• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.168-173
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• 2018

Gastric cancer is still the leading cause of cancer deaths, especially in Asian countries. Recently, many studies have analyzed cell-free nucleic acids (cfNAs) circulating in the blood, for the early diagnosis of cancer and monitoring its progression. Circulating tumor nucleic acids (ctNAs) originate in a tumor and contain tumor-related genetic or epigenetic alterations. This review defines the nomenclatures of each form of cfNAs and describes the characteristics of circulating tumor DNA (ctDNA) and microRNA (miRNA), two major forms of ctNAs studied in gastric cancer research to date. We compare available studies on ctDNA, and explain trends observed in studies of miRNAs in gastric cancers. As these new blood-based biomarkers have attracted increasing attention, we have discussed several important points to be considered before the clinical translation of ctNA detection. We have also discussed the current status of research in this field, and clinical applications of specific ctNAs as tumor markers for gastric cancer diagnosis.

• Journal of Digestive Cancer Research
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• v.6 no.2
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• pp.59-63
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• 2018

Over the past decade, circulating tumor cell have received tremendous attention as new biomarkers and basic research subjects.In recent years, research on circulating tumor DNA, exosomes and microRNAs has also been actively conducted.These circulating tumor markers have the potential to become the basis of precision medicine, such as determining the genome / immune profile, monitoring response and tolerance, and selecting therapeutic agents beyond the early diagnosis and prognosis prediction.In this article, we introduce the diagnostic methods, efficacy, meaning, and applicability of various circulating tumor markers.

• Journal of Digestive Cancer Research
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• v.8 no.1
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• pp.56-60
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• 2020

In recent years, liquid biopsy has received immense attention. Liquid biopsy is a minimally invasive method used for obtaining biological fluids including urine, pleural fluid and, mostly, peripheral blood. Liquid biopsy involves various targets including circulating tumors cells (CTCs), circulating cell-free tumor DNA (ctDNA), and microRNA (miRNA). Colorectal cancer (CRC), like other solid tumors, shed tumor cells into the bloodstream. Analysis of these CTCs, as well as ctDNA is the primary objective of the liquid biopsy. Evaluation of CTC or ctDNA offers information about early tumor release, development of tumor metastasis and also about mechanisms involved in tumor resistance to treatment.

• BMB Reports
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• v.48 no.3
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• pp.127-128
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• 2015

Tumor metastasis involves circulating and tumor-initiating capacities of metastatic cancer cells. Hepatic TM4SF5 promotes EMT for malignant growth and migration. Hepatocellular carcinoma (HCC) biomarkers remain unexplored for metastatic potential throughout metastasis. Here, novel TM4SF5/CD44 interaction-mediated self-renewal and circulating tumor cell (CTC) capacities were mechanistically explored. TM4SF5-dependent sphere growth was correlated with $CD133^+$, $CD24^-$, ALDH activity, and a physical association between CD44 and TM4SF5. The TM4SF5/CD44 interaction activated c-Src/STAT3/ Twist1/ B mi1 signaling for spheroid formation, while disturbing the interaction, expression, or activity of any component in this signaling pathway inhibited spheroid formation. In serial xenografts of less than 5,000 cells/injection, TM4SF5-positive tumors exhibited locally-increased CD44 expression, suggesting tumor cell differentiation. TM4SF5-positive cells were identified circulating in blood 4 to 6 weeks after orthotopic liver-injection. Anti-TM4SF reagents blocked their metastasis to distal intestinal organs. Altogether, our results provide evidence that TM4SF5 promotes self-renewal and CTC properties supported by $CD133^+/TM4SF5^+/CD44^+^{(TM4SF5-bound)}/ALDH^+/CD24^-$ markers during HCC metastasis.

• Journal of Veterinary Science
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• v.22 no.5
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• pp.75.1-75.10
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• 2021

Background: Programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) have important roles in tumor evasion of the immune system. Objectives: This study aimed to assess the diagnostic utility of circulating PD-1 and PD-L1 levels in healthy dogs and dogs with tumors. Methods: Circulating PD-1 and PD-L1 levels in the serum of 71 dogs with tumors were compared with those of 52 healthy dogs by performing enzyme-linked immunosorbent assay (ELISA). Results: The ELISA results revealed higher circulating PD-1 and PD-L1 levels in dogs with tumors (2.9 [2.2-3.7] ng/mL; median [IQR] and 2.4 [1.4-4.4] ng/mL, respectively) than in healthy dogs (2.4 [1.9-3.0] ng/mL; p = 0.012 and 1.4 [0.9-2.1] ng/mL; p < 0.001, respectively). Especially, there was a significant difference in circulating PD-1 levels between healthy dogs and dogs with malignant epithelial tumors (2.4 [1.9-3.0] ng/mL and 3.1 [2.6-4.4] ng/mL, respectively; p < 0.01). In addition, there was a significant difference in circulating PD-L1 levels between healthy dogs and dogs with lymphomas (1.4 [0.9-2.1] ng/mL and 2.7 [1.6-5.8] ng/mL, respectively; p < 0.001). Conclusion: This study indicates that circulating PD-1 and PD-L1 have potential as tumor diagnostic biomarkers in dogs with tumors.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.75-81
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• 1998

Effects of swainsonine (SW: 8${\alpha}$, ${\beta}$-indolizidine-1alpha, 2${\alpha}$, 8${\beta}$-triol from Locoweed) on the cellular and nonspecific immune responses of lipopolysaccharide (LPS) wer e studied in ICR mice. Mice were divided into 4 groups (10mice/group), and LPS was given to each mouse 1 hr after i.p. injection with 3.7mg/kg of SW by i.p. injection twice a week for 14 days at a dose of 2mg/kg. Immune responses of the delayed-type hypersensitivity response (DTH) to sheep red blood cells (s-RBC), phagocytic activity and natural killer (NK) cell activity were evaluated. LPS treatment didn`t affect NK cell activity, phagocytic activity, DTH to s-RBC compared with those in controls, and phagocytic activity of sareoma 180 tumor bearing mice. However, circulating leukocytes were significantly decreased. Combinaton of LPS and SW increased circulating leukocytes significantly compared vath that in LPS alone, and DTH to s-RBC, NK cell activity and phagocytic activities of normal and sarcoma tumor bearing mice were not affected. These findings indicate that SW didn`t affected the cellular immune responses suppressed by LPS but significantly increased circulating leukocytes.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.157-161
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• 2018

Liquid biopsy, the analysis of circulating biomarkers from peripheral blood, such as circulating tumor cells (CTCs) and circulating tumor DNA, and exosomes, offers a less invasive, new source of cancer-derived materials that may reflect the status of the disease better and thereby contribute to personalized treatment. Recent advances in microfluidics and molecular analysis technologies have resulted in greatly improved CTC enumeration and detection. In this article, we review commercially available technologies used to isolate CTCs from peripheral blood, including immunoaffinity and label-free, physical property-based isolation methods. Although enormous technological progress has been made, especially within the last decade, only a few CTC detection methods have been approved for routine clinical use. Here, we provide an overview of the current CTC isolation methods and examples of their potential application for early diagnosis, prognosis, treatment monitoring, and prediction of resistance to cancer therapy. Furthermore, the challenges that remain to be addressed before such tools are implemented for routine use in clinical settings are discussed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8429-8433
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• 2014

Circulating tumor cells (CTCs) are believed to be particularly important and a reliable marker of malignancy. However, the prognostic significance of CTCs detected in patients with small cell lung cancer (SCLC) is still unclear. We therefore aimed to assess the prognostic relevance of CTCs using a meta-analysis. We searched PubMed for relevant studies and statistical analyses were conducted to calculate the hazard ratio (HR) and 95% confidence intervals (CIs) using fixed or random-effect models according to the heterogeneity of included studies. A total of 7 papers covering 440 SCLC patients were combined in the final analysis. The meta-analysis revealed that CTCs were significantly associated with shorter overall survival (HR=1.9; 95%CI: 1.19-3.04; Z=2.67; P<0.0001) and progression-free survival (HR=2.6; 95%CI: 1.9-3.54; Z=6.04; P<0.0001). The results thus suggest that the presence of CTCs indicates a poor prognosis in patients with SCLC. Further well-designed prospective studies are required to explore the clinical applications of CTCs in SCLC.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.460-465
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• 2021

Background: Metastasis and recurrence of primary cancer are the main causes of cancer mortality. Disseminated tumor cells refer to cancer cells that cause metastasis from primary cancer to other organs. Several recent studies have suggested that circulating tumor cells (CTCs) are associated with the clinical stage, cancer recurrence, cancer metastasis, and prognosis. There are several methods of isolating CTCs from whole blood; in particular, using a membrane filtration system is advantageous due to its cost-effectiveness and availability in clinical settings. In this study, an animal model of lung cancer was established in nude mice using the human large cell lung cancer cell line H460. Methods: Six-week-old nude mice were used. The H460 lung cancer cell line was injected subcutaneously into the nude mice. Blood samples were obtained from the orbital area before cell line injection, 2 weeks after injection, and 2 weeks after tumor excision. Blood samples were filtered using a polycarbonate 12-well Transwell membrane (Corning Inc., Corning, NY, USA). An indirect immunofluorescence assay was performed with the epithelial cell adhesion molecule antibody. The number of stained cells was counted using fluorescence microscopy. Results: The average size of the tumor masses was 35.83 mm. The stained cells were counted before inoculation, 2 weeks after inoculation, and 2 weeks after tumor excision. Cancer cells generally increased after inoculation and decreased after tumor resection. Conclusion: The CTC detection method using the commercial polycarbonate 12-well Transwell (Corning Inc.) membrane is advantageous in terms of cost-effectiveness and convenience.

• BMB Reports
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• v.57 no.6
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• pp.273-280
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• 2024

Cancer cells metastasize to distant organs by altering their characteristics within the tumor microenvironment (TME) to effectively overcome challenges during the multistep tumorigenesis. Plasticity endows cancer cell with the capacity to shift between different morphological states to invade, disseminate, and seed metastasis. The epithelial-to-mesenchymal transition (EMT) is a theory derived from tissue biopsy, which explains the acquisition of EMT transcription factors (TFs) that convey mesenchymal features during cancer migration and invasion. On the other hand, adherent-to-suspension transition (AST) is an emerging theory derived from liquid biopsy, which describes the acquisition of hematopoietic features by AST-TFs that reprograms anchorage dependency during the dissemination of circulating tumor cells (CTCs). The induction and plasticity of EMT and AST dynamically reprogram cell-cell interaction and cell-matrix interaction during cancer dissemination and colonization. Here, we review the mechanisms governing cellular plasticity of AST and EMT during the metastatic cascade and discuss therapeutic challenges posed by these two morphological adaptations to provide insights for establishing new therapeutic interventions.