Programmed Death 1 and Cytotoxic T-Lymphocyte-Associated Protein 4 Gene Expression in Peripheral Blood Mononuclear Cells Can Serve as Prognostic Biomarkers for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly aggressive form of liver cancer with poor prognosis. The lack of reliable biomarkers for early detection and accurate diagnosis and prognosis poses a significant challenge to its effective clinical management. In this study, we investigated the diagnostic and prognostic potential of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expression in peripheral blood mononuclear cells (PBMCs) in HCC. PD-1 and CTLA-4 gene expression was analyzed comparatively using PBMCs collected from HCC patients and healthy individuals. The results revealed higher PD-1 gene expression levels in patients with multifocal tumors, lymphatic invasion, or distant metastasis than those in their control counterparts. However, conventional serum biomarkers of liver function do not exhibit similar correlations. In conclusion, PD-1 gene expression is associated with OS and PFS and CTLA-4 gene expression is associated with OS, whereas the serum biomarkers analyzed in this study show no significant correlation with survival in HCC. Hence, PD-1 and CTLA-4 expressed in PBMCs are considered potential prognostic biomarkers for patients with HCC that can facilitate prediction of malignancy, response to currently available HCC treatments, and overall survival.

Prospective Characterization of Circulating Tumor Cell Kinetics in Patients With Oligometastatic Disease Receiving Definitive Intent Radiation Therapy

PURPOSE

There are currently no predictive molecular biomarkers to identify patients with oligometastatic disease (OMD) who will benefit from definitive-intent radiation therapy (RT). We prospectively characterized circulating tumor cell (CTC) kinetics in patients with OMD undergoing definitive-intent RT.

METHODS

This prospective correlative biomarker study included patients with any solid malignancy ≤5 metastatic sites in ≤3 anatomic organ systems undergoing definitive-intent RT to all disease sites. Circulating tumor cells (CTCs) were captured and enumerated using a biomimetic cell rolling and nanotechnology-based assay functionalized with antibodies against epithelial cell adhesion molecule, against human epidermal growth factor receptor 2, and against epidermal growth factor receptor before and during RT and at follow-up visits up to 2 years post-RT.

RESULTS

We enrolled 43 patients with a median follow-up of 14.3 months. The pretreatment CTC level (cells captured/mL) was not associated with the number of disease sites (median one metastatic site/patient, range 1-5) or metastasis location (bone, brain, visceral) on Wilcoxon signed-rank test, P > .05. Post-RT, 56% of patients received systemic therapy, and 72% of patients experienced subsequent local or systemic progression. For 90% of patients, a CTC level <15 within 130 days post-RT corresponded to a durable control of irradiated lesions. Patients with a favorable versus an unfavorable clearance profile experienced significantly longer progression-free survival after RT (median 13 v 4 months, log-rank test, P = .0011). On logistic regression, CTC level >15 at a given time point was associated with clinical disease progression within the subsequent 6 months (odds ratio 3.31, P = .007). In 26% of patients with disease progression, a CTC level >15 preceded radiographic or clinical progression.

CONCLUSION

CTCs may serve as a biomarker for disease control in OMD and may predict disease progression before standard assessments for patients receiving diverse cancer-directed therapies.

Circulating tumor cell abundance in head and neck squamous cell carcinoma decreases with successful chemoradiation and cetuximab treatment

Head and neck squamous cell carcinoma (HNSCC) is a common and deadly cancer. Circulating tumor cell (CTC) abundance may a valuable, prognostic biomarker in low- and intermediate-risk patients. However, few technologies have demonstrated success in detecting CTCs in these populations. We prospectively collected longitudinal CTC counts from two cohorts of patients receiving treatments at our institution using a highly sensitive device that purifies CTCs using biomimetic cell rolling and dendrimer-conjugated antibodies. In patients with intermediate risk human papillomavirus (HPV)-positive HNSCC, elevated CTC counts were detected in 13 of 14 subjects at screening with a median of 17 CTC/ml (range 0.2-2986.5). A second cohort of non-metastatic, HPV- HNSCC subjects received cetuximab monotherapy followed by surgical resection. In this cohort, all subjects had elevated baseline CTC counts median of 73 CTC/ml (range 5.4-332.9) with statistically significant declines during treatment. Interestingly, two patients with recurrent disease had elevated CTC counts during and following treatment, which also correlated with growth of size and ki67 expression in the primary tumor. The results suggest that our device may be a valuable tool for evaluating the success of less intensive treatment regimens.

Nanotechnology and machine learning enable circulating tumor cells as a reliable biomarker for radiotherapy responses of gastrointestinal cancer patients

A highly sensitive, circulating tumor cell (CTC)-based liquid biopsy was used to monitor gastrointestinal cancer patients during treatment to determine if CTC abundance was predictive of disease recurrence. The approach used a combination of biomimetic cell rolling on recombinant E-selectin and dendrimer-mediated multivalent immunocapture at the nanoscale to purify CTCs from peripheral blood mononuclear cells. Due to the exceptionally high numbers of CTCs captured, a machine learning algorithm approach was developed to efficiently and reliably quantify abundance of immunocytochemically-labeled cells. A convolutional neural network and logistic regression model achieved 82.9% true-positive identification of CTCs with a false positive rate below 0.1% on a validation set. The approach was then used to quantify CTC abundance in peripheral blood samples from 27 subjects before, during, and following treatments. Samples drawn from the patients either prior to receiving radiotherapy or early in chemotherapy had a median 50 CTC ml-1 whole blood (range 0.6-541.6). We found that the CTC counts drawn 3 months post treatment were predictive of disease progression (p = .045). This approach to quantifying CTC abundance may be a clinically impactful in the timely determination of gastrointestinal cancer progression or response to treatment.

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.

Prospective characterization of circulating tumor cell kinetics in patients treated with radiation therapy per definitive intent oligometastatic paradigm

3053

Background: Definitive intent oligometastatic paradigm describes a state with limited metastatic sites amenable to comprehensive radiation therapy (RT). We characterized circulating tumor cell (CTC) kinetics in response to definitive RT among patients with oligometastatic cancer and identify a CTC kinetic profile associated with progression free survival (PFS). Methods: In this single-institution prospective correlative biomarker study, we enrolled patients with any solid malignancy, ≤ 5 metastatic sites in ≤3 anatomic organ systems undergoing definitive intent RT to all disease sites. Blood specimens were collected prior to RT (baseline), during RT and at follow up visits up to 24 months post RT. Additional lines of therapy were administered per standard of care. CTCs were captured and enumerated using a previously reported nanotechnology-based assay functionalized with aEpCAM, aHER-2, and aEGFR to facilitate biomimetic cell rolling and dendrimer-mediated multivalent binding. Disease status was assessed per RECIST 1.1 criteria. On exploratory analysis disease status was correlated with CTCs as a continuous and ordinal variable (cut-point upper bound of the 3rd quartile). A favorable CTC clearance profile was defined as a decrease in CTC count between pre-treatment and end of treatment - an unfavorable CTC clearance profile was defined as the opposite. Results: We enrolled 43 patients with median follow up of 14.3 months corresponding to 255 CTC measurements. Median baseline CTC count was 28 CTCs/ml (range 0.17-1085). Thirty four patients (79%) received stereotactic body radiation therapy. On Wilcoxon signed-rank test there was no association between pre-treatment CTC count and number of disease sites (median 1 metastatic site/patient, range 1-5) nor metastases site (bone, brain, visceral), p > 0.05. Thirty one patients (72%) experienced local or systemic progression at subsequent time points. For 90% of patients, a CTC count <15/ml < 100 days post-RT corresponded to durable local control of irradiated lesions. Patients with a favorable versus unfavorable clearance profile had significantly longer PFS (median 13 vs 4 months, log rank test, p = 0.0011). During the post-RT period 24 patients (56%) went on to receive systemic therapy (cytotoxic chemotherapy, hormone therapy, immunotherapy, kinase inhibitors). On logistic regression, CTC > 15/ml at a given time point was associated with clinical disease progression within the subsequent 6 months (odds ratio 3.31, p = 0.007). An increase in CTCs to > 15/ml preceded radiographic or biochemical progression in 8 of 31 (26%) of patients experiencing disease progression. Conclusions: Our data suggests CTCs may serve as a biomarker for disease control in oligometastatic disease and may predict disease progression prior to standard assessments for patients receiving diverse therapies. Clinical trial information: NCT03161821.

Bimodal liquid biopsy for cancer immunotherapy based on peptide engineering and nanoscale analysis

Despite its high potential, PD-L1 expressed by tumors has not been successfully utilized as a biomarker for estimating treatment responses to immunotherapy. Circulating tumor cells (CTCs) and tumor-derived exosomes that express PD-L1 can potentially be used as biomarkers; however, currently available assays lack clinically significant sensitivity and specificity. Here, a novel peptide-based capture surface is developed to effectively isolate PD-L1-expressing CTCs and exosomes from human blood. For the effective targeting of PD-L1, this study integrates peptide engineering strategies to enhance the binding strength and specificity of a β-hairpin peptide derived from PD-1 (pPD-1). Specifically, this study examines the effect of poly(ethylene glycol) spacers, the secondary peptide structure, and modification of peptide sequences (e.g., removal of biologically redundant amino acid residues) on capture efficiency. The optimized pPD-1 configuration captures PD-L1-expressing tumor cells and tumor-derived exosomes with 1.5-fold (p = 0.016) and 1.2-fold (p = 0.037) higher efficiencies, respectively, than their whole antibody counterpart (aPD-L1). This enhanced efficiency is translated into more clinically significant detection of CTCs (1.9-fold increase; p = 0.035) and exosomes (1.5-fold increase; p = 0.047) from patients' baseline samples, demonstrating stronger correlation with patients' treatment responses. Additionally, we confirmed that the clinical accuracy of our system can be further improved by co-analyzing the two biomarkers (bimodal CTC/exosome analysis). These data demonstrate that pPD-1-based capture is a promising approach for capturing PD-L1-expressing CTCs and exosomes, which can be used as a reliable biomarker for cancer immunotherapy.

Branched, dendritic, and hyperbranched polymers in liquid biopsy device design

The development of minimally invasive tests for cancer diagnosis and prognosis will aid in the research of new treatments and improve survival rates. Liquid biopsies seek to derive actionable information from tumor material found in routine blood samples. The relative scarcity of tumor material in this complex mixture makes isolating and detecting cancerous material such as proteins, circulating tumor DNA, exosomes, and whole circulating tumor cells a challenge for device engineers. This review describes the chemistry and applications of branched and hyperbranched to improve the performance of liquid biopsy devices. These polymers can improve the performance of a liquid biopsy through several mechanisms. For example, polymers designed to increase the affinity of capture enhance device sensitivity. On the other hand, polymers designed to increase binding avidity or repel nonspecific adsorption enhance device specificity. Branched and hyperbranched polymers can also be used to amplify the signal from small amounts of detected material. The further development of hyperbranched polymers in liquid biopsy applications will enhance device capabilities and help these critical technologies reach the oncology clinic where they are sorely needed. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > Diagnostic Nanodevices.

Machine-Learning-Based Clinical Biomarker Using Cell-Free DNA for Hepatocellular Carcinoma (HCC)

Simple Summary

Circulating cell-free DNA (cfDNA) has attracted a great deal of scientific interest as a predictive biomarker for the diagnosis and prognosis of hepatocellular carcinoma (HCC). HCC result in high mortality due to the absence of blood biomarkers for early diagnosis and prognosis. We established cfD_HCC as a new scoring system by applying a machine learning algorithm that integrates the expression profiles of cfDNA. Based on this, it was possible to accurately predict the clinico-pathological characteristics of patients with HCC as well as improve their survival.

Abstract

(1) Background: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Although various serum enzymes have been utilized for the diagnosis and prognosis of HCC, the currently available biomarkers lack the sensitivity needed to detect HCC at early stages and accurately predict treatment responses. (2) Methods: We utilized our highly sensitive cell-free DNA (cfDNA) detection system, in combination with a machine learning algorithm, to provide a platform for improved diagnosis and prognosis of HCC. (3) Results: cfDNA, specifically alpha-fetoprotein (AFP) expression in captured cfDNA, demonstrated the highest accuracy for diagnosing malignancies among the serum/plasma biomarkers used in this study, including AFP, aspartate aminotransferase, alanine aminotransferase, albumin, alkaline phosphatase, and bilirubin. The diagnostic/prognostic capability of cfDNA was further improved by establishing a cfDNA score (cfD_HCC), which integrated the total plasma cfDNA levels and cfAFP-DNA expression into a single score using machine learning algorithms. (4) Conclusion: The cfD_HCC score demonstrated significantly improved accuracy in determining the pathological features of HCC and predicting patients’ survival outcomes compared to the other biomarkers. The results presented herein reveal that our cfDNA capture/analysis platform is a promising approach to effectively utilize cfDNA as a biomarker for the diagnosis and prognosis of HCC.

Dendrimers for cancer immunotherapy: Avidity-based drug delivery vehicles for effective anti-tumor immune response

Cancer immunotherapy, or the utilization of a patient's own immune system to treat cancer, has shifted the paradigm of cancer treatment. Despite meaningful responses being observed in multiple studies, currently available immunotherapy platforms have only proven effective to a small subset of patients. To address this, nanoparticles have been utilized as a novel carrier for immunotherapeutic drugs, achieving robust anti-tumor effects with increased adaptive and durable responses. Specifically, dendrimer nanoparticles have attracted a great deal of scientific interest due to their versatility in various therapeutic applications, resulting from their unique physicochemical properties and chemically well-defined architecture. This review offers a comprehensive overview of dendrimer-based immunotherapy technologies, including their formulations, biological functionalities, and therapeutic applications. Common formulations include: (1) modulators of cytokine secretion of immune cells (adjuvants); (2) facilitators of the recognition of tumorous antigens (vaccines); (3) stimulators of immune effectors to selectively attack cells expressing specific antigens (antibodies); and (4) inhibitors of immune-suppressive responses (immune checkpoint inhibitors). On-going works and prospects of dendrimer-based immunotherapies are also discussed. Overall, this review provides a critical overview on rapidly growing dendrimer-based immunotherapy technologies and serves as a guideline for researchers and clinicians who are interested in this field. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Hierarchically Multivalent Peptide-Nanoparticle Architectures: A Systematic Approach to Engineer Surface Adhesion

The multivalent binding effect has been the subject of extensive studies to modulate adhesion behaviors of various biological and engineered systems. However, precise control over the strong avidity-based binding remains a significant challenge. Here, a set of engineering strategies are developed and tested to systematically enhance the multivalent binding of peptides in a stepwise manner. Poly(amidoamine) (PAMAM) dendrimers are employed to increase local peptide densities on a substrate, resulting in hierarchically multivalent architectures (HMAs) that display multivalent dendrimer-peptide conjugates (DPCs) with various configurations. To control binding behaviors, effects of the three major components of the HMAs are investigated: i) poly(ethylene glycol) (PEG) linkers as spacers between conjugated peptides; ii) multiple peptides on the DPCs; and iii) various surface arrangements of HMAs (i.e., a mixture of DPCs each containing different peptides vs DPCs cofunctionalized with multiple peptides). The optimized HMA configuration enables significantly enhanced target cell binding with high selectivity compared to the control surfaces directly conjugated with peptides. The engineering approaches presented herein can be applied individually or in combination, providing guidelines for the effective utilization of biomolecular multivalent interactions using DPC-based HMAs.

Chemically and Biologically Engineered Bacteria-Based Delivery Systems for Emerging Diagnosis and Advanced Therapy

Bacteria are one of the main groups of organisms, which dynamically and closely participate in human health and disease development. With the integration of chemical biotechnology, bacteria have been utilized as an emerging delivery system for various biomedical applications. Given the unique features of bacteria such as their intrinsic biocompatibility and motility, bacteria-based delivery systems have drawn wide interest in the diagnosis and treatment of various diseases, including cancer, infectious diseases, kidney failure, and hyperammonemia. Notably, at the interface of chemical biotechnology and bacteria, many research opportunities have been initiated, opening a promising frontier in biomedical application. Herein, the current synergy of chemical biotechnology and bacteria, the design principles for bacteria-based delivery systems, the microbial modulation, and the clinical translation are reviewed, with a special focus on the emerging advances in diagnosis and therapy.

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.

[Operative efficacy of 13 malignant uterine tumors after Cf-252 intracavitary irradiation]

Objective: To investigate the surgical therapeutic efficacy of uterine tumors patients underwent Cf-252 neutron intra-cavity and external radiotherapy, and evaluate the application value of Cf-252 neutron radiotherapy. Methods: Thirteen cases of uterine tumor with local suspicious lesions or poor prognostic factors after CF-252 neutron intracavity and external radiotherapy were treated with surgery. Among them, 12 cases underwent extrafascial hysterectomy, 1 case underwent extensive hysterectomy and lymphadenectomy. The postoperative pathology and follow-up results were used to evaluate the efficacy. Results: Nine cases showed severe response to radiotherapy in postoperative cervical pathological tissues without residual tumor, and survived for more than 3-14 years, the median survival time was 8 years. All of 4 cases with residual tumor died within 1 year. Delayed healing of vaginal wounds occurred in 3 of the 12 cases. Conclusions: Cf-252 is a good brachytherapy source. The cervical tissue shows severe response to radiotherapy and prolonged healing time of vaginal wound is observed in some cases after CF-252 radiotherapy. To those uterine tumor patients with local suspicious lesions or poor prognostic factors after CF-252 neutron intracavity and external radiotherapy, extrafascial hysterectomy is a safe and feasible treatment method.

Enhanced detection of cell-free DNA (cfDNA) enables its use as a reliable biomarker for diagnosis and prognosis of gastric cancer

Although circulating cell-free DNA (cfDNA) is a promising biomarker for the diagnosis and prognosis of various tumors, clinical correlation of cfDNA with gastric cancer has not been fully understood. To address this, we developed a highly sensitive cfDNA capture system by integrating polydopamine (PDA) and silica. PDA-silica hybrids incorporated different molecular interactions to a single system, enhancing cfDNA capture by 1.34-fold compared to the conventional silica-based approach (p = 0.001), which was confirmed using cell culture supernatants. A clinical study using human plasma samples revealed that the diagnostic accuracy of the new system to be superior than the commercially available cfDNA kit, as well as other serum antigen tests. Among the cancer patients, plasma cfDNA levels exhibited a good correlation with the size of a tumor. cfDNA was also predicative of distant metastasis, as the median cfDNA levels of metastatic cancer patients were ~60-fold higher than those without metastasis (p = 0.008). Furthermore, high concordance between tissue biopsy and cfDNA genomic analysis was found, as HER2 expression in cfDNA demonstrated an area under ROC curve (AUC) of 0.976 (p <0.001) for detecting patients with HER2-positive tumors. The new system also revealed high prognostic capability of cfDNA, as the concentration of cfDNA was highly associated with the survival outcomes. Our novel technology demonstrates the potential to achieve efficient detection of cfDNA that may serve as a reliable biomarker for gastric tumor.

Surface engineering for efficient capture of circulating tumor cells in renal cell carcinoma: From nanoscale analysis to clinical application

Sensitive detection of circulating tumor cells (CTCs) from patients' peripheral blood facilitates on-demand monitoring of tumor progression. However, clinically significant capture of renal cell carcinoma CTCs (RCC-CTCs) remains elusive due to their heterogenous surface receptor expression. Herein, a novel capture platform is developed to detect RCC-CTCs through integration of dendrimer-mediated multivalent binding, a mixture of antibodies, and biomimetic cell rolling. The nanoscale binding kinetics measured using atomic force microscopy reveal that dendrimer-coated surfaces exhibit an order of magnitude enhancement in off-rate kinetics compared to surface without dendrimers, which translated into cell capture improvements by ~60%. Selectin-induced cell rolling facilitates surface recruitment of cancer cells, further improving cancer cell capture by up to 1.7-fold. Lastly, an antibody cocktail targeting four RCC-CTC surface receptors, which included epithelial cell adhesion molecule (EpCAM), carbonic anhydrase IX (CA9), epidermal growth factor receptor (EGFR), and hepatocyte growth factor receptor (c-Met), improves the capture of RCC cells by up to 80%. The optimal surface configuration outperforms the conventional assay solely relying on EpCAM, as demonstrated by detecting significantly more CTCs in patients' samples (9.8 ± 5.1 vs. 1.8 ± 2.0 CTCs mL-1). These results demonstrate that the newly engineered capture platform effectively detects RCC-CTCs for their potential use as tumor biomarkers.

Abstract 6439: CapioCyte™ technology for efficient capture and downstream analysis of circulating tumor cells from renal cell carcinoma

Objective:

The objective of this work was to obtain highly sensitive purification and post-capture analysis of renal cell carcinoma (RCC) circulating tumor cells (CTCs) using CapioCyte™ technology.

Background:

Circulating tumor cells (CTCs) may be a highly valuable source of actionable information for the practice of precision medicine. However, CTCs are exceptionally rare in peripheral blood. The CapioCyte™ chip purifies live CTCs through a combination of biomimetic cell rolling and dendrimer-mediated multivalent immunorecognition. The CapioCyte™ platform has been previously shown to isolate CTCs with high sensitivity from peripheral blood collected from patients with head and neck cancer using a mixture of antibodies against epithelial cell adhesion molecule (EpCAM), human epidermal growth factor receptor 2 (HER2), and epidermal growth factor receptor (EGFR) [Myung et al., Clinical Cancer Research 2018, 24(11):2539-2547]. However, this antibody cocktail is not universally applicable to all types of cancer. In particular, renal cell carcinoma (RCC), having no clinically actionable circulating biomarkers, often do not express HER2. To address this, we have employed a new antibody mixture targeting EpCAM, EGFR, carbonic anhydrase IX (CAIX), and hepatocyte growth factor receptor (c-MET). Our study presents enhanced capture of CTCs from renal cancer, demonstrating the modular nature of our CapioCyte™ technology.

Methods:

Antibody-coated beads were used to determine the functional recognition of ACHN and 786-O RCC cell lines. Flow channel experiments and atomic force microscopy (AFM) force spectroscopy measurements were used to quantify off-rate kinetics. A clinical pilot study of 7 RCC patients (pre-treatment) and 5 healthy controls was performed to validate the CapioCyte™ surface tuned for RCC capture. In recent work, CTCs recovered from the CapioCyte™ surface were sequenced using 10X Chromium system with v3 chemistry and analyzed using RaceID clustering and Gene Set Enrichment Analysis (GSEA).

Results:

The optimized mixture of EpCAM, CAIX, EGFR, and c-MET showed 80% enhancement in the capture of RCC cell lines compared to the mixture of EpCAM, EGFR, and HER2. Force spectroscopy measurements were used to show that dendrimers contributed to an order of magnitude enhancement in off-rate kinetics. In patient samples, the RCC capture surface isolated a total of 9.8 +/- 5.1 CTC ml-1 whole blood compared to just 1.8 +/- 2.0 CTC ml-1 with the conventional three-antibody mixture. Finally, preliminary results show the detection of oncogenic signatures within two additional peripheral blood samples.

Conclusions:

The prototype CapioCyte™ platform is a flexible liquid biopsy that can be tuned for various disease indications. Here, enhanced capture of RCC CTCs was demonstrated in clinical blood samples with high sensitivity. Proof-of-concept RNA sequencing shows the promise of CapioCyte™ in providing further clinically-actionable information from CTCs.

Citation Format: Jiyoon Bu, Michael J. Poellmann, Marco Reyes-Martinez, Andrew Armstrong, Daniel George, Tian Zhang, Andrew Z. Wang, seungpyo hong. CapioCyte™ technology for efficient capture and downstream analysis of circulating tumor cells from renal cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6439.

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.

Multi-modal liquid biopsy platform for cancer screening: screening both cancer-associated rare cells and cancer cell-derived vesicles on the fabric filters for a reliable liquid biopsy analysis

Circulating tumor cells (CTCs) are receiving a great amount of scientific interest as a diagnostic biomarker for various types of cancer. Despite the recent progress in the development of highly sensitive CTC isolation devices, post-capture analysis of CTCs is still hindered by technical challenges associated with their rarity. Herein, we present a multi-modal CTC screening platform which is capable to analyze CTCs and CTC-derived extracellular vesicles (EVs), simultaneously from a single sample. Cytochalasin B (CB) treatment promotes cells to release large number of EVs from their surface, as demonstrated by CB-treated cells (5 µg/mL for 3 h) secreting 3.5-fold more EVs, compared to the non-treated cells. CB further generates 1.7-fold more EVs from the cells captured on our CTC filtration device (the fabric filter), compared to those from the cell culture flasks, owing to its multiple pore structure design which reduces the non-specific binding of EVs. Both CB-treated cancer cells and CB-induced EVs are found to overexpress tumor-associated markers, demonstrating a potential for the development of CTC dual-screening platform. Collectively, the results presented in this study reveal that our multi-modal cancer screening platform can synergistically improve the reliability and efficacy of the current CTC analysis systems.

Abstract 410: Quantification and downstream analysis of circulating tumor cells isolated using CapioCyteTM liquid biopsy

Background: Circulating tumor cells (CTCs) have great potential as biomarkers for the diagnosis and prognosis of many cancers. The CapioCyteTM chip isolates live CTCs through a unique combination of biomimetic cell rolling and nanoparticle-mediated multivalent immunorecognition. Recently-published work reported the highly sensitive and specific CTC capture from 24 patients in a pilot study [Myung et al., Clinical Cancer Research 2018, 24(11):2439-2547]. Here, we report results from additional cohorts of patients and demonstrate downstream analysis of captured CTCs.

Methods: Peripheral blood samples were collected from patients undergoing radiotherapy (RT) (n=12; oligometastic n = 5, head and neck cancer n = 1, non small cell lung cancer n = 2, prostate cancer n = 3, cervical cancer n = 1) or immunotherapy (n=4). Samples were processed the next day by CapioCyteTM chips designed for the immunoisolation cells expressing epithelial cell adhesion molecule (EpCAM), human epidermal growth factor-2 (HER-2), and epidermal growth factor receptor (EGFR). Captured CTCs were identified by immunocytochemistry as containing round nuclei, positive expression of cytokeratin, and negative expression of CD45. Select samples were recovered from the capture surface and submitted for single cell gene expression assays (RNASeq) using 10X Genomics Chromium barcoding and Illumina next-generation sequencing.

Results: Immunocytochemical staining identified CTCs in all pre-treatment blood samples from patients undergoing RT (mean 95 CTC/ml whole blood, SE 54, range 4-680) and immunotherapy (mean 70 CTC/ml whole blood, SE 16, range 39-104). CTC counts decreased with time points collected during and post-treatment, consistent with other measures of treatment progress. Single cell RNASeq confirmed the presence of tumor-derived cells in select samples and, importantly, demonstrated the ability to conduct downstream analysis of CTCs isolated on the CapioCyteTM chip.

Conclusions: The CapioCyteTM chip effectively captures CTCs for quantification and downstream analysis requiring viable cells such as RNASeq. The liquid biopsy technology has great potential to contribute to diagnosis and personalized treatment of cancer.

Citation Format: Michael J. Poellmann, Jiyoon Bu, Dominic Moon, Kyle Wagner, Andrew Z. Wang, Seungpyo Hong. Quantification and downstream analysis of circulating tumor cells isolated using CapioCyteTM liquid biopsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 410.

Post-debulking circulating tumor cell as a poor prognostic marker in advanced stage ovarian cancer: A prospective observational study

Circulating tumor cells (CTCs) have received enormous attention as a novel biomarker in various malignant diseases. We investigated the clinical association between the presence of perioperative CTCs and survival outcomes in women with ovarian cancer. In a total of 30 women who were scheduled to undergo a surgical treatment for ovarian cancer, peripheral blood samples were obtained before and after surgery. CTCs were isolated and counted using the optimized tapered-slit filter (TSF) platform. The association between the presence of perioperative CTCs and tumor features was evaluated. The impact of the presence of perioperative CTCs on progression-free survival (PFS) and overall survival (OS) rates were analyzed using a Kaplan-Meier method. The median age was 58 (range, 24-77) years, and the median follow-up period was 31.5 (range, 1-41) months. Overall, the CTC detection rate was not significantly different before and after surgery (76.7% vs 57.1%, P = .673). The presence of postoperative CTCs was not significantly associated with 3-year PFS (29.1% vs 58.3%, P = .130) and OS (84.4% vs 80.0%, P = .559) rates in the whole study population. In advanced stage, PFS rate in patients with postoperative CTCs had lower PFS rates than those without postoperative CTCs, although there was no statistical significance (18.8% vs 57.1%, P = .077). Postoperative CTC was more frequently detected in women who had lymph node involvement than those who did not (7/7 [100%] vs 3/10 [30.0%], P = .010). The presence of postoperative CTCs as detected using the TSF platform seems to be associated with poorer PFS rates in women with ovarian cancer of advanced stage. Further study with a larger population is warranted to validate our study findings.

Sub-lethal hyperthermia promotes epithelial-to-mesenchymal-like transition of breast cancer cells: implication of the synergy between hyperthermia and chemotherapy

Thermotherapy has demonstrated a potential to be an effective non-surgical technique to treat breast cancer.

Peptide-nanoparticle conjugates: a next generation of diagnostic and therapeutic platforms?

Peptide-nanoparticle conjugates (PNCs) have recently emerged as a versatile tool for biomedical applications. Synergism between the two promising classes of materials allows enhanced control over their biological behaviors, overcoming intrinsic limitations of the individual materials. Over the past decades, a myriad of PNCs has been developed for various applications, such as drug delivery, inhibition of pathogenic biomolecular interactions, molecular imaging, and liquid biopsy. This paper provides a comprehensive overview of existing technologies that have been recently developed in the broad field of PNCs, offering a guideline especially for investigators who are new to this field.

Would antioxidant-loaded nanoparticles present an effective treatment for ischemic stroke?

Ischemic stroke is a leading cause of death and disability worldwide and is in urgent need of new treatment options. The only approved treatment for stroke restores blood flow to the brain, but much of the tissue damage occurs during the subsequent reperfusion. Antioxidant therapies that directly address ischemia-reperfusion injury have shown promise in preclinical results. In this review, we discuss that reformulating antioxidant therapies as nanomedicine can potentially overcome the barriers that have kept these therapies from succeeding in the clinic. We begin by reviewing the pathophysiology of ischemic stroke with a focus on the effects of reperfusion injury. Next, we review nanotherapeutic systems designed to treat the disease with a focus on those addressing reperfusion injury. Mechanisms of passive and active transport required to traverse a blood–brain barrier are discussed. Finally, we conclude by outlining design parameters for potentially successful nanomedicines as front-line therapeutics for ischemic stroke.

[Identification of Methamphetamine Abuse and Selegiline Use： Chiral Analysis of Methamphetamine and Amphetamine in Urine]

OBJECTIVES

To study the content variation of selegiline and its metabolites in urine, and based on actual cases, to explore the feasibility for the identification of methamphetamine abuse and selegiline use by chiral analysis.

METHODS

The urine samples were tested by chiral separation and LC-MS/MS method using CHIROBIOTIC™ V2 chiral liquid chromatography column. The chiral analysis of methamphetamine and amphetamine were performed on the urine samples from volunteers of selegiline use and drug addicts whom suspected taking selegiline.

RESULTS

After 5 mg oral administration, the positive test time of selegiline in urine was less than 7 h. The mass concentrations of R（-）-methamphetamine and R（-）-amphetamine in urine peaked at 7 h which were 0.86 μg/mL and 0.18 μg/mL and couldn't be detected after 80 h and 168 h, respectively. The sources of methamphetamine and amphetamine in the urine from the drug addicts whom suspected taking selegiline were analysed successfully by present method.

CONCLUSIONS

The chiral analysis of methamphetamine and amphetamine, and the determination of selegiline's metabolites can be used to distinguish methamphetamine abuse from selegiline use.

High-purity capture and release of circulating exosomes using an exosome-specific dual-patterned immunofiltration (ExoDIF) device

We present a microfluidic device for the capture and release of circulating exosomes from human blood. The exosome-specific dual-patterned immunofiltration (ExoDIF) device is composed of two distinct immuno-patterned layers, and is capable of enhancing the chance of binding between the antibody and exosomes by generating mechanical whirling, thus achieving high-throughput exosome isolation with high specificity. Moreover, follow-up recovery after the immuno-affinity based isolation, via cleavage of a linker, enables further downstream analysis. We verified the performance of the present device using MCF-7 secreted exosomes and found that both the concentration and proportion of exosome-sized vesicles were higher than in the samples obtained from the conventional exosome isolation kit. We then isolated exosomes from the human blood samples with our device to compare the exosome level between cancer patients and healthy donors. Cancer patients show a significantly higher exosome level with higher selectivity when validating the exosome-sized vesicles using both electron microscopy and nanoparticle tracking analysis. The captured exosomes from cancer patients also express abundant cancer-associated antigens, the epithelial cell adhesion molecule (EpCAM) on their surface. Our simple and rapid exosome recovery technique has huge potential to elucidate the function of exosomes in cancer patients and can thus be applied for various exosome-based cancer research studies.

Circulating tumor cells in the differential diagnosis of adnexal masses

The aim of this study was to evaluate circulating tumor cell (CTC) detection in the differential diagnosis of adnexal masses. A total of 87 preoperative women with an indeterminate adnexal mass were prospectively enrolled. Preoperative diagnostic modalities including CTC detection, risk of ovarian malignancy algorithm, risk of malignancy index, and computed tomography or magnetic resonance imaging were compared. Forty-three (49.4%) benign tumors, 13 (14.9%) borderline malignant masses, and 31 (35.7%) cancers were pathologically confirmed. Forty-nine (56.3%) cases were positive for CTCs: 19/43 (44.2%) benign, 10/10 (100%) early-stage, and 14/21 (66.7%) advanced-stage cancer. CTC detection had sensitivities of 77.4%, 100%, and 100% for benign vs. all stage cancer (n = 74), benign vs. stage I–II cancer (n = 53), and benign vs. stage I cancer (n = 49), respectively. CTC detection had a specificity of 55.8% across all comparisons. The sensitivities of the other modalities assayed were decreased in stage I–II cancer and stage I cancer vs. benign masses. Receiver operating characteristic curves showed that CTCs, of which the area under the curve was modest in all stage cancer (0.655), had the widest area under the curve among the evaluated modalities in stage I–II cancer and stage I cancer (0.768 for both). In conclusion, our study findings suggest that preoperative CTCs could have a substantial role in differentiating early stage cancer from benign tumors for adnexal masses.

Abstract 4306: Combined effects of chemotherapy to reduce metastasis caused by insufficient hyperthermia

Hyperthermia therapy is one of the most widely studied non-surgical methods for breast tumors, which eliminates tumor by inducing acute stress on tumor cells. However, it has been extensively known that the viability of the tumor cells is highly influenced by the applied temperature. Insufficient thermal stress during hyperthermia treatments may alter tumor microenvironment by promoting epithelial to mesenchymal-like transition (EMT) and as a result, enhancing the outgrowth of residual tumor cells. Therefore, cells that have survived from sublethal thermal stress and experienced EMT may cause substantial clinical problems. In this case, hyperthermia requires additional therapy in order to promote cell death of more invasive tumor cells that have resisted to the thermal stimulus. In this study, we confirmed that the co-treatment of chemotherapy with hyperthermia may overcome the phenotypical transition caused by insufficient heat treatment. After exposing breast cancer cells (MCF-7) into two different temperature conditions (42°C and 47°C) for an hour, we have verified that 10.51 ± 1.71% and 18.27 ± 10.66% of cells experienced apoptosis or necrosis when the cells were exposed to 42°C and 47°C, respectively. At the same time, cancer cells showed higher invasiveness, spear-like morphology, and enhanced migratory behaviors as the exposed temperature increases, which is mainly shown among the cells that have experienced EMT. Further western blot assay and quantitative real-time polymerase chain reaction (qRT-PCR) using mesenchymal marker (vimentin) and epithelial marker (E-cadherin) also support that the mesenchymal-like phenotype has been highly increased on the cells that have resisted to the thermal stress. However, when chemotherapy was conducted after the heat treatment, cell viability was highly reduced. Paclitaxel (11.7 nM), cisplatin (3.3 μM), and combination of two anticancer drugs were treated for 24 hours on the cells that have been exposed to different temperatures, respectively. As a result, death rate of tumor cells has increased from 11.31 to 66.69%. Especially, when paclitaxel and cisplatin were co-treated, the death rate was up to 73.75 ± 4.37% after cells were exposed to 47°C. In conclusion, cancer cells that have survived from insufficient hyperthermia showed high potential to promote metastasis or recurrence but additional chemotherapy can successfully reduce the side effects induced by insufficient hyperthermia treatment.

Citation Format: Tae Hee Lee, Jiyoon Bu, Byoung Hyuck Kim, Young Jun Kim, Yoon-Tae Kang, Jung Eun Moon, Young-Ho Cho. Combined effects of chemotherapy to reduce metastasis caused by insufficient hyperthermia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4306. doi:10.1158/1538-7445.AM2017-4306

Enhancement of isolation sensitivity for the viable heterogeneous circulating tumor cells swelled by hypo-osmotic pressure

We have applied a hypo-osmotic gradient for enhancing the isolation of viable heterogeneous circulating tumor cells.

Dual-patterned immunofiltration (DIF) device for the rapid efficient negative selection of heterogeneous circulating tumor cells

The analysis of circulating tumor cells (CTCs) is an emerging field for estimating the metastatic relapse and tumor burden of cancer patients. However, the isolation of CTCs is still challenging due to their ambiguity, rarity, and heterogeneity. Here, we present an anti-CD45 antibody based dual-patterned immunofiltration (DIF) device for the enrichment of heterogeneous CTC subtypes by effective elimination of leukocytes. Our uniquely designed dual-patterned layers significantly enhance the binding chance between immuno-patterns and leukocytes due to the fluidic whirling and the increased binding sites, thus achieving superior negative selection in terms of high-throughput and high purity. From the experiments using lung cancer cells, 97.07 ± 2.79% of leukocytes were eliminated with less than 10% loss of cancerous cells at the flow rate of 1 mL h^-1. To verify the device as a potential diagnostic tool, CTCs were collected from 11 cancer patients' blood and an average of 283.3 CTC-like cells were identified while less than 1 CTC-like cells were found from healthy donors. The samples were also analyzed by immunohistochemistry and the reverse transcription polymerase chain reaction to identify their heterogeneous characteristics. These remarkable results demonstrate that the present device could help to understand the unknown properties or undiscovered roles of CTCs with a non-biased view.

Chemotherapy uptake and wait times in early-stage non-small-cell lung cancer

BACKGROUND

Treatment uptake and elapsed times along the care path have emerged as potential quality indicators for cancer care delivery. This retrospective study examined changes in adjuvant chemotherapy uptake and elapsed times along the care path for patients in 2005 and in 2007 who had early-stage non-small-cell lung cancer (nsclc) and who underwent curative-intent surgery in Nova Scotia, Canada.

METHODS

All patients who underwent curative-intent surgery for stages i-iii nsclc in the two years of interest were included. Logistic regression and general linear models were used to examine factors associated with chemotherapy uptake patterns and, at various resolutions (low, intermediate, high), elapsed times between all care events in the care path.

RESULTS

In the 223 patients who underwent curative-intent surgery (108 in 2005, 115 in 2007), several factors were associated with uptake patterns and elapsed times. Cohort year (2007 vs. 2005) was not associated with referral to medical oncology [odds ratio (or): 1.05; 95% confidence interval (ci): 0.51 to 2.15; p = 0.905], but it was associated with less treatment after referral (or: 0.34; 95% ci: 0.11 to 1.00; p = 0.057) and less overall uptake (or: 0.35; 95% ci: 0.13 to 0.95; p = 0.040). Patients were referred sooner to medical oncology in 2007 than in 2005 (21 days vs. 35 days, p = 0.008), but experienced longer waits between consultation and chemotherapy delivery (18 days vs. 7 days, p = 0.001).

CONCLUSIONS

Significant differences were observed in care patterns over time. Frequent monitoring of care patterns at high resolution may optimize insights into emerging trends within cancer care systems.

A modified fractal zone plate with extended depth of focus in spectral domain optical coherence tomography

In optical coherence tomography (OCT) systems, there is a trade-off between the depth of focus (DOF) and lateral resolution when conventional lenses are used. We propose a new method that employs a modified fractal generalized zone plate (MFraGZP) combined with a conventional lens to improve the trade-off effect, with an extended DOF of about 2.5 mm (14 times larger) while the lateral resolution is maintained at ~9.5 μm. As an example, images of the calibration microspheres are obtained and demonstrated with the extended DOF in a spectral domain OCT system.

Manipulation of surface plasmon polaritons by phase modulation of incident light

Manipulation of surface plasmon polaritons (SPP) by phase modulation of incident light beams is proposed with analytical and numerical verifications when an optical vortex (OV) beam is employed as an example. Fundamental functionalities of a plasmonic chip such as in-plane focusing, coupling and multiplexing of SPP by sequentially varying the topological charge of OV beam are demonstrated. Complementary to the manually-controlled optical-path-different technique reported in literature, the proposed method reveals a direct phase transform from OV beam to SPP with dynamic and reconfigurable advantages.

Deterministic relief dielectric structures to realize phase modulation of surface-plasmon polaritons

We propose a modified effective-refractive-index model for the design of relief dielectric structures on a metal surface to realize phase modulation of surface-plasmon polaritons (SPPs). In this model, the length of the dielectric structure is optimized to reach phase shifting between the SPP waves transmitted through dielectric structure and those directly propagated with the consideration of SPP losses. Specifically, a one-dimensional dielectric Fresnel zone plate is designed by employing the proposed model to demonstrate phase modulation of SPPs for the highest focusing efficiency.