Chris Fegan
Cardiff University
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Publication
Featured researches published by Chris Fegan.
Journal of Clinical Oncology | 2005
Paul Moreton; Ben Kennedy; Guy Lucas; Michael Leach; Saad M.B. Rassam; Andrew P. Haynes; Jane Tighe; David Oscier; Chris Fegan; Andy C. Rawstron; Peter Hillmen
PURPOSE To test whether eradication of minimal residual disease (MRD) in B-cell chronic lymphocytic leukemia (CLL) by alemtuzumab is associated with a prolongation of treatment-free and overall survival. PATIENTS AND METHODS Ninety-one previously treated patients with CLL (74 men and 17 women; median age, 58 years [range, 32 to 75 years]; 44 were refractory to purine analogs) received a median of 9 weeks of alemtuzumab treatment between 1996 and 2003. Regular bone marrow assessments by MRD flow cytometry were performed with the aim of eradicating detectable MRD (< 1 CLL cell in 10(5) normal cells). RESULTS Responses according to National Cancer Institute-sponsored working group response criteria were complete remission (CR) in 32 patients (36%), partial remission (PR) in 17 patients (19%), and no response (NR) in 42 patients (46%). Twenty-two (50%) of 44 purine analog-refractory patients responded to alemtuzumab. Detectable CLL was eradicated from the blood and marrow in 18 patients (20%). Median survival was significantly longer in MRD-negative patients compared with those achieving an MRD-positive CR, PR, or NR. Patients achieving an MRD-negative CR had a longer treatment-free survival than patients with MRD-positive CRs, PR, or NR: MRD-negative CRs, not reached; MRD-positive CRs, 20 months; PRs, 13 months; NR, 6 months (P < .0001). Overall survival for the 18 patients with MRD-negative remissions was 84% at 60 months. Eight (47%) of the MRD-negative patients converted to MRD positivity at a median of 28 months. CONCLUSION MRD-negative remission in CLL is achievable with alemtuzumab, leading to an improved overall and treatment-free survival.
Blood | 2008
Chris Pepper; Thet Thet Lin; Guy Pratt; Saman Hewamana; Paul Brennan; Louise Hiller; Robert Kerrin Hills; Rachel Ward; Jane Starczynski; Belinda Austen; Laura Hooper; Tatjana Stankovic; Chris Fegan
Bcl-2 family proteins play a critical role in the regulation of apoptosis in chronic lymphocytic leukemia (CLL). However, their association with established prognostic markers is unknown. In this study, we analyzed the expression of Bcl-2, Bax, and Mcl-1 in 185 CLL patients and evaluated their relationship with other prognostic markers, in vitro sensitivity to fludarabine, and clinical outcome. Mcl-1 expression was significantly correlated with stage of disease (P < .001), lymphocyte doubling time (P = .01), V(H) gene mutation status (P < .001), CD38 expression (P < .001), and ZAP-70 expression (P = .003). In addition, Mcl-1 and Mcl-1/Bax ratios showed strong correlations with in vitro resistance to fludarabine (P = .005 and P < .001, respectively). Furthermore, elevated Mcl-1 expression and Mcl-1/Bax ratios were predictive of time to first treatment in the whole cohort (P < .001 and P < .001, respectively) and in stage A patients only (P = .002 and P = .001, respectively). Taken together, our data show that Mcl-1 is a key controller of in vitro drug resistance and is an important regulator of disease progression and outcome in CLL. It therefore represents a promising therapeutic target in this incurable condition. The close correlation between Mcl-1 expression and V(H) gene mutation status, CD38 expression, and ZAP-70 expression offers a biologic explanation for their association with adverse prognosis.
Blood | 2008
Saman Hewamana; Suhair Alghazal; Thet Thet Lin; Matthew Clement; Christopher Jenkins; Monica L. Guzman; Craig T. Jordan; Sundar Neelakantan; Peter A. Crooks; Alan Kenneth Burnett; Guy Pratt; Chris Fegan; Clare Rowntree; Paul Brennan; Chris Pepper
In this study, we characterized nuclear factor kappaB (NF-kappaB) subunit DNA binding in chronic lymphocytic leukemia (CLL) samples and demonstrated heterogeneity in basal and inducible NF-kappaB. However, all cases showed higher basal NF-kappaB than normal B cells. Subunit analysis revealed DNA binding of p50, Rel A, and c-Rel in primary CLL cells, and Rel A DNA binding was associated with in vitro survival (P = .01) with high white cell count (P = .01) and shorter lymphocyte doubling time (P = .01). NF-kappaB induction after in vitro stimulation with anti-IgM was associated with increased in vitro survival (P < .001) and expression of the signaling molecule ZAP-70 (P = .003). Prompted by these data, we evaluated the novel parthenolide analog, LC-1, in 54 CLL patient samples. LC-1 induced apoptosis in all the samples tested with a mean LD(50) of 2.8 microM after 24 hours; normal B and T cells were significantly more resistant to its apoptotic effects (P < .001). Apoptosis was preceded by a marked loss of NF-kappaB DNA binding and sensitivity to LC-1 correlated with basal Rel A DNA binding (P = .03, r(2) = 0.15). Furthermore, Rel A DNA binding was inversely correlated with sensitivity to fludarabine (P = .001, r(2) = 0.3), implicating Rel A in fludarabine resistance. Taken together, these data indicate that Rel A represents an excellent therapeutic target for this incurable disease.
Blood | 2010
Thet Thet Lin; Boitelo T. Letsolo; Rhiannon E. Jones; Jan Rowson; Guy Pratt; Saman Hewamana; Chris Fegan; Chris Pepper; Duncan Martin Baird
We performed single-molecule telomere length and telomere fusion analysis in patients at different stages of chronic lymphocytic leukemia (CLL). Our work identified the shortest telomeres ever recorded in primary human tissue, reinforcing the concept that there is significant cell division in CLL. Furthermore, we provide direct evidence that critical telomere shortening, dysfunction, and fusion contribute to disease progression. The frequency of short telomeres and fusion events increased with advanced disease, but importantly these were also found in a subset of early-stage patient samples, indicating that these events can precede disease progression. Sequence analysis of fusion events isolated from persons with the shortest telomeres revealed limited numbers of repeats at the breakpoint, subtelomeric deletion, and microhomology. Array-comparative genome hybridization analysis of persons displaying evidence of telomere dysfunction revealed large-scale genomic rearrangements that were concentrated in the telomeric regions; this was not observed in samples with longer telomeres. The telomere dynamics observed in CLL B cells were indistinguishable from that observed in cells undergoing crisis in culture after abrogation of the p53 pathway. Taken together, our data support the concept that telomere erosion and subsequent telomere fusion are critical in the progression of CLL and that this paradigm may extend to other malignancies.
Nature Genetics | 2014
Helen E. Speedy; Maria Chiara Di Bernardo; Georgina P. Sava; Martin J. S. Dyer; Amy Holroyd; Yufei Wang; Nicola J. Sunter; Larry Mansouri; Gunnar Juliusson; Karin E. Smedby; Göran Roos; Sandrine Jayne; Aneela Majid; Claire Dearden; Andrew G. Hall; Tryfonia Mainou-Fowler; Graham Jackson; Geoffrey Summerfield; Robert J. Harris; Andrew R. Pettitt; David Allsup; James R Bailey; Guy Pratt; Chris Pepper; Chris Fegan; Richard Rosenquist; Daniel Catovsky; James M. Allan; Richard S. Houlston
Genome-wide association studies (GWAS) of chronic lymphocytic leukemia (CLL) have shown that common genetic variation contributes to the heritable risk of CLL. To identify additional CLL susceptibility loci, we conducted a GWAS and performed a meta-analysis with a published GWAS totaling 1,739 individuals with CLL (cases) and 5,199 controls with validation in an additional 1,144 cases and 3,151 controls. A combined analysis identified new susceptibility loci mapping to 3q26.2 (rs10936599, P = 1.74 × 10−9), 4q26 (rs6858698, P = 3.07 × 10−9), 6q25.2 (IPCEF1, rs2236256, P = 1.50 × 10−10) and 7q31.33 (POT1, rs17246404, P = 3.40 × 10−8). Additionally, we identified a promising association at 5p15.33 (CLPTM1L, rs31490, P = 1.72 × 10−7) and validated recently reported putative associations at 5p15.33 (TERT, rs10069690, P = 1.12 × 10−10) and 8q22.3 (rs2511714, P = 2.90 × 10−9). These findings provide further insights into the genetic and biological basis of inherited genetic susceptibility to CLL.
Nature Genetics | 2013
Daniel Chubb; Niels Weinhold; Peter Broderick; Bowang Chen; David C. Johnson; Asta Försti; Jayaram Vijayakrishnan; Gabriele Migliorini; Sara E. Dobbins; Amy Holroyd; Dirk Hose; Brian A. Walker; Faith E. Davies; Walter A. Gregory; Graham Jackson; Julie Irving; Guy Pratt; Chris Fegan; James A. L. Fenton; Kai Neben; Per Hoffmann; Markus M. Nöthen; Thomas W. Mühleisen; Lewin Eisele; Fiona M. Ross; Christian Straka; Hermann Einsele; Christian Langer; Elisabeth Dörner; James M. Allan
To identify variants for multiple myeloma risk, we conducted a genome-wide association study with validation in additional series totaling 4,692 individuals with multiple myeloma (cases) and 10,990 controls. We identified four risk loci at 3q26.2 (rs10936599, P = 8.70 × 10−14), 6p21.33 (rs2285803, PSORS1C2, P = 9.67 × 10−11), 17p11.2 (rs4273077, TNFRSF13B, P = 7.67 × 10−9) and 22q13.1 (rs877529, CBX7, P = 7.63 × 10−16). These data provide further evidence for genetic susceptibility to this B-cell hematological malignancy, as well as insight into the biological basis of predisposition.
Bone Marrow Transplantation | 2000
Suparno Chakrabarti; Ke Collingham; Chris Fegan; D. Pillay; D. Milligan
Adenovirus has been recognised as an important pathogen in BMT recipients, especially in patients with GVHD and those receiving T cell-depleted allografts. We report adenovirus infections from an ongoing surveillance study in four patients after a non-myeloablative transplant and their improved outcome following withdrawal of immunosuppression in two patients and donor lymphocyte infusion for relapsed disease in the others. We discuss the control of adenovirus infections following immune manipulations and the feasibility of adoptive immunotherapy for post-transplant adenovirus infections. Bone Marrow Transplantation (2000) 26, 305–307.
Bone Marrow Transplantation | 1999
Suparno Chakrabarti; Ke Collingham; Chris Fegan; D. Milligan
Fulminant hepatic failure due to adenovirus infection is a rare complication following stem cell transplantation. We report this complication in an unrelated bone marrow transplant recipient 30 weeks post-transplant. Treatment with intravenous ribavirin was started within 36 h of admission, but he succumbed to unusually fulminant hepatic failure. Adenovirus type 2 was isolated from stool surveillance samples and from post-mortem liver samples. Adenovirus DNA was detected by PCR in blood and sputum samples at admission and was identified in post-mortem liver tissue by electron microscopy. Implications of the failure of ribavirin therapy are discussed.
Cancer Research | 2010
Andrea G. S. Buggins; Chris Pepper; Piers E.M. Patten; Saman Hewamana; Satyen Gohil; Jane Moorhead; Najeem'deen Folarin; Deborah Yallop; N. Shaun B. Thomas; Ghulam J. Mufti; Chris Fegan; Stephen Devereux
Chronic lymphocytic leukemia (CLL) cells rapidly undergo apoptosis in vitro, suggesting that the in vivo microenvironment provides crucial antiapoptotic signals. Overexpression of the antiapoptotic proteins Bcl-2 and Mcl-1 is a hallmark of CLL, and their expression is further enhanced in the lymphoid tissues. However, the high levels of Mcl-1 found in peripheral blood samples, coupled with its short half-life, led us to hypothesize that it must be actively maintained in the peripheral circulation. Coculture of CLL cells with human vascular endothelial cells significantly enhanced tumor cell survival, an effect that was not observed with normal B cells. This was associated with elevated levels of the antiapoptotic proteins Bcl-2, Mcl-1, and Bcl-X(L) and marked increased expression of CD38 and CD49d, both of which are associated with clinically aggressive disease. Because CD38, CD49d, and some Bcl-2 family genes are transcriptional targets for NF-κB, we assessed NF-κB activation following coculture with endothelial cells. DNA binding of the NF-κB subunit Rel A was significantly increased and strongly correlated with changes in transcription of CD38, CD49d, BCL2, MCL1, and BCLXL, effects that were reversed by a peptide inhibitor of Rel A. These effects were not observed following coculture with nonendothelial cell lines. Therefore, CLL cells receive specific survival signals following interaction with endothelial cells mediated through the activation of NF-κB and the induction of downstream target genes. This type of interaction in the peripheral vasculature may explain the constitutive NF-κB activation and the overexpression of Bcl-2 family proteins commonly seen in this disease.
Bone Marrow Transplantation | 1998
S. A. Brown; A. Goringe; Chris Fegan; S. V. Davies; John Charles Giddings; J. A. Whittaker; Alan Kenneth Burnett; Christopher H. Poynton
Hepatic veno-occlusive disease (VOD) of the liver is a common complication following high-dose cytotoxic therapy for bone marrow transplantation (BMT). The major pathological changes are seen in centrilobular (zone 3) hepatocytes and adjacent endothelium. Glutathione (GSH) becomes depleted following chemotherapy and experimental evidence suggests reduced levels predispose to centrilobular hepatocyte and endothelial cell injury. Animal studies have shown that glutamine infusions can maintain GSH levels and protect against free radical injury. We have prospectively studied the effect of glutamine supplementation during BMT. Thirty-four patients undergoing BMT were randomised to receive either glycl-L-glutamine (n = 18) or an isonitrogenous mixture of non-essential amino acids (n = 16). Glutamine was shown to significantly preserve protein C (days +4 and +7, P < 0.05) and albumin levels (days 0 and +4, P < 0.02). markers of thrombin and plasmin generation (thrombin-antithrombin, prothrombin fragment f1+2 and plasmin-antiplasmin levels) were not significantly changed between the two groups. these findings suggest that glutamine preserves hepatic function but does not alter thrombin or plasmin generation during bmt. previous studies have shown reductions in protein c, albumin, factor x and factor vii levels post bmt. falling protein c levels have been shown to be predictive of severe vod. these data suggest a role for glutamine in the protection of hepatic function following bmt.