplant efficiency.

Single nucleotide polymorphism array-based karyotyping in acute myeloid leukemia or myelodysplastic syndrome with trisomy 8 as the sole chromosomal abnormality.

The clinical heterogeneity of patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) with trisomy 8 as the sole abnormality may result from cytogenetically undetectable genetic changes. The purpose of this study was to identify hidden genomic aberrations not detected by metaphase cytogenetics (MC) using high-resolution single nucleotide polymorphism array (SNP-A)-based karyotyping in AML/MDS patients with a sole trisomy 8. The study group included 8 patients (3 AML and 5 MDS) and array-based karyotyping was done using whole-genome SNP-A (SNP 6.0 and SNP 2.7M). By SNP-A, additional genomic aberrations not detected by MC were identified in 2 patients: 1 AML patient exhibited a copy-neutral loss of heterozygosity (CN-LOH) of 3q21.1-q29 and 11q13.1-q25 and the other patient with MDS (refractory cytopenia with unilineage dysplasia) had CN-LOH of 2p25.3-p15. In particular, the latter patient progressed to AML 18 months after the diagnosis. In 3 patients, aberrations in addition to trisomy 8 were not identified by SNP-A. In the remaining 3 patients, SNP-A could not detect trisomy 8, while trisomy 8 was found in 25-67% of metaphase cells by MC. This study suggests that additional genomic aberrations may in fact be present even in cases of trisomy 8 as sole abnormality by MC, and SNP-A could be a useful karyotyping tool to identify hidden aberrations such as CN-LOH.

Sequential vincristine, adriamycin, dexamethasone (VAD) followed by bortezomib, thalidomide, dexamethasone (VTD) as induction, followed by high-dose therapy with autologous stem cell transplant and consolidation therapy with bortezomib for newly diagnosed multiple myeloma: results of a phase II trial.

Incorporation of novel agents has resulted in an improved response rate and reduced side effects in multiple myeloma. This has prompted combining novel agents in induction chemotherapy in patients with newly diagnosed multiple myeloma. Our patients received 2 cycles of vincristine, adriamycin, dexamethasone (VAD) and then 2 cycles of bortezomib, thalidomide, dexamethasone (VTD) chemotherapy as an induction treatment. Subsequently, autologous stem cell transplantation was performed, and bortezomib was administered as a consolidation therapy. Seventy-one patients were enrolled, and 65 were evaluable for response. After 2 cycles of VAD, the overall response rate was 69%. After VTD, the response rate improved to 97% with a complete response (CR) and near CR rate of 27%. Importantly, patients with cytogenetics, having poor prognostic features, all responded after VTD. Autologous stem cells were successfully collected in all 58 patients with a median CD34+ cell count of 7.12 × 10(6)/kg (range, 1.94-44.7 × 10(6)/kg), except in 1 patient (2%). After ASCT, 36 patients completed bortezomib maintenance with a combined CR and near CR rate approaching 75%. Median time to response was rapid (1.6 months). With a median follow-up duration of 52.7 months, the median TTP was 29.4 months and median OS was not reached. Toxicities proved manageable. In conclusion, sequential VAD and VTD induction therapy in patients with newly diagnosed multiple myeloma was active with manageable toxicity and excellent stem cell yields. The incorporation of bortezomib as a consolidation therapy improved the clinical outcome with the expense of rather frequent development of peripheral neuropathy.

Proinflammatory cytokine IL-1beta stimulates IL-8 synthesis in mast cells via a leukotriene B4 receptor 2-linked pathway, contributing to angiogenesis.

Recent studies have suggested that mast cells have critical roles in angiogenesis. However, the detailed mechanism by which mast cells contribute to angiogenesis is not yet clearly understood, especially in response to proinflammatory cytokines. In this study, we showed that the proinflammatory cytokine IL-1beta induces the synthesis of IL-8, a potent angiogenic factor, in human mast cells via the leukotriene B(4) receptor (BLT)2. We also characterized the BLT2 downstream signaling pathway and determined that BLT2-mediated IL-8 synthesis involves the upregulation of Nox1, a member of the NADPH oxidase family, Nox1-dependent reactive oxygen species generation and the subsequent activation of the redox-sensitive transcription factor NF-kappaB. For instance, knockdown of BLT2 and Nox1 with specific small interfering RNA, treatment with a specific BLT2 antagonist, LY255283, or treatment with a potential Nox inhibitor, diphenylene iodonium, suppressed IL-1beta-induced IL-8 synthesis. We found that the conditioned media collected from IL-1beta-treated human mast cell line HMC-1 had significantly enhanced angiogenic activity that could be dramatically attenuated by either small interfering RNA knockdown of BLT2 or treatment with neutralizing Ab to IL-8. Finally, the experiments were repeated using human primary cord blood-derived mast cells, and the results were clearly reproduced. Taken together, our results suggest that BLT2-Nox1-reactive oxygen species-dependent pathway plays a role in promoting the secretion of IL-8 from human mast cells in response to the proinflammatory cytokine IL-1beta, thus contributing to angiogenesis.

Long-term follow-up results of cytarabine-containing chemotherapy for acute promyelocytic leukemia.

BACKGROUND/AIMS: We evaluated the feasibility and long-term efficacy of the combination of cytarabine, idarubicin, and all-trans retinoic acid (ATRA) for treating patients with newly diagnosed acute promyelocytic leukemia (APL). METHODS: We included 87 patients with newly diagnosed acute myeloid leukemia and a t(15;17) or promyelocytic leukemia/retinoic acid receptor alpha (PML-RARα) mutation. Patients received 12 mg/m2/day idarubicin intravenously for 3 days and 100 mg/m2/day cytarabine for 7 days, plus 45 mg/m2/day ATRA. Clinical outcomes included complete remission (CR), relapse-free survival (RFS), overall survival (OS), and the secondary malignancy incidence during a 20-year follow-up. RESULTS: The CR, 10-year RFS, and 10-year OS rates were 89.7%, 94.1%, and 73.8%, respectively, for all patients. The 10-year OS rate was 100% for patients that achieved CR. Subjects were classified according to the white blood cell (WBC) count in peripheral blood at diagnosis (low-risk, WBC < 10,000/mm3; high-risk, WBC ≥ 10,000/mm3). The low-risk group had significantly higher RFS and OS rates than the high-risk group, but the outcomes were not superior to the current standard treatment (arsenic trioxide plus ATRA). Toxicities were similar to those observed with anthracycline plus ATRA, and higher than those observed with arsenic trioxide plus ATRA. The secondary malignancy incidence after APL treatment was 2.7%, among the 75 patients that achieved CR, and 5.0% among the 40 patients that survived more than 5 years after the APL diagnosis. CONCLUSION: Adding cytarabine to anthracycline plus ATRA was not inferior to anthracycline plus ATRA alone, but it was not comparable to arsenic trioxide plus ATRA. The probability of secondary malignancy was low.

Comprehensive DNA repair gene expression analysis and its prognostic significance in acute myeloid leukemia.

BACKGROUND: Deficiency in DNA damage response (DDR) pathway and accumulation of DNA damage increases mutation rates resulting in genomic instability and eventually increases the risk of cancer. The aim of our study was to investigate expressions of DNA repair genes as new prognostic biomarkers in acute myeloid leukemia (AML). METHODS: We utilized The Cancer Genome Atlas AML project (TCGA-LAML cohort, 15 acute promyelocytic leukemia (APL) and 155 non-APL AML) for the expression data of DNA repair genes. For validation, clinical samples (Ewha study group, 9 APL and 72 non-APL AML patients) were analyzed for the expression of 22 DNA repair genes using a custom RT2 Profiler PCR Array. RESULTS: APL patients presented significantly lower expression of DNA repair genes than non-APL AML patients in both study groups. Among non-APL AML patients, high expression levels of PARP1, XRCC1, and RAD51 were associated with poor overall survival (OS) probability in both study groups. Furthermore, Cox regression analysis showed that increased expression levels of PARP1, XRCC1, RAD51, BRCA1 and MRE11A could be independent risk factors for OS in the Ewha study group. Among non-APL patients of the Ewha study group, the OS probability of DDR-overexpressed group with at least one gene or more showing Z score greater than 1.5 was poorer than that of DDR non-overexpressed group. CONCLUSION: In the current study, the DNA repair gene expression profile of APL patients was different from that of non-APL AML patients. Overexpression of DNA repair genes could be a poor prognostic biomarker in non-APL AML.

Unsorted human adipose tissue-derived stem cells promote angiogenesis and myogenesis in murine ischemic hindlimb model.

We examined the protective effect of unsorted human adipose tissue-derived stem cells (hADSCs) with a short-term culture in endothelial differentiation medium on tissue repair after ischemic injury. hADSCs were isolated from human subcutaneous adipose tissue and cultured in vitro in endothelial differentiation medium for 2wks before transplantation. Cultured hADSCs showed a typical mesenchymal stromal cell-like phenotype, positive for endothelial-specific markers including VE-cadherin, Flt-1, eNOS, and vWF but not CD31. Two hours after ligation of the femoral artery and vein, mice were injected with the unselected hADSCs locally near the surgery site and tested for tissue perfusion and repair. Tissue perfusion rates of the ischemic limbs were significantly higher in the group treated with hADSCs compared with those of the control mice as early as post-operative day 3 (median 195.3%/min; interquartile range, 82.0-321.1 vs. median 47.1%/min; interquartile range, 18.0-58.7; p=0.001 by Friedman two-way analysis). Subsequently, the mice treated with hADSC showed better prognosis at 4wks after surgery, and the histological analysis revealed increased vascular density and reduced muscle atrophy in the hADSC-transplanted limbs. Moreover, hADSC-treated muscle contained differentiated myocytes positive for human NF-κB and myogenin antigen. These results collectively indicate that unsorted hADSCs after a 2-wk-in vitro culture have a therapeutic potential in ischemic tissue injury via inducing both angiogenesis and myogenesis.

Bortezomib, thalidomide, dexamethasone induction therapy followed by melphalan, prednisolone, thalidomide consolidation therapy as a first line of treatment for patients with multiple myeloma who are non-transplant candidates: results of the Korean Multiple Myeloma Working Party (KMMWP).

Bortezomib (VELCADE), thalidomide and dexamethasone (VTD), as well as melphalan, prednisolone, and thalidomide (MPT) therapy, are highly effective in patients with multiple myeloma. We evaluated the responses and survival times of 35 patients treated with VTD followed by MPT. All patients were newly diagnosed and non-transplantation candidates. Patients received six cycles of VTD, which were followed by eight cycles of MPT. Approximately 97% of patients exhibited early responses to therapy, as early as the second cycle of VTD. Thirty percent of the responses were high quality, which was defined as a complete response (CR), a near-CR or a very good partial response. High-risk patients were defined as patients with any of the following aberrations: del(13), t(4;14), or del(17p). The remaining patients were defined as standard risk. Eleven high-risk patients showed 100% response rates, including 91% high-quality responses. In contrast, 13 standard-risk patients exhibited 92% response rates, including 61% high-quality responses. The overall 2-year survival rates were 60% in high-risk patients and 85% in standard-risk patients, which was not significantly different. As a first-line therapy, VTD followed by MPT has the potential to provide high-quality responses with durable remission among elderly and high-risk patients (clinicaltrials.gov identifier: NCT00320476).

Peroxiredoxin 3 Has Important Roles on Arsenic Trioxide Induced Apoptosis in Human Acute Promyelocytic Leukemia Cell Line via Hyperoxidation of Mitochondrial Specific Reactive Oxygen Species.

NB4 cell, the human acute promyelocytic leukemia (APL) cell line, was treated with various concentrations of arsenic trioxide (ATO) to induce apoptosis, measured by staining with 7-amino-actinomycin D (7-AAD) by flow cytometry. 2', 7'-dichlorodihydro-fluorescein-diacetate (DCF-DA) and MitoSOXTM Red mitochondrial superoxide indicator were used to detect intracellular and mitochondrial reactive oxygen species (ROS). The steady-state level of SO2 (Cysteine sulfinic acid, Cys-SO2H) form for peroxiredoxin 3 (PRX3) was measured by a western blot. To evaluate the effect of sulfiredoxin 1 depletion, NB4 cells were transfected with small interfering RNA and analyzed for their influence on ROS, redox enzymes, and apoptosis. The mitochondrial ROS of NB4 cells significantly increased after ATO treatment. NB4 cell apoptosis after ATO treatment increased in a time-dependent manner. Increased SO2 form and dimeric PRX3 were observed as a hyperoxidation reaction in NB4 cells post-ATO treatment, in concordance with mitochondrial ROS accumulation. Sulfiredoxin 1 expression is downregulated by small interfering RNA transfection, which potentiated mitochondrial ROS generation and cell growth arrest in ATO-treated NB4 cells. Our results indicate that ATO-induced ROS generation in APL cell mitochondria is attributable to PRX3 hyperoxidation as well as dimerized PRX3 accumulation, subsequently triggering apoptosis. The downregulation of sulfiredoxin 1 could amplify apoptosis in ATO-treated APL cells.

Characterization of phenotypically distinct B-cell subsets and receptor-stimulated mitogen-activated protein kinase activation in human cord blood B cells.

Human cord blood (CB) is a valuable source of hematopoietic stem cells, but clinical reports have indicated slow recovery of B-cell development and function after CB transplantation. To investigate the basis of these B-cell defects in reconstitution, we characterized B cells purified from CB. We compared B-cell receptor activation and B-cell subsets in CB, bone marrow (BM), and peripheral blood (PB). We found that in CB B cells activation of extracellular signal-regulated kinase (ERK) and p38 following ligation of CD40 but not of the B-cell antigen receptor (BCR) was inefficient. The patterns of expression of CD5, CD34, and CD40 in the B-cell population of CB were similar to those in PB rather than in BM. The B cells in CB contained an increased proportion of B cells expressing a high level of CD24 and a low proportion of B cells expressing CD27, pointing to the presence of circulating CD24high immature transitional and CD27(-) naive B cells. CD40-mediated activation of ERK and p38 was also minimal in these B cells of CB. These findings may account for the functional defects of B cells in transplanted CB.

A case of Wernicke's encephalopathy following fluorouracil-based chemotherapy.

The pyrimidine antimetabolite 5-fluorouracil (5-FU) is a chemotherapeutic agent used widely for various tumors. Common side effects of 5-FU are related to its effects on the bone marrow and gastrointestinal epithelium. Neurotoxicity caused by 5-FU is uncommon, although acute and delayed forms have been reported. Wernicke's encephalopathy is an acute, neuropsychiatric syndrome resulting from thiamine deficiency, and has significant morbidity and mortality. Central nervous system neurotoxicity such as Wernicke's encephalopathy following chemotherapy with 5-FU has been reported rarely, although it has been suggested that 5-FU can produce adverse neurological effects by causing thiamine deficiency. We report a patient with Wernicke's encephalopathy, reversible with thiamine therapy, associated with 5-FU-based chemotherapy.

Prognostic significance of CD44s expression in biliary tract cancers.

BACKGROUND: CD44 is an essential surface glycoprotein component of the hyaluronan receptor and is associated with adhesion and metastasis in many solid tumors. There are several isoforms of CD44, including CD44 standard (CD44s) and 10 CD44 variants (CD44v1 to CD44v10). We evaluated the clinical significance of CD44s and CD44v6 in biliary tract cancers. METHODS: Patients who had been diagnosed with primary biliary tract cancers were enrolled onto the study, and tissue specimens were obtained during surgery. Paraffin-embedded tissue sections were evaluated for the presence of CD44s and CD44v6 by immunohistochemical staining. We decided CD44s and CD44v6 expression as overexpression, which shows an intensity grade of >10%. Clinical data of all patients were reviewed. RESULTS: Ninety-five patients (35 men and 60 women; median age, 64 years; range, 37-86 years) were evaluated. The incidence of overexpression (>10%) of CD44s was 49%, and that of CD44v6 was 17%. The median postoperative follow-up duration was 34.3 months, and the median overall survival was 12.2 months. The Cox proportional hazard ratio (HR) test identified CD44s overexpression (0% to 10% vs. 10% to 100%; HR, .420; 95% confidence interval [95% CI], .211-.837; P = .014) and cancer stage as prognostic factors. However, the expression of CD44v6 (0% to 10% vs. 10% to 100%; HR, 1.462; 95% CI, .630-3.393; P = .377) had no prognostic significance for survival. CONCLUSIONS: CD44s overexpression is useful as a marker of a poor prognosis for biliary tract cancer. Aggressive postoperative therapy should be considered for such patients.

Clinicopathological Characteristics of Hyperdiploidy with High-Risk Cytogenetics in Multiple Myeloma.

In multiple myeloma (MM), hyperdiploidy (HD) is known to impart longer overall survival. However, it is unclear whether coexistent HD ameliorates the adverse effects of known high-risk cytogenetics in MM patients. To address this issue, we investigated the clinicopathological characteristics of HD with high-risk cytogenetics in MM. Ninety-seven patients with MM were included in the study. For metaphase cytogenetics (MC), unstimulated cells from bone marrow aspirates were cultured for either 24 or 48 hours. To detect HD by interphase fluorescence in situ hybridization (iFISH), we assessed trisomies of chromosomes 5, 7, 9, 11, 15, and 17. Of the 97 MM patients, 40 showed HD. The frequency of co-occurrence of HD and high-risk cytogenetics was 14% (14/97). When the clinicopathological characteristics were compared between the two groups of HD with high-risk cytogenetics vs. non-HD (NHD) with high-risk cytogenetics, the level of beta 2 microglobulin and stage distribution significantly differed (P=0.020, P=0.032, respectively). This study shows that some of the clinicopathological characteristics of MM patients with high-risk cytogenetics differ according to HD or NHD status.

GATA1 Expression in BCR/ABL1-negative Myeloproliferative Neoplasms.

BACKGROUND: This study aimed to determine GATA1 expression levels to better characterize subgroups in BCR/ABL1-negative myeloproliferative neoplasms (MPNs). METHODS: This study enrolled 49 patients diagnosed as having BCR/ABL1-negative MPN on the basis of the 2016 World Health Organization classification : nine polycythemia vera (PV), 17 essential thrombocythemia (ET), 12 prefibrotic primary myelofibrosis (prePMF), and 11 overt primary myelofibrosis (PMF). Relevant clinical and laboratory data were retrieved from the medical records. The molecular analysis of CALR and MPL mutations and quantification of JAK2 V617F allele burden were performed. GATA1 expression was assessed by an immunohistochemical assay on bone marrow biopsy. GATA1 expression was analyzed serially in 18 patients. RESULTS: GATA1 expression decreased significantly in PMF compared with that in other subtypes, while no statistical difference was identified between ET and prePMF. GATA1 expression did not differ according to the mutation profiles or the allele burden of JAK2 V617F, but it decreased significantly in patients with overt fibrosis or leukemic transformation. CONCLUSIONS: Our results suggest that GATA1 expression is significantly low in PMF and decreases with progressive fibrosis and possibly with leukemic transformation, although our attempt to accurately distinguish between subgroups using GATA1 immunohistochemical approach did not achieve statistical significance. A large patient cohort with long term follow-up is required to evaluate the prognostic value of GATA1 expression.

Gene expression profile related to prognosis of acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous group of diseases with respect to biology and clinical course. Through genome-wide scanning, we can have an improvement of the diagnosis and assay system of AML. Microarray was performed for the identification of acute myeloid leukemia prognosis. We divided patients into two groups (good prognosis group, GPG and poor prognosis group, PPG) based on differences in the individual reactions to treatment. Gene expression profiles were analyzed using microarray. Among genes up-regulated at least two-fold and down-regulated at least 0.5-fold in HL-60, we chose three up-regulated genes (PPP2CA, ME3, and CCDN2) and three down-regulated genes (GLO1, ANXA2, and BMI1) and confirmed the expression of these six genes by RT-PCR. We created a leukemia-specific subclass microarray, based on the gene expression profiles. Clinical samples from the bone marrow of four patients were hybridized on this microarray. Among the genes selected by the microarray technology, NB4, silenced TRIB3 and overexpressed XRN2 were not differentiated in spite of treatment with ATRA. This indicates that XRN2 and TRIB3 play an important role in cell differentiation. These data provided an expression profile for the diagnosis and prognosis of AML patients and identified candidate genes that might allow the prognosis of AML through the relative comparison of the expression level of genes between GPG and PPG.

Early imatinib-mesylate-induced hepatotoxicity in chronic myelogenous leukaemia.

Imatinib mesylate is the first molecule of targeted therapy in chronic myelogenous leukaemia inhibiting constitutively activated BCR-ABL kinase. There are no long-term follow-up studies of large sample sizes to assess the toxicity of the use of imatinib mesylate over 10 years. Several cases of hepatotoxicity, including fatal liver failure, have been associated with the long-term use of imatinib mesylate. We report here on a patient who experienced immediate dominant cholestatic damage of the liver and mild hepatocyte damage during imatinib mesylate therapy. This differs from most reports showing dominantly acute hepatitis with necrosis associated with the use of imatinib mesylate.

A multicenter retrospective analysis of adverse events in Korean patients using bortezomib for multiple myeloma.

The proteasome inhibitor bortezomib has demonstrated clinical activity in patients with multiple myeloma (MM). Adverse events, including thrombocytopenia and peripheral neuropathy, have affected 30% to 60% of patients overall, and interrupted therapy in 10% to 20%. No prior toxicity data are available for Asian patients who have used bortezomib for MM. We used National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, to review the clinical records of patients with an MM diagnosis from 25 centers in Korea. The included patients were treated with bortezomib alone or in combination with other agents, including thalidomide. Ninety-five MM patients were treated. The patients had a median age of 60 years (range, 42-77 years). The median number of previous treatments was 3 (range, 0-10), and 39% of the patients had been treated with 4 or more major classes of agents, including thalidomide (67%), and autologous stem cell transplantation (51%). Regimens included bortezomib only in 38 patients (40%), bortezomib plus dexamethasone in 34 patients (36%), and bortezomib plus a thalidomide-containing regimen in 23 patients (24%). The analysis of patient response to therapy revealed a complete response (CR) or a near-CR in 31 patients (33%) and a partial response in 30 patients (32%), for an objective response rate of 65% in 93 patients. The most common adverse events reported were thrombocytopenia (47%), sensory neuropathy (42%), anemia (31%), and leukopenia (31%). Thirteen patients (14%) stopped therapy because of adverse events (neuropathy, 8; infection, 4; diarrhea, 1). Neuropathy greater than grade 2 was more frequent in patients who received 4 or more prior therapy regimens (17/37) than in those who received 3 or fewer (14/58). In addition, therapy including thalidomide was significantly correlated with neuropathy of grades 1 to 3 (P = .001). We identified 6 therapy-related deaths (6%) within 20 days after the last dose of bortezomib. The causes of death were infection in 3 patients, disease progression in 2 patients, and suicide in 1 patient. The incidences of thrombocytopenia and neurotoxicity were similar; however, gastrointestinal toxicities were relatively low in Korean patients compared with those reported in Western studies. Significant neuropathy was associated with the number of prior regimens and combination with thalidomide. These findings provide useful information for clinicians and patients using bortezomib.