• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.139-147
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• 2019

Stem cells are progenitor cells that are capable of self-renewal and differentiation into various cells. Especially, pluripotent stem cells (PSCs) have in vivo and in vitro differentiation capacity into three germ layers and can proliferate infinitely. The differentiation ability of PSCs can be applied for regenerative medicine and tissue engineering. In domestic animals, their PSCs have a potential for preclinical therapy as well as the production of transgenic animals and agricultural usage such as cultured meat. Among several domestic animals, a pig is considered as an ideal model for biomedical and agricultural purposes mentioned above. In this reason, studies for pig PSCs including embryonic stem cells (ESCs), embryonic germ cells (EGCs) and induced pluripotent stem cells (iPSCs) have been conducted for decades. Therefore, this review will discuss the history of PSCs derived from various origins and recent progress in pig PSC research field.

• Biomedical Science Letters
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• v.25 no.2
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• pp.159-169
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• 2019

Breast cancer stem cells (BCSCs) in breast cancer cells have self-renewal ability and differentiation potential. They are also resistant to drugs after chemotherapy. To overcome this resistance, we designed negatively charged 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG)-based liposomes for drug delivery. These liposomes have enhanced the therapeutic effects of a range of antitumor therapies by increasing the cellular uptake and improving drug delivery to targets sites. In this study, we investigated whether DMPG-POPC liposomes, including the neutral lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholin (POPC), can specifically bind to MCF-7 breast cancer cells and increase cellular uptake compared with that by CHOL-POPC liposomes. We also estimated the cytotoxicity of DMPG-POPC liposomes encapsulated with both metformin (Met) and sodium salicylate (Sod) against breast cancer cells and BCSCs compared with that of the free drugs. Our results demonstrated that these dual drug-encapsulated liposomes significantly enhanced the cytotoxic and anti-colony formation abilities compared with individual drug-encapsulated liposomes or free drugs in BCSCs. Overall, our results suggest that DMPG-POPC liposomes containing two drugs (Met + Sod) show promise for synergistic anti-cancer therapy of breast cancer by increasing drug delivery efficiency into breast cancer cells and BCSCs.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.126-140
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• 2022

Stem cells can be applied usefully in basic research and clinical field due to their differentiation and self-renewal capacity. The aim of this study was to establish an effective novel therapeutic cellular source and create its molecular expression profile map to elucidate the possible therapeutic mechanism and signaling pathway. We successfully obtained a mesenchymal stem cell population from human embryonic stem cells (hESCs) cultured on chemically defined feeder-free conditions and treated with connective tissue growth factor (CTGF) and performed the expressive proteomic approach to elucidate the molecular basis. We further selected 12 differentially expressed proteins in CTGF-induced hESC-derived mesenchymal stem cells (C-hESC-MSCs), which were found to be involved in the metabolic process, immune response, cell signaling, and cell proliferation, as compared to bone marrow derived-MSCs(BM-MSCs). Moreover, these up-regulated proteins were potentially related to the Wnt/β-catenin pathway. These results suggest that C-hESC-MSCs are a highly proliferative cell population, which can interact with the Wnt/β-catenin signaling pathway; thus, due to the upregulated cell survival ability or downregulated apoptosis effects of C-hESC-MSCs, these can be used as an unlimited cellular source in the cell therapy field for a higher therapeutic potential. Overall, the study provided valuable insights into the molecular functioning of hESC derivatives as a valuable cellular source.

• Journal of Nutrition and Health
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• v.37 no.5
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• pp.406-414
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• 2004

The purposes of this study were 1) to investigate the importance level on factors affecting the foodservice management contract perceived by the clients in the office building, government and public offices and manufacturing company in Seoul and Kyungi 2) to compare the perceived importance levels of the present contract and future contract 3) to compare the perceived importance levels of the competitive bid with those of the private contract. To collect the data on the perceived importance level on the affecting the foodservice management contract, the questionnaires were developed by the delphi technique and modified by the pilot test. The questionnaires consisted of 4 categories and 19 items on the factors affecting the foodservice management contract and the importance level on the factors were measured by 5-likert scale. From March 12 to April 13 in 2003, the self-administrative questionnaires were mailed to 280 clients. The questionnaires were responded from the 50 clients (respondent rate: 25％). On the factors affecting the present contract and the future contract, among the 4 categories (the appropriateness of foodservice operation plan, the evaluation of the foodservice company, sales ability, the conditions of the cost in the contract), the importance level of the appropriateness of foodservice operation plan was higher than those of the other categories. In the comparison of the perceived importance level between the present contract and the future contract, the importance level of 4 items (sanitation and safety management plan, menu management plan, service management plan, food cost per meal) in the future contract were significantly higher than those in the present contract (p＜.01, p＜.05, p＜.05, p＜.01). There were the significant differences between the private contract and competitive bid on the factors affecting the present contract in the 3 items, which were $\ulcorner$renewal plan for interior and environment$\lrcorner$, $\ulcorner$strategic alliance with the contractor$\lrcorner$, $\ulcorner$lobby of the foodservice company$\lrcorner$ (p＜.05, p＜.05, p＜.05). And on the factors affecting the future contract, there were significant differences in the 2 items, which were $\ulcorner$renewal plan for interior and environment$\lrcorner$and $\ulcorner$cost per meal$\lrcorner$in comparing the competitive bid and private contract (p＜.05, p＜.01). The clients perceived the appropriateness of foodservice operation plan was more important than the other categories in the future foodservice management contract. It was proposed that the foodservice management contract company should focus on the foodservice operation to satisfy the customers and clients in order to get more contract in the future.

• Reproductive and Developmental Biology
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• v.37 no.3
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• pp.143-148
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• 2013

Spermatogenesis is initiated from spermatogonial stem cells (SSCs) that has an ability of self-renewal and unipotency to generate differentiating germ cells. The objective of this study is to develop the simple method for derivation of SSCs using non-sorting of both spermatogonia and feeder cells. Simply uncapsulated mouse testes were treated with enzymes followed by surgical mincing, and single cells were cultured in stempro-$34^{TM}$ cell culture media at $37^{\circ}C$. After 5 days of culture, aciniform of SSC colony was observed, and showed a strong alkaline phosphatase activity. Molecular characterization of mouse SSCs showed that most of the mouse SSC markers such as integrin ${\alpha}6$ and ${\beta}1$, CD9 and Stra8. In addition, pluripotency embryonic stem cell (ESC) marker Oct4 were expressed, however Sox2 expression was lowered. Interestingly, expression of SSC markers such as Vasa, Dazl and PLZF were stronger than mouse ESC (mESC). This data suggest that generated mouse SSCs (mSSCs) in this study has at least similar biomarkers expression to mESC and mSSCs derived from other study. Immunocytochemistry using whole mSSC colony also confirmed that mSSCs generated from this study expressed SSC specific biomarkers such as c-kit, Thy1, Vasa and Dazl. In conclusion, mSSCs from 5 days old mouse testes were successfully established without sorting of spermatogonia, and this cells expressed both mESC and SSC specific biomarkers. This simple derivation method for mSSCs may facilitate the study of spermatogenesis.

• Molecules and Cells
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• v.43 no.4
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• pp.384-396
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• 2020

Breast cancer is one of the most common life-threatening malignancies and the top cause of cancer deaths in women. Although many conventional therapies exist for its treatment, breast cancer still has many handicaps to overcome. Cancer stem cells (CSCs) are a well-known cause of tumor recurrences due to the ability of CSCs for self-renewal and differentiation into cell subpopulations, similar to stem cells. To fully treat breast cancer, a strategy for the treatment of both cancer cells and CSCs is required. However, current strategies for the eradication of CSCs are non-specific and have low efficacy. Therefore, surface biomarkers to selectively treat CSCs need to be developed. Here, 34 out of 641 surface biomarkers on CSCs were identified by proteomic analysis between the human breast adenocarcinoma cell line MCF-7 and MCF-7-derived CSCs. Among them, carcinoembryonic antigen-related cell adhesion molecules 6 (CEACAM6 or CD66c), a member of the CEA family, was selected as a novel biomarker on the CSC surface. This biomarker was then experimentally validated and evaluated for use as a CSC-specific marker. Its biological effects were assessed by treating breast cancer stem cells (BCSCs) with short hairpin (sh)-RNA under oxidative cellular conditions. This study is the first to evaluate the biological function of CD66c as a novel biomarker on the surface of CSCs. This marker is available as a moiety for use in the development of targeted therapeutic agents against CSCs.

• Korean journal of food and cookery science
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• v.20 no.5
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• pp.423-435
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• 2004

The purposes of this study were to compare, through a factor analysis, the perceived level of importance of 4 categories of features relating to food service management between salespeople and clients, to establish an effective marketing strategy for successful contracting. To obtain data on the perceived level of importance level of the factors affecting foodservice management contracts, questionnaires were developed using the Delphi technique, which were modified by apilot test. The questionnaires consisted of 4 categories and 19 items on the factors affecting foodservice management contracts, with the importance level of these factors measured on a 5 point-Likert type scale. Between March 12 and April 13 2003, the self-administrative questionnaires were mailed to the 60 salespeople and 280 clients. A total of 50 clients (25%) and 48 salespeople(77%) responded to the questionnaires. As a result, forprivate contracts and in competitive biding, the differences of the perceived importance level between the salespeople and clients of the 3 categories (the appropriateness of foodservice operation plan, sales ability, the conditions and costs of the contract) were significant. For the 5 items relating to private contracts, Field trip, Menu Management Plan, Sanitation and Safety Management, Cost per meal and Food Cost per meal, both the salespeople and clients perceived high levels of importance for all these items. For competitive biding, both the salespeople and clients perceived high levels of importance for the 6 item the Foodservice operation supportive system, Field trip, Menu Management Plan, Renewal plans for interior and environment, Cost per meal and Food Cost per meal.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5579-5587
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• 2013

Research indicates that a small population of cancer cells is highly tumorigenic, endowed with the capacity for self-renewal, and has the ability to differentiate into cells that constitute the bulk of tumors. These cells are considered the "drivers" of the tumorigenic process in some tumor types, and have been named cancer stem cells (CSC). Epithelial-mesenchymal transition (EMT) appears to be involved in the process leading to the acquisition of stemness by epithelial tumor cells. Through this process, cells acquire an invasive phenotype that may contribute to tumor recurrence and metastasis. CSC have been identified in human head and neck squamous cell carcinomas (HNSCC) using markers such as CD133 and CD44 expression, and aldehyde dehydrogenase (ALDH) activity. Head and neck cancer stem cells reside primarily in perivascular niches in the invasive fronts where endothelial-cell initiated events contribute to their survival and function. Clinically, CSC enrichment has been shown to be enhanced in recurrent disease, treatment failure and metastasis. CSC represent a novel target of study given their slow growth and innate mechanisms conferring treatment resistance. Further understanding of their unique phenotype may reveal potential molecular targets to improve therapeutic and survival outcomes in patients with HNSCC. Here, we discuss the state-of-the-knowledge on the pathobiology of cancer stem cells, with a focus on the impact of these cells on head and neck tumor progression, metastasis and recurrence due to treatment failure.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.761-766
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• 2012

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.2
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• pp.133-141
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• 2008

Stem cells have self-renewal capacity, long-term viability, and multiline age potential. Adult bone marrow contains mesenchymal stem cells. Bone marrow-derived mesenchymal stem cells (BMSCs) are progenitors of skeletal tissue components and can differentiate into adipocytes, chondrocytes, osteoblasts, and myoblasts in vitro and undergo differentiation in vivo. However, the clinical use of BMSCs has presented problems, including pain, morbidity, and low cell number upon harvest. Recent studies have identified a putative stem cell population within the adipose tissue. Human adipose tissue contains pluripotent stem cells simillar to bone marrow-derived stem cells that can differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. Human adipose tissue-derived stem cells (ATSCs) could be proposed as an alternative source of adult bone marrow stem cells, and could be obtained in large quantities, under local anesthesia, with minimal discomfort. Human adipose tissue obtained by liposuction was processed to obtain ATSCs. In this study, we compared the osteogenic differentiation of ATSCs in a specific osteogenic induction medium with that in a non-osteogenic medium. ATSCs were incubated in an osteogenic medium for 28 days to induce osteogenesis respectively. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific bone sialoprotein, osteocalcin, collagen type I and alkaline phosphatase, bone morphogenic protein 2, bone morphogenic protein 6 was confirmed by RT-PCR. ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. Since this cell population can be easily identified through fluorescence microscopy, it may be an ideal source of ATSCs for further experiments on stem cell biology and tissue engineering. The present results show that ADSCs have an ability to differentiate into osteoblasts. In the present study, we extend this approach to characterize adipose tissue-derived stem cells.