Asian Cohort for Alzheimer's Disease (ACAD) pilot study on genetic and non-genetic risk factors for Alzheimer's disease among Asian Americans and Canadians

INTRODUCTION

Clinical research in Alzheimer's disease (AD) lacks cohort diversity despite being a global health crisis. The Asian Cohort for Alzheimer's Disease (ACAD) was formed to address underrepresentation of Asians in research, and limited understanding of how genetics and non-genetic/lifestyle factors impact this multi-ethnic population.

METHODS

The ACAD started fully recruiting in October 2021 with one central coordination site, eight recruitment sites, and two analysis sites. We developed a comprehensive study protocol for outreach and recruitment, an extensive data collection packet, and a centralized data management system, in English, Chinese, Korean, and Vietnamese.

RESULTS

ACAD has recruited 606 participants with an additional 900 expressing interest in enrollment since program inception.

DISCUSSION

ACAD's traction indicates the feasibility of recruiting Asians for clinical research to enhance understanding of AD risk factors. ACAD will recruit > 5000 participants to identify genetic and non-genetic/lifestyle AD risk factors, establish blood biomarker levels for AD diagnosis, and facilitate clinical trial readiness.

HIGHLIGHTS

The Asian Cohort for Alzheimer's Disease (ACAD) promotes awareness of under-investment in clinical research for Asians. We are recruiting Asian Americans and Canadians for novel insights into Alzheimer's disease. We describe culturally appropriate recruitment strategies and data collection protocol. ACAD addresses challenges of recruitment from heterogeneous Asian subcommunities. We aim to implement a successful recruitment program that enrolls across three Asian subcommunities.

Immune Checkpoint Inhibition and Single Fraction Stereotactic Radiosurgery in Non-Small Cell Lung Cancer Brain Metastases: An International Multicenter Study of 395 Patients

PURPOSE/OBJECTIVE(S)

Brain metastases most commonly arise from non-small cell lung cancer (NSCLC). In recent years, immune checkpoint inhibitors (ICI) have demonstrated improvements in overall survival (OS) in NSCLC. However, concerns remain about the risk of radiation necrosis (RN) when ICI are administered with stereotactic radiosurgery (SRS).

MATERIALS/METHODS

Logistic regression was used to evaluate prognostic factors associated with the development of any grade RN and symptomatic RN. Cumulative incidence of RN was evaluated using competing risks analysis and the Fine and Gray model, where the null hypothesis was rejected for p < 0.05.

RESULTS

There were 395 patients with 2,513 brain metastases treated across 11 international institutions included in the analysis. The median follow-up was 14.2 months. Median patient age was 67 years (Interquartile Range [IQR]: 61-73), 53.4% were male, the median Karnofsky Performance Status was 80 (IQR: 80-90), and 88.6% has active extracranial disease at the time of SRS. The median margin dose was 19 Gy (IQR: 18-20), 97.5% of patients were treated on the Gamma Knife ®, 3.8% underwent prior whole brain radiation therapy (WBRT). The median V12 Gy was 5.2 cm3 and 36.5% of patients had a V12 Gy ≥ 10 cm3, anti-PD-1 agents were administered in 91.6% of patients. A V12 Gy ³ 10 cm3 was associated with an increased risk of developing any grade RN; odds ratio (OR): 2.12, p = 0.04 and OR: 2.18; p = 0.03 on univariable and multivariable analysis, respectively. Similarly, a V12 Gy ≥ 10 cm3 was associated with an increased risk of developing symptomatic RN; OR: 3.80, p = 0.003 and OR: 3.95; p = 0.003 on univariable and multivariable analysis, respectively. Receipt of concurrent ICI and prior WBRT were not statistically significant. At 1-year, the cumulative incidence of any grade and symptomatic RN was 4.8% and 3.8%, respectively. The cumulative incidence of any grade RN was 3.8% vs. 5.3% for the concurrent and non-concurrent groups at 1-year, respectively (p = 0.35). The cumulative incidence of symptomatic RN was 3.8% vs. 3.6% for the concurrent and non-concurrent groups at 1-year, respectively (p = 0.95).

CONCLUSION

The risk of any grade and symptomatic RN following SRS and ICI administration for NSCLC brain metastases increases as the V12 Gy exceeds 10 cm3. Concurrent ICI and SRS does not appear to increase this risk. Radiosurgical planning techniques should aim to minimize the V12 Gy.

MR Neurography of Greater Occipital Nerve Neuropathy: Initial Experience in Patients with Migraine

BACKGROUND AND PURPOSE

MR imaging of peripheral nerves (MR neurography) allows improved assessment of nerve anatomy and pathology. The objective of this study was to evaluate patients with unilateral occipital neuralgia using MR neurography and to assess the differences in greater occipital nerve signal and size between the symptomatic and asymptomatic sides.

MATERIALS AND METHODS

In this case-control evaluation using MR neurography, bilateral greater occipital nerve caliber, signal intensity, signal-to-noise ratios, and contrast-to-noise ratios were determined by 2 observers.

RESULTS

Among 18 subjects with unilateral occipital migraines, the average greater occipital nerve diameter for the symptomatic side was significantly greater at 1.77 ± 0.4 mm than for the asymptomatic side at 1.29 ± 0.25 mm (P = .001). The difference in nerve signal intensity between the symptomatic and asymptomatic sides was statistically significant at 269.06 ± 170.93 and 222.44 ± 170.46, respectively (P = .043). The signal-to-noise ratios on the symptomatic side were higher at 15.79 ± 4.59 compared with the asymptomatic nerve at 14.02 ± 5.23 (P = .009). Contrast-to-noise ratios were significantly higher on the symptomatic side than on the asymptomatic side at 2.57 ± 4.89 and -1.26 ± 5.02, respectively (P = .004). Intraobserver performance was good to excellent (intraclass coefficient correlation, 0.68-0.93), and interobserver performance was fair to excellent (intraclass coefficient correlation, 0.54-0.81).

CONCLUSIONS

MR neurography can be reliably used for the diagnosis of greater occipital nerve neuropathy in patients with unilateral occipital migraines with a good correlation of imaging findings to the clinical presentation.

Interfacial rheology of coexisting solid and fluid monolayers

Biologically relevant monolayer and bilayer films often consist of micron-scale high viscosity domains in a continuous low viscosity matrix. Here we show that this morphology can cause the overall monolayer fluidity to vary by orders of magnitude over a limited range of monolayer compositions. Modeling the system as a two-dimensional suspension in analogy with classic three-dimensional suspensions of hard spheres in a liquid solvent explains the rheological data with no adjustable parameters. In monolayers with ordered, highly viscous domains dispersed in a continuous low viscosity matrix, the surface viscosity increases as a power law with the area fraction of viscous domains. Changing the phase of the continuous matrix from a disordered fluid phase to a more ordered, condensed phase dramatically changes the overall monolayer viscosity. Small changes in the domain density and/or continuous matrix composition can alter the monolayer viscosity by orders of magnitude.

Neural mechanisms of response inhibition and impulsivity in 22q11.2 deletion carriers and idiopathic attention deficit hyperactivity disorder

•22q11DS offers a compelling model to understand the neural substrates of attentional dysfunction.•First study directly comparing neural function in 22q11DS vs. ADHD patients•22q11DS and ADHD patients show a shared deficit in RI-related activation.•ADHD patients showed greater activity in the middle frontal gyrus than 22q11DS during RI.•Neural activity is inversely correlated with self-reported Cognitive Impulsivity in 22q11DS.

MicroRNA-101-mediated Akt activation and estrogen-independent growth

MicroRNAs are gene regulators that work through a posttranscriptional repression mechanism. Dysregulation of microRNA expression could lead to a variety of disorders, in particular, human cancer, and has also been implicated in antihormone therapy resistance. However, little is known whether microRNAs have a role in estrogen-independent growth, leading to tamoxifen resistance in estrogen receptor (ER)-positive tumors. In this study, we use an in vivo selection system against a microRNA library using the MCF-7 model and demonstrate that miR-101 promotes estrogen-independent growth and causes the upregulation of phosphorylated Akt (pAkt) without impacting the ER level or activity. Importantly, although miR-101 suppresses cell growth in normal estradiol (E2)-containing medium, it promotes cell growth in E2-free medium. Moreover, estrogen deprivation greatly enhances miR-101-mediated Akt activation. Finally, we show that MAGI-2 (membrane-associated guanylate kinase), a scaffold protein required for PTEN (phosphatase and tensin homolog) activity, is a direct target for miR-101; suppression of MAGI-2 by miR-101 reduces PTEN activity, leading to Akt activation. Taken together, these results not only establish a role for miR-101 in estrogen-independent signaling but also provide a mechanistic link between miR-101 and Akt activation.

Albumin-Binding and Angiogenic Domains of SPARC Located at Its C-Terminus

Background: SPARC (Secreted Protein Acidic and Rich in Cysteine) is an albumin-binding glycoprotein overexpressed in breast cancer and is associated with poor prognosis and shorter overall survival. We have previously shown that SPARC expression appeared to correlate with response to nanoparticle albumin-bound (nab) paclitaxel (Abraxane) in head-and-neck and pancreatic-cancer patients. To further define the role of SPARC, recombinant-human SPARC (rhSPARC) was characterized to identify its albumin-binding and angiogenic domain.Materials and methods: The albumin-binding site on SPARC was defined by testing the binding of Alexa 488-labeled BSA to immobilized rhSPARC in a solid-phase-binding assay and in a competitive-binding assay in presence of increasing concentration of various SPARC-derived peptides. The angiogenic activity of rhSPARC was evaluated using a HUVEC tube-formation assay.Results: The SPARC albumin-binding assay revealed a pattern of saturable and specific binding with an estimated Kd of 700 µM very near the known plasma concentration of albumin (600 µM). Competitive binding with Cathepsin K-digested SPARC and SPARC-derived peptides defined the albumin-binding domain to be amino acids 209-223 in the C-terminal region. In the HUVEC tube-formation assay, rhSPARC was pro-angiogenic at 10 µg/ml and anti-angiogenic at 100 µg/ml. The angiogenic domain of SPARC was located to the C-terminal of SPARC.Discussion: The albumin-binding domain of SPARC was located to residues aa209-223, supporting its role as a target for nab-technology-based drug delivery. We confirmed that SPARC can promote angiogenesis at physiological concentrations, contributing to the role of SPARC in a more aggressive tumor phenotype. The angiogenic domain of SPARC is located within a 54-aa sequence of its C-terminus. SPARC could be a potential therapeutic target and a biomarker for predicting response to nab-paclitaxel.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2144.

Phase II study of dasatinib in non-small cell lung cancer (NSCLC)

e19015

Background: Lung cancer is the leading cause of cancer-related deaths. Better systemic therapies are needed. One potential therapeutic target is c-Src which is expressed and activated in NSCLC patient tumors where it can mediate invasion, angiogenesis, and proliferation. Additionally, epidermal growth factor receptor (EGFR) and c-Src cooperate to promote NSCLC survival. We are conducting a phase II study of dasatinib, a tyrosine kinase inhibitor of c-Src, Abl, c-Kit, PDGFR, Btk, and EphA2. The primary objective is to determine the rate of progression free survival at 12 weeks in patients with metastatic NSCLC treated with dasatinib as front line therapy. Methods: Patients with metastatic NSCLC were treated with dasatinib (100 mg BID), with PET/CT scans every 6 weeks. KRAS and EGFR mutations, EGFR copy number, and pSrc expression were measured in pre-treatment biopsies. Blood was collected pretreatment and on day 21 to measure drug exposure (PK), pharmacodynamics (PD), and serum cytokine levels. Results: Twenty five patients have enrolled on study. Of the 16 patients evaluable for response: 1 had a partial response (PR) with no evidence of recurrence for at least 18 months (male smoker with adenocarcinoma and KRAS mutation); 6 patients had stable disease (SD) which includes 3 patients with prolonged stable disease for 4, 6, and 18 months; 9 had progressive disease (PD). Only 4 patients had a significant change in SUV (>25%): decreased in 2 with PR and SD and increased in 2 with PD and SD. There is currently no clear association between EGFR and KRAS mutational analysis and response, although the sample number is small. Only 2 patients have activating EGFR mutations: one with SD and one with PD. PK, PD, and cytokine data will be presented. The most common grade 3/4 toxicity is dyspnea/pleural effusion that has led to a reduced dasatinib starting dose in subsequent patients. Conclusions: Dasatinib as a single agent has activity in a subset of patients with NSCLC. Planned correlative studies may lead to the discovery of biomarkers that predict response. Toxicities observed were consistent with prior dasatinib phase I studies in solid tumor patients. Supported by NCI/CTEP (NIH contract N01-CM-62202), The Commonwealth Foundation for Cancer Research and Bristol-Myers Squibb.

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Cross-sectional survey of the extent and indicators of hepatitis C virus infection in Houston Department of Health and Human Services' sexually transmitted disease clinics

To evaluate the prevalence and indicators of hepatitis C virus (HCV) infection in Houston and determine the effectiveness of targeted HCV screening in sexually transmitted disease (STD) clinics. We performed a cross-sectional survey in low-risk and high-risk groups in Houston. This included a blinded survey of HCV conducted in 1010 STD clinic clients having serological syphilis tests, and 1885 multi-speciality group practice patients having metabolic blood work. This was followed with a targeted hepatitis C survey of 822 high-risk clients from STD clinics. The seroprevalence of hepatitis C infection in the blinded survey was 3.9% (95% CI 3.0-4.8) in the multi-speciality group and 5.0% (95% CI 3.7-6.3) in the STD clinics. Prevalence of hepatitis C infection among targeted STD clinic clients was significantly higher at 15.3% (95% CI 12.7-17.7). Risk factors that correlated with HCV infection after logistic regression included: injection drug use (OR = 10, 95% CI = 3.4-30.3), heroin use (OR = 6.6, 95% CI = 2.2-20.5), non-transfusion/ transplantation blood exposure (OR = 3.0, 95% CI = 1.3-6.9), sharing equipment to snort drugs (OR = 2.5, 95% CI 1.2-5.4), and age above 25 years (OR = 51, 95% CI = 9-47). This study demonstrates that targeting clients in STD clinics for known risk behaviours is an effective way to identify cases of HCV infection. STD clinics allow access to clients with both drug use and sexual risk behaviours and are a useful location for targeting hepatitis C screening and prevention efforts.

Feeding demand conditions and plasma cortisol in socially-housed squirrel monkey mother-infant dyads

Previous studies have demonstrated that experimentally altering the accessibility and availability of food can have profound impact on behavior and adrenocortical activity in nonhuman primate species. In this study, groups of mother-infant squirrel monkey dyads were housed in either high demand (HFD: 120% normal daily food intake provided), low demand (LFD: 600% normal daily food intake provided) or variable demand (VFD: alternating two-week blocks of low demand and high demand) conditions for 12 weeks. During the 12-week experimental foraging phase, animals in the HFD group exhibited prolonged and consistent cortisol elevations. The cortisol levels in the VFD group reflected the ambient demand condition, with higher levels exhibited during the high demand phases of the study, and lower values when the low demand condition was in effect. Overall, mothers were more affected by the experimental manipulation than were infants. The experimental condition did not affect the infants' response to a 24-h separation from their mothers. A suppression of cortisol levels, particularly in the HFD group, was observed upon resumption of ad-libitum feeding.