Interaction between handgrip strength and vitamin D deficiency on all-cause mortality in community-dwelling older adults: a prospective cohort study

OBJECTIVE

Muscle strength decline and vitamin D deficiency are coexisting conditions associated with multiple adverse health outcomes. This prospective study aimed to investigate the multiplicative and additive interactions between handgrip strength (HS) and serum 25-hydroxyvitamin D [25(OH)D] on all-cause mortality in Chinese community-dwelling older adults.

STUDY DESIGN

This is a population-based cohort study.

METHODS

2635 older adults (85.15 ± 12.01 years) were recruited from the Chinese Longitudinal Healthy Longevity Survey (2012-2018). Low HS was defined according to the Asian Working Group for Sarcopenia 2019 updated consensus (<28 kg for men and <18 kg for women). Serum 25(OH)D < 50 nmol/L were defined as vitamin D deficiency. Cox proportional hazard models were used to examine the association of HS and 25(OH)D with all-cause mortality. Socio-demographics, health status, and clinical characteristics were included as covariates.

RESULTS

1715 (65.09 %) and 1885 (71.54 %) participants had low HS and vitamin D deficiency, respectively. During a median follow-up of 3.52 years, 1107 older people died. After multivariable adjustment, both HS and 25(OH)D levels were inversely associated with all-cause mortality risk (Ps < 0.001). The hazard ratios (HRs) of low HS and vitamin D deficiency for all-cause mortality were 1.73 (95 % CI: 1.41-2.13) and 1.61 (95 % CI: 1.32-1.93), respectively. Although significant multiplicative interactions were not found, the association between low HS and all-cause mortality was attenuated in the higher 25(OH)D subgroup than in the lower 25(OH)D subgroup (stratified by 50 nmol/L). The multiple-adjusted HR of mortality for combined low HS and vitamin D deficiency was 2.18 (95 % CI: 1.73-2.56), which was higher than that for these two conditions alone. Significant additive interactions between low HS and vitamin D deficiency on mortality were observed (relative excess risk due to interaction: 0.71, 95 % CI: 0.37-1.05).

CONCLUSIONS

Low HS and low 25(OH)D levels synergistically increased the risk of all-cause mortality. Our results added new insights to the priority of early detection for older adults with comorbid muscle strength decline and vitamin D deficiency.

[Burden of hemorrhagic stroke and hypertensive heart disease attributed to alcohol consumption in China]

Objective: To describe the prevalence of alcohol consumption and the burden of hemorrhagic stroke and hypertensive heart disease attributed to alcohol consumption in adults aged ≥20 years in 31 provinces in China from 2005 to 2018. Methods: Data from several national representative surveys was used to estimate provincial alcohol exposure level of adults aged ≥20 years from 2005 to 2018 by using kriging interpolation and locally weighted regression methods. Global disease burden research method and data, and China's death cause surveillance data were used to calculate the population attributable fraction (PAF) of hemorrhagic stroke and hypertensive heart disease and the deaths due to alcohol consumption in men and women aged ≥20 years in 31 provinces in China. China census data of 2010 were used to calculate the attributable standardized mortality rate. Results: In 2005 and 2018, the prevalence of alcohol consumption was 58.7% (95%CI: 57.8%-59.5%) and 58.4% (95%CI: 57.6%-59.3%), respectively, in men and 17.0% (95%CI: 16.6%-17.4%) and 18.7% (95%CI:18.1%-19.3%), respectively, in women. The daily alcohol intake was 24.6 (95%CI: 23.8-25.3) g and 27.7 (95%CI: 26.8-28.7) g, respectively, in men and 6.3 (95%CI: 6.0-6.5) g and 5.3 (95%CI: 5.0-5.6) g, respectively, in women. Alcohol exposure level was higher in the provinces in central and eastern China than in western provinces. The lowest exposure level was found in northwestern provinces. From 2005 to 2018, the PAF of hemorrhagic stroke death due to alcohol consumption increased from 5.5% to 6.8%, the attributable deaths increased from 50 200 to 59 100, while the PAF of hypertensive heart disease death due to alcohol consumption increased from 7.0% to 7.7%, the attributable deaths increased from 15 200 to 29 300. The PAF of hypertensive heart disease and hemorrhagic stroke was higher in men than in women, and in central and eastern provinces than in western provinces. In 2018, the standardized mortality rates of hemorrhagic stroke and hypertensive heart disease attributed to alcohol consumption were 4.58/100 000 and 2.11/100 000, respectively. Conclusions: The prevalence of alcohol consumption in men and daily alcohol intake of drinkers were relatively high in China, especially in eastern provinces. Alcohol exposure level was lower in women than in men. Regional measures should be taken to reduce the alcohol intakes in men and current drinkers in order to reduce the health problems caused by alcohol consumption.

Emerging micro-nanotechnologies for extracellular vesicles in immuno-oncology: from target specific isolations to immunomodulation

Extracellular vesicles (EVs) have been hypothesized to incorporate a variety of crucial roles ranging from intercellular communication to tumor pathogenesis to cancer immunotherapy capabilities. Traditional EV isolation and characterization techniques cannot accurately and with specificity isolate subgroups of EVs, such as tumor-derived extracellular vesicles (TEVs) and immune-cell derived EVs, and are plagued with burdensome steps. To address these pivotal issues, multiplex microfluidic EV isolation/characterization and on-chip EV engineering may be imperative towards developing the next-generation EV-based immunotherapeutics. Henceforth, our aim is to expound the state of the art in EV isolation/characterization techniques and their limitations. Additionally, we seek to elucidate current work on total analytical system based technologies for simultaneous isolation and characterization and to summarize the immunogenic capabilities of EV subgroups, both innate and adaptive. In this review, we discuss recent state-of-art microfluidic/micro-nanotechnology based EV screening methods and EV engineering methods towards therapeutic use of EVs in immune-oncology. By venturing in this field of EV screening and immunotherapies, it is envisioned that transition into clinical settings can become less convoluted for clinicians.

Isolation of circulating tumor cells to diagnose melanoma and evaluate the efficacy of surgical resection using melanoma-specific microsystem

Melanoma is one of the most aggressive skin cancers due to its potential to metastasize widely in the body. The risk of metastasis is increased with later detection and increased thickness of the primary lesion, thus early identification and surgical removal is critical for higher survival rates for patients. However, even with appropriate treatment, some patients will develop recurrence which may be difficult to identify until advanced or causing symptoms. Recent advances in liquid biopsy have proposed less-invasive alternatives for cancer diagnosis and monitoring using minimal/zero invasion at sample collection, and circulating tumor cells(CTCs) have been considered a promising blood-based surrogate marker of primary tumors. However, previous CTC technologies relying on epithelial-cell adhesion molecules have limited to epithelial cells, thus hampering use of CTCs for non-epithelial cancers such as melanoma. Here, we used the Melanoma-specific OncoBean platform(MelanoBean) conjugated with melanoma specific antibodies(MCAM and MCSP). The device was used in comprehensive studies for diagnosing melanoma and evaluating surgery efficacy based on change in the number and characteristics of CTCs and CTC-clusters pre- and post-surgical treatment. Our study demonstrated that melanoma patients(n=45) at all stages(I-IV) have a noticeable number of MCTCs as well as MCTC-clusters compared to healthy donors(n=9)(P=0.0011), and surgical treatment leads to a significant decrease in the number of CTCs(P<0.0001). The CTCs recovered from the device underwent molecular profiling for melanoma-associated genes expression using multiplexed qRT-PCR, demonstrating the ability to monitor molecular signature through treatment. The presented MelanoBean and the comprehensive approach will empower prognostic value of CTCs in melanoma in much larger cohort studies.

Abstract 2792: On-chip evaluation of cancer cell-extracellular vesicle interactions using a novel microfluidic microsystem (CellExoChip)

Introduction: Analytical methods of extracellular vesicles (EVs) is becoming an increasingly promising field of study due to them being an effective biomarker for cancers. EVs are present in various types of body fluids, which can be easily used for diagnostic purpose. Prior research has explored numerous techniques for isolating and analyzing these EVs based on their physical and biochemical properties, however, the complexity of biological samples makes conventional EV isolation difficult to exclusively extract EVs of a certain type of cell. Current downstream analysis methods lack the ability to differentiate exosomes of different origins in a sample. Recent studies suggested the presence of certain proteins in cancer exosomes that facilitates preferential uptake of the exosomes by organ-specific cancer cells, called organotropism. Using this unique property, we devised a microfluidic platform to examine the uptake of specific exosomes onto their respective progenitor cell lines, thus aiming to use the interaction for cancer diagnosis purposes.

Methods: The CellExoChip was prepared following the standard PDMS-based soft lithography method. The device consists of an inlet and outlet, with dimensions of 22x22 mm with a cell capture area of about 50 mm2. The microfluidic device was functionalized by Streptavidin and the cancer cells were biotinylated with EZ-Link-NHS-Biotin to create an intense affinity between the cells and the device. We further injected dyed exosomes with different origins through the device and evaluated their specific uptake using fluorescence microscope.

Results: The prepared CellExoChip successfully immobilized over 1,500 cells onto the surface and viability evaluation demonstrated that only 6.79% of the initial cells were sacrificed during the biotinylation and on-chip binding process. The average on-chip cell viability showed 75.47±7.68%. The uptake of lung cancer cell exosomes into three different cancer cell lines (lung, bladder and breast) was measured on chip. The relative uptake of lung cell exosomes by the respective lung cells was 100% compared to the bladder cells and breast cell which were 15.87% and 40.31%, respectively. We extended this specific uptake evaluation to other LungCell-LungExo combinations using H1650, A549, and in-house CTC cell line, CTCR5, and the results demonstrated the organotropism nature of the exosomes in lung cancer.

Discussion and conclusion: We present a novel screening method to accurately characterize specific cancer-derived EVs using a microfluidic platform. This process bypasses the requirement of analyzing and profiling these embedded proteins prior to EV isolation. Our microfluidic device facilitates this interaction between cells and exosomes through the diagnosis process of liquid biopsy.

Citation Format: Kruthi Srinivasa Raju, Zeqi Niu, Joseph Marvar, Shawn Fortna, Nna-Emeka Onukwugha, Yoon-Tae Kang, Sunitha Nagrath. On-chip evaluation of cancer cell-extracellular vesicle interactions using a novel microfluidic microsystem (CellExoChip) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2792.

[Investigation on status of dyslipidemia in Chinese females aged 35 years or above]

Objective: To investigate the prevalence, awareness, treatment and control status of dyslipidemia among females aged ≥35 years old across China. Methods: Participants were selected by stratified multistage random sampling method in the "Twelfth Five-Year Plan" National Science and Technology Support Project "Survey on the Prevalence of Important Cardiovascular Diseases and Key Technology Research in China" project. This study is a retrospective, cross-sectional study. A total of 17 418 females aged 35 years and over were included in the current study. The basic information such as age, medical history and menopause was collected by questionnaire. The blood lipid parameters were derived from clinical laboratory examinations. The prevalence of dyslipidemia and the rate of awareness, treatment, and control of dyslipidemia were analyzed in females aged 35 years and over. Results: The age of participants was (56.2±13.0) years old, and the prevalence of dyslipidemia was 33.1% (5 765/17 418). The prevalence rates of high total cholesterol, hypertriglyceridemia, low HDL-C and high LDL-C were 9.7% (1 695/17 418), 11.1% (1 925/17 418), 10.9% (1 889/17 418) and 7.3% (1 262/17 418), respectively. The prevalence of dyslipidemia increased with age and the prevalence of dyslipidemia in women who were not married, Han, menarche age>16 years, obesity, central obesity, alcohol consumption, diabetes, hypertension and family history of cardiovascular disease were higher than those without such characteristics (P<0.05). There were 10 432 (59.9%) menopausal females in this cohort and prevalence of dyslipidemia of these participants was 38.8% (4 048/10 432), which was higher than that of non-postmenopausal females (24.6%, 1 717/6 986) (P<0.05). The awareness rates, treatment rates and control rates of dyslipidemia were 33.9% (1 953/5 765), 15.1% (870/5 765) and 2.5% (143/5 765) respectively among females aged 35 years and over in China. Conclusion: The prevalence of dyslipidemia in Chinese females aged 35 years and over is high, and its awareness, treatment, and control rates need to be optimized.

[Application of Mendelian randomization in ophthalmology and other medical fields]

In recent years, the application of Mendelian randomization has become more and more widely in the world. By taking genes as instrumental variables, it can eliminate the interference of confounding factors and reverse causality in the system, and effectively judge the causal correlation between exposure factors and outcomes, which has a unique advantage for etiological exploration in the medical field. This article reviews the application of Mendelian randomization in ophthalmology and provides new ideas for the development of correlational and causal studies in Ophthalmology. (Chin J Ophthalmol, 2021, 57: 791-795).

Microfluidic device for high-throughput affinity-based isolation of extracellular vesicles

Immunoaffinity based EV isolation technologies use antibodies targeting surface markers on EVs to provide higher isolation specificity and purity compared to existing approaches. One standing challenge for researchers is how to release captured EVs from the substrate to increase downstream and biological studies. The strong binding between the antibody and antigen or the antibody and substrate is commonly unbreakable without operating at conditions outside of the critical physiological range, making the release of EVs problematic. Additionally, immuno-affinity approaches are usually low-throughput due to their low flow velocity to ensure adequate time for antibody-antigen binding. To overcome these limitations, we modified the OncoBean chip, a previously reported circulating tumor cell isolation microfluidic device. The OncoBean chip is a radial flow microfluidic device with bean-shape microposts functionalized with biotin-conjugated EPCAM antibody through biotin-avidin link chemistry. It was demonstrated that the high surface area and varying shear rate provided by the bean-shaped posts and the radial flow design in the chip, enabled efficient capture of CTCs at high flow rate. We replace the anti-EPCAM with antibodies that recognize common EV surface markers to achieve high-throughput EV isolation. Moreover, by incorporating desthiobiotin-conjugated antibodies, EVs can be released from the device after capture, which offers a significant improvement over the existing isolation. The released EVs were found to be functional by confirming their uptake by cells using flow cytometry and fluorescent microscopy. We believe the proposed technology can facilitate both the study of EVs as cell-to-cell communicators and the further identification of EV markers.

Isolation and Profiling of Circulating Tumor-Associated Exosomes Using Extracellular Vesicular Lipid-Protein Binding Affinity Based Microfluidic Device

Extracellular vesicles (EVs) are emerging as a potential diagnostic test for cancer. Owing to the recent advances in microfluidics, on-chip EV isolation is showing promise with respect to improved recovery rates, smaller necessary sample volumes, and shorter processing times than ultracentrifugation. Immunoaffinity-based microfluidic EV isolation using anti-CD63 is widely used; however, anti-CD63 is not specific to cancer-EVs, and some cancers secrete EVs with low expression of CD63. Alternatively, phosphatidylserine (PS), usually expressed in the inner leaflet of the lipid bilayer of the cells, is shown to be expressed on the outer surface of cancer-associated EVs. A new exosome isolation microfluidic device (new ExoChip), conjugated with a PS-specific protein, to isolate cancer-associated exosomes from plasma, is presented. The device achieves 90% capture efficiency for cancer cell exosomes compared to 38% for healthy exosomes and isolates 35% more A549-derived exosomes than an anti-CD63-conjugated device. Immobilized exosomes are then easily released using Ca2+ chelation. The recovered exosomes from clinical samples are characterized by electron microscopy and western-blot analysis, revealing exosomal shapes and exosomal protein expressions. The new ExoChip facilitates the isolation of a specific subset of exosomes, allowing the exploration of the undiscovered roles of exosomes in cancer progression and metastasis.

Multiplex isolation and profiling of extracellular vesicles using a microfluidic DICE device

Profiling of extracellular vesicles (EVs) is an emerging area in the field of liquid biopsies because of their innate significance in diseases and abundant information reflecting disease status. However, unbiased enrichment of EVs and thorough profiling of EVs is challenging. In this paper, we present a simple strategy to immobilize and analyze EVs for multiple markers on a single microfluidic device and perform differentiated immunostaining-based characterization of extracellular vesicles (DICE). This device, composed of four quadrants with a single inlet, captures biotinylated EVs efficiently and facilitates multiplexed immunostaining to profile their extracellular proteins, allowing for a multiplexed approach for non-invasive cancer diagnostics in the future. From controlled sample experiments using cancer cell line derived EVs and specific fluorescence staining with lipophilic dyes, we identified that the DICE device is capable of isolating biotinylated EVs with 84.4% immobilization efficiency. We extended our study to profile EVs of 9 clinical samples from non-small cell lung cancer (NSCLC) patients and healthy donors and found that the DICE device successfully facilitates immunofluorescent staining for both the NSCLC patients and the healthy control. This versatile and simple method to profile EVs could be extended to EVs of any biological origin, promoting discoveries of the role of EVs in disease diagnostics and monitoring.

Abstract 1334: Dual-isolation of CTCs and cancer exosomes from blood samples with melanoma using immunoaffinity based OncoBean microfluidic devices

Introduction: Melanoma is among the most aggressive cancers, and its incidence continues to grow. Due to the lack of promising markers to predict the disease and onset of metastasis, early detection and evaluation of treatment efficacy have been hampered. Recent advances in liquid biopsy have proposed alternatives for diagnosing disease with the merits of enabling continuous monitoring and non-invasiveness. CTCs and cancer exosomes are evolving as promising biomarkers due to their innate capability of having cancer-associated molecules and signatures. However, simultaneous isolation of CTCs and exosomes using the same methods from the identical samples has not been studied yet. Here, we propose the use of the OncoBean microfluidic device conjugated with melanoma specific antibodies, MCAM and MCSP for the simultaneous isolation. Using whole blood samples from patients, CTCs and exosomes are specifically isolated from the same samples and then undergo molecular profiling for comprehensive studies.

Methods: OncoBean devices were fabricated by soft lithography using polydimethylsiloxane (PDMS). The fabricated devices were conjugated with biotinylated MCSP and MCAM, using Neutralavidin-biotin chemistry. Using 6ml blood samples, 3ml of whole blood and 3ml of plasma were used for CTC isolation and melanoma-associated exosome isolation, respectively. In order to remove cellular debris, the plasma sample was filtered using a 200nm filter. After CTC isolation, captured cells were stained with fluorescent antibodies for melanoma specific (Melan-A and S100), leukocyte (CD45), and nucleus (DAPI) markers. The captured and stained CTCs were enumerated with consideration of size, nucleus to cytoplasm ratio and melanoma marker expression. The isolated exosomes were examined by scanning electron microscopy (SEM) to evaluate their abundance and size. The protein concentration and exosomal protein expression were evaluated by protein extraction using RIPA buffer.

Results: All melanoma patient samples showed 1-35 CTCs per 3ml of blood. Healthy donors had no CTCs. The abundance of isolated exosomes was evaluated by SEM and showed sizes ranging from 117-143nm. The average exosomal protein from melanoma was 28.6±19.2μg/ml, considerably higher than that of healthy donor, 11.0±3.1μg/ml. The exosomes isolated by OncoBean tested positively for the common exosomal protein, CD9, implying that the present device isolated melanoma exosomes specifically.

Discussion and conclusion: We showed that melanoma patients have both circulating tumor cells and cancerous exosomes in their blood samples. Even though their absolute CTC number and exosomal protein concentration showed no high correlation, simultaneous isolation using the identical microfluidic devices will be helpful for further verification of disease and cross validation according to their roles in disease.

Citation Format: Yoon-Tae Kang, Ting-Wen Lo, Thomas Hadlock, Emma Purcell, Aaron Kramer, Monica De Reguera, Scott Alan McLean, Sunitha Nagrath. Dual-isolation of CTCs and cancer exosomes from blood samples with melanoma using immunoaffinity based OncoBean microfluidic devices [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 1334.

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.

[Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China]

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient's medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

Detection of circulating tumour cells and their potential use as a biomarker for advanced renal cell carcinoma

INTRODUCTION

The aim of this study was to detect circulating tumour cells (CTCs) in patients with advanced renal cell carcinoma (RCC) using a novel CTC detection platform. Furthermore, we evaluated the clinical outcomes associated with a CTC-positive status.

METHODS

A total of 34 patients with advanced RCC (stage III or IV) were prospectively enrolled, and 104 peripheral blood samples were analyzed for the presence of CTCs at various time points. CTCs were isolated using a tapered-slit filter, which captures CTCs based on size and deformability. The presence of CTCs was confirmed using both staining and morphological criteria. CTC status was then correlated with clinical characteristics and survival outcomes.

RESULTS

CTCs were detected in 62% of patients during the pre-treatment period, and the median CTC count was 2 (interquartile range 1-3). During the followup period, CTCs were detected in 56% (18/32), 65% (20/31), and 41% (7/17) of patients at one week, one month, and three months after treatment, respectively. Overall, CTCs were found in 57.9% (66/114) of blood samples in the range of 1-7 cells. Although no statistical significance was found, CTC detection in patients with stage IV disease was more common than in patients with stage III disease (68.4% vs. 53.3%). Two-year progression-free survival and cancer-specific survival tended to be lower in CTC-positive patients compared with CTC-negative patients.

CONCLUSIONS

The tapered-slit filter is an efficient technique to detect CTCs in advanced RCC.

Cytopathological Study of the Circulating Tumor Cells filtered from the Cancer Patients' Blood using Hydrogel-based Cell Block Formation

Circulating tumor cells have emerged as biomarkers for estimating the tumor burden and metastatic potential of cancer patients. However, to date, most of studies and applications of circulating tumor cells have been conducted and applied to epithelial cancers such as breast, colorectal, and prostate tumor. The only FDA-cleared method, CellSearch, makes use of antibody against epithelial surface protein expressed on CTCs, thus obstructing wide application for various cancers with non-epithelial and semi-epithelial characteristics including renal cell carcinoma. Due to rarity and ambiguity of CTCs, designed experiment including non-biased CTC isolation and subsequent cytopathological study for finding applicable immunomarkers are urgently needed for clinical use of CTCs for less-studied cancers. Here, in order to construct the fundamental step for CTC diagnosis without limitation of its epithelial characteristics, we present the simple and novel method which incorporate both label-free CTC isolation and pathological study using hydrogel-based cell block formation. Six cell lines from lung, ovarian, kidney cancers were used to make cell block and analyzed by conventional immunocytochemical staining method to find the candidate markers for CTC. Especially for renal cancer, the physically isolated CTCs were further immunocytochemically examined with the screened candidate markers by cell block construction, and verified their clinical utility using blood samples from patients with renal cell carcinoma. This comprehensive study demonstrates that the present approach can be used to find the potential markers for any type of cancers regardless of their epithelial characteristics and isolate the specific type of CTCs in label-free manners.

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.

Label-free Rapid Viable Enrichment of Circulating Tumor Cell by Photosensitive Polymer-based Microfilter Device

We present a clinical device for simple, rapid, and viable isolation of circulating tumor cells (CTCs) from cancer patient bloods. In spite of the clinical importance of CTCs, the lack of easy and non-biased isolation methods is a big hurdle for implementing CTC into clinical use. The present device made of photosensitive polymer was designed to attach to conventional syringe to isolate the CTCs at minimal resources. Its unique tapered-slits on the filter are capable not only to isolate the cell based on their size and deformability, but also to increase sample flow rate, thus achieving label-free rapid viable CTC isolation. We verified our device performance using 9 different types of cancer cells at the cell concentration from 5 to 100cells/ml, showing that the device capture 77.7% of the CTCs while maintaining their viability of 80.6%. We extended our study using the 18 blood samples from lung, colorectal, pancreatic and renal cancer patients and captured 1-172 CTCs or clustered CTCs by immunofluorescent or immunohistochemical staining. The captured CTCs were also molecularly assayed by RT-PCR with three cancer-associated genes (CK19, EpCAM, and MUC1). Those comprehensive studies proved to use our device for cancer study, thereby inaugurating further in-depth CTC-based clinical researches.

Abstract 1719: Dual-profiling of CTC and exosome from the cultured circulating tumor cells using stimuli-responsive degaradable hydrogels

Introduction: Liquid biopsy based on sub-micron or nanosized particles in human body fluid have been received vast attention due to their non-invasive characteristics and enabling multiple check-up. Circulating tumor cells (CTCs), as well as exosome are the most promising markers in liquid biopsy, however, dual isolation and profiling have been hampered due to their size difference and limited quantity for analysis. We proposed the novel and simple methods for both isolation and study their similarity between them. Using the label-free CTC filtration device and anti-CD63 antibody-conjugated degradable hydrogel, the CTCs and the CTCs-derived exosome are specifically isolated, and each samples were followed by molecular study after recovery. This versatile platform facilitates the comprehensive study of two biomarkers with reflecting their inherent characteristics, thus paving the way for revealing their roles in cancer progression and metastasis.

Methods: In order to make stimuli-responsive degradable hydrogel, poly (vinyl alcohol) and alginate were mixed under constant stirring at 85 °C. The mixture was poured into the mold and dried for 24 hours. Then, the dried sheet was immersed into 100 mM calcium chloride solution to achieve gelation through ionic interaction. Subsequently, the anti-CD63 antibody was immobilized onto the prepared hydrogels via cross-linking. For the dual-profiling, the hydrogel and the filters containing the captured breast cancer cells by microfiltration were incubated with the exosome-depleted cell culture media for 6 hours. The captured cells were released from the device and the hydrogels were degraded by adding EDTA. The cell and exosome lysate were prepared using RIPA buffer at 4 °C. The supernatant was collected by centrifugation followed by western-blot assay. Four different markers, including exosome-specific marker (CD63), cancer-associated markers (EpCAM, vimentin), and a housekeeping marker (β-actin), were used.

Results: All exosome and cell samples highly expressed the housekeeping marker. Especially, two exosome samples dissociated from the hydrogel showed CD63 predominantly, which support the secretion of exosome from the cancer cells. The samples from the released cancer cells from the device did not express CD63 remarkably. To verify the phenotypical similarity between cell and exosome, expressions of the epithelial marker (EpCAM) and mesenchymal marker (vimentin) were examined. The exosome and cell from MCF-7, epithelial cancer cell, showed higher expression of EpCAM then vimentin. On the contrary to this, the samples from MDA-MB-231, mesenchymal cell, showed higher vimentin expression then EpCAM.

Discussion and conclusion: We showed that exosome follow the phenotypical characteristics of mother-cells. This dual profiling would be helpful for in-depth study of cancer with consideration of its heterogeneity and complexity.

Citation Format: Yoon-Tae Kang, Young Jun Kim, Tae Hee Lee, Jae-Eul Shim, Young-Ho Cho. Dual-profiling of CTC and exosome from the cultured circulating tumor cells using stimuli-responsive degaradable hydrogels [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 1719. doi:10.1158/1538-7445.AM2017-1719

Abstract 3775: Hydrogel-assisted pathological study of the circulating tumor cells filtered from the renal cell carcinoma patients’ blood

Introduction: Circulating tumor cells (CTCs), defined as tumor cells detached from the primary tumor site and circulating in the peripheral blood, are a promising marker to get the information about tumor status and metastatic potential. However, the limited detection ability as well as their biased specificity of current CTC isolation struggle from understanding the comprehensive characteristics of CTCs. In addition, previous CTC isolation depending on epithelial cell adhesion molecule (EpCAM) antibody make their cytological and pathological study hard. We developed the methods which capture CTCs based on their size and deformability, and construct a hydrogel-assisted cell block for verifying the diagnostic utility for various cancer-associated immuno-markers and their pathological studies.

Methods: Two renal cell carcinoma cell lines, SN12C and 769P, and 7 different cancer patients’ blood with renal cell carcinoma were used. To find the applicable markers for diagnosing renal cell carcinoma, we constructed the cell blocks of two cell lines. For the encapsulation of the cells, 4 % alginate was prepared by dissolving in deionized water under constant stirring at 85 °C. Then, the separately prepared renal cancer cells were gently mixed into the dissolved alginate solution. After careful mixing, the solution was loaded into calcium chloride solution drop by drop using volume pipette, followed by 15 min of further incubation with constant stirring. Next, the cell-containing beads were applied to the commonly used procedure for paraffin tissue blocks, and 8 different cancer-associated immuno-markers (EpCAM, CK (AE1/AE3), CAM5.2, EMA, CD10, CA IX, RCC, and vimentin) were stained with each dissected cell blocks. The CTCs from the 7 clinical samples were isolated by tapered-slit filter, and cell containing slides were immunohistochemically stained and examined by pathologist.

Results: The four markers, EpCAM, CK (AE1/AE3), CD10, and vimentin in the SN12C cell block were highly expressed. The three markers, CK (AE1/AE3), CD10, and vimentin in the 769-P cell block were predominantly expressed. The EpCAM, CK (AE1/AE3), and CD10 are chosen as the potential immunomarkers for CTC-based diagnosing for RCC. In the clinical study using the 0.5-3.0 ml of blood samples, CTCs were successfully isolated and detected immunohistochemically in 57.1 % (4 of 7) of patients and ranged from 1 to 5. Of 4 CTC positive samples, two had CK (AE1/AE3) positive, each one had EpCAM and CD10 positive CTCs, respectively.

Discussion and conclusion: Although the vimentin is highly expressed in both cell blocks, due to diffuse positivity for leukocyte, single use of vimentin for cancer diagnosis is limited. This comprehensive study including immuno-markers screening and their applicability test with clinical samples demonstrates the clinical utility of the present device and hydrogel-assisted cell block for CTC isolation and cancer studies.

Citation Format: Yoon-Tae Kang, Young Jun Kim, Tae Hee Lee, Hee Jin Chang, Hyun-Moo Lee, Young-Ho Cho. Hydrogel-assisted pathological study of the circulating tumor cells filtered from the renal cell carcinoma patients’ blood [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 3775. doi:10.1158/1538-7445.AM2017-3775

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

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.

Poly(ethylene glycol)-Modified Tapered-Slit Membrane Filter for Efficient Release of Captured Viable Circulating Tumor Cells

The grafting of poly(ethylene glycol) (PEG) onto an SU8 microfilter has been demonstrated for efficient capture and release of circulating tumor cells (CTCs). Previous CTC filters showed low cell release efficiency due to hydrophobic surfaces, even though their capture efficiency was considerable. PEG, a hydrophilic polymeric compound mainly used to form nonfouling thin films on silicon surfaces, induces repulsive force so that the nonspecific adsorption of the surface is incomparably reduced in comparison with unmodified filter surfaces. The effectiveness of PEG-modified CTC filters was verified through lung (H358) and colorectal (SW620) cancer cells spiked, respectively, in phosphate-buffered saline (PBS) and unprocessed whole blood. The modified SU8 filters achieved approximately 37.7% and 22.8% improvement in release efficiency without significant changes in cell viability and capture efficiency. In order to verify the filter's potential for clinical applications, we extended our experiments using cancer patient blood samples. Six blood samples from colorectal and lung cancer patients were processed, and captured CTCs were efficiently released. From these experiments, the present PEG-modified filter captures and releases on average 14 ± 7.4 CTCs/mL, including EpCAM-negative CTCs, which could not be captured by previous single antibody-based methods. The antibody-free isolation with enhanced release efficiency facilitates viable cell retrieval, which is significant to CTC culture and comprehensive molecular study for verifying the mechanism of metastasis and cancer.

Tapered-slit membrane filters for high-throughput viable circulating tumor cell isolation

This paper presents tapered-slit membrane filters for high-throughput viable circulating tumor cell (CTC) isolation. The membrane filter with a 2D array of vertical tapered slits with a gap that is wide at the entrance and gradually decreases with depth, provide minimal cell stress and reduce 82.14% of the stress generated in conventional straight-hole filters. We designed two types of tapered-slit filters, Filters 6 and 8, respectively, containing the tapered slits with outlet widths of 6 μm and 8 μm at a slit density of 34,445/cm(2) on the membrane. We fabricated the vertical slits with a tapered angle of 2 ° on a SU8 membrane by adjusting the UV expose dose and the air gap between the membrane and the photomask during lithography. In the experimental study, the proposed tapered-slit filter captured 89.87% and 82.44% of the cancer cells spiked in phosphate buffered saline (PBS) and diluted blood (blood: PBS = 1:4), respectively, at a sample flow rate of 5 ml per hour, which is 33.3 times faster than previous lateral tapered-slit filters. We further verified the capability to culture on chip after capturing: 72.33% of cells among the captured cells still remained viable after a 5-day culture. The proposed tapered-slit membrane filters verified high-throughput viable CTC isolation capability, thereby inaugurating further advanced CTC research for cancer diagnosis and prognosis.

Synthesis and properties of nanohybrid materials with SiO2 and epoxy resin

SiO2-epoxy nanohybrid materials were synthesized by hybridization of surface-modified colloidal silica nanoparticle (CS) and epoxy resin. The CS was surface-modified with either methyltrimethoxysilane (MTMS) or phenyltrimethoxysilane (PTMS) followed by the solvent exchange with dimethylacetamide (DMAc) to have a homogenous dispersion in epoxy resin. Various amounts of surface-modified CS were mixed with epoxy resin. The chemical structures of surface-modified CS were investigated with FT-IR spectroscopy. The particle sizes of CS and surface-modified CS were measured with DLS. The morphology of hybrid materials analyzed using FE-SEM and AFM showed homogeneous dispersion in epoxy resin. The optical and thermal properties of the hybrid materials determined by refractive index meter and DSC were lower in RI and higher in Tg than neat epoxy resin, respectively.

Effect of SiO2-acryl nanohybrid coating layers on transparent conducting oxide-poly(ethylene terephthalate) superstrate

SiO2-acryl nanohybrid coating layers were produced by hybridizing acrylic resin and surface-modified colloidal silica (CS) nanoparticles. First, CS nanoparticles were modified with methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) by a sol-gel process. The surface-modified CS nanoparticles were then solvent-exchanged to be homogeneous in acrylic resin. The Hybrid materials were mixed in variation with the amount of surface-modified CS nanoparticles, coated with poly(ethylene terephthalate) (PET), then finally cured by UV light to obtain a hybrid coating layer. Field emission scanning electron microscopy (FE-SEM), particle size analysis (using a Zetasizer), and atomic force microscopy (AFM) were performed to determine the morphology of the hybrid thin-films. Thermogravimetric analysis (TGA) was used to investigate the thermal properties. Fourier-transform infrared (FTIR), ultraviolet-visible (UVNis) spectroscopies, and pencil hardness were used to obtain the details of chemical structures, optical properties, and hardness, respectively. The hybrid thin films had shown to be enhanced properties compared to their urethane acrylate prepolymer (UAP) coating film.

Design of a PC-based multimedia telemedicine system for brain function teleconsultation

During time-critical brain surgery, the detection of developing cerebral ischemia is particularly important because early therapeutic intervention may reduce the mortality of the patient. The purpose of this system is to provide an efficient means of remote teleconsultation for the early detection of ischemia, particularly when subspecialists are unavailable. The hardware and software design architecture for the multimedia brain function teleconsultation system including the dedicated brain function monitoring system is described. In order to comprehensively support remote teleconsultation, multi-media resources needed for ischemia interpretation were included: EEG signals, CSA, CD-CSA, radiological images, surgical microscope video images and video conferencing. PC-based system integration with standard interfaces and the operability over the Ethernet meet the cost-effectiveness while the modular software was customized with a diverse range of data manipulations and control functions necessary for shared workspace and standard interfaces.

Development of a medical record and radiographic image transmission system using a high-speed communication network

A medical record and radiographic image transmission system has been developed using a high-speed communication network. The databases are designed to store and transmit the data acquired from the scanner. To maximally utilize the communication bandwidth, the medical records and radiographic images are compressed using the G3 facsimile and JPEG coding standard method, respectively. TCP/IP, OOP and Windows-based system software enable a modular design, future expandability, open system interconnectivity, and diverse image manipulation functions.