PubMed Health⌕ Search

Biomedical subjects

N H Russell

Publications and source records attributed to N H Russell.

At least 19 recordsLinked to original sources
PubMed2006

DNA repair contributes to the drug-resistant phenotype of primary acute myeloid leukaemia cells with FLT3 internal tandem duplications and is reversed by the FLT3 inhibitor PKC412.

The presence of internal tandem duplications (ITD) mutations in the FMS-like tyrosine kinase 3 (FLT3) receptor influences the risk of relapse in acute myeloid leukaemia (AML). We have investigated DNA repair in FLT3-ITD and wild-type (WT) cells. Using the comet assay, we have demonstrated that the FLT3 inhibitor PKC412 significantly inhibits repair of DNA damage in the MV4-11-FLT3-ITD cell line and FLT3-ITD patient samples but not in the HL-60-FLT3-WT cell line or FLT3-WT patient samples. Following the discovery that transcript levels of the DNA repair gene RAD51 are significantly correlated with FLT3 transcript levels in FLT3-ITD patients, we further investigated the role of RAD51 in FLT3-ITD-AML. The reduction in DNA repair in PKC412-treated FLT3-ITD cells was shown to be associated with downregulation of RAD51 mRNA and protein expression and correlates with the maintenance of phosphorylated H2AX levels, implying that PKC412 inhibits the homologous recombination double-strand break repair pathway in FLT3-ITD cells. Using FLT3-short interfering RNA (siRNA), we also demonstrated that genetic silencing of FLT3 results in RAD51 downregulation in FLT3-ITD cells but not in FLT3-WT cells. This work suggests that the use of FLT3 inhibitors such as PKC412 may reverse the drug-resistant phenotype of FLT3-ITD-AML cells by inhibiting repair of chemotherapy-induced genotoxic damage and thereby reduce the risk of disease relapse.

DNA Repair↗
PubMed2005

The impact of donor gender on outcome of allogeneic hematopoietic stem cell transplantation for multiple myeloma: reduced relapse risk in female to male transplants.

The impact of the donor gender on outcome in HLA-identical sibling donor hematopoietic stem cell transplantation for multiple myeloma was studied in a retrospective registry study of 1312 patients (476 male to male (M --> M); 334 female to male (F --> M); 258 male to female (M --> F); 244 female to female (F --> F) reported to the European Group for Blood and Marrow Transplantation (EBMT). The best overall survival (OS) from the time of transplantation was found in F --> F (median 41 months) with no significant difference between other groups (median 25 months in M --> M, 18 months in F --> M, 19 months in M --> F) despite a significantly higher nonrelapse mortality in F --> M. This was due to a significantly lower relapse rate (REL) in F --> M compared to all other groups. Before 1994, OS was poorer in F --> M than in M --> M, which improved to similarity from 1994 onwards (median 29 months in M --> M and 25 months in F --> M). The reduced REL contributed to this improvement in F --> M indicting a gender-specific graft vs myeloma effect. Therefore, a female donor is as good as a male one for male patients, while for female patients gender disparity is a negative factor for outcome.

Adult↗
PubMed2005

Donor lymphocyte infusions can result in sustained remissions in patients with residual or relapsed lymphoid malignancy following allogeneic haemopoietic stem cell transplantation.

We treated 17 patients with refractory (n = 7) or relapsed lymphoid malignancy (n = 10) following allogeneic HSCT with donor lymphocyte infusions (DLI). Patients with low-grade disease received DLI alone (n = 7) or following radiotherapy (n = 1). Patients with aggressive disease (n = 9) received prior chemotherapy. Nine out of 15 patients receiving DLI from sibling donors responded after one (n = 6), two (n = 2) and three (n = 1) infusions. Both MUD recipients achieved CR after two and three DLI. In all, 10/17 patients achieved CR including 3/4 patients with chronic lymphatic leukaemia (CLL), 4/4 with mantle cell lymphoma (MCL), 3/4 with follicular NHL but 0/5 with aggressive NHL/Richters. The median CD3 cell dose to achieve CR for siblings was 2 x 10(7)/kg. One patient with CLL had a second transplant following DLI-induced aplasia and is in CR at 14 months giving a final CR rate of 64%. Grade II-IV acute GVHD developed in 45% and chronic GVHD in 8/9 evaluable patients. Of the 11 patients finally achieving CR, one patient with MCL relapsed at 18 months post-DLI but all others remain in remission with a median follow-up of 40 months (range 12-64 months). Low-grade NHL and MCL have a high response rate and sustained remissions following DLI. Aggressive disease responds poorly however, despite pre-DLI chemotherapy.

Adult↗
PubMed2005

Management of chronic myeloid leukaemia in relapse following donor lymphocyte infusion induced remission: a retrospective study of the Clinical Trials Committee of the British Society of Blood & Marrow Transplantation (BSBMT).

Donor lymphocyte infusion (DLI) can restore remission in a high percentage of patients with chronic myeloid leukaemia (CML) who relapse after allogeneic stem cell transplant (SCT). Subsequent relapses after a DLI-induced remission do occur and the optimal management of these patients is not defined. A retrospective study of the practice of UK transplant centres was conducted. In all, 13 patients from seven centres were identified: all were treated for relapse post allogeneic SCT with DLI and achieved either a complete cytogenetic (n=5) or molecular (n=8) remission. All patients subsequently had a second relapse, at molecular (n=7), cytogenetic (n=4) and haematological (n=2) levels. Further DLI was used in the treatment of 11 patients, imatinib mesylate in three and chemotherapy in two. The two patients with haematological relapse died of blastic disease. The remaining 11 patients achieved either a complete cytogenetic (n=2) or molecular (n=9) remission. Nine patients remain in molecular remission at a median follow-up of 29 months, seven of whom had received DLI alone as treatment for second relapse, one DLI plus imatinib and one imatinib alone. Toxicity following DLI for second relapse was low. Longer follow-up will be required to see if these second DLI-induced remissions will be durable.

Adult↗
PubMed2005

Analysis of outcome following allogeneic haemopoietic stem cell transplantation for myeloma using myeloablative conditioning--evidence for a superior outcome using melphalan combined with total body irradiation.

We have undertaken a retrospective multicentre analysis of 139 patients (median age 44.4 years) undergoing allogeneic haematopoietic stem cell transplantation (HSCT) for multiple myeloma using myeloablative conditioning. The majority of patients received total body irradiation (TBI) combined with either melphalan (56.9%) or cyclophosphamide (28.5%). Overall, transplant-related mortality (TRM) was 37.9% at 1 year and was not significantly different for patients receiving melphalan/TBI compared with cyclophosphamide/TBI. The overall complete remission (CR) rate, including patients in CR at the time of transplant, was greater for patients receiving melphalan/TBI (64.7%) compared with cyclophosphamide/TBI (47.2%)(P = 0.085). A significantly higher proportion of patients with continuing disease at the time of transplant achieved CR post-transplant following melphalan/TBI conditioning compared with cyclophosphamide/TBI (52.9% and 33.4% respectively, P = 0.009). Relapse/progression rates at 5 years were significantly lower for melphalan/TBI (36.7%) compared with cyclophosphamide/TBI (80.8%, P < 0.0001) and remained significant in multivariate analysis. This resulted in an overall survival at 5 years of 44.1% and 28.1% for melphalan/TBI and cyclophosphamide/TBI, respectively (P = 0.059). These results demonstrate that the type of conditioning for sibling allogeneic HSCT for myeloma has a major effect on transplant outcome.

Adult↗
PubMed2005

Low dose erythropoietin is effective in reducing transfusion requirements following allogeneic HSCT.

Blood transfusions are frequently required for several weeks after allogeneic transplantation due to inadequate erythropoiesis and defective erythropoietin production. Because red cell transfusion is not without complications in this setting, we sought to avoid them using recombinant human erythropoietin (rhEpo) therapy. We treated 53 patients following allogeneic transplantation for haematological malignancy, using rhEpo at a dose of 10 000 units subcutaneously twice weekly. The median time of commencement of rhEpo was 61 days post-transplant (range 19-465 days), and the median haemoglobin (Hb) concentration was 9.4 g dL(-1) (range 7.0-10.7 g dL(-1)). Thirty patients responded to rhEpo and required no further transfusion with a median rise in Hb after 2 weeks of therapy of 1.5 g (0.7-4.1 g dL(-1)). Erythropoietin (Epo) was discontinued at a median of 5 weeks (range 2-36), when the median Hb concentration was 12.3 g dL(-1) (range 10.0-14.3 g dL(-1)). Those patients who failed to respond to rhEpo frequently had additional reasons for anaemia including cytomegalovirus (CMV) reactivation and treatment, major ABO incompatibility, disease relapse, graft rejection or other transplant-related complications. We conclude that a short course of rhEpo is an effective treatment for anaemia arising following allogeneic hematopoietic cell transplantation, and can avoid the need for transfusion in this setting.

Anemia↗
PubMed2004

Interleukin-1beta maintains an apoptosis-resistant phenotype in the blast cells of acute myeloid leukaemia via multiple pathways.

Blast cell survival in suspension culture is associated with chemoresistance in acute myeloid leukaemia (AML). Autonomous production of IL-1beta by AML blasts is linked with a proliferative response, although its role in survival and hence apoptosis-resistance has not been examined in this disease. Cells that secreted more than 19.7 pg/ml IL-1beta were significantly more resistant to spontaneous apoptosis in 48-h culture than those that produced less than 19.7 pg/ml IL-1beta (P=0.008). Exogenous rhIL-1beta significantly enhanced 48-h survival in 25/29 blast cell samples (P=0.0001). IL-1 receptor ligation is known to activate at least three survival pathways: those mediated by PI-3 kinase, IL-1 receptor-associated kinase (IRAK) and ceramidase. In apoptosis-sensitive AML blasts with a strong survival response to rhIL-1beta, inhibitors of all three pathways down-modulated an IL-1beta-mediated increase in blast survival, but only the inhibition of all three pathways totally eliminated viable blasts. In apoptosis-resistant and apoptosis-sensitive primary AML samples, the three inhibitors all increased apoptosis in vitro after 48 h. Exogenous rhIL-1beta induced the hyperphosphorylation of Bcl-2. It also increased the activation of NF-kappaB in 5/15 blast samples. IL-1beta-mediated survival pathways may be a factor in apoptosis-resistance in primary AML blasts, and may therefore contribute to chemoresistance.

Amidohydrolases↗
PubMed2004

The use of a national transplant registry to benchmark transplant outcome for patients undergoing autologous and allogeneic stem cell transplantation in the United Kingdom and Ireland.

As part of its clinical governance programme the British Society for Blood and Marrow Transplantation (BSBMT) undertook an analysis of transplant outcome for adults undergoing human leucocyte antigen - identical sibling allogeneic transplantation for chronic myeloid leukaemia (CML) in first chronic phase (CP1) or autologous transplantation for Hodgkin's disease (HD). The study aimed to compare transplant-related mortality (TRM) and survival for patients reported to the BSBMT with patients transplanted in the rest of Europe, reported to the European Group for Blood and Marrow Transplantation (EBMT). The outcomes for 104 allogeneic transplants for CML in 24 UK/Irish centres were compared with 775 allografts in 145 other European centres. For HD, 241 autografts from 38 UK/Irish centres were compared with 1145 transplants in 239 other European centres. For both diseases, the cohorts were broadly matched with the exception of CML, where 85% of patients were transplanted <1 year from diagnosis in the UK/Ireland compared with 68% in the EBMT (P = 0.001). Cox regression analysis was undertaken using known delineated variables affecting transplant outcome in addition to the registry of origin. The adjusted survival curves for CML showed no significant differences between the two groups, with 3-year survival probabilities of 70.2% and 67.1% for the EBMT and BSBMT cohorts respectively. Likewise, the analysis for HD showed overlapping survival curves, with 3-year survival probabilities of 71.8% (EBMT) and 70.8% (BSBMT). TRM was not statistically different in either disease. This study demonstrates the potential for using national registries to benchmark transplant outcome against the EBMT registry.

Adolescent↗
PubMed2003

Allogeneic transplantation for multiple myeloma: late relapse may occur as localised lytic lesion/plasmacytoma despite ongoing molecular remission.

Allogeneic SCT for myeloma may be curative for young patients, but its role remains controversial because of a reported high TRM in some series. Since 1991, we have performed 25 allografts for myeloma using fully matched sibling donors. Of the 18 evaluable patients, 13 achieved CR at a median time of 2.5 months post-transplant. The five patients who were not in CR when assessed at 3 months received a short course of alpha-interferon and four subsequently achieved CR with this approach at a median of 82 days. One patient who failed to respond to IFN went on to achieve CR after four doses of DLI therapy, thus giving an overall CR rate of 72%. Seven patients have relapsed at a median of 4.7 years post-transplant (range 1.38-7.7 years) including two patients who had received IFN therapy. In five of these cases, relapse has been as a localised area of bone disease or isolated plasmacytoma with no evidence of marrow involvement by trephine biopsy or molecular analysis. All patients with localised relapse were treated with local radiotherapy +/-DLI and four are currently disease free despite two patients having had further treatment for a second localised lesion. Six patients died of TRM (24%) and the OS at 8 years is currently 69% with an EFS of 26%. These results suggest that allogeneic SCT for myeloma can be carried out with an acceptable TRM and a high CR rate. However, late relapses as localised disease may be a frequent finding and may represent foci of myeloma not eradicated by the conditioning. The use of pretransplant MRI scanning and top-up radiotherapy to involved areas may be useful in preventing this type of relapse.

Adult↗
PubMed2003

High-dose melphalan followed by radical radiotherapy for the treatment of massive plasmacytoma of the chest wall.

We report three cases of massive chest wall plasmacytoma, each greater than 10 cm in diameter, without evidence of overt myeloma, whom we treated with a combination of VAD chemotherapy consolidated by high-dose melphalan and autologous peripheral blood stem cell transplantation and radical radiotherapy. All three patients completed all components of their therapy without experiencing any major side effects and one patient has had a durable remission. The other two patients have had disease progression but at sites other than the original tumour.

Antineoplastic Agents, Alkylating↗
PubMed2003

Methylation of the hMLH1 promoter and its association with microsatellite instability in acute myeloid leukemia.

The hMLH1 and hMSH2 genes are involved in the DNA mismatch repair (MMR) pathway. Defects in either of these genes have been associated with genetic instability in a wide variety of malignancies. A molecular mechanism involved in aberrant MMR gene expression is the epigenetic silencing of transcription by promoter methylation. The importance of MMR promoter methylation in leukemia is presently unclear and we have therefore undertaken a detailed analysis of the promoter regions of hMLH1 and hMSH2 using the technique of bisulfite genomic sequencing. DNA from 55 patients with acute myeloid leukemia (AML) including 23 patients with therapy-related AML (t-AML) have been analyzed. Two patients with de novo AML demonstrated extensive methylation throughout the whole hMLH1 region sequenced, one of whom had previously shown widespread genetic instability, measured as microsatellite instability (MSI). However methylation of hMLH1 was not found in t-AML which has previously been associated with MSI. In addition, methylation was seen at a restricted region of the hMLH1 promoter in both AML patients and healthy controls. The significance of this methylated region of the hMLH1 promoter is uncertain, however, our results confirm that in some patients with AML extensive methylation of hMLH1, but not of hMSH2 may occur, and as is the case in solid tumors this can be associated with the presence of a defective DNA mismatch repair pathway resulting in MSI.

Acute Disease↗