Citations

BackgroundBiomarkers that have been developed largely for the study of patients with clinically diagnosed Alzheimer's disease (AD) can also be used in the study of cognitively normal individuals who may harbor underlying AD pathology.MethodsA meeting of invited experts on AD biomarkers was held on November 11 and 12, 2004 to review currently available data and to discuss unmet needs for biomarker research in presymptomatic AD.ResultsNeuroimaging biomarkers have been studied to some extent in subjects at risk for AD. These imaging techniques include volumetric magnetic resonance imaging and positron emission tomography using either fluorodeoxyglucose or newer ligands that bind directly to amyloid plaque. Similarly, biochemical measures from cerebrospinal fluid or other physiologic fluids are emerging as potentially useful tools. Such biomarkers may be used either as diagnostic tools or as indicators of disease severity when followed longitudinally. A clinical diagnosis of asymptomatic individuals using biomarkers and studies involving asymptomatic subjects may raise logistical and ethical concerns.ConclusionsThe technical development of biomarkers that are used for presymptomatic AD diagnosis and for longitudinally measuring disease severity is evolving rapidly. Ethical and privacy considerations must be made before such biomarkers can be applied routinely to asymptomatic populations.

Abstract Aromatase [cytochrome P450 19 (CYP19)] is a critical enzyme for estrogen biosynthesis, and aromatase inhibitors are of increasing importance in the treatment of breast cancer. We set out to identify and characterize genetic polymorphisms in the aromatase gene, CYP19, as a step toward pharmacogenomic studies of aromatase inhibitors. Specifically, we “resequenced” all coding exons, all upstream untranslated exons plus their presumed core promoter regions, all exon-intron splice junctions, and a portion of the 3′-untranslated region of CYP19 using 240 DNA samples from four ethnic groups. Eighty-eight polymorphisms were identified, resulting in 44 haplotypes. Functional genomic studies were done with the four nonsynonymous coding single nucleotide polymorphisms (cSNP) that we observed, two of which were novel. Those cSNPs altered the following amino acids: Trp39Arg, Thr201Met, Arg264Cys, and Met364Thr. The Cys264, Thr364, and double variant Arg39Cys264 allozymes showed significant decreases in levels of activity and immunoreactive protein when compared with the wild-type (WT) enzyme after transient expression in COS-1 cells. A slight decrease in protein level was also observed for the Arg39 allozyme, whereas Met201 displayed no significant changes in either activity or protein level when compared with the WT enzyme. There was also a 4-fold increase in apparent Km value for Thr364 with androstenedione as substrate. Of the recombinant allozymes, only the double mutant (Arg39Cys264) displayed a significant change from the WT enzyme in inhibitor constant for the aromatase inhibitors exemestane and letrozole. These observations indicate that genetic variation in CYP19 might contribute to variation in the pathophysiology of estrogen-dependent disease.

ABSTRACT The Ref1 and Lv1 postentry restrictions in human and monkey cells have been analyzed for lentiviruses in the primate and ungulate groups, but no data exist for the third (feline) group. We compared feline immunodeficiency virus (FIV) to other restricted (human immunodeficiency virus type 1 [HIV-1], equine infectious anemia virus [EIAV]) and unrestricted (NB-tropic murine leukemia virus [NB-MLV]) retroviruses across wide ranges of viral inputs in cells from multiple primate and nonprimate species. We also characterized restrictions conferred to permissive feline and canine cells engineered to express rhesus and human TRIM5α proteins and performed RNA interference (RNAi) against endogenous TRIM5α. We find that expression of rhesus or human TRIM5α proteins in feline cells restricts FIV, impairing pseudotyped vector transduction and viral replication, but rhesus TRIM5α is more restricting than human TRIM5α. Notably, however, canine cells did not support restriction by human TRIM5α and supported minimal restriction by rhesus TRIM5α, suggesting that these proteins may not function autonomously or that a canine factor interferes. Stable RNAi knockdown of endogenous rhesus TRIM5α resulted in marked increases in FIV and HIV-1 infectivities while having no effect on NB-MLV. A panel of nonprimate cell lines varied widely in susceptibility to lentiviral vector transduction, but normalized FIV and HIV-1 vectors varied concordantly. In contrast, in human and monkey cells, relative restriction of FIV compared to HIV-1 varied from none to substantial, with the greatest relative infectivity deficit for FIV vectors observed in human T-cell lines. Endogenous and introduced TRIM5α restrictions of FIV could be titrated by coinfections with FIV, HIV-1, or EIAV virus-like particles. Arsenic trioxide had complex and TRIM5α-independent enhancing effects on lentiviral but not NB-MLV infection. Implications for human gene therapy are discussed.

A number of recently developed and promising approaches to antitumoral immunotherapy are being investigated as potential treatments for advanced prostate cancer. These approaches largely revolve around strategies to increase antigen-specific T-cell activation against prostate tumors as well as precise manipulations of critical co-regulatory receptors that help to maintain and prolong the activity of antigen-presenting cells and T cells that are capable of mediating tumor regression. Herein, we describe the experience with the most recent and promising approaches pertaining to prostate cancer immunotherapy. Additionally, we discuss the mechanistic basis for these approaches as well as current limitations that must still be addressed in order to propel immunotherapy into the forefront of prostate cancer treatment.

Abstract Rationale Pulmonary lymphangioleiomyomatosis is a progressive cystic lung disease that is associated with infiltration of atypical smooth muscle–like cells. Previous descriptions of clinical characteristics of subjects with lymphangioleiomyomatosis have been based on a limited number of patients. Objectives To describe the clinical characteristics of subjects with pulmonary lymphangioleiomyomatosis, both sporadic and tuberous sclerosis–related forms. Methods Over a 3-yr period, from 1998 to 2001, 243 subjects with pulmonary lymphangioleiomyomatosis were enrolled into a national registry; 13 subjects who had already undergone lung transplantation were excluded for the purposes of this report. Measurements and Main Results All 230 subjects were women, aged 18 to 76 yr (mean ± SE, 44.5 ± 0.65 yr). The average age at onset of symptoms was 38.9 ± 0.73 yr and at diagnosis was 41.0 ± 0.65 yr. Tuberous sclerosis complex was present in 14.8% of subjects. Pulmonary manifestations, most commonly spontaneous pneumothorax, were the primary events leading to the diagnosis in 86.5% of cases. Nearly 55% of the subjects were being treated with a progesterone derivative. An obstructive pattern on pulmonary function testing was observed in 57.3% of the subjects, whereas 33.9% had normal spirometric results. Women with tuberous sclerosis–related lymphangioleiomyomatosis were younger and had less impaired lung function compared with those with the sporadic form. Conclusions The age range of women afflicted with pulmonary lymphangioleiomyomatosis is broader than previously appreciated and the degree of pulmonary function can be quite variable, with one-third of subjects having normal spirometry at enrollment into this registry.

Abstract Protein kinase C (PKC) isozymes have long been implicated in carcinogenesis. However, little is known about the functional significance of these enzymes in human cancer. We recently showed that the atypical PKC (aPKC) isozyme PKCι is overexpressed in human non–small cell lung cancer (NSCLC) cells and that PKCι plays a critical role in the transformed growth of the human lung adenocarcinoma A549 cell line in vitro and tumorigenicity in vivo. Here we provide compelling evidence that PKCι is an oncogene in NSCLC based on the following criteria: (a) aPKCι is overexpressed in the vast majority of primary NSCLC tumors; (b) tumor PKCι expression levels predict poor survival in patients with NSCLC; (c) the PKCι gene is frequently amplified in established NSCLC cell lines and primary NSCLC tumors; (d) gene amplification drives PKCι expression in NSCLC cell lines and primary NSCLC tumors; and (e) disruption of PKCι signaling with a dominant negative PKCι allele blocks the transformed growth of human NSCLC cells harboring PKCι gene amplification. Taken together, our data provide conclusive evidence that PKCι is required for the transformed growth of NSCLC cells and that the PKCι gene is a target for tumor-specific genetic alteration by amplification. Interestingly, PKCι expression predicts poor survival in NSCLC patients independent of tumor stage. Therefore, PKCι expression profiling may be useful in identifying early-stage NSCLC patients at elevated risk of relapse. Our functional data indicate that PKCι is an attractive target for development of novel, mechanism-based therapeutics to treat NSCLC.