Multidimensional fragmentomic profiling of cell-free DNA released from patient-derived organoids.

BACKGROUND: Fragmentomics, the investigation of fragmentation patterns of cell-free DNA (cfDNA), has emerged as a promising strategy for the early detection of multiple cancers in the field of liquid biopsy. However, the clinical application of this approach has been hindered by a limited understanding of cfDNA biology. Furthermore, the prevalence of hematopoietic cell-derived cfDNA in plasma complicates the in vivo investigation of tissue-specific cfDNA other than that of hematopoietic origin. While conventional two-dimensional cell lines have contributed to research on cfDNA biology, their limited representation of in vivo tissue contexts underscores the need for more robust models. In this study, we propose three-dimensional organoids as a novel in vitro model for studying cfDNA biology, focusing on multifaceted fragmentomic analyses. RESULTS: We established nine patient-derived organoid lines from normal lung airway, normal gastric, and gastric cancer tissues. We then extracted cfDNA from the culture medium of these organoids in both proliferative and apoptotic states. Using whole-genome sequencing data from cfDNA, we analyzed various fragmentomic features, including fragment size, footprints, end motifs, and repeat types at the end. The distribution of cfDNA fragment sizes in organoids, especially in apoptosis samples, was similar to that found in plasma, implying occupancy by mononucleosomes. The footprints determined by sequencing depth exhibited distinct patterns depending on fragment sizes, reflecting occupancy by a variety of DNA-binding proteins. Notably, we discovered that short fragments (< 118 bp) were exclusively enriched in the proliferative state and exhibited distinct fragmentomic profiles, characterized by 3 bp palindromic end motifs and specific repeats. CONCLUSIONS: In conclusion, our results highlight the utility of in vitro organoid models as a valuable tool for studying cfDNA biology and its associated fragmentation patterns. This, in turn, will pave the way for further enhancements in noninvasive cancer detection methodologies based on fragmentomics.

Healing and stent coverage with the new ultrathin sirolimus-eluting stent with abluminal biodegradable polymer.

BACKGROUND: Genoss drug-eluting stent (DES) (Genoss Company Limited) is a new ultrathin sirolimus-eluting stent with an abluminal biodegradable polymer and a cobalt-chromium platform. AIMS: The aim of this study was to evaluate vascular healing and neointimal coverage after implantation of the Genoss DES using optical coherence tomography (OCT) 6 months postimplantation. METHODS: From August 22, 2019 to June 17, 2020, this multicenter, observational, investigator-initiated study enrolled 20 patients who underwent OCT examination 6 months after Genoss DES implantation and provided informed consent. An analyst, blinded to the patients' and procedural information analyzed OCT images at an independent core laboratory. RESULTS: Of the 20 patients, 19 with 27 stents in 21 lesions from 21 vessels were included in the analysis, while one patient withdrew consent and was unwilling to undergo follow-up OCT. OCT analysis was performed 204.4 ± 31.9 days after Genoss DES implantation. A total of 4285 stent struts from 661 cross-sections were analyzed. Strut tissue coverage was observed in 98.7 ± 4.3% of struts, with 0.1 ± 1.2% malapposed struts per lesion. The mean thickness of neointimal hyperplasia (NIH) on the covered struts was 0.12 ± 0.04 mm. CONCLUSIONS: Six months after stent implantation, most Genoss DES struts were covered with a thin layer of NIH that was evenly distributed along the stent length. This pilot study evaluated the outcomes of 6 months dual antiplatelet therapy in the context of ultrathin strut stents, providing insight into developing ethical standards and a scientific foundation for conducting an adequately designed clinical trial.

Dendrimer-Peptide Conjugates for Effective Blockade of the Interactions between SARS-CoV-2 Spike Protein and Human ACE2 Receptor.

The coronavirus disease 2019 (COVID-19) pandemic has threatened the stability of global healthcare, which is becoming an endemic issue. Despite the development of various treatment strategies to fight COVID-19, the currently available treatment options have shown varied efficacy. Herein, we have developed an avidity-based SARS-CoV-2 antagonist using dendrimer-peptide conjugates (DPCs) for effective COVID-19 treatment. Two different peptide fragments obtained from angiotensin-converting enzyme 2 (ACE2) were integrated into a single sequence, followed by the conjugation to poly(amidoamine) (PAMAM) dendrimers. We hypothesized that the strong multivalent binding avidity endowed by dendrimers would help peptides effectively block the interaction between SARS-CoV-2 and ACE2, and this antagonist effect would be dependent upon the generation (size) of the dendrimers. To assess this, binding kinetics of the DPCs prepared from generation 4 (G4) and G7 PAMAM dendrimers to spike protein of SARS-CoV-2 were quantitatively measured using surface plasmon resonance. The larger dendrimer-based DPCs exhibited significantly enhanced binding strength by 3 orders of magnitude compared to the free peptides, whereas the smaller one showed a 12.8-fold increase only. An in vitro assay using SARS-CoV-2-mimicking microbeads also showed the improved SARS-CoV-2 blockade efficiency of the G7-peptide conjugates compared to G4. In addition, the interaction between the DPCs and SARS-CoV-2 was analyzed using molecular dynamics (MD) simulation, providing an insight into how the dendrimer-mediated multivalent binding effect can enhance the SARS-CoV-2 blockade. Our findings demonstrate that the DPCs having strong binding to SARS-CoV-2 effectively block the interaction between ACE2 and SARS-CoV-2, providing a potential as a high-affinity drug delivery system to direct anti-COVID payloads to the virus.

Impact of Trimetazidine on the Incident Heart Failure After Coronary Artery Revascularization.

ABSTRACT: Abnormal myocardial metabolism is a common pathophysiological process underlying ischemic heart disease and heart failure (HF). Trimetazidine is an antianginal agent with a unique mechanism of action that regulates myocardial energy metabolism and might have a beneficial effect in preventing HF in patients undergoing myocardial revascularization. We aimed to evaluate the potential benefit of trimetazidine in preventing incident hospitalization for HF after myocardial revascularization. Using the common data model, we identified patients without prior HF undergoing myocardial revascularization from 8 hospital databases in Korea. To compare clinical outcomes using trimetazidine, database-level hazard ratios (HRs) were estimated using large-scale propensity score matching for each database and pooled using a random-effects model. The primary outcome was incident hospitalization for HF. The secondary outcome of interest was major adverse cardiac events (MACEs). After propensity score matching, 6724 and 11,211 patients were allocated to trimetazidine new-users and nonusers, respectively. There was no significant difference in the incidence of hospitalization for HF between the 2 groups (HR: 1.08, 95% confidence interval [CI], 0.88-1.31; P = 0.46). The risk of MACE also did not differ between the 2 groups (HR: 1.07, 95% CI, 0.98-1.16; P = 0.15). In conclusion, the use of trimetazidine did not reduce the risk of hospitalization for HF or MACE in patients undergoing myocardial revascularization. Therefore, the role of trimetazidine in contemporary clinical practice cannot be expanded beyond its current role as an add-on treatment for symptomatic angina.

Impaired Blastocyst Formation in Lnx2-Knockdown Mouse Embryos.

Ligand of Numb-protein X 2 (LNX2) is an E3 ubiquitin ligase that is known to regulate Notch signaling by participating in NUMB protein degradation. Notch signaling is important for differentiation and proliferation in mammals, and plays a significant role in blastocyst formation during early embryonic development. In this study, we investigated Lnx2 in mouse preimplantation embryos. Expression analysis showed that Lnx2 is expressed in oocytes and preimplantation embryos. Lnx2-knockdown embryos normally progress to the morula stage, but the majority of them do not develop into normal blastocysts. Transcript analysis revealed that the expression levels of genes critical for cell lineage specification, including octamer-binding transcription factor 4 (Oct4), are increased in Lnx2 knockdown embryos. Furthermore, the expression levels of Notch and Hippo signaling-related genes are also increased by Lnx2 knockdown. Collectively, our results show that Lnx2 is important for blastocyst formation in mice, suggest that this may act via lineage specification of inner cell mass, and further show that Lnx2 may be involved in transcriptionally regulating various genes implicated in early embryonic development.

Cross-decoration of dendritic cells by non-inherited maternal antigen-containing extracellular vesicles: Potential mechanism for PD-L1-based tolerance in cord blood and organ transplantation.

Exposure to non-inherited maternal antigens (NIMA) during the fetal period induces lifelong split tolerance to grafts expressing these allo-antigens. In adult mice, the production of extracellular vesicles (EVs) from maternal microchimeric cells causes cross-decoration (XD) of offspring dendritic cells (DC) with NIMA and upregulation of PD-L1, contributing to NIMA tolerance. To see how this may apply to humans, we tested NIMA acquisition by fetal DCS in human cord blood. The average percentage of NIMA-XD among total DCs was 2.6% for myeloid and 4.5% for Plasmacytoid DC. These cells showed higher PD-L1 expression than their non-XD counterparts (mDC: p = .0016; pDC: p = .024). We detected CD9+ EVs bearing NIMA and PD-L1 in cord blood. To determine if this immune regulatory mechanism persists beyond the pregnancy, we analyzed NIMA-expressing kidney and liver transplant recipients. We found donor antigen XD DCs in peripheral blood and graft-infiltrating DCs. As in cord blood, the pattern of donor antigen expression was punctate, and PD-L1 expression was upregulated, likely due to both protein and miRNA acquired from EV. Our findings support a mechanism for split tolerance to NIMAs that develops during pregnancy and is recapitulated in adult transplant recipients.

Native Ion Mobility-Mass Spectrometry-Enabled Fast Structural Interrogation of Labile Protein Surface Modifications at the Intact Protein Level.

Protein sialylation has been closely linked to many diseases including Alzheimer's disease (AD). It is also broadly implicated in therapeutics operating in a pattern-dependent (e.g., Neu5Ac vs Neu5Gc) manner. However, how the sialylation pattern affects the AD-associated, transferrin-assisted iron/Aß cellular uptake process remains largely ill-defined. Herein, we report the use of native ion mobility-mass spectrometry (IM-MS)-based fast structural probing methodology, enabling well-controlled, synergistic, and in situ manipulation of mature glycoproteins and attached sialic acids. IM-MS-centered experiments enable the combinatorial interrogation of sialylation effects on Aß cytotoxicity and the chemical, conformational, and topological stabilities of transferrin. Cell viability experiments suggest that Neu5Gc replacement enhances the transferrin-assisted, iron loading-associated Aß cytotoxicity. Native gel electrophoresis and IM-MS reveal that sialylation stabilizes transferrin conformation but inhibits its dimerization. Collectively, IM-MS is adapted to capture key sialylation intermediates involved in fine-tuning AD-associated glycoprotein structural microheterogeneity. Our results provide the molecular basis for the importance of sustaining moderate TF sialylation levels, especially Neu5Ac, in promoting iron cellular transportation and rescuing iron-enhanced Aß cytotoxicity.

Dendritic-Linear Copolymer and Dendron Lipid Nanoparticles for Drug and Gene Delivery.

Polymers constitute a diverse class of macromolecules that have demonstrated their unique advantages to be utilized for drug or gene delivery applications. In particular, polymers with a highly ordered, hyperbranched structure─"dendrons"─offer significant benefits to the design of such nanomedicines. The incorporation of dendrons into block copolymer micelles can endow various unique properties that are not typically observed from linear polymer counterparts. Specifically, the dendritic structure induces the conical shape of unimers that form micelles, thereby improving the thermodynamic stability and achieving a low critical micelle concentration (CMC). Furthermore, through a high density of highly ordered functional groups, dendrons can enhance gene complexation, drug loading, and stimuli-responsive behavior. In addition, outward-branching dendrons can support a high density of nonfouling polymers, such as poly(ethylene glycol), for serum stability and variable densities of multifunctional groups for multivalent cellular targeting and interactions. In this paper, we review the design considerations for dendron-lipid nanoparticles and dendron micelles formed from amphiphilic block copolymers intended for gene transfection and cancer drug delivery applications. These technologies are early in preclinical development and, as with other nanomedicines, face many obstacles on the way to clinical adoption. Nevertheless, the utility of dendron micelles for drug delivery remains relatively underexplored, and we believe there are significant and dramatic advancements to be made in tumor targeting with these platforms.

AXL regulates neuregulin1 expression leading to cetuximab resistance in head and neck cancer.

BACKGROUND: The receptor tyrosine kinase (RTK) epidermal growth factor receptor (EGFR) is overexpressed and an important therapeutic target in Head and Neck cancer (HNC). Cetuximab is currently the only EGFR-targeting agent approved by the FDA for treatment of HNC; however, intrinsic and acquired resistance to cetuximab is a major problem in the clinic. Our lab previously reported that AXL leads to cetuximab resistance via activation of HER3. In this study, we investigate the connection between AXL, HER3, and neuregulin1 (NRG1) gene expression with a focus on understanding how their interdependent signaling promotes resistance to cetuximab in HNC. METHODS: Plasmid or siRNA transfections and cell-based assays were conducted to test cetuximab sensitivity. Quantitative PCR and immunoblot analysis were used to analyze gene and protein expression levels. Seven HNC patient-derived xenografts (PDXs) were evaluated for protein expression levels. RESULTS: We found that HER3 expression was necessary but not sufficient for cetuximab resistance without AXL expression. Our results demonstrated that addition of the HER3 ligand NRG1 to cetuximab-sensitive HNC cells leads to cetuximab resistance. Further, AXL-overexpressing cells regulate NRG1 at the level of transcription, thereby promoting cetuximab resistance. Immunoblot analysis revealed that NRG1 expression was relatively high in cetuximab-resistant HNC PDXs compared to cetuximab-sensitive HNC PDXs. Finally, genetic inhibition of NRG1 resensitized AXL-overexpressing cells to cetuximab. CONCLUSIONS: The results of this study indicate that AXL may signal through HER3 via NRG1 to promote cetuximab resistance and that targeting of NRG1 could have significant clinical implications for HNC therapeutic approaches.

8-Shogaol inhibits rheumatoid arthritis through targeting TAK1.

Rheumatoid arthritis (RA) is a chronic immune-mediated disorder, mainly characterized by synovial inflammation and joint damage. If insufficiently treated, RA can lead to irreversible joint destruction and decreased life expectancy. While better understanding of the pathologies and the development of new antirheumatic drugs have improved the outcome of individuals with RA, many patients still cannot achieve remission and experience progressive disability. Fibroblast-like synoviocytes (FLS) have gained attention due to its pivotal role in RA pathogenesis and thus targeting FLS has been suggested as an attractive therapeutic strategy. To identify candidate molecules with strong inhibitory activity against FLS inflammation, we tested the effect of 315 natural extracts against IL-17-mediated IL-6 production. Zingiber officinale was found as the top hit and further analysis on the active compound responsible led to the discovery of 8-shogaol as a potent molecule against synovitis. 8-Shogaol displayed significant inhibitory effects against TNF-α-, IL-1ß-, and IL-17-mediated inflammation and migration in RA patient-derived FLS (RA-FLS) and 3D synovial culture system. 8-Shogaol selectively and directly inhibited TAK1 activity and subsequently suppressed IKK, Akt, and MAPK signaling pathways. Moreover, treatment with 8-shogaol reduced paw thickness and improved walking performance in the adjuvant-induced arthritic (AIA) rat model. 8-Shogaol also reversed pathologies of joint structure in AIA rats and decreased inflammatory biomarkers in the joints. Collectively, we report a novel natural compound that inhibits RA through reversing pathologies of the inflamed synovium via targeting TAK1.

Discovery of acquired molecular signature on immune checkpoint inhibitors in paired tumor tissues.

BACKGROUND: Immune checkpoint inhibitor (ICI) has an emerging role in several types of cancer. However, the mechanisms of acquired resistance (AR) to ICI have not been elucidated yet. To identify these mechanisms, we analyzed the pre- and post-ICI paired tumor samples in patients with AR. METHODS: Six patients with renal cell carcinoma, urothelial cell carcinoma, or head and neck cancer, who showed an initial response to ICI followed by progression and had available paired tissue samples, were retrospectively analyzed. Whole exome sequencing, RNA sequencing, and multiplex immunohistochemistry were performed on pre-treatment and resistant tumor samples. RESULTS: The median time to AR was 370 days (range, 210 to 739). Increased expression of alternative immune checkpoints including TIM3, LAG3, and PD-1 as well as increased CD8+ tumor-infiltrating lymphocytes were observed in post-treatment tumor than in pre-treatment tumor of a renal cell carcinoma patient. In contrast, CD8+ T cells and immunosuppressive markers were all decreased at AR in another patient with human papillomavirus-positive head and neck squamous cell carcinoma. This patient had an evident APOBEC-associated signature, and the tumor mutation burden increased at AR. Resistant tumor tissue of this patient harbored a missense mutation (E542K) in PIK3CA. No significant aberrations of antigen-presenting machinery or IFN-γ pathway were detected in any patient. CONCLUSIONS: Our study findings suggest that the observed increase in immunosuppressive markers after ICI might contribute to AR. Moreover, APOBEC-mediated PIK3CA mutagenesis might be an AR mechanism. To validate these mechanisms of AR, further studies with enough sample size are required.

Boosting Unassisted Alkaline Solar Water Splitting Using Silicon Photocathode with TiO2 Nanorods Decorated by Edge-Rich MoS2 Nanoplates.

To construct a highly efficient photoelectrochemical tandem device with silicon photocathode operating in alkaline conditions, it is desirable to develop stable and active catalysts which enable the photocathode to reliably perform under an alkaline environment. With nanostructured passivation layer and edge-exposed transition metal disulfides, silicon photocathode provides new opportunities for achieving unbiased alkaline solar water splitting. Here, the TiO2 nanorod arrays decorated by edge-rich MoS2 nanoplates are elaborately synthesized and deposited on p-Si. The vertically aligned TiO2 nanorods fully stabilize the Si surface and improve anti-reflectance. Moreover, MoS2 nanoplates with exposed edge sites provide catalytically active regions resulting in the kinetically favored hydrogen evolution under an alkaline environment. Interfacial energy band bending between p-Si and catalyst layers facilitates the transport of photogenerated electrons under steady-state illumination. Consequently, the MoS2 nanoplates/TiO2 nanorods/p-Si photocathode exhibits significantly improved photoelectrochemical-hydrogen evolution reaction (PEC-HER) performance in alkaline media with a high photocurrent density of 10 mA cm-2 at 0 V versus RHE and high stability. By integrating rationally designed photocathode with earth-abundant Fe60 (NiCo)30 Cr10 anode and perovskite/Si tandem photovoltaic cell, an unassisted alkaline solar water splitting is accomplished with a current density of 5.4 mA cm-2 corresponding to 6.6% solar-to-hydrogen efficiency, which is the highest among p-Si photocathodes.

Size-Dependent Drug Loading, Gene Complexation, Cell Uptake, and Transfection of a Novel Dendron-Lipid Nanoparticle for Drug/Gene Co-delivery.

Dendron micelles have shown promising results as a multifunctional delivery system, owing to their unique molecular architecture. Herein, we have prepared a novel poly(amidoamine) (PAMAM) dendron-lipid hybrid nanoparticle (DLNP) as a nanocarrier for drug/gene co-delivery and examined how the dendron generation of DLNPs impacts their cargo-carrying capabilities. DLNPs, formed by a thin-layer hydration method, were internally loaded with chemo-drugs and externally complexed with plasmids. Compared to generation 2 dendron DLNP (D2LNPs), D3LNPs demonstrated a higher drug encapsulation efficiency (31% vs 87%) and better gene complexation (minimal N/P ratio of 20:1 vs 5:1 for complexation) due to their smaller micellar aggregation number and higher charge density, respectively. Furthermore, D3LNPs were able to avoid endocytosis and subsequent lysosomal degradation and demonstrated a higher cellular uptake than D2LNPs. As a result, D3LNPs exhibited significantly enhanced antitumor and gene transfection efficacy in comparison to D2LNPs. These findings provide design cues for engineering multifunctional dendron-based nanotherapeutic systems for effective combination cancer treatment.

Immunoavidity-Based Capture of Tumor Exosomes Using Poly(amidoamine) Dendrimer Surfaces.

Tumor-derived blood-circulating exosomes have potential as a biomarker to greatly improve cancer treatment. However, effective isolation of exosomes remains a tremendous technical challenge. This study presents a novel nanostructured polymer surface for highly effective capture of exosomes through strong avidity. Various surface configurations, consisting of multivalent dendrimers, PEG, and tumor-targeting antibodies, were tested using exosomes isolated from tumor cell lines. We found that a dual layer dendrimer configuration exhibited the highest efficiency in capturing cultured exosomes spiked into human serum. Importantly, the optimized surface captured a > 4-fold greater amount of tumor exosomes from head and neck cancer patient plasma samples than that from healthy donors. Nanomechanical analysis using atomic force microscopy also revealed that the enhancement was attributed to multivalent binding (avidity) and augmented short-range adhesion mediated by dendrimers. Our results support that the dendrimer surface detects tumor exosomes at high sensitivity and specificity, demonstrating its potential as a new cancer liquid biopsy platform.

An Avidity-Based PD-L1 Antagonist Using Nanoparticle-Antibody Conjugates for Enhanced Immunotherapy.

Upregulation of programmed death ligand 1 (PD-L1) allows cancer cells to evade antitumor immunity. Despite tremendous efforts in developing PD-1/PD-L1 immune checkpoint inhibitors (ICIs), clinical trials using such ICIs have shown inconsistent benefits. Here, we hypothesized that the ICI efficacy would be dictated by the binding strength of the inhibitor to the target proteins. To assess this, hyperbranched, multivalent poly(amidoamine) dendrimers were employed to prepare dendrimer-ICI conjugates (G7-aPD-L1). Binding kinetics measurements using SPR, BLI, and AFM revealed that G7-aPD-L1 exhibits significantly enhanced binding strength to PD-L1 proteins, compared to free aPD-L1. The binding avidity of G7-aPD-L1 was translated into in vitro efficiency and in vivo selectivity, as the conjugates improved the PD-L1 blockade effect and enhanced accumulation in tumor sites. Our results demonstrate that the dendrimer-mediated multivalent interaction substantially increases the binding avidity of the ICIs and thereby improves the antagonist effect, providing a novel platform for cancer immunotherapy.

Nanoparticle Conjugation Stabilizes and Multimerizes ß-Hairpin Peptides To Effectively Target PD-1/PD-L1 ß-Sheet-Rich Interfaces.

ß-Hairpin peptides present great potential as antagonists against ß-sheet-rich protein surfaces, of which wide and flat geometries are typically "undruggable" with small molecules. Herein, we introduce a peptide-dendrimer conjugate (PDC) approach that stabilizes the ß-hairpin structure of the peptide via intermolecular forces and the excluded volume effect as well as exploits the multivalent binding effect. Because of the synergistic advantages, the PDCs based on a ß-hairpin peptide isolated from an engineered programmed death-1 (PD-1) protein showed significantly higher affinity (avidity) to their binding counterpart, programmed death-ligand 1 (PD-L1), as compared to free peptides (by up to 5 orders of magnitude). The enhanced binding kinetics with high selectivity was translated into an improved immune checkpoint inhibitory effect in vitro, at a level comparable to (if not better than) that of a full-size monoclonal antibody. The results demonstrate the potential of the PDC system as a novel class of inhibitors targeting ß-strand-rich protein surfaces, such as PD-1 and PD-L1, displaying its potential as a new cancer immunotherapy platform.

Piceatannol reduces resistance to statins in hypercholesterolemia by reducing PCSK9 expression through p300 acetyltransferase inhibition.

The purpose of this study was to investigate the role of piceatannol (PT) in statin (rosuvastatin and simvastatin) resistance and tolerance and its association with PCSK9 expression via its p300 inhibitory (p300i) activity. An in vitro study was performed using HepG2 cells that were exposed to statins (rosuvastatin or simvastatin) with or without PT in delipidated serum (DLPS) medium. In the statin exposed conditions, PCSK9 expression was reduced following PT treatment when compared to HepG2 cells w/o PT treatment. Furthermore, no significant difference was observed in the expression of the transcription factors SREBP2 and HNF1α, which regulate PCSK9 expression. This resulted in low density lipoprotein receptor (LDLR) stabilization and reduced cellular cholesterol levels. This indicates that PT epigenetically controls statin-induced PCSK9 expression. Interestingly, PT attenuated p300 histone acetyltransferase (HAT) activity. Moreover, simulation of PT-p300 binding suggested that PT inhibits p300 as PT could be docked in the p300 HAT domain. Furthermore, inhibition of p300 HAT activity using C-646, a selective p300 inhibitor, or through an siRNA system effectively reduced PCSK9 induction upon statin exposure in HepG2 cells. The chromatin immunoprecipitation (ChIP) assays revealed that PT blocked the recruitment of p300 to the PCSK9 promoter region. In summary, PT attenuated statin-induced PCSK9 expression by inhibiting p300 HAT activity. Finally, co-administration of simvastatin and PT for 10 weeks further reduced plasma low-density lipoprotein-cholesterol (LDL-C) levels and stabilized the hepatic LDLR protein level compared with those resulting from single treatment of simvastatin in a high-fat diet-induced hypercholesterolemia mouse model. Our findings indicate that PT is a new nutraceutical candidate to reduce the statin resistance and tolerance that occurs in patients with hypercholesterolemia.

Dendrimer-Based Platform for Effective Capture of Tumor Cells after TGFß1-Induced Epithelial-Mesenchymal Transition.

Detection of circulating tumor cells (CTCs) relying on their expression of epithelial cell markers, such as epithelial cell adhesion molecule (EpCAM), has been commonly used. However, this approach unlikely captures CTCs that have undergone the process of epithelial-mesenchymal transition (EMT). In this study, we have induced EMT of in vitro prostate (PCa) and breast cancer (BCa) cell lines by treatment of transforming growth factor ß 1 (TGFß1), a pleiotropic cytokine with transition-regulating activities. We found that the TGFß1-treated, post-EMT cells exhibited up to a 45% reduction in binding affinity to antibodies against EpCAM (aEpCAM). To overcome this limitation, we designed our capture platform that integrates a unique combination of biomimetic cell rolling, dendrimer-mediated multivalent binding, and antibody cocktails of aEpCAM/aEGFR/aHER-2. Our capture surfaces resulted in up to 98% capture efficiency of post-EMT cells from mixtures of TGFß1-treated and untreated cancer cells spiked in culture media and human blood. In a clinical pilot study, our CTC device was also able to capture rare CTCs from PCa patients with significantly enhanced capture sensitivity and purity compared to the control surface with aEpCAM only, demonstrating its potential to provide a reliable detection solution for CTCs regardless of their EMT status.

Computational characterization of chromatin domain boundary-associated genomic elements.

Topologically associated domains (TADs) are 3D genomic structures with high internal interactions that play important roles in genome compaction and gene regulation. Their genomic locations and their association with CCCTC-binding factor (CTCF)-binding sites and transcription start sites (TSSs) were recently reported. However, the relationship between TADs and other genomic elements has not been systematically evaluated. This was addressed in the present study, with a focus on the enrichment of these genomic elements and their ability to predict the TAD boundary region. We found that consensus CTCF-binding sites were strongly associated with TAD boundaries as well as with the transcription factors (TFs) Zinc finger protein (ZNF)143 and Yin Yang (YY)1. TAD boundary-associated genomic elements include DNase I-hypersensitive sites, H3K36 trimethylation, TSSs, RNA polymerase II, and TFs such as Specificity protein 1, ZNF274 and SIX homeobox 5. Computational modeling with these genomic elements suggests that they have distinct roles in TAD boundary formation. We propose a structural model of TAD boundaries based on these findings that provides a basis for studying the mechanism of chromatin structure formation and gene regulation.

Tumor penetration of Sub-10 nm nanoparticles: effect of dendrimer properties on their penetration in multicellular tumor spheroids.

Ultrasmall nanoparticles (NPs, <10 nm) have promise in cancer treatment, yet little is known about how NP physical properties influence penetration through solid tumors. To elucidate the role of NP size and structure, we prepared a series of sub-10 nm poly(amidoamine) (PAMAM) dendrimers and gold NPs (AuNP), and evaluated penetration in multicellular tumor spheroids (MCTS). Smaller generation 2 dendrimers (G2-NH2, 2.9 nm diameter) penetrated 2.5-fold deeper than larger G7-NH2 (8.1 nm) (P = 0.0005). Despite increased accumulation within MCTS, electrostatic cell interactions and ligand (folic acid, FA)-mediated targeting had minimal influence on penetration. NP rigidity played a minor role in penetration, with smaller rigid AuNP (2 nm) penetrating significantly more than larger AuNP (4 nm) (3-fold, P = 0.014; G2-NH2 vs. G4-NH2, 2.8-fold, P = 0.033). Our findings highlight the importance of rational NP design and provide design cues for tailored NP distributions within solid tumors.