Blood gene signature for early hepatocellular carcinoma detection in patients with chronic hepatitis B.

PURPOSE: Up to 25% of chronic hepatitis B (CHB) patients eventually develop hepatocellular carcinoma (HCC), a disease with poor prognosis unless detected early. This study identifies a blood-based RNA biomarker panel for early HCC detection in CHB. MATERIALS AND METHODS: A genome-wide RNA expression study was performed using RNA extracted from blood samples from Malaysian patients (matched HCC, CHB, controls). Genes differentiating HCC from controls were selected for further testing using quantitative real-time polymerase chain reaction. Finally, a 6-gene biomarker panel was identified and characterized using a training set (cohort I = 126), and tested against 2 test sets (cohort II = 222; cohort III = 174). The total number of samples used for each group is: HCC + CHB = 143, CHB = 211, control = 168. RESULTS: Our gene panel displays a consistent trend distinguishing HCC from controls in our test sets, with an area under receiver-operating characteristic curve of 0.9 in cohort III. Our independent test set (cohort III) showed that the gene panel had a sensitivity of 70% with a specificity of 92%. The biomarker profile for HCC was consistently detected in a small subgroup of CHB patients, thus potentially predicting early, preclinical cases of cancer that should be screened more intensively. CONCLUSION: The biomarkers identified in this study can be used as the basis of a blood-based test for the detection of early HCC in CHB.

Blood-based biomarkers of aggressive prostate cancer.

PURPOSE: Prostate cancer is a bimodal disease with aggressive and indolent forms. Current prostate-specific-antigen testing and digital rectal examination screening provide ambiguous results leading to both under-and over-treatment. Accurate, consistent diagnosis is crucial to risk-stratify patients and facilitate clinical decision making as to treatment versus active surveillance. Diagnosis is currently achieved by needle biopsy, a painful procedure. Thus, there is a clinical need for a minimally-invasive test to determine prostate cancer aggressiveness. A blood sample to predict Gleason score, which is known to reflect aggressiveness of the cancer, could serve as such a test. MATERIALS AND METHODS: Blood mRNA was isolated from North American and Malaysian prostate cancer patients/controls. Microarray analysis was conducted utilizing the Affymetrix U133 plus 2·0 platform. Expression profiles from 255 patients/controls generated 85 candidate biomarkers. Following quantitative real-time PCR (qRT-PCR) analysis, ten disease-associated biomarkers remained for paired statistical analysis and normalization. RESULTS: Microarray analysis was conducted to identify 85 genes differentially expressed between aggressive prostate cancer (Gleason score ≥8) and controls. Expression of these genes was qRT-PCR verified. Statistical analysis yielded a final seven-gene panel evaluated as six gene-ratio duplexes. This molecular signature predicted as aggressive (ie, Gleason score ≥8) 55% of G6 samples, 49% of G7(3+4), 79% of G7(4+3) and 83% of G8-10, while rejecting 98% of controls. CONCLUSION: In this study, we have developed a novel, blood-based biomarker panel which can be used as the basis of a simple blood test to identify men with aggressive prostate cancer and thereby reduce the overdiagnosis and overtreatment that currently results from diagnosis using PSA alone. We discuss possible clinical uses of the panel to identify men more likely to benefit from biopsy and immediate therapy versus those more suited to an "active surveillance" strategy.

Whole blood transcriptome correlates with treatment response in nasopharyngeal carcinoma.

BACKGROUND: Treatment protocols for nasopharyngeal carcinoma (NPC) developed in the past decade have significantly improved patient survival. In most NPC patients, however, the disease is diagnosed at late stages, and for some patients treatment response is less than optimal. This investigation has two aims: to identify a blood-based gene-expression signature that differentiates NPC from other medical conditions and from controls and to identify a biomarker signature that correlates with NPC treatment response. METHODS: RNA was isolated from peripheral whole blood samples (2 x 10 ml) collected from NPC patients/controls (EDTA vacutainer). Gene expression patterns from 99 samples (66 NPC; 33 controls) were assessed using the Affymetrix array. We also collected expression data from 447 patients with other cancers (201 patients) and non-cancer conditions (246 patients). Multivariate logistic regression analysis was used to obtain biomarker signatures differentiating NPC samples from controls and other diseases. Differences were also analysed within a subset (n=28) of a pre-intervention case cohort of patients whom we followed post-treatment. RESULTS: A blood-based gene expression signature composed of three genes - LDLRAP1, PHF20, and LUC7L3 - is able to differentiate NPC from various other diseases and from unaffected controls with significant accuracy (area under the receiver operating characteristic curve of over 0.90). By subdividing our NPC cohort according to the degree of patient response to treatment we have been able to identify a blood gene signature that may be able to guide the selection of treatment. CONCLUSION: We have identified a blood-based gene signature that accurately distinguished NPC patients from controls and from patients with other diseases. The genes in the signature, LDLRAP1, PHF20, and LUC7L3, are known to be involved in carcinoma of the head and neck, tumour-associated antigens, and/or cellular signalling. We have also identified blood-based biomarkers that are (potentially) able to predict those patients who are more likely to respond to treatment for NPC. These findings have significant clinical implications for optimizing NPC therapy.

Amelioration of the Alzheimer's disease phenotype by absence of 12/15-lipoxygenase.

BACKGROUND: Alzheimer's disease (AD) is a chronic neurodegenerative disorder whose initiating events are not known. Increasing evidence suggests that oxidative stress and inflammation play a role in its pathogenesis. 12/15 Lipoxygenase (12/15LO) by oxidizing polyunsaturated fatty acids forms hydroperoxyacids, which are potent pro-oxidants and inflammatory mediators. Previously, we reported that this metabolic pathway is increased in AD. METHODS: Here we explore the effect of genetic deletion of 12/15LO on the AD-like phenotype of the tg2576 transgenic mice. RESULTS: Genetic absence of this enzyme results in a significant reduction in amyloid-ß (Aß) production and deposition and an improvement of cognitive deficits. In vivo and in vitro studies show that the effect of this enzymatic pathway on amyloidosis is mediated by modulation of Aß precursor protein processing via the ß secretase (BACE) proteolytic cascade, which ultimately results in altered formation of Aß peptides. CONCLUSIONS: Our findings support the novel hypothesis that blockade of 12/15LO in the central nervous system by modulating BACE proteolytic pathway could be an effective therapy for prevention or treatment of AD.

Expression profile of FcgammaRIIb on leukocytes and its dysregulation in systemic lupus erythematosus.

FcgammaRIIb (CD32B, Online Mendelian Inheritance in Man 604590), an IgG FcR with a tyrosine-based inhibitory motif, plays a critical role in the balance of tolerance and autoimmunity in murine models. However, the high degree of homology between FcgammaRIIb and FcgammaRIIa in humans and the lack of specific Abs to differentiate them have hampered study of the normal expression profile of FcgammaRIIb and its potential dysregulation in autoimmune diseases such as systemic lupus erythematosus (SLE). Using our newly developed anti-FcgammaRIIb mAb 4F5 which does not react with FcgammaRIIa, we found that FcgammaRIIb is expressed on the cell surface of circulating B lymphocytes, monocytes, neutrophils, myeloid dendritic cells (DCs), and at very low levels on plasmacytoid DCs from some donors. Normal donors with the less frequent 2B.4 promoter haplotype have higher FcgammaRIIb expression on monocytes, neutrophils, and myeloid DCs similar to that reported for B lymphocytes, indicating that FcgammaRIIb expression on both myeloid and lymphoid cells is regulated by the naturally occurring regulatory single nucleotide polymorphisms in the FCGR2B promoter. FcgammaRIIb expression in normal controls is up-regulated on memory B lymphocytes compared with naive B lymphocytes. In contrast, in active SLE, FcgammaRIIb is significantly down-regulated on both memory and plasma B lymphocytes compared with naive and memory/plasma B lymphocytes from normals. Similar down-regulation of FcgammaRIIb on myeloid-lineage cells in SLE was not seen. Our studies demonstrate the constitutive regulation of FcgammaRIIb by natural gene polymorphisms and the acquired dysregulation in SLE autoimmunity, which may identify opportunities for using this receptor as a therapeutic target.

Modulation of nuclear factor-kappa B activity by indomethacin influences A beta levels but not A beta precursor protein metabolism in a model of Alzheimer's disease.

Epidemiological studies show that some nonsteroidal anti-inflammatory drugs, nonspecific inhibitors of the cyclooxygenase enzyme, reduce the incidence of Alzheimer's disease (AD). We determined the impact of two nonsteroidal anti-inflammatory drugs on A beta levels, deposition, and metabolism in a mouse model (the Tg2576) of AD-like amyloidosis. To this end, mice were treated with indomethacin and nimesulide continuously from 8 months of age until they were 15 months old. At the end of the study, indomethacin significantly reduced A beta(1-40) and A beta(1-42) levels in both cortex and hippocampus. This decrease was coincidental with a significant reduction of the nuclear factor (NF)-kappa B activity. By contrast, nimesulide had no effect on both A beta peptides and NF-kappa B. Consistently, mice receiving indomethacin, but no nimesulide, showed a significant reduction in the amyloid burden compared with placebo. Neither drug had an effect on plasma levels of A beta peptides or the A beta precursor protein metabolism. In vitro studies confirmed that genetic absence of this factor reduces the anti-amyloidogenic effect of indomethacin. These findings indicate that chronic administration of indomethacin by blocking the activation of the NF-kappa B significantly reduces the amyloid pathology in Tg2576 mice, and provide insights into the mechanisms by which this drug could slow progression of AD.

Early vitamin E supplementation in young but not aged mice reduces Abeta levels and amyloid deposition in a transgenic model of Alzheimer's disease.

Increased brain oxidative stress is a key feature of Alzheimer's disease (AD) and manifests predominantly as lipid peroxidation. However, clinical evidence that antioxidants can affect the clinical course of the disease is limited. In the present study, we investigated the effect of the antioxidant Vitamin E on the AD-like phenotype when given to a transgenic mouse model (Tg2576) of the disease before or after the amyloid plaques are deposited. One group of Tg2576 received Vitamin E starting at 5 months of age until they were 13 months old, the second group started at 14 months of age until they were 20 months old. Brain levels of 8,12-iso-iPF2alpha-VI, a specific marker of lipid peroxidation, were significantly reduced in both groups of mice receiving Vitamin E compared with placebo. Tg2576 administered with Vitamin E at a younger age showed a significant reduction in Abeta levels and amyloid deposition. By contrast, mice receiving the diet supplemented with Vitamin E at a later age did not show any significant difference in either marker when compared with placebo. These results support the hypothesis that oxidative stress is an important early event in AD pathogenesis, and antioxidant therapy may be beneficial only if given at this stage of the disease process.