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Finbarr E Cotter

Publications and source records attributed to Finbarr E Cotter.

18 recordsLinked to original sources
PubMed2006

Trinucleotide repeat dynamic mutation identifying susceptibility in familial and sporadic chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) has a strong hereditary component, but an understanding of predisposition genes is poor. Anticipation with familial CLL has been reported, although the molecular mechanism is unknown. Expansion of trinucleotide repeat sequences underlies anticipation observed in neurodegenerative disease. A polymerase chain reaction-based assay was used to analyse the stability of ten CCG- and CAG-trinucleotide repeat tracts in 18 CLL families and 140 patients with the sporadic form of the disease. The study suggests that anticipation, if it occurs in CLL, is not linked to CCG- and CAG-repeat expansion, however, variation in repeat length at certain loci (FRA16A) may permit identification of susceptible family members. In addition, polymorphisms with prognostic significance were identified. These were high length (but not expanded) repeats at FRA11B (P = 0.01), ATXN1 (P = 0.032) and ATXN3 (P = 0.022), all associated with poor risk disease.

Age of Onset↗
PubMed2006

Genomic and expression profiling identifies the B-cell associated tyrosine kinase Syk as a possible therapeutic target in mantle cell lymphoma.

Among B-cell lymphomas mantle cell lymphoma (MCL) has the worst prognosis. By using a combination of genomic and expression profiling (Affymetrix GeneChip Mapping 10k Xba131 and U133 set), we analysed 26 MCL samples to identify genes relevant to MCL pathogenesis and that could represent new therapeutic targets. Recurrent genomic deletions and gains were detected. Genes were identified as overexpressed in regions of DNA gain on 3q, 6p, 8q, 9q, 16p and 18q, including the cancer genes BCL2 and MYC. Among the transcripts with high correlation between DNA and RNA, we identified SYK, a tyrosine kinase involved in B-cell receptor signalling. SYK was amplified at DNA level, as validated by fluorescence in situ hybridisation (FISH) analysis, and overexpressed at both RNA and protein levels in the JeKo-1 cell line. Low-level amplification, with protein overexpression of Syk was demonstrated by FISH in a small subset of clinical samples. After treatment with low doses of the Syk inhibitor piceatannol, cell proliferation arrest and apoptosis were induced in the cell line overexpressing Syk, while cells expressing low levels of Syk were much less sensitive. A combination of genomic and expression profiling suggested Syk inhibition as a new therapeutic strategy to be explored in lymphomas.

Apoptosis↗
PubMed2005

Identification of a potential role for POU2AF1 and BTG4 in the deletion of 11q23 in chronic lymphocytic leukemia.

Deletions of 11q in chronic lymphocytic leukemia (CLL) are usually associated with progressive disease and poor prognosis. A novel translocation within the previously identified 11q minimal region has been defined in a patient with CLL. The breakpoint is between genes POU2AF1 and BTG4. POU2AF1 is a B-cell-specific transcriptional coactivator, and BTG4 is a member of the BTG family of negative regulators of the cell cycle, making both of them good candidate genes for the pathogenesis of 11q- CLL. POU2AF1 was observed to be differentially expressed in the cells of patients with CLL compared to its expression in normal B cells in the absence of mutations. This may reflect ongoing stimulation and active accessory signaling in CLL cells. BTG4 could contribute to CLL pathogenesis following inactivation by haploinsufficiency.

Base Sequence↗
PubMed2004

Targeting mitochondria to overcome conventional and bortezomib/proteasome inhibitor PS-341 resistance in multiple myeloma (MM) cells.

Bortezomib (PS-341), a selective inhibitor of proteasomes, induces apoptosis in multiple myeloma (MM) cells; however, prolonged drug exposure may result in cumulative toxicity and the development of chemoresistance. Here we show that combining PK-11195 (PK), an antagonist to mitochondrial peripheral benzodiazepine receptors (PBRs), with bortezomib triggers synergistic anti-MM activity even in doxorubicin-, melphalan-, thalidomide-, dexamethasone-, and bortezomib-resistant MM cells. No significant cytotoxicity was noted in normal lymphocytes. Low-dose combined PK and bortezomib treatment overcomes the growth, survival, and drug resistance conferred by interleukin-6 or insulin growth factor within the MM bone marrow milieu. The mechanism of PK + bortezomib-induced apoptosis includes: loss of mitochondrial membrane potential; superoxide generation; release of mitochondrial proteins cytochrome-c (cyto-c) and Smac; and activation of caspases-8/-9/-3. Furthermore, PK + bortezomib activates c-Jun NH2 terminal kinase (JNK), which translocates to mitochondria, thereby facilitating release of cyto-c and Smac from mitochondria to cytosol. Blocking JNK, by either dominant-negative mutant (DN-JNK) or cotreatment with a specific JNK inhibitor SP600125, abrogates both PK + bortezomib-induced release of cyto-c/Smac and induction of apoptosis. Together, these preclinical studies suggest that combining bortezomib with PK may enhance its clinical efficacy, reduce attendant toxicity, and overcome conventional and bortezomib resistance in patients with relapsed refractory MM.

Antineoplastic Agents↗
PubMed2004

Immunoglobulin heavy chain genes somatic hypermutations and chromosome 11q22-23 deletion in classic mantle cell lymphoma: a study of the Swiss Group for Clinical Cancer Research.

Mantle cell lymphoma (MCL) shares immunophenotypic and karyotypic features with chronic lymphocytic leukaemia. The latter comprises two distinct entities with prognosis dependent upon immunoglobulin heavy chain (IgH) gene mutational status and the presence of 11q deletion. We evaluated the relevance of IgH gene mutational status, IgV gene family usage and presence of 11q deletion in a series of 42 histologically reviewed classical MCL cases to determine the prognostic impact. VH3 was the most common VH family, with VH3-21 being the most frequent individual VH gene. Approximately 30% of the cases had a IgH somatic mutation rate higher than 2%, but was only higher than 4% in <10% of cases. Half of the cases had deletion of chromosome 11q21-telomere (11q21->ter), with two minimal deleted regions, at 11q22.2 and 11q23.2. There was no association between 11q loss and IgH gene somatic mutation rate; the use of VH3-21 gene could be associated with a better prognosis.

Aged↗
PubMed2004

Unraveling biologic therapy for Bcl-2-expressing malignancies.

Cancer cells that express excessive levels of Bcl-2 pose a major problem in the delivery of curative therapy. Most treatments for such cancer involve chemotherapy to induce the apoptotic process. While these therapies often result in disease control for periods of time, failure to initiate apoptosis as a result of acquired resistance limits the effectiveness of treatment for many common hematopoietic and solid malignancies, and ultimately death from the malignancy still occurs. Various anti-apoptotic proteins of the Bcl-2 family that localize to the mitochondria appear to be involved in this resistance mechanism. However, recent advances in the understanding of malignant cell biology, achieved through both genomics and proteomics, have made it possible to explore novel approaches directed at re-establishing sensitivity to chemotherapy, presenting an attractive strategy for cancer treatment. In this article we discuss how this may be achieved by lowering Bcl-2 anti-apoptotic protein expression using antisense oligonucleotides or, alternatively, by functionally antagonizing Bcl-2 using ligands of the mitochondrial benzodiazepine receptor.

Animals↗
PubMed2004

Microarray transcript profiling distinguishes the transient from the acute type of megakaryoblastic leukaemia (M7) in Down's syndrome, revealing PRAME as a specific discriminating marker.

Transient myeloproliferative disorder (TMD) is a unique, spontaneously regressing neoplasia specific to Down's syndrome (DS), affecting up to 10% of DS neonates. In 20-30% of cases, it reoccurs as progressive acute megakaryoblastic leukaemia (AMKL) at 2-4 years of age. The TMD and AMKL blasts are morphologically and immuno-phenotypically identical, and have the same acquired mutations in GATA1. We performed transcript profiling of nine TMD patients comparing them with seven AMKL patients using Affymetrix HG-U133A microarrays. Similar overall transcript profiles were observed between the two conditions, which were only separable by supervised clustering. Taqman analysis on 10 TMD and 10 AMKL RNA samples verified the expression of selected differing genes, with statistical significance (P < 0.05) by Student's t-test. The Taqman differences were also reproduced on TMD and AMKL blasts sorted by a fluorescence-activated cell sorter. Among the significant differences, CDKN2C, the effector of GATA1-mediated cell cycle arrest, was increased in AMKL but not TMD, despite the similar level of GATA1. In contrast, MYCN (neuroblastoma-derived oncogene) was expressed in TMD at a significantly greater level than in AMKL. MYCN has not previously been described in leukaemogenesis. Finally, the tumour antigen PRAME was identified as a specific marker for AMKL blasts, with no expression in TMD. This study provides markers discriminating TMD from AMKL-M7 in DS. These markers have the potential as predictive, diagnostic and therapeutic targets. In addition, the study provides further clues into the pathomechanisms discerning self-regressive from the progressive phenotype.

Acute Disease↗
PubMed2003

Acquired mutations in GATA1 in neonates with Down's syndrome with transient myeloid disorder.

Transient myeloid disorder is a unique self-regressing neoplasia specific to Down's syndrome. The transcription factor GATA1 is needed for normal growth and maturation of erythroid cells and megakaryocytes. Mutations in GATA1 have been reported in acute megakaryoblastic leukaemia in Down's syndrome. We aimed to investigate changes in GATA1 in patients with Down's syndrome and either transient myeloid disorder (n=10) or acute megakaryoblastic leukaemia (n=6). We recorded mutations eliminating exon 2 from GATA1 in all patients with transient myeloid disorder (age 0-24 days) and in all with acute megakaryoblastic leukaemia (age 14-38 months). The range of mutations did not differ between patients with each disorder. Patients with transient myeloid disorder with mutations in GATA1 can regress spontaneously to complete remission, and mutations do not necessarily predict later acute megakaryoblastic leukaemia.

Child, Preschool↗
PubMed2003

Role of DNA methylation in the suppression of Apaf-1 protein in human leukaemia.

Apaf-1 protein deficiency occurs in human leukaemic blasts and confers resistance to cytochrome-c-dependent apoptosis. Demethylation treatment with 5-aza-2'-deoxycytidine (5aza2dc) increased the sensitivity of the K562 leukaemic cell line to UV light-induced apoptosis in association with increased Apaf-1 protein levels. There was no correlation between Apaf-1 protein expression and Apaf-1 mRNA levels after the demethylation treatment. Methylation-specific polymerase chain reaction was used to show that the methylation can occur within the Apaf-1 promoter region in leukaemic blasts. Apaf-1 DNA methylation was demonstrated in acute myeloid leukaemia, chronic myeloid leukaemia and acute lymphoid leukaemia, suggesting that it is not specific to a particular leukaemia subtype. Apaf-1 protein expression did not correlate with Apaf-1 mRNA levels in human leukaemic blasts. Some leukaemic cells expressed high levels of Apaf-1 mRNA but low levels of Apaf-1 protein. This study suggests that Apaf-1 DNA promoter methylation might contribute to the inactivation of Apaf-1 expression. However, Apaf-1 protein levels might also be controlled at post-transcription level.

Apoptosis↗
PubMed2002

Molecular follow-up in gastric mucosa-associated lymphoid tissue lymphomas: early analysis of the LY03 cooperative trial.

Gastric marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT)-type can regress after anti-Helicobacter pylori treatment. The International Extranodal Lymphoma Study Group, the United Kingdom Lymphoma Group, and the Groupe d'Etude des Lymphomes de l'Adulte have conducted a trial to ascertain whether the addition of chlorambucil is of benefit after anti-H pylori therapy. At the last interim analysis, 105 (55%) of 189 patients had achieved a complete histologic remission after anti-Helicobacter therapy. To further assess the ability of treatment to eradicate the lymphoma clone, we analyzed the gastric biopsies from a subset of the patients by polymerase chain reaction (PCR) targeted to the immunoglobulin heavy chain genes as a molecular marker for minimal residual disease. Sixty-two cases were examined at diagnosis. Fifty-four cases were monoclonal by PCR. Forty-two of these patients achieved histologic complete remission (hCR) after anti-Helicobacter treatment: 34 cases underwent molecular follow-up analysis. Fifteen patients (44%) were in molecular remission with a median follow-up of 2 years after antibiotic treatment and of 1 year after the achievement of hCR. Less than half of the patients with MALT lymphoma can achieve sustained molecular remission after anti-Helicobacter therapy. The presence of molecular disease in the absence of histologic disease does not appear to be associated with histologic relapse, but, given the indolent nature of MALT lymphomas, a longer follow-up is needed.

Antineoplastic Agents, Alkylating↗
PubMed2002

In vitro and in vivo downregulation of MRP1 by antisense oligonucleotides: a potential role in neuroblastoma therapy.

The expression of MRP1 (multidrug resistance protein-1) is associated with chemoresistance and poor prognosis in neuroblastoma. MRP1 antisense oligonucleotides were used in an in vivo mouse-human xenograft model of neuroblastoma to downregulate MRP1. The MRP1 ASO reduced protein levels of MRP1 to an average of 40% of the nil treated controls (p = 0.007). There was significant chemosensitisation to single-agent chemotherapy, VP16 (etoposide), at 1 microg/mL (p = 0.035) and 10 microg/mL (p = 0.02) in comparison to tumours not receiving oligonucleotides. In contrast, MDR1-ASO produced significant chemosensitisation only at 10 microg/mL of VP16 (p = 0.029). No significant chemosensitisation was seen following nonsense oligonucleotides. The downregulation of MRP1 was also associated with an increase in tumour cell death (79% increase in apoptosis index p = 0.0313) and a reduction in cell turnover (42% reduction in mitotic index p = 0.0313), which was not seen with any other oligonucleotide. This new and novel perspective of MRP1 function, which is an apparent involvement in apoptosis and cell cycle progression in neuroblasts, presents a fresh avenue for investigation of the biologic consequences of MRP1 expression that occurs in many tumour cell types. Our work is the first to concurrently explore the effects of downregulation of MRP1 and MDR1 by antisense oligonucleotides in a neuroblastoma xenograft model. It provides rationale for the investigation of therapy adjuvants such as antisense oligonucleotides in the treatment of this malignancy.

Animals↗
PubMed2002

Association of mutations in the NALP3/CIAS1/PYPAF1 gene with a broad phenotype including recurrent fever, cold sensitivity, sensorineural deafness, and AA amyloidosis.

OBJECTIVE: Familial cold urticaria (FCU) and Muckle-Wells syndrome (MWS) are dominantly inherited autoinflammatory disorders that cause rashes, fever, arthralgia, and in some subjects, AA amyloidosis, and have been mapped to chromosome 1q44. Sensorineural deafness in MWS, and provocation of symptoms by cold in FCU, are distinctive features. This study was undertaken to characterize the genetic basis of FCU, MWS, and an overlapping disorder in French Canadian, British, and Indian families, respectively. METHODS: Mutations in the candidate gene NALP3, which has also been named CIAS1 and PYPAF1, were sought in the study families, in a British/Spanish patient with apparent sporadic MWS, and in matched population controls. Identified variants were sought in 50 European subjects with uncharacterized, apparently sporadic periodic fever syndromes, 48 subjects with rheumatoid arthritis (RA), and 19 subjects with juvenile idiopathic arthritis (JIA). RESULTS: Point mutations, encoding putative protein variants R262W and L307P, were present in all affected members of the Indian and French Canadian families, respectively, but not in controls. The R262W variant was also present in the subject with sporadic MWS. The V200M variant was present in all affected members of the British family with MWS, in 2 of the 50 subjects with uncharacterized periodic fevers, and in 1 of 130 Caucasian and 2 of 48 Indian healthy controls. No mutations were identified among the subjects with RA or JIA. CONCLUSION: These findings confirm that mutations in the NALP3/CIAS1/PYPAF1 gene are associated with FCU and MWS, and that disease severity and clinical features may differ substantially within and between families. Analysis of this gene will improve classification of patients with inherited or apparently sporadic periodic fever syndromes.

Adult↗
PubMed2002

PK11195, a peripheral benzodiazepine receptor ligand, chemosensitizes acute myeloid leukemia cells to relevant therapeutic agents by more than one mechanism.

Like Bcl-2, peripheral benzodiazepine receptors (pBzRs) reside in mitochondrial pores, are frequently over-expressed in tumor cells, and can protect cells from apoptotic cell death. We now show that the high-affinity, pBzR-specific ligand, PK11195, chemosensitizes AML cells to relevant chemotherapeutics, but is relatively non-toxic as a single agent, and does not chemosensitize normal myeloid cells. PK11195 can block p-glycoprotein efflux in AMLs, contributing to increased daunomycin toxicity in efflux-competent AMLs, but can also sensitize AMLs to cytarabine and DNR-sensitize efflux-incompetent AMLs, presumably via mitochondrial pore effects documented in other models. Therefore, PK11195 might contribute to improved clinical outcomes in AML.

Acute Disease↗
PubMed2002

Alloantigen-specific T-cell depletion in a major histocompatibility complex fully mismatched murine model provides effective graft-versus-host disease prophylaxis in the presence of lymphoid engraftment.

Graft-versus-host disease (GvHD) is a multistep immune process involving lymphocyte activation, proliferation and target cell killing. We have devised a novel method for the selective depletion of alloreactive cells from haematopoietic stem cell grafts which retains a pool of immunocompetent lymphocytes possessing antiviral activity with the potential to hasten immune reconstitution. The method is based upon the expression of the activation antigen CD69 on responding donor lymphocytes in a cytokine-modified mixed lymphocyte culture (mMLC) and depletion of these cells by paramagnetic bead sorting. We have previously demonstrated the in vitro efficacy of this system for the removal of alloreactive cells in both human leucocyte antigen-mismatched and -matched settings. Here, we describe a non-obese diabetic/severe combined immunodeficient murine model of aggressive GvHD in which we have tested its in vivo efficacy. Murine recipients of infusions of non-manipulated major histocompatibility complex class I and class II mismatched donor T cells suffered rapid onset of acute, and generally fatal, GvHD. This model is akin to aggressive clinical transfusion-related GvHD. Recipients of lymphocyte infusions depleted of CD69+ alloreactive donor cells ex vivo and monitored for 10 weeks post infusion demonstrated significantly improved survival (71.4% compared with 12.5% in the non-manipulated group) and the absence of clinical GvHD despite the presence of circulating donor lymphocytes.

Animals↗
PubMed2002

Mantle cell lymphoma: new treatments targeted to the biology.

Mantle cell lymphoma (MCL) represents a distinct lymphoma subtype. The prognosis of patients with MCL is the poorest among lymphoma patients and the response to conventional treatments is inadequate. New approaches targeted to the biology of MCL and the genetics underlying the disease are being studied. Monoclonal antibodies directed at molecules expressed on MCL cells are already used in the clinical setting. This article reviews the literature on these and other new possible treatment modalities.

Aged↗