Palliative Liver Radiotherapy (RT) for Symptomatic Hepatocellular Carcinoma (HCC)

This study aims at evaluating the symptom response, response duration, and toxicity of single dose palliative liver radiotherapy (RT) for symptomatic HCC patients. We reviewed unresectable HCC patients treated with palliative RT in our institution. Eligible patients were unsuitable or refractory to trans-arterial chemoembolization (TACE) and stereotactic body radiotherapy (SBRT), with an index symptom of pain or abdominal discomfort. The primary outcome was the percentage of patients with clinical improvement of index symptom at 1 month. Secondary outcomes were response duration, toxicities, alpha-feto protein (AFP) response, and radiological response. Fifty-two patients were included in the study. The index symptom was pain in 34 patients (65.4%), and abdominal discomfort (34.6%) in 18 patients. At 1 month, 51.9% of patients had improvement of symptoms. Median time to symptom progression was 89 days (range: 12–392 days). Treatment was well tolerated with only 2 patients (3.8%) developing grade 3 GI toxicities. AFP response, radiological response rate, and disease control rate at 3 months were 48.6%, 15.1%, and 54.5% respectively. Half of the patients had improvement of index symptoms after receiving palliative liver RT with median response duration of 3 months. The treatment was well tolerated with minimal toxicities.

Corrigendum: A Distinct Subset of Highly Proliferative and Lentiviral Vector (LV)-Transducible NK Cells Define a Readily Engineered Subset for Adoptive Cellular Therapy

[This corrects the article DOI: 10.3389/fimmu.2019.02001.].

A Distinct Subset of Highly Proliferative and Lentiviral Vector (LV)-Transducible NK Cells Define a Readily Engineered Subset for Adoptive Cellular Therapy

Genetic engineering is an important tool for redirecting the function of various types of immune cells and their use for therapeutic purpose. Although NK cells have many beneficial therapeutic features, genetic engineering of immune cells for targeted therapy focuses mostly on T cells. One of the major obstacles for NK cell immunotherapy is the lack of an efficient method for gene transfer. Lentiviral vectors have been proven to be a safe tool for genetic engineering, however lentiviral transduction is inefficient for NK cells. We show in this study that lentiviral vectors pseudotyped with a modified baboon envelope glycoprotein can transduce NK cells 20-fold or higher in comparison to VSV-G pseudotyped lentiviral vector. When we investigated the mechanism of transduction, we found that activated NK cells expressed baboon envelope receptor ASCT-2. Further analysis revealed that only a subset of NK cells could be expanded and transduced with an expression profile of NK56bright, CD16dim, TRAILhigh, and CX3CR1neg. Using CD19-CAR, we could show that CD19 redirected NK cells efficiently and specifically kill cell lines expressing CD19. Taken together, the results from this study will be important for future genetic modification and for redirecting of NK cell function for therapeutic purpose.

Phase I-II Clinical Trial Assessing Safety and Efficacy of Umbilical Cord Blood Mononuclear Cell Transplant Therapy of Chronic Complete Spinal Cord Injury

Umbilical cord blood-derived mononuclear cell (UCB-MNC) transplants improve recovery in animal spinal cord injury (SCI) models. We transplanted UCB-MNCs into 28 patients with chronic complete SCI in Hong Kong (HK) and Kunming (KM). Stemcyte Inc. donated UCB-MNCs isolated from human leukocyte antigen (HLA ≥4:6)-matched UCB units. In HK, four patients received four 4-μl injections (1.6 million cells) into dorsal entry zones above and below the injury site, and another four received 8-μl injections (3.2 million cells). The eight patients were an average of 13 years after C5-T10 SCI. Magnetic resonance diffusion tensor imaging of five patients showed white matter gaps at the injury site before treatment. Two patients had fiber bundles growing across the injury site by 12 months, and the rest had narrower white matter gaps. Motor, walking index of SCI (WISCI), and spinal cord independence measure (SCIM) scores did not change. In KM, five groups of four patients received four 4-μl (1.6 million cells), 8-μl (3.2 million cells), 16-μl injections (6.4 million cells), 6.4 million cells plus 30 mg/kg methylprednisolone (MP), or 6.4 million cells plus MP and a 6-week course of oral lithium carbonate (750 mg/day). KM patients averaged 7 years after C3-T11 SCI and received 3-6 months of intensive locomotor training. Before surgery, only two patients walked 10 m with assistance and did not need assistance for bladder or bowel management before surgery. The rest could not walk or do their bladder and bowel management without assistance. At about a year (41-87 weeks), WISCI and SCIM scores improved: 15/20 patients walked 10 m ( p = 0.001) and 12/20 did not need assistance for bladder management ( p = 0.001) or bowel management ( p = 0.002). Five patients converted from complete to incomplete (two sensory, three motor; p = 0.038) SCI. We conclude that UCB-MNC transplants and locomotor training improved WISCI and SCIM scores. We propose further clinical trials.

Phase I/II randomized controlled trial of autologous bone marrow-derived mesenchymal stem cell therapy for chronic stroke

AIM

To examine the safety and efficacy of mesenchymal stem cell (MSC) therapy for intracerebral haemorrhage with neurological dysfunctions for a year.

METHODS

MSC were ex vivo expanded from 29 mL (17-42 mL) autologous bone marrow. Patients were randomized to have two intravenous injections of autologous MSC or placebos in four weeks apart. Neurological functions and clinical outcomes were monitored before treatment and at 12^th, 16^th, 24^th, 36^th and 60^th week upon completion of the treatment.

RESULTS

A mean of 4.57 × 10⁷ (range: 1.43 × 10⁷-8.40 × 10⁷) MSC per infusion was administered accounting to 8.54 × 10⁵ (2.65 × 10⁵-1.45 × 10⁶) per kilogram body weight in two occasions. There was neither adverse event at time of administration nor sign of de novo tumour development among patients after monitoring for a year post MSC therapy. Neuro-restoration and clinical improvement in terms of modified Barthel index, functional independence measure and extended Glasgow Outcome Scale were evident among patients having MSC therapy compared to patients receiving placebos.

CONCLUSION

Intravenous administration of autologous bone marrow-derived MSC is safe and has the potential of improving neurological functions in chronic stroke patients with severe disability.

miR-181d regulates human dendritic cell maturation through NF-κB pathway

OBJECTIVES

MicroRNAs (miRNAs) are considered as the cellular regulators which post-transcriptionally modulate gene expression in diverse biological processes including cell development and immunity. In this study, we investigated functions of miR-181d in dendritic cells (DCs) maturation, and the underlying mechanisms were also explored.

MATERIALS AND METHODS

Here we did the miRNA screening in human DCs in response to lipopolysaccharides (LPS) by quantitative real-time PCR (qRT-PCR). The expressions of DCs maturation markers were measured after miRNA mimics transfections. The pharmacological inhibitors of signalling pathways were applied to examine miR-181d effect on DCs maturation by Western blot. Luciferase assay and mixed lymphocyte reaction (MLR) were also performed to reveal the target gene of miR-181d and test the viability of T cells treated with miR-181d transfected DCs.

RESULTS

Overexpression of miR-181d per se is sufficient to promote DCs maturation, and up-regulate CD80 and CD83 expressions without LPS. Besides, we showed that miR-181d activated NF-κB pathway and also promoted the expression of pro-inflammatory cytokine IL12 and TNF-α. Inhibition of NF-κB pathway suppressed DCs maturation. Luciferase reporter assay and target gene knockdown assay indicated that miR-181d targets regulator cylindromatosis (CYLD), a primary negative regulator of NF-κB pathway. MLR assay showed that miR-181d-transfected DCs could promote T-cell proliferation than iDCs in vitro.

CONCLUSION

Our study demonstrates that miR-181d is required for DCs maturation through the activation of NF-κB pathway by targeting CYLD.

Indiscernible Benefit of Double-Unit Umbilical Cord Blood Transplantation in Children: A Single-Center Experience from Hong Kong

Double-unit umbilical cord blood (DU-UCB) may extend the use of UCB transplantation and improve clinical outcomes. Data in the literature show that single-unit dominance happened in a vast majority of recipients, and the mechanism is unknown. We examined the clinical relevance and engraftment kinetics of DU-UCB transplant in 65 consecutive children who underwent unrelated single-unit ( n = 25) and double-unit ( n = 40) UCB transplantation for various hematological malignancies ( n = 45) and nonmalignant disorders ( n = 20). Our result showed no discernible benefit to children receiving double-unit transplant over those receiving single-unit transplant when the total nucleated cell (TNC) doses are ≥2.5 × 107/kg, in terms of the hastening of the engraftment of neutrophils and platelets, reduction of nonengraftment, disease recurrence, early mortality, and graft-versus-host disease, despite significantly higher numbers of TNCs in double units. Further analyses demonstrated that the phenomena were not associated with underlying disease, duration of UCB storage, postthaw viability, HLA disparity, ABO incompatibility, gender, or doses of TNCs, CD34+ cells, CD3+ cells, or colony-forming units. Engrafting units in DU-UCB transplants were notably associated with higher CD34+ cell dose. Chimerism studies demonstrated that single-unit dominance started before neutrophil engraftment in DU-UCB transplants. Data from the study suggested no advantage of infusing double-unit UCB, if an adequately dosed single-unit UCB is available. Successful prediction of the dominant graft would optimize algorithms of UCB selection and maximize the long-term engraftment of chosen units.

MycN Is Critical for the Maintenance of Human Embryonic Stem Cell-Derived Neural Crest Stem Cells

The biologic studies of human neural crest stem cells (hNCSCs) are extremely challenging due to the limited source of hNCSCs as well as ethical and technical issues surrounding isolation of early human embryonic tissues. On the other hand, vast majority of studies on MycN have been conducted in human tumor cells, thus, the role of MycN in normal human neural crest development is completely unknown. In the present study, we determined the role of MycN in hNCSCs isolated from in vitro-differentiating human embryonic stem cells (hESCs). For the first time, we show that suppression of MycN in hNCSCs inhibits cell growth and cell cycle progression. Knockdown of MycN in hNCSCs increases the expression of Cdkn1a, Cdkn2a and Cdkn2b, which encodes the cyclin-dependent kinases p21^CIP1, p16 ^INK4a and p15^INK4b. In addition, MycN is involved in the regulation of human sympathetic neurogenesis, as knockdown of MycN enhances the expression of key transcription factors involved in sympathetic neuron differentiation, including Phox2a, Phox2b, Mash1, Hand2 and Gata3. We propose that unlimited source of hNCSCs provides an invaluable platform for the studies of human neural crest development and diseases.

Unfolded protein response is required for the definitive endodermal specification of mouse embryonic stem cells via Smad2 and β-catenin signaling

Tremendous efforts have been made to elucidate the molecular mechanisms that control the specification of definitive endoderm cell fate in gene knockout mouse models and ES cell (ESC) differentiation models. However, the impact of the unfolded protein response (UPR), because of the stress of the endoplasmic reticulum on endodermal specification, is not well addressed. We employed UPR-inducing agents, thapsigargin and tunicamycin, in vitro to induce endodermal differentiation of mouse ESCs. Apart from the endodermal specification of ESCs, Western blotting demonstrated the enhanced phosphorylation of Smad2 and nuclear translocation of β-catenin in ESC-derived cells. The inclusion of the endoplasmic reticulum stress inhibitor tauroursodeoxycholic acid to the induction cultures prevented the differentiation of ESCs into definitive endodermal cells even when Activin A was supplemented. Also, the addition of the TGF-β inhibitor SB431542 and the Wnt/β-catenin antagonist IWP-2 negated the endodermal differentiation of ESCs mediated by thapsigargin and tunicamycin. These data suggest that the activation of the UPR appears to orchestrate the induction of the definitive endodermal cell fate of ESCs via both the Smad2 and β-catenin signaling pathways. The prospective regulatory machinery may be helpful for directing ESCs to differentiate into definitive endodermal cells for cellular therapy in the future.

Quantitative assessment of gait and neurochemical correlation in a classical murine model of Parkinson's disease

Background

Gait deficits are important clinical symptoms of Parkinson’s disease (PD). However, existing behavioral tests for the detection of motor impairments in rodents with systemic dopamine depletion only measure akinesia and dyskinesia, and data focusing on gait are scarce. We evaluated gait changes in the methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced C57BL/6 murine model of PD by using a computer-assisted CatWalk system. Correlations of gait parameters with tyrosine hydroxylase (TH) protein levels in the substantia nigra (SN) were also investigated.

Results

The gait readouts, including the walking duration, variation of walking speed, step cycle, duty cycle, stance, initial dual stance, terminal dual stance, three- and four-point supports, and the base of support between hind limbs was noted to increase significantly one week after MPTP injection. In contrast, values of the stride length, cadence, swing speed, and diagonal dual support decreased substantially following MPTP treatment (p < 0.05). All of these changes lasted for three weeks after the last MPTP administration. Except for the stance in the fore limbs and the swing speed in the hind limbs, the gait variability in the PD mice showed a closer correlation with the protein levels of TH in the SN than the walking distances in the conventional open field test. Coordination parameters of the regularity index and step pattern were not affected in mice treated with MPTP.

Conclusion

Data of the study suggest that the computer-assisted CatWalk system can provide reliable and objective criteria to stratify gait changes arising from MPTP-induced bilateral lesions in C57/BL6 mice. The extent of gait changes was noted to correlate with the expression of the biomarker for dopaminergic neurons. This novel analytical method may hold promise in the study of disease progression and new drug screening in a murine PD model.

The combined expression of Pdx1 and MafA with either Ngn3 or NeuroD improves the differentiation efficiency of mouse embryonic stem cells into insulin-producing cells

The use of pancreatic β-cells differentiated from embryonic stem (ES) cells or induced pluripotent stem (iPS) cells is a promising strategy in cell therapy. Pancreatic β-cell development is regulated by the sequential expression of a molecular network of transcription factors. In this experiment, we adopted a three-step differentiation protocol to differentiate mES (mouse ES) cells into insulin-secreting cells and overexpressed transcription factors by adenoviral vectors at various combinations at different time of differentiation. We found that the coexpression of Pdx1 and MafA with either Ngn3 or NeuroD, especially at the final stage of the three-step differentiation, significantly increased the differentiation efficiency. It also increased the glucose-stimulated insulin and C-peptide secretion in insulin-secreting cells derived from mES cells compared to the control green fluorescent protein (GFP) vector-transduced group. For the first time, we have demonstrated that the coexpression of Pdx1 and MafA during a specific time window of development can act synergistically with either Ngn3 or NeuroD to promote the differentiation of mES cells into insulin-secreting cells.

Improved survival outcome of childhood acute myeloid leukemia with intensified chemotherapy in Chinese children

With the use of intensive chemotherapy and hematopoietic stem cell transplantation (HSCT), the prognosis of childhood acute myeloid leukemia (AML) improved over the last 2 decades. Survival data of Chinese pediatric patients were seldom reported. The authors adopted modified UK Medical Research Council (MRC) AML protocols for treatment of childhood AML since 1994. From 1994 to 2008, the outcomes of Chinese AML patients were studied. Sixty-eight patients were studied. The median age at diagnosis was 9.9 years. Twenty-five patients (36.8%) had favorable cytogenetic karyotypes, including t(15;17), t(8;21) and inv(16). Complete remission (CR) rate was 91.2%. The relapse rate was 29.4%. For non-M3 patients, the 5-year overall survival (pOS) was 64% ± 7% and event-free survival (pEFS) was 53% ± 7%. For those non-good-risk patients who achieved CR, there were no significant differences in outcomes between patients who received HSCT in CR1 and those received chemotherapy alone (5-year pOS 80% ± 13% and 69% ± 9%, P = .52), 5-year pEFS 69% ± 15% and 55% ± 10%, P = .40). The pOS of the 20 relapsed patients was 29% ± 11%. Sixteen patients with t(8;21) and inv(16) had similar outcome with those without favorable cytogenetics (pOS 66% ± 12% versus 65% ± 7%, P = .39; pEFS 60% ± 11% versus 54% ± 8%, P = .45). Patients who achieved CR after 2 or more courses of chemotherapy and presenting white blood cell count (WBC) ≥ 100 × 10(9)/L had poorer outcome (pOS 40% versus 80%P < .01; 43% versus 70%, P = .02, respectively). Intensified chemotherapy improved outcome of Chinese AML children. CR after first course of chemotherapy and WBC at diagnosis were important prognostic factors.

Umbilical cord-derived mesenchymal stem cells with forced expression of hepatocyte growth factor enhance remyelination and functional recovery in a rat intracerebral hemorrhage model

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) carries a high mortality rate, with survivors commonly left with permanent neurological deficits. Mesenchymal stem cell (MSC) transplantation promotes functional recovery in experimental ICH, and treatment with hepatocyte growth factor (HGF) is beneficial in ischemic stroke.

OBJECTIVE

We hypothesize that transplantation of MSCs with previous transduction of HGF has an additive effect in promoting neurological recovery through myelin and axonal regeneration.

METHODS

HGF transduction to human umbilical cord-derived MSCs using lentiviral plasmid pWPI-HGF-GFP was prepared. One week after a collagenase-induced ICH, 80 male Sprague-Dawley rats were divided into 3 groups for stereotactic injection of phosphate-buffered saline (group I), MSC transplant (group II), and HGF-transduced MSC transplant (group III), respectively, into the left ventricle. The animals were assessed weekly for 5 weeks using the Rotarod motor function test, at which time they were killed for Luxol fast blue myelin staining and appropriate immunohistochemistry and Western blotting.

RESULTS

Animals receiving transplanted HGF-transduced MSCs (group III) exhibited significantly better motor function recovery than animals treated with MSCs alone (group II), which in turn performed better than the phosphate-buffered saline controls at 2 weeks after transplantation. Luxol fast blue staining of myelin displayed significantly less demyelination and significantly higher reactivity in myelin basic protein and growth-associated protein-43 in immunohistochemistry and Western blotting and significantly reduced myelin-associated glycoprotein activity in group III animals.

CONCLUSION

Animals transplanted with HGF-transduced MSCs 1 week after experimental ICH were shown to achieve a better neurological recovery. This improved neurological recovery from ICH is attributed to nerve fiber remyelination and axonal regeneration.

Comparative proteomic analysis of mesenchymal stem cells derived from human bone marrow, umbilical cord and placenta: implication in the migration

Umbilical cord (UC) and placenta (P) have been suggested as alternatives to bone marrow (BM) as sources of mesenchymal stem cells (MSC) for cell therapy, with both UC- and P-MSC possess immunophenotypic and functional characteristics similar to BM-MSC. However, under defined conditions, the migration capacity of BM- and P-MSC was found to be 5.9- and 3.2-folds higher than that of UC-MSC, respectively. By the use of 2-DE and combined MS and MS/MS analysis, six differentially expressed proteins were identified among these MSC samples, with five of them known to be involved in cell migration as migration enhancing or inhibiting proteins. Interestingly, the expression levels of those proteins reflect perfectly the migration capacity of corresponding MSC, which is also proved by in vitro overexpression and silencing techniques. Our study indicates that a bunch of migration-related proteins are pivotal in governing the migration capacity of MSC.

Neurotrophism of bone marrow stromal cells to embryonic stem cells: noncontact induction and transplantation to a mouse ischemic stroke model

Embryonic stem (ES) cell-derived cell products may serve as a source of cells for regenerative medicine. Currently available technologies for the induction of ES cells into neural lineage cells require extended culturing in vitro and complex procedural manipulations, with variable yields of heterogeneous cells, which have hindered the prospective use of cell derivatives for treatment of ischemic stroke. We established a simple and efficient method to derive mouse ES cells into neural lineage cells using an 8-day coculture with the bone marrow stromal cells MS5, followed by a 6-day propagation culture and a 4-day selection culture. The protocol generated a relatively high yield of neural lineage cells without any mesodermal and endodermal lineage commitment. In in vivo study, these derived cells could improve the cognitive function of ischemic stroke mice. Three weeks after transplantation, migration of implanted cells to lesioned areas was noted. It was also evident of a normalization of pyramidal neuron density and morphology in hippocampal CA1 region. One (1/17) episode of teratoma development was noted. Data suggested that MS5 cells may exert a neurotrophic effect to enhance neural differentiation of ES cells and MS5-induced ES cell-derived cells appeared to be applicable to cell therapy for ischemic stroke.

Comparative proteomic analysis of mesenchymal stem cells derived from human bone marrow, umbilical cord, and placenta: implication in the migration

Umbilical cord (UC) and placenta (P) have been suggested as alternatives to bone marrow (BM) as sources of mesenchymal stem cells (MSC) for cell therapy, with both UC- and P-MSC possess immunophenotypic and functional characteristics similar to BM-MSC. However, their migration capacity, which is indispensable during tissue regeneration process, is unclear. Under defined conditions, the migration capacity of BM- and P-MSC was found 5.9- and 3.2-folds higher than that of UC-MSC, respectively. By the use of 2-DE and combined MS and MS/MS analysis, six differentially expressed proteins were identified among these MSC samples, with five of them known to be involved in cell migration as migration enhancing or inhibiting proteins. Consistent with their migration capacity, the levels of migration enhancing proteins including cathepsin B, cathepsin D and prohibitin,were significantly lower in UC-MSC when compared with those in BM- and P-MSC. For the migration inhibiting proteins such as plasminogen activator inhibitor-1 (PAI-1) and manganese superoxide dismutase, higher expression was found in the UC-MSC. We also showed that the overexpression of the PAI-1 impaired the migration capacity of BM- and P-MSC while silencing of PAI-1 enhanced the migration capacity of UC-MSC. Our study indicates that PAI-1 and other migration-related proteins are pivotal in governing the migration capacity of MSC.

Implantation of neural stem cells embedded in hyaluronic acid and collagen composite conduit promotes regeneration in a rabbit facial nerve injury model

The implantation of neural stem cells (NSCs) in artificial scaffolds for peripheral nerve injuries draws much attention. NSCs were ex-vivo expanded in hyaluronic acid (HA)-collagen composite with neurotrophin-3, and BrdU-labeled NSCs conduit was implanted onto the ends of the transected facial nerve of rabbits. Electromyography demonstrated a progressive decrease of current threshold and increase of voltage amplitude in de-innervated rabbits after implantation for one, four, eight and 12 weeks compared to readouts derived from animals prior to nerve transection. The most remarkable improvement, observed using Electrophysiology, was of de-innervated rabbits implanted with NSCs conduit as opposed to de-innervated counterparts with and without the implantation of HA-collagen, NSCs and HA-collagen, and HA-collagen and neurotrophin-3. Histological examination displayed no nerve fiber in tissue sections of de-innervated rabbits. The arrangement and S-100 immunoreactivity of nerve fibers in the tissue sections of normal rabbits and injured rabbits after implantation of NSCs scaffold for 12 weeks were similar, whereas disorderly arranged minifascicles of various sizes were noted in the other three arms. BrdU+ cells were detected at 12 weeks post-implantation. Data suggested that NSCs embedded in HA-collagen biomaterial could facilitate re-innervations of damaged facial nerve and the artificial conduit of NSCs might offer a potential treatment modality to peripheral nerve injuries.

The plant mannose-binding lectin NTL preserves cord blood haematopoietic stem/progenitor cells in long-term culture and enhances theirex vivoexpansion

Ex vivo expansion of haematopoietic stem and progenitor cells in cytokine combinations is effective in promoting differentiation and proliferation of multilineage progenitor cells, but often results in reduction of self-renewable stem cells. This study investigated the effect of a mannose-binding lectin, NTL, purified from Narcissus tazetta var. chinensis, on prolonged maintenance and expansion of cord blood CD34+ cells. Our results showed that the presence of NTL or Flt-3 ligand (FL) significantly preserved a population of early stem/progenitor cells in a serum- and cytokine-free culture for 35 d. The effect of NTL on the ex vivo expansion of CD34+ cells in the presence of stem cell factor, thrombopoietin (TPO) and FL was also investigated. NTL-enhanced expansion of early progenitors (CD34+, CD34+CD38-, mixed colony-forming units and CFU-GEMM) and committed progenitor cells (granulocyte CFU, erythroid burst-forming units/CFU and megakayocyte CFU) after 8 and 12 d of culture. Six weeks after transplanting 12 d-expanded cells to non-obese diabetic severe combined immunodeficient mice, increased engraftment of human CD45+ cells was observed in the bone marrow of animals that received NTL-treated cells. The dual functions of NTL on long-term preservation and expansion of early stem/multilineage progenitor cells could be developed for applications in various cell therapy strategies, such as the clinical expansion of CD34+ cells for transplantation.

Trophism of neural progenitor cells to embryonic stem cells: neural induction and transplantation in a mouse ischemic stroke model

Embryonic stem cell (ESC)-derived products have emerged as a promising cell source for neuroregeneration. C17.2 neural precursor cells were noted to express genes of neurotrophins and neuroprotective factors and to be enable to enhance proliferation, neuritogenesis, and differentiation of SH-SY5Y and SK-N-AS neuroblasts, suggesting their neurotrophic potential. We used C17.2 cells as neurotrophic chaperones to induce ESCs, D3, and E14TG2a into neural lineage cells. Significantly greater numbers of Sox-2(+), Musashi-1(+), and nestin(+) neurospheres developed in noncontact cocultures than in cultures of ESCs without C17.2 support or with 50% conditioned medium after 8 days. Immunoreactivity of the neuronal, astrocytic and oligodendrocytic markers was evident in cultures further differentiated for 10 days. Expression of Pax-6, Otx-1, and Nurr-1 genes suggested neuroectodermal precursors in products encompassing neural stem cells, dopaminergic neurons, astrocytes, and oligodendrocytes. Alpha-fetoprotein, GATA-4, Brachyury, Nkx-2.5, and Myf-5 genes were not detected, indicating any mesodermal and endodermal cells. However, weak expression of Oct-4 was noted. Behavioral assessment of ischemic mice 2 weeks after transplantation revealed significant improvement in cognitive function compared with that in ischemic sham-operated mice. Tracking bromodeoxyuridine-labeled products demonstrated that mostly implanted cells were localized along the needle track of the injection in the brain parenchyma, whereas some migrated to the striatum, cortex, nerve fiber bundle of the corpus callosum, and hippocampus in the ipsilateral hemisphere. One episode (of 22) of teratoma development was noted. Data from this study suggest a paradigm of trophism of neural progenitor cells for induction of ESCs into neural lineage cells.

Effect of resveratrol on proliferation and differentiation of embryonic cardiomyoblasts

Resveratrol (trans-3,5,4'-trihydroxystilbene), a polyphenolic compound found largely in the skins of red grapes, has been used as a nutritional supplement or an investigational new drug for prevention of cardiovascular diseases. Previous reports showed that resveratrol had a protective effect against oxidative agent-induced cell injury. Our studies indicate that resveratrol plays a role in the differentiation of cardiomyoblasts. The cardiomyoblast cell line, H9c2, was exposed to 30-120 microM resveratrol for up to 5 days. Resveratrol inhibits cardiomyoblast proliferation without causing cells injury. Moreover, resveratrol treatment modulated the differentiation of morphological characteristics including elongation and cell fusion in cardiomyoblasts. Proliferation and differentiation of H9c2 cells were further revealed by measurement of the mRNA expression of a cell cycle marker (CDK2), a differentiation marker (myogenin), and a contractile apparatus protein (MLC-2). Gene expression analysis revealed that resveratrol promoted entry into cell cycle arrest but extended the myogenic differentiation progress. These results have implications for the role of resveratrol in modulating cell cycle control and differentiation in cardiomyoblasts.

Indiscernible benefit of high-resolution HLA typing in improving long-term clinical outcome of unrelated umbilical cord blood transplant

The success of allogeneic hematopoietic stem cell transplantation depends in part on the accuracy of human leukocyte antigen (HLA) matching between the donor-recipient pair. The higher the number of matching HLA alleles, the smaller the chance that the transplant recipient will develop complications. Umbilical cord blood (UCB) transplantation was noted to result in a remarkably low frequency and severity of graft-versus-host disease (GvHD) and graft rejection compared to that in unrelated bone marrow transplant recipients. At present most banks match UCB donors for respective recipients by HLA-A, -B low-resolution typing and -DRB1 high-resolution typing. We retrospectively conducted high-resolution sequence-based HLA typing on DNA samples available from 65 Chinese UCB-recipient pairs typed previously by using low-resolution sequence-specific oligonucleotide probes and sequence-specific primers, and evaluated the clinical outcome. High-resolution typing revealed imperceptible HLA alleles that were hardly identified in low-resolution typing. Univariate analyses demonstrated no significant correlation between the extents of high-resolution HLA disparity with engraftment, graft failure, acute GvHD, transplant-related mortality and long-term 6-year overall survival. Data from the study suggest that high-resolution typing for HLA-A, -B and -DRB1 contributed no substantial improvement to UCB transplant outcome. Low-resolution typing appears to be amenable to matching UCB-recipient pairs without compromising the quality of transplant.

Banking and transplantation of umbilical cord blood in Guangzhou, China

BACKGROUND

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSC) for transplantation of patients with hematologic malignancies or hereditary diseases.

METHODS

We developed a provincial UCB bank in Guangzhou, China, using good manufacturing practices and standard operating procedures to address donor eligibility, collection, characterization, processing, storage and release from quarantine. The banking activities were analyzed.

RESULTS

From June 1998 to May 2005, 8623 UCB units of Han ethnic origin were collected; 4147 (48.1%) were stored, while 4476 (51.9%) were discarded as a result of pre-determined exclusion criteria. A median volume of 95.5 mL (range 60-227.7) and 1.2 x 10(9) (0.8-9.3) nucleated cells were collected. The cell viability was 97.8% (90-100%). The CD34+ cell count of 3691 (89.0%) UCB units was 5.2 x 10(6) (0.3-131.6) and clonogenic assays of 4036 (97.3%) UCB units demonstrated 9.8 x 10(5) (0.04-135.8) CFU-GM, 0.3 x 10(5) (0.0-18.6) CFU-GEMM and 8.8 x 10(5) (0.0-74.2) BFU-E. A total of 0.4% (15/3863) UCB derived from babies known to have health problems at age 6 months was discarded. Up to May 2005, 151 units were issued for transplantation to 127 patients [90 (70.9%) children and 37 (29.1%) adults]. The infused nucleated cells in unrelated single-unit recipients were 3.4 x 10(7)/kg (1.7-14.9) for adults (n=19) and 5.7 x 10(7)/kg (2.0-20.5) for children (n=71), respectively. The numbers of days for the engraftment of neutrophils among 65 children and 22 adults were 17 (7-41) and 20 (10-42), respectively.

DISCUSSION

Data of this study show that stringent procedures and comprehensive policies are requisite for pursuing the banking and release of quality UCB for successful transplantation.

Modulation and impact of class I major histocompatibility complex by neural stem cell-derived neurotrophins on neuroregeneration

Transplantation of neural stem cells (NSC) has shown to elicit functional recovery in experimental animal and human models of neural disorders pertaining to cell loss or degeneration. However, the underlying mechanisms of the regimen are not well understood. The scenarios lead to the speculation of neuroregeneration and replacement of lost neurons in both the central nervous system (CNS) and the peripheral nervous system (PNS). The repair per se is extremely complex involving the re-building and modulation of synapses, neurites, neural cells and glial cells. Neurotrophins, which nourish the CNS and the PNS, may attribute to the functional improvement after neural stem cell transplantation. Recent studies suggested the CNS plasticity may be modulated by the class I major histocompatibility complex (MHC), which are in turn regulated by neurotrophins. Based upon these findings, we speculate that the neurotrophins derived from the transplanted NSC may modulate the expression of the major histocompatibility complex in the injured microenvironment to facilitate neurological recovery. The proposition may have clues on the development of novel treatment modality to cure CNS injury.

HLA-B67 may be a male-specific HLA marker of susceptibility to relapsed childhood ALL in Hong Kong Chinese and HLA-A33 or HLA-B17 signifies a higher presentation leukocytosis: a retrospective analysis on 53 transplant candidates (1989–2003)

We performed a retrospective analysis on the human leukocyte antigen (HLA) data of 53 consecutive Chinese patients with high-risk childhood acute lymphoblastic leukemia (ALL) diagnosed from 1989 to 2003. A significantly higher frequency of HLA-B67 in the male relapse group of patients [OR, 23.08; 95% CI, 5.31-100.36; p = 0.0042; for statistical significance after Bonferroni correction (Bc) p (Bc) < 0.0083] was identified after Bonferroni correction. Although not surviving the Bonferroni correction, gender effects on the association were also observed with HLA-A11, HLA-A32, HLA-A33, and HLA-B22, which were however more prevalent in the female patients and particularly those developing relapse. Two patients with HLA-A29 and HLA-B7 revealed significantly shortened survivals, suggestive of their potential prognostic impacts. Notably, for the first time, we found a significant correlation of leukocyte count with HLA types, where HLA-A33 (p = 0.006) or HLA-B17 (p < 0.001) signifies higher leukocytosis at presentation. Taken together, our findings support the involvement of HLA in Chinese high-risk childhood ALL.

Migration of bone marrow stem cells in ischaemic brain

Stem cell therapy has been demonstrated to be effective in the management of haematological malignancy and solid cancer, but its role in neurodegenerative conditions remains uncertain. We hypothesize that: (1) ventricular delivery of bone marrow stem cells improves functional outcome in experimental ischaemia of the mouse brain; and (2) this improved outcome is due to migration of bone marrow stem cells to areas of ischaemia. Twelve mice with transient cerebral hemisphere ischaemia were randomly allocated to receive bone marrow stem cells or saline. The six animals that underwent cell therapy were found to perform better and committed fewer errors in the water maze system compared with the six control mice. Migration of these bone marrow stem cells was evident within the ventricular cerebro-spinal fluid (CSF) system and the brain parenchyma. This could also occur in clusters of cells. Preferential migration of these cells took place in lesioned areas.

Preclinical ex vivo expansion of G-CSF-mobilized peripheral blood stem cells: effects of serum-free media, cytokine combinations and chemotherapy

OBJECTIVES

Ex vivo expansion of granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSC) is a promising approach for overcoming the developmental delay of bone marrow (BM) reconstitution after transplantation. This project investigated the effects of culture duration, serum-free media, cytokine combinations, and chemotherapy on the outcomes of expansion.

METHODS

Enriched CD34+ cells were cultured for 8 or 10 d in serum-free media (QBSF-60 or X-Vivo 10) and four combinations of cytokines consisting of recombinant human pegylated-megakaryocyte growth and development factor, stem cell factor, flt-3 ligand, G-CSF, interleukin (IL)-6, platelet-derived growth factor (PDGF), and IL-1beta.

RESULTS

Eight days of culture in QBSF-60 significantly supported efficient expansions of CD34+ cells, CD34+ CD38- cells, colony-forming units (CFU) of myeloid, erythroid, megakaryocytic, and mixed lineages to 3.76-, 14.4-, 28.3-, 24.0-, 38.1-, and 15.7-fold, respectively. Whilst PDGF or IL-6 enhanced the expansion of early, myeloid, and erythroid progenitors, IL-1beta specifically promoted the megakaryocytic lineage. Engraftment of human CD45+ cells were detectable in all non-obese diabetic/severe-combined immunodeficient mice transplanted with expanded PBSC from donor samples, being 5.80 +/- 3.34% of mouse BM cells. The expansion and engraftment capacity of CD34+ cells from subjects postchemotherapy were significantly compromised across the panel of progenitor cells.

CONCLUSION

Our results provided an optimized protocol for PBSC expansion, applicable to ameliorating neutropenia and thrombocytopenia in post-BM transplant patients by the prompt provision of progenitor cells. For postchemotherapy patients, expansion products might provide committed progenitors for improving short-term engraftment, but not self-renewable stem cells.

Multipotent neural precursors express neural and hematopoietic factors, and enhance ex vivo expansion of cord blood CD34+ cells, colony forming units and NOD/SCID-repopulating cells in contact and noncontact cultures

In view of the possible crosstalks between hematopoiesis and neuropoiesis, we evaluated two microenvironments, murine neonatal neural cell line C17.2 and primary embryonic aorta-gonad-mesonephros (AGM) stromal cells, on the ex vivo expansion of CD34+ cells from human cord blood. In a contact culture system, C17.2 or AGM cells significantly enhanced the expansion of CD34+ cells to a panel of early and committed hematopoietic progenitor cells. In a noncontact transwell system, pre-established C17.2 cells significantly increased the expansion of total nucleated cells, CD34+ cells and multilineage colony forming cells (P<0.01). Expanded cells were infused into nonobese diabetic/severe-combined immunodeficient mice. The engraftment of human (hu)CD45+ cells in the bone marrow of these mice was consistently higher in all the 10 experiments conducted with the support of C17.2 cells when compared with those in respective control groups (11.9 vs 2.43%, P=0.03). Using RT-PCR and Southern blot analysis, we showed that AGM and C17.2 cells expressed a panel of hematopoietic, bone morphogenetic and neurotrophic factors. Our data provided the first evidence on the promoting effects of a neural progenitor cell line on hematopoiesis at a noncontact condition. The mechanism could be mediated by the expression of multilineage regulatory factors.

Childhood acute myeloid leukemia with CBFbeta-MYH11 rearrangement: study of incidence, morphology, cytogenetics, and clinical outcomes of Chinese in Hong Kong

We analyzed 43 consecutive cases of pediatric acute myeloid leukemia (AML) for the presence of the CBFbeta-MYH11 rearrangement using molecular techniques in a regional hospital in Hong Kong. Five cases (11.6%), 3 girls and 2 boys, ranging in age from 8 months to 14 years old, were found positive for the CBFbeta-MYH11 rearrangement. Morphologically, they were FAB M2 or M4 with or without eosinophilia (Eo). Typical M4Eo was observed in only one case. The molecular findings were in complete concordance with cytogenetic data, which revealed inv(16)(p13q22) in all and also gains of chromosome 4, 8, 22, and Y in one patient. Clinically, all 5 patients achieved complete remission after chemotherapy with favorable outcomes except for the patient with infantile AML, who relapsed 11 months after diagnosis, underwent cord blood transplantation, and was in second remission. This is the first clinicopathological study and documentation of the incidence of CBFbeta-MYH11 in childhood AML of Chinese in Hong Kong.

Establishment and characterization of a cytogenetically complex Chinese multiple myeloma-derived cell line with homozygous p53 deletion and cyclin E overexpression

We describe the establishment and characterization of a new myeloma-derived cell line (MM17), originating from the sacral plasmacytoma of a 54-year-old Chinese woman diagnosed with multiple myeloma (MM). MM17 was confirmed morphologically and immunophenotypically to be clonal plasma cells positive for CD38 and CD138 and negative for EBV marker. Authenticity was confirmed using comparative genomic hybridization and DNA fingerprinting studies on bone marrow aspirate, sacral tumor tissue and MM17. Combined G-banding and multicolor fluorescence in situ hybridization analyses demonstrated a primarily hypodiploid karyotype with two sidelines sharing common stemline aberrations: +6, -7, -10, -13, -14, -17, -X, der(1;17)(q10;q10), t(2;7)(q23;q11.2), t(8;14)(q24;q32) and ins(16;1)(q13;?q22q41); and a number of hypertriploid cells. The involvement of p53 alteration and cyclin E overexpression, both with relevance to the induction of chromosomal instability, was investigated in MM17 and together with two other MM derived cell lines (U266 and IM-9) for cyclin E expression. Homozygous deletion of p53 gene hitherto not reported in MM, was detected. Both MM17 and U266 with complex cytogenetic aberrations demonstrated overexpression of cyclin E1 and E2, whereas IM-9 with a normal karyotype showed cyclin E2 but not E1 overexpression. These data suggested that E1 but not E2 overexpression was associated with chromosomal abnormalities observed in MM17 and U266, which provides the first supporting evidence for the link of cyclin E and chromosomal instability in MM. This is the first characterized Chinese MM-derived cell line with homozygous p53 deletion which may serve as a valuable in vitro system for studying MM pathogenesis particularly for Chinese.

Translocation (11;13)(q23;q14) as the sole abnormality in a childhood de novo acute myelocytic leukemia

We report a case of childhood de novo acute myelocytic leukemia (AML) with hyperleukocytosis with monoblastic features and deranged hemostasic function. G-band karyotyping demonstrated a previously unreported t(11;13)(q23;q14) in metaphase preparations from a fluorodeoxyuridine synchronized 1-day culture of leukophoresed cells. Multicolor fluorescence in situ hybridization revealed no cryptic rearrangements except for the translocation. Reverse transcriptase polymerase chain reaction showed no concomitant positivity of AML1/ETO, BCR/ABL, PML/RARA, and CBFbeta/MYH11 resulting from t(8;21)(q22;q22), t(9;22)(q34;q11), t(15;17)(q22;q11), and inv(16) (p13q22), respectively. This report of childhood de novo AML harboring t(11;13)(q23;q14) as the sole cytogenetic abnormality provides more data on the leukemogenesis of de novo AML with a 11q23 rearrangement.

Unrelated umbilical cord blood transplantation in children: experience of the Hong Kong Red Cross Blood Transfusion Service

OBJECTIVE

To review the outcome of unrelated umbilical cord blood transplantation in children using cord blood from the Hong Kong Red Cross Blood Transfusion Service.

DESIGN

Retrospective study.

PATIENTS

Records of eight patients who received unrelated umbilical cord blood transplants between 1999 and 2003 were reviewed.

MAIN OUTCOME MEASURES

Engraftment of haematopoietic cells and graft-versus-host disease after transplantation.

RESULTS

The median age of the patients was 4.9 years (range, 1.0-9.4 years). Five patients had acute leukaemia, one had non-Hodgkin's lymphoma, one had X-linked adrenoleukodystrophy, and one had mucolipidosis. The infused umbilical cord blood units contained a median of 6.7 x 10(7) /kg nucleated cells and 4.0 x 10(5) /kg CD34-positive cells. Neutrophil engraftment was achieved at a median of 13 days (range, 11-19 days) and, for seven patients, platelet engraftment was achieved at a median of 39 days (range, 24-98 days). Acute graft-versus-host disease occurred in all patients (grades I to III). One of the patients died because of encephalitis; of the other seven, five developed chronic graft-versus-host disease of the skin. At a median follow-up of 2 years, the four patients with leukaemia and the one with non-Hodgkin's lymphoma remained in continuous complete remission; the patient with adrenoleukodystrophy showed stabilisation of neurological condition.

CONCLUSION

The Hong Kong Red Cross Blood Transfusion Service Cord Blood Bank stored cord blood units of good quality for transplantation, the outcome of which was comparable to that of bone marrow transplantation.

Lymphocyte subsets and natural killer cell cytotoxicity after laparoscopically assisted resection of rectosigmoid carcinoma

BACKGROUND

Laparoscopically assisted resection of colorectal carcinoma is technically feasible and minimally invasive. Postoperative immunosuppression also may be reduced. This study compared the lymphocyte subsets and natural killer (NK) cell cytotoxicity in patients after laparoscopically assisted resection with those after open resection of rectosigmoid carcinoma.

METHODS

In this study, 40 patients with rectosigmoid carcinoma, but no evidence of metastasis, were randomized to receive either laparoscopically assisted or conventional open resection of the tumor. Blood was collected before the operation, then 24 h, 72 h, and 8 days after the operation for studies of lymphocyte subsets and NK cell cytotoxicity.

RESULTS

The lymphocyte subsets and NK cell cytotoxicity of both groups showed typical suppression after surgery. The suppression of T cell activation and NK-like T cells was significantly less after laparoscopically assisted resection than in after open resection, whereas the difference in other lymphocyte subsets and NK cell cytotoxicity was not significant.

CONCLUSION

This study showed that some cellular components of the immune system are less suppressed after laparoscopically assisted than after conventional open resection of rectosigmoid carcinoma. This may have implications for tumor recurrence and long-term patient survival.

Frequent RASSF1A promoter hypermethylation and K-ras mutations in pancreatic carcinoma

Recently, we have characterized the Ras association domain family 1A gene (RASSF1A) at the segment 3p21.3, which is frequently lost in variety of human cancers and epigenetically inactivated in many types of primary tumors, such as lung, breast, kidney, prostate and thyroid carcinomas. Here, we investigated the methylation status of the RASSF1A CpG island promoter in the pathogenesis of pancreatic cancer. RASSF1A hypermethylation was detected in 29 out of 45 (64%) primary adenocarcinomas, in 10 out of 12 (83%) endocrine tumors and in eight out of 18 (44%) pancreatitis samples. In seven out of eight pancreas cancer cell lines, RASSF1A was silenced and was retranscribed after treatment with 5-aza-2'-deoxycytidine. Additionally, we analysed the aberrant methylation frequency of cell cycle inhibitor p16(INK4a) and K-ras gene mutations in the pancreatic samples. p16 inactivation was detected in 43% of adenocarcinomas, in 17% of neuroendocrine tumors, in 18% of pancreatitis and in 63% of pancreas cancer cell lines. K-ras mutations were detected in 16 out of 45 (36%) primary adenocarcinomas. Pancreatic adenocarcinomas with K-ras mutation have significantly less RASSF1A methylation and vice versa (P=0.001, chi(2) test). In conclusion, our data indicate that inactivation of the RASSF1A gene is a frequent event in pancreatic cancer and suggest an inverse correlation between RASSF1A silencing and K-ras activation.

Infrared spectroscopic identification of beta-thalassemia

BACKGROUND

The aim of this study was to investigate the potential of infrared (IR) spectroscopy as a fast and reagent-free adjunct tool in the diagnosis and screening of beta-thalassemia.

METHODS

Blood was obtained from 56 patients with beta-thalassemia major, 1 patient with hemoglobin H disease, and 35 age-matched controls. Hemolysates of blood samples were centrifuged to remove stroma. IR absorption spectra were recorded for duplicate films dried from 5 microL of hemolysate. Differentiation between the two groups of hemoglobin spectra was by two statistical methods: an unsupervised cluster analysis and a supervised linear discriminant analysis (LDA).

RESULTS

The IR spectra revealed changes in the secondary structure of hemoglobin from beta-thalassemia patients compared with that from controls, in particular, a decreased alpha-helix content, an increased content of parallel and antiparallel beta-sheets, and changes in the tyrosine ring absorption band. The hemoglobin from beta-thalassemia patients also showed an increase in the intensity of the IR bands from the cysteine -SH groups. The unsupervised cluster analysis, statistically separating spectra into different groups according to subtle IR spectral differences, allowed separation of control hemoglobin from beta-thalassemia hemoglobin spectra, based mainly on differences in protein secondary structure. The supervised LDA method provided 100% classification accuracy for the training set and 98% accuracy for the validation set in partitioning control and beta-thalassemia samples.

CONCLUSION

IR spectroscopy holds promise in the clinical diagnosis and screening of beta-thalassemia.

Detection of micrometastasis of neuroblastoma to bone marrow and tumor dissemination to hematopoietic autografts using flow cytometry and reverse transcriptase-polymerase chain reaction

BACKGROUND

The identification of neuroblastoma metastases to bone marrow (BM) is requisite in staging disease for risk-adopted therapy. However, micrometastases were not elucidated fully.

METHODS

Flow cytometry (FCM) with CD45/CD56/CD81 and reverse transcriptase-polymerase chain reactions (RT-PCR) for tyrosine hydroxylase (TH) transcripts were used to evaluate neuroblastoma in bilateral BM aspirates at diagnosis, BM autografts, peripheral blood stem cell (PBSC) collections, and CD34(+) cell products of 27 children.

RESULTS

TH transcripts were amplified in histology-negative (H(-)) BM specimens from seven patients (four patients with Stage 3 disease, two with Stage 4 disease, and one with Stage 4S disease), revealing a prevalence of submicroscopic metastasis. The median number of CD45(-)CD81(+)CD56(+) cells in four H(-) TH(-) BM samples from two patients with Stage 1 and Stage 2 disease, respectively, was comparable to that encountered in 10 normal BM controls (0.003% [range, 0.002-0.004%] vs. 0.004% [0-0.008%], P = 0.724). In six H(-) TH(+) BM specimens from three patients whom were otherwise diagnosed with neuroblastoma Stage 3, 0.031% (0.009-0.06%) CD45(-)CD81(+)CD56(+) cells were detected. Besides, 1.474% (0.088-3.009%) CD45(-)CD81(+)CD56(+) cells were identified in four H(-) TH(+) BM specimens from two patients at Stage 4. TH transcripts were evident in four of five BM autografts and in 22 of 45 (48.9%) PBSC specimens. FCM demonstrated 0.018% and 0.049% CD45(-)CD81(+)CD56(+) cells in two TH(+) BM autografts, respectively. The number of CD45(-)CD81(+)CD56(+) cells was higher in 19 TH(+) PBSC specimens than in 20 TH(-) PBSC specimens (0.026% [0.006-1.128%] vs. 0% [0-0.009%], P < 0.0001). CD34(+) cell selection achieved 2.9 (2.1-3.5) log depletion of CD45(-)CD81(+)CD56(+) cells in four manipulated products, rendering six of seven PBSC autografts TH-free.

CONCLUSIONS

FCM in combination with RT-PCR evaluated neuroblastoma micrometastasis and assessed the purity of hematopoietic autografts for transplant. However, the clinical relevance remains to be elucidated.

Chromosomal aberrations of multiple myeloma in Chinese patients at diagnosis: a study by combined G-banding and multicolor spectral karyotyping

Cytogenetic investigation of multiple myeloma (MM) has been difficult by conventional methods and most of the data have been derived from western population where incidence of MM is much higher as compared to that of Asians. The current study represents the first report of chromosomal aberrations of multiple myeloma in Chinese. We investigated 25 consecutive Chinese patients with MM for chromosomal aberrations at diagnosis using G-banding and multicolor spectral karyotyping (SKY). Of the 21 patients successfully analyzed by G-banding, 11 patients revealed cytogenetic abnormalities showing complex numerical and structural aberrations, which were further characterized with SKY. An abnormal karyotype significantly associated with blastic MM was observed. Consistent with the western literature, structural rearrangements involving chromosomes 1, 6, 8, 19, numerical abnormalities of gains in chromosomes 9, 3, and 5, and losses in chromosomes 13 and 14 were observed. However, there were notably higher incidences of -22/22q- (4/11) and structural aberrations of chromosome X but a lower incidence of -X. The biological implications of these findings, if confirmed, deserve further evaluation.

Implication of maternal-cell contamination in the clinical banking of umbilical cord blood

BACKGROUND

The increasing utilization of human UC blood (UCB) in transplantation has drawn attention to the need for rationalization of selection, collection, processing, testing, banking and release of UCB. However, the issue of maternal blood contamination has not been well addressed. There are concerns that maternal T cells might elicit GvHD post-UCB transplant.

METHODS

Maternal T cells in 58 male UCB allografts were enumerated using fluorescent in situ hybridization and flow cytometry. Obstetric factors, preceding labor, multi-parity and gestational age, were also analyzed.

RESULTS

Levels of maternal cells of 0.75-5.25% were found in 15.5% (9/58) UCB. There was no association of maternal-cell contamination with preceding labor [25% (2/8) with previous delivery versus 35.4% (17/48) first born, P = 0.702], nor any correlation with multi-parity [37.5% (3/8) para > or = 3 versus 16.7% (8/48) para < 3, P = 0.181]. Gestation age of newborns also exhibited no association with maternal-cell contamination (39.47 weeks in newborn UCB with maternal cells, versus 39.58 weeks without: P = 0.674). The extrapolated maternal T cells/kg in nine UCB transplants were 1.05 x 10(5) +/- 1.12 x 10(5) (3.40 x 10(4) - 3.18 x 10(5)).

DISCUSSION

In relation to the arbitrary threshold of 1 x 10(5) T cells/kg in HLA-mismatched transplants utilizing T-cell depleted BM, 22.2% (2/9) of UCB transplants having maternal-cell contamination might be at risk of GvHD. Data support the need for testing for maternal blood in UCB, and evaluating the clinical relevance of GvHD in patients post-UCB transplant. The establishment of guidelines and standards for release of such UCB collections would be advisable in evidence-based UCB transplantation.

Trehalose ameliorates the cryopreservation of cord blood in a preclinical system and increases the recovery of CFUs, long-term culture-initiating cells, and nonobese diabetic-SCID repopulating cells

BACKGROUND

The cryopreservation of HPCs in DMSO has been practiced by cord blood (CB) banks worldwide. Inevitably, some detriment to biologic function occurs as the result of freezing injuries and DMSO toxicity. Trehalose, a disaccharide, is a natural cryoprotectant in organisms capable of surviving extreme dehydration and cold. The objective of this study was to establish the cryopreservation of CB under preclinical conditions using trehalose as a supplement to DMSO.

STUDY DESIGN AND METHODS

In a preclinical protocol, the effects of 5-percent trehalose with 10-percent DMSO or 5-percent DMSO on the cryopreservation of CB MNCs or nucleated cells (NCs) were further evaluated. The read-out system consisted of a panel of HPCs: early progenitors (CFU-GEMM, long-term culture-initiating cells [LTC-IC]) and committed progenitors (CFU-GM, CFU/BFU-E, CFU-megakaryocyte [CFU-MK]). The homing and engraftment capacity of these cells were assessed in nonobese diabetic (NOD)-SCID mice.

RESULTS

Trehalose increased the recoveries of CFU-GM, CFU/BFU-E, CFU-GEMM, and LTC-IC by over 7.25 percent (mean), 11.9 percent, 19.2 percent, and 12.9 percent, respectively, when compared with those in paired CB samples cryopreserved in 10-percent DMSO. Freezing and thawing reduced the yields of CFU-MK by 35.5 percent (mean) and 28.4 percent in MNC and NC samples, respectively, and the inclusion of 5-percent trehalose significantly retrieved these progenitor cells to over 90 percent of fresh samples. The improved recovery of functional HPLs was reflected by their multilineage engraftment in NOD-SCID mice.

CONCLUSION

Trehalose at 5 percent significantly ameliorates the cryopreservation of CB progenitor cells at a preclinical protocol. The increased recoveries of these cells might potentially improve the engraftment outcomes of CB transplants.

Mixed chimerism after bone marrow transplantation for thalassemia major

Thirty-four thalassemia patients were studied for chimerism by fluorescent in situ hybridization or variable number tandem repeats after bone marrow transplantation. Mixed chimerism was detected in 9 patients with host cells ranging from 4 to 56%. One had graft rejection and the others were transfusion independent. Mixed chimerism was common but mostly without deleterious effect.

Bone marrow transplantation for beta-thalassaemia major by an HLA-mismatched parent

A six-year-old boy was diagnosed with beta-thalassaemia major during infancy. Since then, he required monthly blood transfusion and irregular iron chelation therapy. He had hepatosplenomegaly and elevated liver enzymes; the serum ferritin was up to 3800 ng/mL. An echocardiogram showed left-ventricular enlargement. His one-antigen-mismatched mother was chosen as a bone marrow donor. He was pretreated with intensive red blood cell transfusion and hydroxyurea for 6 weeks prior to conditioning. The conditioning included total body irradiation (300 cGy), busulfan (14 mg/kg), cyclophosphamide (160 mg/kg) and anti-thymocyte globulin (rabbit; 90 mg/kg). Marrow cell dose was 5.4 x 108/kg. Graft versus host disease (GVHD) prophylaxis included cyclosporine A (CSA) and methylprednisolone. Neutrophil engraftment occurred on day 23. Grade II acute GVHD occurred on day 45. The patient developed complications including septicaemia, haemorrhagic cystitis, intracranial haemorrhage and heart failure. He subsequently recovered from the complications without sequelae. The patient remained transfusion-independent at a follow-up examination after 18 months. This case suggested that a mismatched family member may be considered as a bone marrow donor for beta-thalassaemia major. In places where conventional treatment is not feasible, for example, in China, this approach may be an alternative option. A more intensive immunosuppressive regimen and a higher marrow cell dose may be important for successful engraftment. High-dose anti-thymocyte globulin may also prevent severe GVHD.

Second transplant for a thalassemia patient after graft rejection: with immunosuppression and allogeneic peripheral blood stem cell

A 13-year old girl suffering from beta-thalassaemia major received bone marrow transplantation (BMT) from her HLA identical bother. After initial engraftment, she developed mixed chimerism. Secondary graft rejection occurred at 10 months after BMT and resulted in marrow aplasia. A second transplant with the same bone marrow donor was performed. The patient was conditioned with antithymocyte globulin 90 mg/kg followed by peripheral blood stem cell infusion. There was prompt engraftment and patient reverted to complete chimerism. There were no severe treatment-related complications or acute or chronic graft versus host disease after second transplant. The patient remained transfusion independent at 26 months after second transplant.

Preclinical ex vivo expansion of cord blood hematopoietic stem and progenitor cells: duration of culture; the media, serum supplements, and growth factors used; and engraftment in NOD/SCID mice

BACKGROUND

Ex vivo expansion of cord blood (CB) hematopoietic stem and progenitor cells increases cell dose and may reduce the severity and duration of neutropenia and thrombocytopenia after transplantation. This study's purpose was to establish a clinically applicable culture system by investigating the use of cytokines, serum-free media, and autologous plasma for the expansion of CB cells and the engraftment of expanded product in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice.

STUDY DESIGN AND METHODS

Enriched CB CD34+ cells were cultured in four media (Iscove's modified Dulbecco's medium with FCS, Gibco; X-Vivo-10, BioWhittaker; QBSF-60, Quality Biological; and StemSpan SFEM, Stem Cell Technologies) with four cytokine combinations (thrombopoietin [TPO], SCF, Flt-3 ligand [FL] with and without G-CSF, and/or IL-6). The effect of autologous CB plasma was also investigated. The read-out measures were evaluated on Days 8 and 12. After expansion at the optimized condition, cultured cells were transplanted into sublethally irradiated NOD/SCID mice. The engraftment of human CD45+ cells and subsets in the bone marrow, spleen, and peripheral blood was determined.

RESULTS

QBSF-60 or StemSpan SFEM supported high yields of early progenitors (CD34+ cells, <or= 64.8-fold; CD34+CD38- cells, 330-fold; CFU-granulocyte erythroid macrophage megakaryocyte [GEMM], 248-fold) and CFUs of the myeloid (CFU-GM, 407-fold) and erythroid (BFU/CFU-E, 144-fold) lineages. The expansion of the megakaryocytic lineage was consistently higher in X-Vivo-10 (CFU-megakaryocyte, 684-fold). Autologous plasma promoted colony formation but reduced CD34+ cells and CFU-GEMM. The addition of G-CSF or IL-6 improved cell yields; G-CSF was more effective for committed progenitors. Expansion products from cultures in QBSF-60 with the cytokines engrafted and differentiated into the myeloid and lymphoid lineages in NOD/SCID mice.

CONCLUSION

The data supported the strategy of expansion. The optimized condition may be applicable to clinical expansion for the abrogation or reduction of posttransplant cytopenia.

TEL/AML1 rearrangement and the prognostic significance in childhood acute lymphoblastic leukemia in Hong Kong

The TEL/AML1 rearrangement has been implicated as an independent good prognostic factor in pediatric acute lymphoblastic leukemia (ALL). We examined TEL/AML1 using nested reverse-transcription polymerase chain reaction (RT-PCR) and correlated TEL/AML1 with cytogenetics and immunophenotypes in 75 consecutively analyzed Chinese children with ALL in Hong Kong. TEL/AML1 was detected in 17.9% (12/67) B-lineage ALL at diagnosis but not in 8 T-ALL children or in 34 adults with ALL. E2A/PBX1, MLL/AF4, and BCR/ABL were not found in TEL/AML1+ patients. Coexpression of cross-lineage antigens was associated with TEL/AML1 gene fusion (p = 0.032), with CD13 in 80% (4/5) TEL/AML1+ cohort. Chromosomal abnormalities were demonstrated in 50% of the TEL/AML1+ ALL; however, a cryptic t(12;21) was not detected in these cases. Hyperdiploidy of 47-48 chromosomes was encountered in 25%. Deletion of 12p resulting in the loss of the normal allele of TEL and nonspecific del(6q) were noted in 8% (1/12) and 25% (3/12) of the TEL/AML1+ children, respectively. Rapid clearance of TEL/AML1 was noted in 50% of the patients on completion of the induction therapy; however, 16.7% (2/12) TEL/AML1+ ALL relapsed at a mean of 48.6 months from diagnosis (25 months off-therapy). The incidence of relapses of TEL/AML1+ ALL was comparable to that at diagnosis in B-lineage ALL (14.3% [2/14] vs. 17.9% [12/67], p > 0.05). The relapse rate in TEL/AML1+ ALL was similar to that of TEL/AML1- ALL (16.7% [2/12] vs. 20.6% [13/63], p > 0.05). The duration of first complete remission in TEL/AML1+ ALL was significantly longer as compared to TEL/AML1- ALL (mean [range] in month: 48.6 [47.2 - 50] vs 14.6 [2.9 - 42.3], p < 0.0001). Irrespective of TEL/AML1 rearrangement, the probabilities of the five-year overall survival and the event-free survival of patients were comparable (overall survival: 100% vs. 72.3%, p = 0.166 and event-free survival: 60% vs. 56.2%, p = 0.343). Our data would not suggest a less aggressive treatment regimen for TEL/AML1+ ALL.