Isolating and Concentrating Rare Cancerous Cells in Large Sample Volumes of Blood by Using Dielectrophoresis and Stepping Electric Fields

Guang-Hong Chen,Chun-Ping Jen,Ching-Te Huang,Hsin-Hui Wu,Tatyana N. Zamay,Anna S. Zamay 한국바이오칩학회 2014 BioChip Journal Vol.8 No.2

Detecting rare cells, such as circulatingtumor cells (CTCs), circulating fetal cells, and stemcells, is vital during medical diagnostics and characterization. During carcinogenesis, cancer cells detachfrom the primary tumor into the blood stream, becomingCTCs. Typical rare cell samples are consideredany sample that contains less than 1000 target cellsper milliliter. The volumes of microfluidic devicestypically range from several microliters to nanoliters;this is excessively small for experimenting using lowconcentrationsamples. This study involved isolatingcancerous cells in an open-top chamber with sub-millilitervolumes (0.1 mL) of blood samples by using alysis buffer solution for red blood cells (RBCs), as wellas concentrating cells employing the dielectrophoreticforce generated using stepping electric fields,which were produced using a handheld electric modulethat comprised a voltage-frequency converterand an operational amplifier. To increase the samplevolume, an open-top chamber was fabricated on andbonded to a glass substrate by using circular microelectrodes. The concentrations of cancer cells andRBCs were adjusted to 500 cells/mL and 4×105 cell/mL, respectively, for the experiments. To reduce theinterference of blood cells during detection and isolateCTCs, the RBCs in the sample were lysed in alysis buffer solution before the proposed chip wasused to dielectrophoretically manipulate the rare cancerouscells. The findings indicated that the lysis bufferlysed the erythrocytes and the survivability levelsof the cancerous cells (HeLa and MCF-7) remainedhigh in the lysis buffer. The positive dielectrophoreticcancerous cells were guided based on the direction ofthe stepping electric field because of movement in thehigh-electric-field region; hence, the cancerous cellsconcentrated and collected at the central electrode.

Lab on a fabric: Mass producible and low-cost fabric filters for the high-throughput viable isolation of circulating tumor cells

Bu, Jiyoon,Kang, Yoon-Tae,Lee, Yong-Seok,Kim, Jeongsuk,Cho, Young-Ho,Moon, Byung-In Elsevier 2017 Biosensors & Bioelectronics Vol.91 No.-

<P><B>Abstract</B></P> <P>Circulating tumor cells (CTCs) play an important role in estimating the presence and the metastatic relapse of tumor. Despite of their importance, isolation of viable CTCs is still struggling, since chemical or mechanical damages are unavoidable when separating less than 1000 of CTCs out of billions of other blood components. Furthermore, the current CTC isolation devices show low productivity, since they are produced after a series of complicated fabrication processes. Here, we present a low-cost and mass-producible fabric filters for the viable CTC isolation and the further molecular assay for profiling cancer-associated markers. The fabric filter, produced by polyester monofilament yarns, can be massively produced at extremely low-cost, by showing productivity of ~22filters/s at ~59filters/USD. By utilizing size-based sorting method, the fabric filter is capable to isolate both epithelial and mesenchymal CTCs, while slots with curved walls are beneficial for preventing the cell rupture by reducing 21.6% of mechanical stress compared to the conventional straight-walled slots. We applied our filter to 11 human blood samples and found that the number of CTCs was closely related to the expression level of Ki-67, which is highly overexpressed in proliferative tumors. The fabric filter might be an appropriate caner-screening tool in developing countries, where people suffer from insufficient healthcare services.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present a mass producible and low-cost fabric filter for viable CTC isolation. </LI> <LI> Curved walls in the fabric filter is beneficial for minimizing the cellular damage. </LI> <LI> The fabric filter is capable for viable capture and efficient retrieval. </LI> <LI> CTCs were detected from all patients, while none was found among healthy donors. </LI> <LI> The number of CTCs was closely related with the expression level of Ki-67. </LI> </UL> </P>

Influence of the Amount of Fresh Specimen on the Isolation of Tumor Mesenchymal Stem-Like Cells from High-Grade Glioma

공순행,유지환,이동규,문소형,성경수,박소희,심진경,최란주,윤선진,문주형,김의현,이수재,장종희,강석구 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.10

Purpose: A critical indicator of the overall survival of patients with high-grade glioma is the successful isolation of tumor mesenchymal stem-like cells (tMSLCs), which play important roles in glioma progression. However, attempts to isolate tMSLCs from surgical specimens have not always been successful, and the reasons for this remain unclear. Considering that the amount of surgical high-grade glioma specimens varies, we hypothesized that larger surgical specimens would be better for tMSLC isolation. Materials and Methods: We assessed 51 fresh, high-grade glioma specimens and divided them into two groups according to the success or failure of tMSLC isolation. The success of tMSLC isolation was confirmed by plastic adherence, presenting antigens, tri-lineage differentiation, and non-tumorigenicity. Differences in characteristics between the two groups were tested using independent two sample t-tests, chi-square tests, or Kaplan-Meier survival analysis. Results: The mean specimen weights of the groups differed from each other (tMSLC-negative group: 469.9±341.9 mg, tMSLC positive group: 546.7±618.9 mg), but the difference was not statistically significant. The optimal cut-off value of specimen weight was 180 mg, and the area under the curve value was 0.599. Conclusion: Our results suggested a minimum criterion for specimen collection, and found that the specimen amount was not deeply related to tMSLC detection. Collectively, our findings imply that the ability to isolate tMSLCs is determined by factors other than the specimen amount.

소화기계 암에서의 순환종양세포 분석과 임상적 가치

우형중,신현영,김민석 대한소화기암연구학회 2024 Journal of Digestive Cancer Research (JDCR) Vol.12 No.2

소화기계 암은 전체 암 발병률의 26%를 차지하는 매우흔한 암이며, 암 관련 사망률의 35%를 차지해 다른 암종에 비해 사망률이 높다[1]. 이러한 소화기계 암 환자의 대부분은 암 전이로 인해 사망하며, 특히 폐와 간, 뼈로의 전이가 흔하게 발생한다[2]. 국소암에 비해 원격 전이가 발생한 암의 경우 치료 선택의 폭이 크게 좁아지기 때문에,전이 암세포의 특징을 잘 이해하고 이에 맞는 약물을 선정하는 것은 소화기계 암 환자의 생존율을 높이는데 매우중요하다. 이런 원격 전이의 주요 인자로 잘 알려져 있는 것이 바로 순환종양세포(circulating tumor cell, CTC)이다. CTC는 고형 종양에서 유래하여 epithelial–mesenchymaltransition 과정을 거쳐 순환계로 들어온 암 세포를 말한다. CTC는 일반적인 암 세포에 비해 줄기세포성이 크지만 증식 능력은 다소 감소된 경향을 보인다[3]. 대부분의 CTC는 원발암에서 떨어진 직후부터 주변세포 외 기질과의 상호작용 상실로 일어나는 세포 사멸인 anoikis, 혈류의 전단 응력, 면역세포의 공격으로 인해 대부분 사멸하고, 오직 극소수의 CTC만이 생존하여mesenchymal-epithelial transition 과정 속에서 전이가 일어난다고 알려져 있다[4]. 따라서 환자의 혈액에서 발견되는 CTC는 전이 가능성과 연관되며, CTC의 수를 통해 환자의 예후를 평가할 수있으며 유전분석을 통해 원발암의 유전 변이에 대한 정보를 획득할 수 있다. 본 고에서는 CTC의 소화기계 암에서의 임상적 활용에 대해 논의하고자 한다. Circulating tumor cells (CTCs) are a valuable biomarker for the diagnosis, prognosis, and therapeuticmanagement of gastrointestinal (GI) cancers. A major challenge in GI cancer treatmentis the high rate of metastasis, which significantly contributes to cancer-related mortality. CTCsare crucial in the metastatic cascade, serving as indicators of tumor progression. Therefore, thedetection and molecular characterization of CTCs have prognostic potential for identifyingearly-stage GI cancers and assessing metastatic probability, enabling timely treatment. Moreover,CTC analysis offers a minimally invasive method for real-time monitoring of tumors. Clinicians can adjust therapeutic strategies accordingly by tracking changes in CTC count andmolecular profile. Despite this promising application, no standardized protocol for CTC isolationin GI tract cancers has been established, which poses a barrier to routine clinical use. Thisreview explores the current CTC detection methodologies, their clinical relevance in GI cancermanagement, and the potential integration of CTC analysis into personalized medicine. Wealso discuss the challenges and future directions in CTC research, focusing on clinical validationand the development of standardized procedures to fully realize the utility of CTC countfor improving patient care.

안와에 발생한 고립성 편평세포암종 1예

한대헌,지미정,Dae Heon Han,MD,Mijung Chi,MD,PhD 대한안과학회 2011 대한안과학회지 Vol.52 No.6

Purpose: To report a case of isolated squamous cell carcinoma of the orbit. Case summary: A 75-year-old man with over a 50 pack-year history of smoking presented discomfort and visual disturbance of the left eye for several months. His best-corrected visual acuity was 0.3, intraocular pressure was 9 mm Hg, and extraocular movements were normal. Slit-lamp examinations revealed no specific findings in the anterior segment in the left eye. However, retinal exams showed an oval-shaped, juxtapapillary mass-like lesion associated with retinal folding in the left eye. A huge, distorted echoic mass with an initial prominent spike and low-to-medium internal reflectivity with diminishing amplitude was observed on ocular ultrasonography. Enhanced CT revealed a highly-intense, irregular-circumscribed heterogeneous mass (2.0 × 2.0 × 1.5) in the superomedial quadrant of the left eye. Metastatic workups, including bone scan and CT of the head, neck, chest, and abdomen, were unremarkable. One week after the initial visit, the patient experienced pain and reduced visual acuity (light perception) in the left eye. Following the diagnosis, enucleation with tumor resection and hydroxyapatite implantation was performed. Histopathologic examination revealed a moderated-differentiated squamous cell carcinoma invading the sclera. The patient subsequently underwent radiation treatment and no evidence of recurrence was reported 6 months after surgery. J Korean Ophthalmol Soc 2011;52(6):738-741

혈중 종양 세포 분리 Chip을 이용한 미세 유체 채널 내 입자 유동 연구

김정아(J.A. Kim),김태성(T.S. Kim),조치흠(C.H. Cho),허윤석(Y.S. Heo) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

Circulating tumor cells (CTCs) present in the bloodstream of cancer patients. CTCs provide a potentially accessible source for detection, characterization, and monitoring of nonhematological cancers. We demonstrate the effectiveness of the CTC-Chip for the isolation of ovarian cancer cells by adapting the herringbone-chip (HB-Chip). The motion of the particles on the HB chip are simulated by a unique combination of buoyant, gravitational forces, and helical flows with computational modeling. The real motion of cells are demonstrated by applying polystylene bead and ovarian cancer cells into the microfabricated HB chip. The experimental results from beads and cells are well accordance with the simulated ones, as previous reported by Toner group. Thus, we expect that these modeling and experimental skills will play key roles in the clinical applications on CTC isolation as well as the basic research on characterization of CTCs under flow.

Impact on Prognosis of Lymph Node Micrometastasis and Isolated Tumor Cells in Stage II Colorectal Cancer

오태영,문선미,신의섭,이향란,박선후 대한대장항문학회 2011 Annals of Coloproctolgy Vol.27 No.2

Purpose: Even though the importance of micrometastases (MMS) and isolated tumor cells (ITC) has been brought up by many physicians, its impact on the prognosis in stage II colorectal cancer is uncertain. In this research, we tried to investigate the clinical features of MMS and ITC and to prove any correlation with prognosis. Methods: The research pool was 124 colorectal cancer patients who underwent a curative resection from April 2005 to November 2009. A total of 2,379 lymph nodes (LNs) were examined, and all retrieved LNs were evaluated by immunohistochemical staining with anti-cytokeratin antibody panel. Clinicopathologic parameters and survival rates were compared based on the presence of MMS or ITC and on the micrometastatic lymph node ratio (mmLNR), which is defined as the number of micrometastatic LNs divided by the number of retrieved LNs. Results: Out of 124 patients (26.6%) 33 were found to have MMS or ITC. There were no significant differences in clinicopathologic features, such as gender, tumor location and size, depth of invasion, histologic grade, except for age (P = 0.04). The three-year disease-free survival rate for the MMS or ITC positive group was 85.7%, and that for MMS and ITC negative group was 92.8% (P = 0.209). The three-year disease-free survival rate for the mmLNR > 0.25 group was 73.3%, and that for the mmLNR ≤ 0.25 group was 92.9% (P = 0.03). Conclusion: The presence of MMS or ITC was not closely correlated to the prognosis. However, mmLNR is thought to be a valuable marker of prognosis in cases of stage II colorectal cancer.

Sentinel Lymph Node in Breast Cancer: Review Article from a Pathologist’s Point of View

Sophia K. Apple 대한병리학회 2016 Journal of Pathology and Translational Medicine Vol.50 No.2

Breast cancer staging, in particular N-stage changed most significantly due to the advanced technique of sentinel lymph node biopsy two decades ago. Pathologists have more thoroughly examined and scrutinized sentinel lymph node and found increased number of small volume metastases. While pathologists use the strict criteria from the Tumor Lymph Node Metastasis (TNM) Classification, studies have shown poor reproducibility in the application of American Joint Committee on Cancer and International Union Against Cancer/TNM guidelines for sentinel lymph node classification in breast cancer. In this review article, a brief history of TNM with a focus on N-stage is described, followed by innate problems with the guidelines, and why pathologists may have difficulties in assessing lymph node metastases uniformly. Finally, clinical significance of isolated tumor cells, micrometastasis, and macrometastasis is described by reviewing historical retrospective data and significant prospective clinical trials.

유방암 환자의 감시림프절 생검술에서 발견되는 고립종양세포의 의미

김균지(Gyunji Kim),최재혁(Jae Hyuck Choi),김완욱(Wan Wook Kim),이세경(Se Kyung Lee),임혜인(Hye In Lim),조은윤(Eun Yoon Cho),이정언(Jeong Eon Lee),남석진(Seok Jin Nam),양정현(Jung-Hyun Yang) 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.77 No.6

Purpose: Sentinel lymph node (SLN) biopsy has replaced unnecessary axillary dissection in breast cancer surgery except when the nodes are positive for macrometastasis. But guidelines for isolated tumor cells (ITCs) found in SLNs has not yet been established and further study is ongoing. The goal of this study was to consider the implication of the isolated tumor cells found in the SLNs of Korean breast cancer patients. Methods: Between September 2003 and March 2008, 985 primary breast cancer patients underwent SLN biopsy. On reviewing the medical records, 81 patients were found to have ITCs in SLNs without macrometastasis or micrometastasis. ITCs were detected by serial sectioning and immunohistochemistry. Results: The mean number of detected SLNs was 3.5±1.7. Thirty three patients had multifocally distributed ITCs and 9 had ITCs in multiple SLNs whose N stage was N0 (i+). Completion axillary dissection has been performed in 9 patients and 3 of them (33.3%) finally were found to be N1 or N1mi. Conclusion: The characteristics of ITCs are not clear yet and their prognostic value is still under investigation. Until the significance of ITCs found in SLNs become definite, axillary dissection should be more aggressively considered.

Rare cell analysis technology for personalized precision medicine

김민석,우형중,신현영 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.0