Citations

Abstract Progressive supranuclear palsy is a neurodegenerative disease characterized by the deposition of four-repeat tau in neuronal and glial lesions in the brainstem, cerebellar, subcortical and cortical brain regions. There are varying clinical presentations of progressive supranuclear palsy with different neuroimaging signatures, presumed to be due to different topographical distributions and burden of tau. The classic Richardson syndrome presentation is considered a subcortical variant, whilst progressive supranuclear palsy with predominant speech and language impairment is considered a cortical variant, although the pathological underpinnings of these variants are unclear. In this case-control study, we aimed to determine whether patterns of regional tau pathology differed between these variants and whether tau burden correlated with neuroimaging. Thirty-three neuropathologically confirmed progressive supranuclear palsy patients with either the Richardson syndrome (n = 17) or speech/language (n = 16) variant and ante-mortem magnetic resonance imaging were included. Tau lesion burden was semi-quantitatively graded in cerebellar, brainstem, subcortical and cortical regions and combined to form neuronal and glial tau scores. Regional magnetic resonance imaging volumes were converted to Z-scores using 33 age- and sex-matched controls. Diffusion tensor imaging metrics, including fractional anisotropy and mean diffusivity, were calculated. Tau burden and neuroimaging metrics were compared between groups and correlated using linear regression models. Neuronal and glial tau burden were higher in motor and superior frontal cortices in the speech/language variant. In the subcortical and brainstem regions, only the glial tau burden differed, with a higher burden in globus pallidus, subthalamic nucleus, substantia nigra and red nucleus in Richardson’s syndrome. No differences were observed in the cerebellar dentate and striatum. Greater volume loss was observed in the motor cortex in the speech/language variant and in the subthalamic nucleus, red nucleus and midbrain in Richardson’s syndrome. Fractional anisotropy was lower in the midbrain and superior cerebellar peduncle in Richardson’s syndrome. Mean diffusivity was greater in the superior frontal cortex in the speech/language variant and midbrain in Richardson’s syndrome. Neuronal tau burden showed associations with volume loss, lower fractional anisotropy and higher mean diffusivity in the superior frontal cortex, although these findings did not survive correction for multiple comparisons. Results suggest that a shift in the distribution of tau, particularly neuronal tau, within the progressive supranuclear palsy network of regions is driving different clinical presentations in progressive supranuclear palsy. The possibility of different disease epicentres in these clinical variants has potential implications for the use of imaging biomarkers in progressive supranuclear palsy.

ImportanceFrontotemporal lobar degeneration (FTLD) is relatively rare, behavioral and motor symptoms increase travel burden, and standard neuropsychological tests are not sensitive to early-stage disease. Remote smartphone-based cognitive assessments could mitigate these barriers to trial recruitment and success, but no such tools are validated for FTLD.ObjectiveTo evaluate the reliability and validity of smartphone-based cognitive measures for remote FTLD evaluations.Design, Setting, and ParticipantsIn this cohort study conducted from January 10, 2019, to July 31, 2023, controls and participants with FTLD performed smartphone application (app)–based executive functioning tasks and an associative memory task 3 times over 2 weeks. Observational research participants were enrolled through 18 centers of a North American FTLD research consortium (ALLFTD) and were asked to complete the tests remotely using their own smartphones. Of 1163 eligible individuals (enrolled in parent studies), 360 were enrolled in the present study; 364 refused and 439 were excluded. Participants were divided into discovery (n = 258) and validation (n = 102) cohorts. Among 329 participants with data available on disease stage, 195 were asymptomatic or had preclinical FTLD (59.3%), 66 had prodromal FTLD (20.1%), and 68 had symptomatic FTLD (20.7%) with a range of clinical syndromes.ExposureParticipants completed standard in-clinic measures and remotely administered ALLFTD mobile app (app) smartphone tests.Main Outcomes and MeasuresInternal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy.ResultsIn the 360 participants (mean [SD] age, 54.0 [15.4] years; 209 [58.1%] women), smartphone tests showed moderate-to-excellent reliability (intraclass correlation coefficients, 0.77-0.95). Validity was supported by association of smartphones tests with disease severity (r range, 0.38-0.59), criterion-standard neuropsychological tests (r range, 0.40-0.66), and brain volume (standardized β range, 0.34-0.50). Smartphone tests accurately differentiated individuals with dementia from controls (area under the curve [AUC], 0.93 [95% CI, 0.90-0.96]) and were more sensitive to early symptoms (AUC, 0.82 [95% CI, 0.76-0.88]) than the Montreal Cognitive Assessment (AUC, 0.68 [95% CI, 0.59-0.78]) (z of comparison, −2.49 [95% CI, −0.19 to −0.02]; P = .01). Reliability and validity findings were highly similar in the discovery and validation cohorts. Preclinical participants who carried pathogenic variants performed significantly worse than noncarrier family controls on 3 app tasks (eg, 2-back β = −0.49 [95% CI, −0.72 to −0.25]; P < .001) but not a composite of traditional neuropsychological measures (β = −0.14 [95% CI, −0.42 to 0.14]; P = .32).Conclusions and RelevanceThe findings of this cohort study suggest that smartphones could offer a feasible, reliable, valid, and scalable solution for remote evaluations of FTLD and may improve early detection. Smartphone assessments should be considered as a complementary approach to traditional in-person trial designs. Future research should validate these results in diverse populations and evaluate the utility of these tests for longitudinal monitoring.

Abstract Intratumoral heterogeneity poses a significant challenge to the diagnosis and treatment of glioblastoma (GBM). This heterogeneity is further exacerbated during GBM recurrence, as treatment-induced reactive changes produce additional intratumoral heterogeneity that is ambiguous to differentiate on clinical imaging. There is an urgent need to develop non-invasive approaches to map the heterogeneous landscape of histopathological alterations throughout the entire lesion for each patient. We propose to predictively fuse Magnetic Resonance Imaging (MRI) with the underlying intratumoral heterogeneity in recurrent GBM using machine learning (ML) by leveraging image-localized biopsies with their associated locoregional MRI features. To this end, we develop BioNet, a biologically-informed neural network model, to predict regional distributions of three tissue-specific gene modules: proliferating tumor, reactive/inflammatory cells, and infiltrated brain tissue. BioNet offers valuable insights into the integration of multiple implicit and qualitative biological domain knowledge, which are challenging to describe in mathematical formulations. BioNet performs significantly better than a range of existing methods on cross-validation and blind test datasets. Voxel-level prediction maps of the gene modules by BioNet help reveal intratumoral heterogeneity, which can improve surgical targeting of confirmatory biopsies and evaluation of neuro-oncological treatment effectiveness. The non-invasive nature of the approach can potentially facilitate regular monitoring of the gene modules over time, and making timely therapeutic adjustment. These results also highlight the emerging role of ML in precision medicine.

AbstractINTRODUCTIONGlial fibrillary acidic protein (GFAP) in plasma is a proxy for astrocytic activity and is elevated in amyloid‐β (Aβ)‐positive individuals, making GFAP a potential blood‐based biomarker for Alzheimer's disease (AD).METHODSWe assessed plasma GFAP in 72 Aβ‐positive participants diagnosed with the visual or language variant of AD who underwent Aβ‐ and tau‐PET. Fifty‐nine participants had follow‐up imaging. Linear regression was applied on GFAP and imaging quantities.RESULTSGFAP did not correlate with Aβ‐ or tau‐PET cross‐sectionally. There was a limited positive correlation between GFAP and rates of tau accumulation, particularly in the language variant of AD, although associations were weaker after removing one outlier patient with the highest GFAP level.DISCUSSIONAmong Aβ‐positive AD participants with atypical presentations, plasma GFAP did not correlate with levels of AD pathology on PET, suggesting that the associations between GFAP and AD pathology might plateau during the advanced phase of the disease.

Metabolic and bariatric surgery (MBS) is the most effective therapeutic intervention for patients with obesity, with sleeve gastrectomy (SG) being the most commonly performed primary MBS procedure. Long-term studies have demonstrated that 15–20% of patients require revisional bariatric surgery (RBS) due to weight-related issues or surgical complications. Despite the gold standard being laparoscopic revision, there are other available approaches such as open or robotic-assisted. An extensive literature review was performed for articles from their inception to February 2024. A descriptive review of MBS procedures (SG, Roux-en-Y gastric bypass (RYGB), single anastomosis duodeno-ileostomy (SADI) and biliopancreatic diversion-duodenal switch (BPD-DS)) was carried out to report and compare outcomes between primary and revisional bariatric surgery. A similar review was conducted to compare outcomes of revisional approaches (open, laparoscopic, robotic). RYGB remains the dominant RBS with a similar safety profile compared to revisional SADI and BPD-DS. In terms of the RBS surgical approach, all three options showed comparable short and long-term outcomes, with robotic RBS being associated with longer operative time and variable length of stay. Additional long-term studies are required to further validate our conclusions.

Abstract Background: Cholangiocarcinoma (CCA) is a lethal and heterogenous malignancy of the biliary tree characterized by perineural invasion. About 85% of CCA show activation of YAP signaling, which promotes proliferation, anti-apoptosis, and therapeutic resistance. YAP signaling is mediated by Src family kinases (SFK) by phosphorylation of YAP (pYAPy357). NXP900 is a first-in-class, highly selective, SFK inhibitor with a novel mechanism of action which locks SFK in its closed and inhibited conformation, in contrast to other Src inhibitors such as dasatinib. A phase 1a study of NXP900 in patients with advanced solid tumors was recently initiated. Here, we examined treatment responses of CCA to NXP900 in vitro and in vivo. Methods: Cell viability was determined in seven CCA cell lines by CellTiter-Glo. Cell death and apoptosis were assayed by PI/Hoechst and Caspase-Glo 3/7 assay. CalcuSyn software was used to determine synergistic drug effects. Immunoblot analysis, RT-PCR, and IF staining of YAP localization were used to evaluate YAP knockdown. Clones of human CCA cell lines resistant to NXP900 were generated through escalating exposure to NXP900 over 6 months. Five patient-derived xenograft (PDX) tumors were expanded into flanks of NOD/SCID mice. Tumor bearing mice were randomized 1:1 with 5 mice per arm and treated with vehicle or NXP900 (40 mg/kg) once daily for up to 4 weeks. To determine drivers of sensitivity and resistance, predicted sensitivity scores based on tumor growth were linked to multi-omics (RNA seq and [phospho-]proteomics) of our PDX models. Results: All cell lines were sensitive to NXP900 with IC50 values between 7nM-15µM; IC50’s of resistant clones were 1000 times higher. NXP900 induced more cell death compared to vehicle, which appeared to be through apoptosis. NXP900 inhibited pSrc, decreased pYAPy357, and upregulated inactive pYAPs127. Correspondingly, decreased YAP target gene (Cyr61, NUAK, and CTGF) levels and a nuclear-to-cytoplasmic translocation were observed. NXP900/GemCis combination therapy increased cell death demonstrated a synergistic effect (Combination Indices <1) at all concentrations. In our PDX models, treatment was associated with a significant decrease in tumor growth in 3 models (mean fold change 3.1 vs. 14.2; 1.0 vs. 7.6; 1.4 vs. 2.6). The major resistant signature was the TRK signaling network, involved in nerve growth factor binding activity, while drivers of sensitivity included the SRC network. Conclusion: NXP900 demonstrated therapeutic activity in vitro and in human PDX models. We are currently performing multi-omic approaches in NXP900 sensitive and resistant cell lines to unravel determinants of activity and resistance. Additional in vivo studies will be performed to determine effects of NXP900/GemCis and NXP900/anti-PDL-1 combination therapy. Citation Format: Hendrien Kuipers, Jennifer L. Tomlinson, Danielle M. Carlson, Amro M. Abdelrahman, Erik Jessen, Jack W. Sample, Nathan W. Werneburg, Hannah E. Stumpf, Mark J. Truty, Sumera I. Ilyas, Gregory J. Gores, Rory L. Smoot. Src family kinase inhibition demonstrates antitumor activity in vitro and in patient-derived xenograft models of human cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 614.

Abstract Introduction: Cholangiocarcinoma (CCA) is an aggressive and heterogenous biliary malignancy. Previous therapeutic shortcomings have encouraged the investigation of new strategies, such as targeted therapeutics. YAP/TAZ, transcriptional coactivators of the hippo pathway, have been implicated in the tumorigenesis of CCA along with the Src familiar kinase, LCK. Milk-derived nanovesicles (MNVs) have emerged as a promising biologic delivery apparatus for hepatobiliary malignancy due to their predilection for hepatic uptake. We sought to investigate the utility of aptamer guided MNVs loaded with short interfering RNA (siRNA) targeting YAP, TAZ, and LCK. Methods: MNVs were prepared and loaded with species-specific siRNA prior to decoration with an epithelial cellular adhesion molecule (EpCAM) targeting aptamer. In vitro studies were performed using murine and human CCA cell lines, SB1 and HuCCT-1, respectively. In vivo studies were carried out using C57BL/6 mice following Institutional Animal Care and Use Committee protocols. Results: We previously validated EpCAM as an effective aptamer demonstrated by increased levels of expression in CCA cell lines using immunoblot, RT-PCR and immunofluorescence. Additionally, in vivo experiments demonstrated excellent biodistribution and affinity for tumor-selective uptake. To evaluate knockdown efficacy, CCA cell lines were incubated with EpCAM aptamer guided MNVs individually targeting YAP, TAZ, and LCK which resulted in downregulation of these targets on immunoblot and RT-PCR. MNVs were then loaded with equal concentrations of siRNA targeting YAP, TAZ, and LCK in combination which resulted in similar degrees of gene downregulation compared with single transcriptome targeting MNVs. Due to the role of YAP/TAZ activation in CCA systemic therapy resistance, we investigated the effect of MNVs loaded with either single target or combinatory target siRNA alongside and in combination with gemcitabine and cisplatin (GemCis). Incubation with both combinatory siRNA and GemCis significantly intensified cell death on Pi/Hoechst staining compared with single target knockdown alone. Similar findings were found using separate assays of cell viability, including ATP luminescent quantitation and caspase 3/7 activity. These data suggest MNV transcriptome targeting may induce a state of cell stress which allows for amplification of chemotherapy treatment effect. Conclusion: Aptamer guided, nanovesicle mediated transcriptome targeting is a promising therapeutic strategy in preclinical CCA models that may potentiate chemotherapy response. Our future direction involves further investigating the role of CCA target downregulation and its effect on the tumor immune microenvironment utilizing aptamer guided nanovesicle delivery and inducible knockdown cell lines. Citation Format: Jack W. Sample, Mincheng Yu, Hendrien Kuipers, Danielle M. Carlson, Nathan W. Werneberg, Jennifer L. Tomlinson, Gregory J. Gores, Rory L. Smoot. Milk-derived extracellular nanovesicles: A novel delivery strategy for transcriptome targeting therapies in cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5753.

Abstract Introduction Cholangiocarcinoma (CCA) is a highly lethal, heterogenous biliary malignancy. Despite the development of targeted therapies, treatment success has been hindered by primary or acquired resistance. New therapeutic strategies are necessary to improve outcomes in these patients. NXP800 is a GCN2 small-molecule activator that phosphorylates eIF2a inducing selective ATF4 transcription which stimulates stress-induced genes leading to apoptosis. NXP800 has been previously validated in ovarian cancers with ARID1A mutations, well-known players in cholangiocarcinoma. We sought to determine the treatment efficacy of novel NXP800 in CCA utilizing patient derived xenograft (PDX) preclinical models. Methods In our preliminary studies, four human and two murine CCA cell lines were tested for cell viability using CellTiter-Glo to determine the maximal inhibitory concentration (IC50). Immunoblot analysis of HuCCT-1 cells incubated with 1 mM of NXP800 for 6 hours vs. vehicle was performed. We also evaluated response to GCN2 activation in multiple RNA sequenced PDX models. Xenografts were expanded into the flank of NOD/SCID mice and treatment begun when tumors averaged 120mm3. Tumor bearing mice were treated with NXP800 (35 mg/kg) or vehicle via oral gavage five days on, two days off, for 28 days. Tumor volume and animal weight were collected twice weekly. Predicted sensitive signatures were determined using multi-omics. Results IC50 dose response curves showed nanomolar activity in all six cell lines, ranging from 5-170 nM. Immunoblotting demonstrated an upregulation of phosphorylated eIF2a and in turn upregulation of ATF4 with treatment of NXP800 compared to vehicle. Five PDX tumors from patients with intrahepatic or distal CCA was established and validated by histologic analysis. Molecular characterization of the tumor identified tumor mutation and a total tumor mutational burden. RNA sequencing was completed and identified 21-gene signatures related to YAP activity, which were cross-referenced against our existing PDX model tumor bank. Treatment with NXP800 was associated with a statistically significant decrease in tumor size in three of five PDX models tested, which included an ARID1A, FGFR1, and ATM mutants. Preliminary multi-omics on the PDX models revealed that sensitivity mechanisms were centered around EGFR signaling. Conclusion The novel GCN2 kinase activator, NXP800, has nanomolar efficacy in both human and murine CCA cell lines in vitro. Additionally, NXP800 demonstrated therapeutic activity in multiple cholangiocarcinoma PDX models in vivo. We are opening a Phase 1b clinical trial investigating the effects of NXP800 use in patients with advanced CCA. Future studies determining the cellular effect of GCN2 activation utilizing NXP800 are being conducted. Citation Format: Danielle Marie Carlson, Hendrien Kuipers, Amro Abdelrahman, Erik Jessen, Joshua Roldan Kalil, Jack Sample, Jennifer Tomlinson, Mark Truty, Rory Smoot. A novel GCN2 kinase activator demonstrates therapeutic efficacy in preclinical PDX models of human cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2098.

Abstract Background White matter hyperintensities (WMH) are considered hallmark features of cerebral small vessel disease and have recently been linked to Alzheimer’s disease pathology. Their distinct spatial distributions, namely periventricular versus deep WMH, may differ by underlying age-related and pathobiological processes contributing to cognitive decline. We aimed to identify the spatial patterns of WMH using the 4-scale Fazekas visual assessment and explore their differential association with age, vascular health, Alzheimer’s imaging markers, namely amyloid and tau burden, and cognition. Because our study consisted of scans from GE and Siemens scanners with different resolutions, we also investigated inter-scanner reproducibility and combinability of WMH measurements on imaging. Methods We identified 1144 participants from the Mayo Clinic Study of Aging consisting of older adults from Olmsted County, Minnesota with available structural magnetic resonance imaging (MRI), amyloid, and tau positron emission tomography (PET). WMH distribution patterns were assessed on FLAIR-MRI, both 2D axial and 3D, using Fazekas ratings of periventricular and deep WMH severity. We compared the association of periventricular and deep WMH scales with vascular risk factors, amyloid-PET and tau-PET standardized uptake value ratio, WMH volume, and cognition using Pearson partial correlation after adjusting for age. We also evaluated vendor compatibility and reproducibility of the Fazekas scales using intraclass correlations (ICC). Results Periventricular and deep WMH measurements showed similar correlations with age, cardiometabolic conditions score (vascular risk), and cognition, (p < 0.001). Both periventricular WMH and deep WMH showed weak associations with amyloidosis (R = 0.07, p = < 0.001), and none with tau burden. We found substantial agreement between data from the two scanners for Fazekas measurements (ICC = 0.78). The automated WMH volume had high discriminating power for identifying participants with Fazekas ≥ 2 (area under curve = 0.97). Conclusion Our study investigates risk factors underlying WMH spatial patterns and their impact on global cognition, with no discernible differences between periventricular and deep WMH. We observed minimal impact of amyloidosis on WMH severity. These findings, coupled with enhanced inter-scanner reproducibility of WMH data, suggest the combinability of inter-scanner data assessed by harmonized protocols in the context of vascular contributions to cognitive impairment and dementia biomarker research.