miR-520a-5p regulates Frizzled 9 expression and mediates effects of cigarette smoke and iloprost chemoprevention.

Expression of Frizzled 9 (FZD9) is critical to the activity of the lung cancer chemoprevention agent and prostacyclin analogue, iloprost. FZD9 is required in lung epithelial cells for iloprost to activate peroxisome proliferator activated receptor gamma (PPARG) and related anti-tumor signaling. We aimed to investigate which miRNA regulate FZD9 in the context of cigarette smoke exposure and iloprost treatment. We found that miR-520a-5p binds the FZD9 3'UTR in lung cell lines and alters activity and expression of FZD9 downstream targets. Cigarette smoke condensate (CSC) increases expression of miR-520a-5p, while iloprost decreases expression. Cancer promoting effects of a miR-520a-5p mimic were rescued with iloprost treatment, and effects of cigarette smoke were partially rescued with a miR-520a-5p inhibitor. Here we confirm miR-520a-5p as a regulator of FZD9 activity and a mediator of CSC and iloprost effects in the lung. Targeting miR-520a-5p could be an approach to restoring FZD9 expression and improving response to iloprost lung cancer chemoprevention.

Cancer chemoprevention through Frizzled receptors and EMT.

Frizzled (FZD) transmembrane receptors are well known for their role in ß-catenin signaling and development and now understanding of their role in the context of cancer is growing. FZDs are often associated with the process of epithelial to mesenchymal transition (EMT) through ß-catenin, but some also influence EMT through non-canonical pathways. With ten different FZDs, there is a wide range of activity from oncogenic to tumor suppressive depending on the tissue context. Alterations in FZD signaling can occur during development of premalignant lesions, supporting their potential as targets of chemoprevention agents. Agonizing or antagonizing FZD activity may affect EMT, which is a key process in lesion progression often targeted by chemoprevention agents. Recent studies identified a specific FZD as important for activity of an EMT inhibiting chemopreventive agent and other studies have highlighted the previously unrecognized potential for targeting small molecules to FZD receptors. This work demonstrates the value of investigating FZDs in chemoprevention and here we provide a review of FZDs in cancer EMT and their potential as chemoprevention targets.

Prostacyclin reverses the cigarette smoke-induced decrease in pulmonary Frizzled 9 expression through miR-31.

Half of lung cancers are diagnosed in former smokers, leading to a significant treatment burden in this population. Chemoprevention in former smokers using the prostacyclin analogue iloprost reduces endobronchial dysplasia, a premalignant lung lesion. Iloprost requires the presence of the WNT receptor Frizzled 9 (Fzd9) for inhibition of transformed growth in vitro. To investigate the relationship between iloprost, cigarette smoke, and Fzd9 expression, we used human samples, mouse models, and in vitro studies. Fzd9 expression was low in human lung tumors and in progressive dysplasias. In mouse models and in vitro studies, tobacco smoke carcinogens reduced expression of Fzd9 while prostacyclin maintained or increased expression. Expression of miR-31 repressed Fzd9 expression, which was abrogated by prostacyclin. We propose a model where cigarette smoke exposure increases miR-31 expression, which leads to decreased Fzd9 expression and prevents response to iloprost. When smoke is removed miR-31 is reduced, prostacyclin can increase Fzd9 expression, and progression of dysplasia is inhibited. Fzd9 and miR-31 are candidate biomarkers for precision application of iloprost and monitoring of treatment progress. As we continue to investigate the mechanisms of prostacyclin chemoprevention and identify biomarkers for its use, we will facilitate clinical trials and speed implementation of this valuable prevention approach.

Pathological confirmation of primary lung cancer following breast cancer.

PURPOSE: Studies have shown that women who survive breast cancer have an increased risk of a future primary lung cancer, though many are based only on data recorded in tumor registries and none have conducted pathological confirmation. Previous studies and future use of large registries may be affected by misdiagnosis. METHODS: Pathological analysis was conducted on tumors from 110 women with breast cancer followed by lung cancer using morphology, Estrogen Receptor-alpha (ER), and Thyroid Transcription Factor-1 (TTF1). We developed an algorithm to classify lung tumors as unlikely lung cancer (score=1) to likely lung cancer (score=5). RESULTS: Mean time to diagnosis of lung cancer after breast cancer was 13 years. 76% of breast tumors and 20% of lung tumors were positive for ER and 51% of lung tumors were positive for TTF-1. 86% of the lung tumors were probable primaries, 7% were probable metastases from the breast, and 7% were of undetermined status. 70% of probable metastases had a latency of longer than 10 years. CONCLUSION: Prior studies identifying the association of breast cancer and breast cancer treatments with lung cancer are likely to reflect true associations not confounded by misdiagnosis, as evidenced by the low rate of misclassification detected in this study. Analysis of the years of diagnosis suggests that latency may not be an accurate criterion for assignment of primary status, which could be significant in a clinical setting. These data may also benefit future retrospective studies using large registries.

Association of homocysteine with plasma amyloid beta protein in aging and neurodegenerative disease.

BACKGROUND: Elevated plasma total homocysteine (tHcy) is a risk factor for cardiovascular disease and is reported to be an independent risk factor for Alzheimer disease (AD) and cognitive decline. tHcy may potentiate neurotoxic and vasculopathic processes, including amyloid beta protein (Abeta) metabolism, implicated in neurodegenerative diseases. OBJECTIVE: To examine the relationship of plasma total tHcy levels with clinical, demographic, biochemical, and genetic factors in aging, mild cognitive impairment (MCI), AD, cerebral amyloid angiopathy (CAA), and Parkinson disease (PD). METHODS: Plasma tHcy, folate, vitamin B(12), creatinine, and Abeta levels were assessed in individuals evaluated in the Memory, Stroke, and Movement Disorders Units of Massachusetts General Hospital with diagnoses of AD (n = 145), MCI (n = 47), PD (n = 93), CAA (67), hypertensive intracerebral hemorrhage (hICH) (n = 25), and no dementia (n = 88). RESULTS: The tHcy levels did not differ across AD, MCI, CAA, hICH, and nondemented control subjects but were increased in the PD group (p < 0.01). The elevated levels within the PD group were due to high tHcy in individuals taking levodopa (p < 0.0001). Increasing tHcy was associated with worse cognition in the PD cases, but not the other diagnostic groups. tHcy levels positively correlated with plasma Abeta levels even after adjustments for age and creatinine (p < 0.0001). CONCLUSIONS: Mean tHcy levels increased with age but did not discriminate diagnostic groups aside from significant elevation in patients with PD taking levodopa. The positive association between tHcy and plasma Abeta levels raises the possibility that these circulating factors could interact to affect AD risk and cognition in PD.

The selective muscarinic M1 agonist AF102B decreases levels of total Abeta in cerebrospinal fluid of patients with Alzheimer's disease.

beta-Amyloid (Abeta) deposits in diffuse and compact senile plaques in the brain are one of the defining histopathological features of Alzheimer's disease (AD). Preventing Abeta deposition is a goal of drug therapy for AD, because excessive amounts of Abeta may be toxic to neurons. In preclinical studies, activation of the muscarinic M1 receptor subtype inhibited Abeta secretion from cultured cells. To determine whether a similar sequence occurs in human beings, we administered the selective M1 agonist AF102B to 19 AD patients and measured total Abeta (Abeta(total)) levels in cerebrospinal fluid (CSF) before and during treatment. Abeta(total) levels in CSF decreased in 14 patients by 22%, increased in 3 patients, and were unchanged in 2 patients; the overall decrease in the group as a whole was statistically significant. To test the specificity of the M1 effect, we also measured the relative changes in Abeta(total) levels in CSF during treatments in separate sets of AD patients with the acetylcholinesterase inhibitor physostigmine or the anti-inflammatory drug hydroxychloroquine. CSF Abeta(total) levels did not change significantly in the 9 AD patients in the physostigmine protocol or in the 10 AD patients in the hydroxychloroquine study. These data provide evidence that the activation of M1 receptors reduces Abeta levels in the CSF of AD patients. If this effect also occurs in brain, M1 agonists may have long-term therapeutic benefits by lowering amyloid in AD.

Donepezil therapy in clinical practice: a randomized crossover study.

OBJECTIVE: To determine the efficacy of donepezil hydrochloride for the treatment of Alzheimer disease in patients drawn from clinical practice. DESIGN: Two-center, randomized, placebo-controlled, double-masked crossover study. SETTING: Memory disorders units at Massachusetts General and Brigham and Women's hospitals, Boston. PATIENTS: Sixty individuals (30 men and 30 women; mean +/- SD age, 75.0+/-9.5 years) with probable Alzheimer disease and scores of 20 or less on the information-memory-concentration subscale of the Blessed Dementia Scale. INTERVENTIONS: Placebo wash-in, followed in randomized sequence by (1) donepezil hydrochloride therapy, 5 mg/d, for 6 weeks, followed by placebo washout for 6 weeks and (2) placebo treatment for 6 weeks. PRIMARY OUTCOME MEASURE: Change in Alzheimer's Disease Assessment Scale cognitive subscale scores from the beginning to the end of the two 6-week treatment periods. RESULTS: Among patients completing treatment and testing for both periods (n = 48), subscale scores improved (mean +/- SEM) 2.17+/-0.98 points (95% confidence interval, 0.20-4.10 points) during donepezil therapy relative to placebo therapy (P = .04). Scores returned toward baseline within 3 weeks of drug washout. There was no associated change in caregiver-rated global impression (donepezil vs placebo: proportion improved, 0.24 vs 0.22; proportion worsened, 0.27 vs 0.35; P = .34) or on specific tests of explicit memory or verbal fluency. Contrary to studies with tacrine, the presence of the apolipoprotein E epsilon4 allele did not predict donepezil treatment failure. Most common adverse events related to donepezil therapy were nausea (5 patients), diarrhea (3 patients), and agitation (3 patients). Serious events possibly related to drug use were seizure, pancreatitis, and syncope (1 patient each). CONCLUSION: This independent confirmation of data from phase 3 trials suggests that donepezil therapy modestly improves cognition in patients with Alzheimer disease who are encountered in clinical practice.

Living with a person who has Parkinson's disease: the spouse's perspective by stage of disease. Parkinson's Study Group.

The objective of this study was to examine the experience of spouses caregiving for their spouse with Parkinson's disease (PD) and to determine whether their experiences differed by stage of disease. By using a cross-sectional design and mail questionnaire data from 380 spouse caregivers across 23 sites of the Parkinson Study Group, key caregiver variables were examined by stage of PD. Three categories of variables--caregiver role strain (10 measures), caregiver situation (four measures), and caregiver characteristics (four measures)--were analyzed by using t tests with Bonferroni correction. Specific types and amounts of role strain accumulated as the disease progressed, and they differed significantly between stages (p < 0.05). In the caregiving situation, the mean number of caregiving tasks tripled by stage 4/5. Negative changes in lifestyle plus decreases in predictability in caregivers' lives increased significantly in late-stage disease (p < 0.05). Caregiver characteristics of physical health and preparedness did not significantly differ across stages of disease. Depression was significantly higher by stage 4/5. Mutuality, the positive quality of the relationship as perceived by the caregiving spouse, declined beginning at stage 2. Caregiver strain is experienced across all stages of PD and accumulates significantly as the disease progresses. This study defines types and amounts of strain by stage of disease, which will be helpful in designing formal intervention trials to provide more effective help for spouse caregivers.

Pupil dilation to tropicamide is not specific for Alzheimer disease.

BACKGROUND: The extent of pupil dilation after instillation of a dilute tropicamide solution was proposed as a noninvasive neurobiological diagnostic test for Alzheimer disease (AD). Pupils in patients with AD dilated 23% vs only 5% in control subjects. OBJECTIVE: To determine whether pupil dilation in response to tropicamide distinguishes patients with AD from control subjects without dementia. METHODS: There were 50 patients with AD and 51 control subjects; no participant had primarily ocular pathological conditions or took drugs that affected cholinergic tone. All participants received 1 drop of 0.01% tropicamide in 1 eye and 1 drop of 0.9% saline solution in the other eye in random order. Pupil measurements were obtained using a pupil and corneal reflection tracking system (RK-426 PC system, ISCAN Inc, Burlington, Mass) that illuminated the eye with a low-level infrared source and measured pupil diameters, fixation, and light level every 16.7 milliseconds during each 30-second-measurement. Pupil measurements were obtained from each eye at baseline and 5, 10, 15, and 30 minutes after drop instillation. RESULTS: The increase in pupil size after tropicamide instillation was equal between patients with AD and control subjects. The mean (+/- SD) pupil diameter increased from 4.5 +/- 1.1 to 5.5 +/- 1.1 mm after 30 minutes in patients with AD and from 4.7 +/- 0.9 to 5.8 +/- 0.9 mm in control subjects. Anisocoria and the mean rate of dilation did not differ between patients with AD and control subjects. Eye color and corneal moisture did not affect these results. The extent of pupil dilation in patients with AD was not related to clinical estimates of dementia severity. CONCLUSION: Pupil dilation in response to instillation of 0.01% tropicamide is not useful as an antemortem diagnostic test for AD.

Environment-driven responses in progressive supranuclear palsy.

The neurological signs and behaviors that accompany degenerative diseases associated with fronto-striatal dysfunction are incompletely described. We observed several novel environmentally-driven behaviors in seven patients with progressive supranuclear palsy (PSP). All patients had cognitive deficits with greatest impairments on tests of frontal lobe function, and frontal lobe cerebral perfusion was significantly reduced in 4 of the 5 who had single photon emission computed tomography (SPECT) brain scans. Visual grasping, in which a patient's gaze was attracted to an incidental object in the environment such as a TV set or mirror, was preeminent. Once fixed, there was inability to release the gaze and shift to another object. In other instances, removing a table placed in front of a patient or unbuckling of his seat belt would make him stand up, which was impossible on command. Similarly, playing music would induce rhythmic foot beating, which was never obtained on command. There were compulsive utilization behaviors, such as repetitively picking up and replacing the telephone for no apparent reason. As expected, there were signs of heightened facial reflexes, grasp reflexes, apraxia of eyelid opening, echolalia and echopraxia. We postulate that these stimuli-oriented behaviors stem from parietal lobe disinhibition due to fronto-striatal dysfunction.

Cerebrospinal fluid levels of amyloid beta-protein in Alzheimer's disease: inverse correlation with severity of dementia and effect of apolipoprotein E genotype.

Alzheimer's disease (AD) is characterized by formation in brain of neurofibrillary tangles and of amyloid deposits. The major protein component of the former is tau, while the latter are composed of amyloid beta-peptides (A beta), which are derived by proteolytic cleavage of the amyloid beta-protein precursor (APP). Both tau and various secretory APP derivatives including A beta and APPS are present in human cerebrospinal fluid (CSF). To investigate whether clinical signs of AD are paralleled by changes in CSF levels of these proteins, we correlated quantitative measures of dementia severity with CSF concentrations of A beta, of APPS, and of tau. We found that levels of A beta in CSF of AD patients were inversely correlated both to cognitive and to functional measures of dementia severity. In contrast, levels of APPS and of tau did not correlate with dementia severity. Apolipoprotein E (apoE) genotype did not influence CSF levels of A beta, APPS, or tau, which were similar among AD patients with Apo E epsilon 3/3, epsilon 3/4, and epsilon 4/4 alleles. These data indicate that CSF levels of A beta decrease with advancing severity of dementia in AD and suggest that they are independent of a patient's Apo E genotype.

Idazoxan treatment in progressive supranuclear palsy.

To confirm the preliminary report that increases in norepinephrine neurotransmission improve motor performance, we administered the investigational drug idazoxan (IDA) to nine patients with progressive supranuclear palsy (PSP) according to a double-blind crossover protocol. There were seven women and two men, whose mean age was 70 years and mean duration of illness 4 years. All had an advanced parkinsonian syndrome, supranuclear ocular motor palsies, and poor responses to dopaminergic drugs. During administration of 40 mg tid of IDA, the total score and the motor subscale score of the United Parkinson's Disease Rating Scale significantly decreased. Features that improved most included mobility, balance, gait, and measures of digital dexterity. There were no significant changes in any measure during placebo administration. Corticobulbar manifestations and eye movements were not significantly improved during treatment. Side effects of IDA included transient hypertension, tachycardia, action tremor, flushing, and sweating, but none was so severe that any patient withdrew from the study. Among the few attempted treatments of PSP, IDA is the first medication shown in a double-blind study to improve aspects of motor function.