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ABSTRACT: Simian varicella virus (SVV) infection of rhesus macaques (RM) recapitulates the hallmarks of varicella zoster virus (VZV) infection of humans including the establishment of latency within the sensory ganglia. Various factors including age and immune fitness influence the outcome of primary VZV infection as well as reactivation resulting in herpes zoster (HZ). To increase our understanding of the role of lymphocyte subsets in the establishment of viral latency, we analyzed the latent SVV transcriptome in juvenile RMs depleted of CD4 T, CD8 T, or CD20 B lymphocytes during acute infection. We have previously shown that SVV latency in sensory ganglia of non-depleted juvenile RMs is associated with a limited transcriptional profile. In contrast, CD4 depletion during primary infection resulted in the failure to establish a characteristic latent viral transcription profile in sensory ganglia where we detected 68 out of 69 SVV-encoded open reading frames (ORFs). CD8 depleted RMs displayed a latent transcriptional profile that included additional viral transcripts within the core region of the genome not detected in control RMs. The latent transcriptome of CD20 depleted RMs was comparable to latent transcription in sensory ganglia of control RMs. Lastly, we investigated the impact of age on the establishment of SVV latency. SVV gene expression in ganglia from two aged RMs was more active than in juvenile RMs with the detection of 25 out of 69 SVV transcripts. Therefore, immune fitness at the time of infection modulates the establishment and/or maintenance of SVV latency.
Journal of Virology 05/2013; · 5.40 Impact Factor
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ABSTRACT: In contrast to seasonal influenza virus infections, which typically cause significant morbidity and mortality in the elderly, the 2009 H1N1 virus caused severe infection in young adults. This phenomenon was attributed to the presence of cross-protective antibodies acquired by older individuals during previous exposures to H1N1 viruses. However, this hypothesis could not be empirically tested. To address this question, we compared viral replication and the development of the immune response in naïve young adult and aged female rhesus macaques infected with A/California/04/2009 H1N1 (CA04) virus. We show higher viral loads in the bronchoalveolar lavage (BAL) fluid and nasal and ocular swabs in aged animals, suggesting increased viral replication in both the lower and upper respiratory tracts. T cell proliferation was higher in the BAL fluid but delayed and reduced in peripheral blood in aged animals. This delay in proliferation correlated with a reduced frequency of effector CD4 T cells in old animals. Aged animals also mobilized inflammatory cytokines to higher levels in the BAL fluid. Finally, we compared changes in gene expression using microarray analysis of BAL fluid samples. Our analyses revealed that the largest difference in host response between aged and young adult animals was detected at day 4 postinfection, with a significantly higher induction of genes associated with inflammation and the innate immune response in aged animals. Overall, our data suggest that, in the absence of preexisting antibodies, CA04 infection in aged macaques is associated with changes in innate and adaptive immune responses that were shown to correlate with increased disease severity in other respiratory disease models.
Journal of Virology 08/2012; 86(20):11115-27. · 5.40 Impact Factor
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ABSTRACT: Aging is associated with a general dysregulation in immune function, commonly referred to as "immune senescence". Several studies have shown that female sex steroids can modulate the immune response. However, the impact of menopause-associated loss of estrogen and progestins on immune senescence remains poorly understood. To help answer this question, we examined the effect of ovariectomy on T-cell homeostasis and function in adult and aged female rhesus macaques. Our data show that in adult female rhesus macaques, ovariectomy increased the frequency of naïve CD4 T cells. In contrast, ovariectomized (ovx) aged female rhesus macaques had increased frequency of terminally differentiated CD4 effector memory T cells and inflammatory cytokine-secreting memory T cells. Moreover, ovariectomy reduced the immune response (T-cell cytokine and IgG production) following vaccination with modified vaccinia ankara in both adult and aged female rhesus macaques compared to ovary-intact age-matched controls. Interestingly, hormone therapy (estradiol alone or in conjunction with progesterone) partially improved the T-cell response to vaccination in aged ovariectomized female rhesus macaques. These data suggest that the loss of ovarian steroids, notably estradiol and progesterone, may contribute to reduced immune function in post-menopausal women and that hormone therapy may improve immune response to vaccination in this growing segment of the population.
Age 09/2011; 33(3):275-89. · 6.28 Impact Factor
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ABSTRACT: The growth factor receptor-bound protein-7 gene (GRB7) encodes a multi-domain signal transduction molecule. The purpose of this study was to examine the clinical significance of GRB7 protein expression in human breast cancer. Western blotting analysis of protein extracts from 563 annotated frozen breast tumors was performed. Expression status of GRB7 and HER-2 was correlated with clinical covariates and outcomes. Cox proportional hazards were used to identify factors associated with breast cancer-free interval. The median follow-up was 71 months. P values <0.05 were considered statistically significant (two-sided). A discrepancy between HER-2 and GRB7 protein over-expression was observed. GRB7 protein over-expression was associated with negative estrogen and progesterone receptor status, higher tumor grade, larger primary tumor size, (more) axillary lymph node involvement, higher clinical stage, and shortened breast cancer-free interval. HER-2 protein over-expression was associated only with higher tumor grade. Multi-variate analysis revealed that GRB7 protein over-expression was an independent adverse prognostic factor for breast cancer-free interval (hazard ratio 1.69, 95% confidence interval 1.07-2.67; P = 0.024). The same was true of the subset of patients who did not receive any adjuvant systemic therapy (hazard ratio 1.68, 95% confidence interval 1.16-2.31; P = 0.0055). Using FISH analysis, 32/32 (100%; 95% CI 89-100%) tumors which over-expressed both HER-2 and GRB7 proteins and 1/35 (3%; 95% CI 0-15%) tumors with HER-2 but no GRB7 protein over-expression with Western blotting analysis demonstrated HER-2 gene amplification. GRB7 protein over-expression is an independent adverse prognostic factor in human breast cancer.
Breast Cancer Research and Treatment 06/2011; 127(3):659-69. · 4.43 Impact Factor
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ABSTRACT: The purpose of this study was to determine the neurotoxicity of two commonly used herbicides: picloram and triclopyr and the neuroprotective effects of the mitochondria-targeted antioxidant, SS31. Using mouse neuroblastoma (N2a) cells and primary neurons from C57BL/6 mice, we investigated the toxicity of these herbicides, and protective effects of SS1 peptide against picloram and triclopyr toxicity. We measured total RNA content, cell viability and mRNA expression of peroxiredoxins, neuroprotective genes, mitochondrial-encoded electron transport chain (ETC) genes in N2a cells treated with herbicides and SS31. Using primary neurons from C57BL/6 mice, neuronal survival was studied in neurons treated with herbicides, in neurons pretreated with SS31 plus treated with herbicides, neurons treated with SS31 alone, and untreated neurons. Significantly decreased total RNA content, and cell viability in N2a cells treated with picloram and triclopyr were found compared to untreated N2a cells. Decreased mRNA expression of neuroprotective genes, and ETC genes in cells treated with herbicides was found compared to untreated cells. Decreased mRNA expression of peroxiredoxins 1-6 in N2a cells treated with picloram was found, suggesting that picloram affects the antioxidant enzymes in N2a cells. Immunofluorescence analysis of primary neurons revealed that decreased neuronal branching and degenerating neurons in neurons treated with picloram and triclopyr. However, neurons pretreated with SS31 prevented degenerative process caused by herbicides. Based on these results, we propose that herbicides--picloram and triclopyr appear to damage neurons, and the SS31 peptide appears to protect neurons from herbicide toxicity.
International Journal of Environmental Research and Public Health 01/2011; 8(1):203-21. · 1.61 Impact Factor
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Luka Cicin-Sain,
Susan Smyk-Pearson,
Sue Smyk-Paerson,
Noreen Currier,
Laura Byrd,
Caroline Koudelka,
Tammie Robinson,
Gwendolyn Swarbrick,
Shane Tackitt,
Alfred Legasse,
Miranda Fischer,
Dragana Nikolich-Zugich, Byung Park,
Theodore Hobbs,
Cynthia J Doane,
Motomi Mori,
Michael K Axthelm,
Michael T Axthelm,
Deborah A Lewinsohn,
Janko Nikolich-Zugich
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ABSTRACT: Aging is usually accompanied by diminished immune protection upon infection or vaccination. Although aging results in well-characterized changes in the T cell compartment of long-lived, outbred, and pathogen-exposed organisms, their relevance for primary Ag responses remain unclear. Therefore, it remains unclear whether and to what extent the loss of naive T cells, their partial replacement by oligoclonal memory populations, and the consequent constriction of TCR repertoire limit the Ag responses in aging primates. We show in this study that aging rhesus monkeys (Macaca mulatta) exhibit poor CD8 T cell and B cell responses in the blood and poor CD8 responses in the lungs upon vaccination with the modified vaccinia strain Ankara. The function of APCs appeared to be maintained in aging monkeys, suggesting that the poor response was likely intrinsic to lymphocytes. We found that the loss of naive CD4 and CD8 T cells, and the appearance of persisting T cell clonal expansions predicted poor CD8 responses in individual monkeys. There was strong correlation between early CD8 responses in the transitory CD28+ CD62L- CD8+ T cell compartment and the peak Ab titers upon boost in individual animals, as well as a correlation of both parameters of immune response to the frequency of naive CD8+ T cells in old but not in adult monkeys. Therefore, our results argue that T cell repertoire constriction and naive cell loss have prognostic value for global immune function in aging primates.
The Journal of Immunology 06/2010; 184(12):6739-45. · 5.79 Impact Factor
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ABSTRACT: The purpose of our study was to investigate the effects of the mitochondria-targeted antioxidants, MitoQ and SS31, and the anti-aging agent resveratrol on neurons from a mouse model (Tg2576 line) of Alzheimer's disease (AD) and on mouse neuroblastoma (N2a) cells incubated with the amyloid-beta (Abeta) peptide. Using electron and confocal microscopy, gene expression analysis, and biochemical methods, we studied mitochondrial structure and function and neurite outgrowth in N2a cells treated with MitoQ, SS31, and resveratrol, and then incubated with Abeta. In N2a cells only incubated with the Abeta, we found increased expressions of mitochondrial fission genes and decreased expression of fusion genes and also decreased expression of peroxiredoxins. Electron microscopy of the N2a cells incubated with Abeta revealed a significantly increased number of mitochondria, indicating that Abeta fragments mitochondria. Biochemical analysis revealed that function is defective in mitochondria. Neurite outgrowth was significantly decreased in Abeta-incubated N2a cells, indicating that Abeta affects neurite outgrowth. However, in N2a cells treated with MitoQ, SS31, and resveratrol, and then incubated with Abeta, abnormal expression of peroxiredoxins and mitochondrial structural genes were prevented and mitochondrial function was normal; intact mitochondria were present and neurite outgrowth was significantly increased. In primary neurons from amyloid-beta precursor protein transgenic mice that were treated with MitoQ and SS31, neurite outgrowth was significantly increased and cyclophilin D expression was significantly decreased. These findings suggest that MitoQ and SS31 prevent Abeta toxicity, which would warrant the study of MitoQ and SS31 as potential drugs to treat patients with AD.
Journal of Alzheimer's disease: JAD 01/2010; 20 Suppl 2:S609-31. · 3.74 Impact Factor
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ABSTRACT: The purpose of our study was to investigate microglia and astrocytes that are associated with human mutant amyloid precursor protein and amyloid beta (Abeta). We investigated whether the anti-granulocyte-macrophage-colony stimulating factor (GM-CSF) antibody can suppress microglial activity and decrease Abeta production in Alzheimer's disease transgenic mice (Tg2576 line). An antibody to mouse GM-CSF was introduced by intracerebroventricular (ICV) injections into the brains of 10-month-old Tg2576 male mice. We assessed the effect of several GM-CSF-associated cytokines on microglial activities and their association with Abeta using quantitative real-time RT-PCR, immunoblotting, immunohistochemistry analyses in anti-GM-CSF antibody-injected Tg2576 mice. Using sandwich ELISA technique, we measured intraneuronal Abeta in Tg2576 mice injected with GM-CSF antibody and PBS vehicle-injected control Tg2576 mice. Using double-labeling immunofluorescence analysis of intraneuronal Abeta, Abeta deposits and pro-inflammatory cytokines, we assessed the relationship between Abeta deposits and microglial markers in the Tg2576 mice, and also in the anti-GM-CSF antibody-injected Tg2576 mice. Our real-time RT-PCR analysis showed an increase in the mRNA expression of IL6, CD11c, IL1beta, CD40 and CD11b in the cerebral cortices of the Tg2576 mice compared with their littermate non-transgenic controls. Immunohistochemistry findings of microglial markers agreed with our real-time RT-PCR results. Interestingly, we found significantly decreased levels of activated microglia and Abeta deposits in anti-GM-CSF antibody-injected Tg2576 mice compared with PBS vehicle-injected Tg2576 mice. Findings from our real-time RT-PCR and immunoblotting analysis agreed with immunohistochemistry results. Our double-labeling analyses of intraneuronal Abeta and CD40 revealed that intraneuronal Abeta is associated with neuronal expression of CD40 in Tg2576 mice. Our quantitative sandwich ELISA analysis revealed decreased levels of soluble Abeta1-42 and increased levels of Abeta1-40 in Tg2576 mice injected with the anti-GM-CSF antibody, suggesting that anti-GM-CSF antibody alone decreases soluble Abeta1-42 production and suppresses microglial activity in Tg2576 mice. These findings indicating the ability of the anti-GM-CSF antibody to reduce Abeta1-42 and microglial activity in Tg2576 mice may have therapeutic implications for Alzheimer's disease.
Human Molecular Genetics 08/2009; 18(20):3876-93. · 7.64 Impact Factor
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ABSTRACT: Fatigue is a major nonmotor symptom in Parkinson disease(PD). It is associated with reduced activity and lower quality of life.
To determine if modafinil improves subjective fatigue and physical fatigability in PD.
Nineteen PD patients who reported significant fatigue in the Multidimensional Fatigue Inventory (MFI) participated in this 8-week study. Subjects took their regular medications and were randomly assigned to the treatment group (9 subjects, modafinil 100-mg capsule BID) or placebo group (10 subjects). We used the MFI to measure subjective fatigue and used finger tapping and intermittent force generation to evaluate physical fatigability. Subjects also completed the Epworth Sleepiness Scale (ESS) and the Center of Epidemiological Study-Depression Scale.
There were no significant differences at baseline and at 1 month in finger tapping and ESS between the modafinil and placebo groups. At 2 months, the modafinil group had a higher tapping frequency (P<0.05), shorter dwell time (P<0.05), and less fatigability in finger tapping and tended to have lower ESS scores (P<0.12) than the placebo group. However, there was no difference between groups over time for any dimension of the MFI .
This small study demonstrated that although modafinil may be effective in reducing physical fatigability in PD, it did not improve fatigue symptoms.
Clinical neuropharmacology 07/2009; 32(6):305-10. · 2.35 Impact Factor
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Luka Cicin-Sain,
Ilhem Messaoudi, Byung Park,
Noreen Currier,
Shannon Planer,
Miranda Fischer,
Shane Tackitt,
Dragana Nikolich-Zugich,
Alfred Legasse,
Michael K Axthelm,
Louis J Picker,
Motomi Mori,
Janko Nikolich-Zugich
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ABSTRACT: The loss of naïve T cells is a hallmark of immune aging. Although thymic involution is a primary driver of this naïve T cell loss, less is known about the contribution of other mechanisms to the depletion of naïve T cells in aging primates. We examined the role of homeostatic cycling and proliferative expansion in different T cell subsets of aging rhesus macaques (RM). BrdU incorporation and the expression of the G(1)-M marker Ki-67 were elevated in peripheral naïve CD4 and even more markedly in the naïve CD8 T cells of old, but not young adult, RM. Proliferating naïve cells did not accumulate in old animals. Rather, the relative size of the naïve CD8 T cell compartment correlated inversely to its proliferation rate. Likewise, T cell receptor diversity decreased in individuals with elevated naïve CD8 T cell proliferation. This apparent contradiction was explained by a significant increase in turnover concomitant with the naïve pool loss. The turnover increased exponentially when the naïve CD8 T cell pool decreased below 4% of total blood CD8 cells. These results link the shrinking naïve T cell pool with a dramatic increase in homeostatic turnover, which has the potential to exacerbate the progressive exhaustion of the naïve pool and constrict the T cell repertoire. Thus, homeostatic T cell proliferation exhibits temporal antagonistic pleiotropy, being beneficial to T cell maintenance in adulthood but detrimental to the long-term T cell maintenance in aging individuals.
Proceedings of the National Academy of Sciences 01/2008; 104(50):19960-5. · 9.68 Impact Factor
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Michael W N Deininger,
Jorge Cortes,
Ron Paquette, Byung Park,
Andreas Hochhaus,
Michele Baccarani,
Richard Stone,
Thomas Fischer,
Hagop Kantarjian,
Dietger Niederwieser,
Carlo Gambacorti-Passerini,
Charlene So,
Insa Gathmann,
John M Goldman,
Douglas Smith,
Brian J Druker,
François Guilhot
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ABSTRACT: Clonal cytogenetic abnormalities (CCA) were detected in Philadelphia chromosome (Ph)-negative cells in some patients with chronic myeloid leukemia (CML) who attained a cytogenetic response to imatinib mesylate. In some patients, CCA/Ph-negative status was associated with myelodysplasia or acute myeloid leukemia. The objective of the current study was to determine the prognostic impact of CCA/Ph-negative cells.
The authors compared the pretherapeutic risk factors (Kruskall-Wallis test), exposure to cytotoxic drugs (chi-square test), and overall and progression-free survival (Kaplan-Meyer and logistic regression analysis, respectively) of 515 patients with mostly chronic-phase CML who were treated with imatinib mesylate after failure of interferon-alpha according to whether they attained a major cytogenetic response (MCR) (n = 324 patients), an MCR with CCA/Ph-negative status (n = 30 patients), or no MCR (n = 161 patients).
CCA/Ph-negative status most frequently involved chromosomes Y, 8, and 7. No significant differences in pretherapeutic risk factors were detected between patients who attained an MCR with and without CCA/Ph-negative cells, except that exposure to alkylating agents was more frequent in patients with CCA/Ph-negative cells, and overall and progression-free survival were identical. With a median follow-up of 51 months, only 2 patients developed myelodysplastic syndromes (MDS).
The overall prognosis for patients who had CML with CCA/Ph-negative status was good and was driven by the CML response to imatinib mesylate. Isolated CCA/Ph-negative cells in the absence of morphologic evidence of MDS do not justify a change in therapy.
Cancer 11/2007; 110(7):1509-19. · 4.77 Impact Factor
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ABSTRACT: Normal left ventricular contraction involves a twisting component that helps augment stroke volume, the unwinding of which also very usefully contributes to early diastolic filling. Abnormalities of cardiac twist have been related to abnormal cardiac function. We sought to quantify the twisting action using a new sonographically based angle-independent motion-detecting echo method.
A twist model was developed with a variable-speed motor to rotate a wheel in water bath. A freshly harvested pig heart was mounted on it as a twist phantom. Short axis views were acquired with a GE/VingMed Vivid 7 system (GE Healthcare, Milwaukee, WI) at 3.5 MHz and more than 100 frames/s. Eight different speeds (30-100 cycles/min of winding and unwinding) were studied at 5 degrees of rotation (10 degrees , 20 degrees , 30 degrees , 40 degrees , and 50 degrees ). Data were analyzed off-line for twist analysis with a new 2-dimensional speckle-tracking-based program (2-dimensional strain rate method [2DSR]) embedded in EchoPac software (GE Healthcare). Ten freshly harvested pig hearts were studied in this model.
The 2DSR program tracked the twist well (mean determination at 10 degrees = 16.88 degrees +/- 1.81 degrees [SD]; at 20 degrees = 26.5 degrees +/- 1.05 degrees ; at 30 degrees = 36.47 degrees +/- 1.31 degrees ; at 40 degrees = 44.03 degrees +/- 1.39 degrees ; and at 50 degrees = 54.1 degrees +/- 1.96 degrees ).
The 2DSR program can be used to study twisting action of the heart.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 10/2006; 25(9):1193-8. · 1.25 Impact Factor
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ABSTRACT: Calcitriol, the natural ligand for the vitamin D receptor, has significant potential in prostate cancer treatment. Measurement of its antineoplastic activity in prostate cancer clinical trials may be complicated by effects of calcitriol on prostate-specific antigen (PSA) production. We examined the effects of calcitriol at similar concentration on cell proliferation, androgen receptor (AR) expression, and PSA production in vitro and on PSA concentrations in prostate cancer patients.
LNCaP prostate cancer cell proliferation was examined by cell counts 6 days after exposure to a range of concentrations of calcitriol. AR and PSA protein was quantified in LNCaP cells over 96 hours after exposure to 1 nmol/L calcitriol. Serum PSA and free PSA was serially measured by immunoassay over a period of 8 days in patients with hormone-naïve prostate cancer after a single dose of 0.5 microg/kg calcitriol.
Calcitriol treatment resulted in dose-dependent growth inhibition of LNCaP with approximately 50% growth inhibition at the clinically achievable concentration of 1 nmol/L. Time-dependent up-regulation of AR expression and of PSA production in LNCaP cells was shown at the same concentration. No significant change in serum PSA or free PSA over 8 days was seen in eight subjects treated with a single dose of 0.5 microg/kg calcitriol. The analysis was powered to detect a 1.23-fold change between the baseline and day 8 serum PSA.
At clinically achievable concentrations, calcitriol inhibits growth and induces AR and PSA expression in LNCaP cells. We did not detect similar changes in serum PSA or free PSA in patients exposed to similar concentrations of calcitriol. Thus, a PSA flare, predicted by preclinical systems, is unlikely to occur in patients and therefore unlikely to complicate interpretation of clinical trial outcomes.
Clinical Cancer Research 06/2006; 12(9):2812-6. · 7.74 Impact Factor
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ABSTRACT: Patients with chronic myeloid leukemia (CML) treated with imatinib in early chronic phase tend to have durable remissions, but there is a high rate of relapse in patients with advanced disease. Mutations in the kinase domain of BCR-ABL that impair drug binding have been identified as the major mechanism of resistance. It is not known when exactly these mutations arise, but in some patients retrospective analysis of pretherapeutic samples demonstrated identical mutations, suggesting selection in the presence of drug. In the present study we have used a highly sensitive PCR assay to screen for kinase domain mutations in pretherapeutic samples from CML patients, irrespective of their subsequent response to imatinib. We find that kinase domain mutations are demonstrable in approximately 1/3 of patients with accelerated phase or blast crisis and that the presence of two copies of the Philadelphia chromosome is strongly correlated with mutation detection. Unexpectedly, kinase domain mutant clones were not invariably selected in the presence of drug, suggesting that additional mechanisms must contribute to a fully drug resistant leukemia.
Cell cycle (Georgetown, Tex.) 01/2006; 4(12):1761-6. · 5.36 Impact Factor
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Stephanie G Willis,
Thoralf Lange,
Shadmehr Demehri,
Sandra Otto,
Lucy Crossman,
Dietger Niederwieser,
Eric P Stoffregen,
Shannon McWeeney,
Ines Kovacs, Byung Park,
Brian J Druker,
Michael W Deininger
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ABSTRACT: Mutations in the kinase domain (KD) of BCR-ABL are the leading cause of acquired imatinib resistance. In some cases, identical mutations were detected at relapse and in pretherapeutic specimens, consistent with selection of resistant clones in the presence of drug. However, the incidence of KD mutations in imatinibnaive patients, irrespective of response to therapy, is unknown. We studied mutation frequency in 66 patients with chronic myelogenous leukemia (CML), using cDNA sequencing and allele-specific oligonucleotide-polymerase chain reaction (ASO-PCR) assays for 8 common mutations. Thirteen patients were positive by ASO-PCR only, 1 by ASO-PCR and sequencing, and 1 by sequencing only (overall frequency, 22.7%). T315I was most frequent (12% of patients). Eleven of the 14 patients with positive ASO-PCR had follow-up samples available for sequencing. Wild-type sequence was detected in 6 of 11, 2 different mutations in 1 of 11, and identical mutations in 4 of 11 patients, 2 of whom had achieved major cytogenetic response. In multivariate analysis mutation detection was associated with clonal cytogenetic evolution, exposure to 6-Thioguanine, and a low platelet count, but not with response to imatinib, event-free survival, and overall survival. KD mutants present at low levels do not invariably lead to relapse, and additional factors are required to induce a fully drug-resistant phenotype.
Blood 10/2005; 106(6):2128-37. · 9.90 Impact Factor