• IMMUNE NETWORK
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• 제6권4호
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• pp.179-184
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• 2006

Background: Identification of antigen-specific T cells has yielded valuable information on pathologic process and the disease state. Assays for quantification of inflammatory cytokines or lytic-granule molecules have been generally used to evaluate antigen specific T cell response, however their applicability have been hampered due to the limited source of autologous antigen-presenting target cells (APC). Methods: K562, a leukemic cell line deficient of human leukocyte antigen (HLA), was transfected with a gene encoding HLA-A*02 (K562/ A*02) and its function as stimulator cells in inducing activation of HLA-matched T cells was evaluated by IFN-${\gamma}$ enzyme linked immunospot (ELISPOT) assay. Results: The stable transfectant K562/ A*02 pulsed with HLA- A*02 restricted peptide could specifically induce IFN-${\gamma}$ secretion by CD8+ T cells compared to no detectable secretion by CD4+ T cells. However, CD56+ NK cells secreted IFN-${\gamma}$ in both K562/ A*02 with peptide and without peptide. The number of IFN-${\gamma}$ secreted CD8+ T cells was increased according to the ratio of T cells to K562 and peptide concentration. Formalin-fixed K562/ A*02 showed similar antigen presenting function to live K562/ A*02. Moreover, K562/ A*02 could present antigenicpeptide to not only A*0201 restricted CD8+ T cells but also CD8+ T cells from A*0206 donor. Conclusion: These results suggest that K562/ A*02 could be generally used as target having specificity and negligible background for measuring CD8+ T cell responses and selective use of K562 with responsder matched HLA molecules on its surface as APC may circumvent the limitation of providing HLA-matched autologous target cells.

• 대한한방내과학회지
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• 제27권1호
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• pp.166-177
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• 2006

Objectives : This study was performed to determine if Orostschys japonicus A. Berger has protective effects against CML in K562 cell lines. Materials and Methods : MTT assay, cell proliferation assay, Reverse transcription-polymerase reaction chain, RT-PCR, DNA fragmentation assay, Quantitative PCR were studied. Results : Orostschys japonicus A. Berger had no effects on Bax gene in K562 cell lines, but decreased Bcl-2 gene, and increased the Caspases-3 gene. This is indicate of induced apoptosis in K562 cell lines by Orostschys japonicus A. Berger. Conclusion : These results suggest that Orostschys japonicus A. Berger has effects on apatosis in K562 cell lines.

• IMMUNE NETWORK
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• 제7권2호
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• pp.80-86
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• 2007

Background: CD40-activated B (CD40-B) cells might be an attractive source of autologous antigen-presenting cells (APCs) for immunotherapy due to the convenience to obtain from peripheral blood and expand in vitro. Moreover, CD40-B cells were found to be comparable with DCs in their capacity to raise antigen-specific CD8+ T cells. Here, we have established K562 cells expressing CD40L to expand CD40-activated B cells used for APCs. Methods: After activation of B cell by K562/CD40L, CD40-B cells were examined by counting B cell numbers. Surface expression of CD54, CD80, CD86 and HLA class II was measured by flow cytometry. The CD40-B cells were tested for its function as APC by mixed lymphocyte reactions (MLR) and by induction of T cell responses specific for pp65 peptide in vitro. Results: The expansion of B cells by K562/CD40L increased about 6-folds compared with anti-CD40 or K562. Furthermore, the expression of CD54, CD80, CD86 and HLA class II was up-regulated by K562/CD40L. B cells by K562/CD40L showed comparable antigen presentation activity with mature DCs as shown in MLR, INF-${\gamma}$ ELISPOT assay. Conclusion: These results suggest that K562/CD40L could be used to generate activated B cells as potent APCs which could be useful for cellular vaccination and adoptive immunotherapy.

• 대한핵의학회지
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• 제37권3호
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• pp.178-189
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• 2003

목적: 다약제내성이 유발된 암세포에서 $^{99m}Tc-sestamibi$와 $^{99m}Tc-tetrofosmin$의 암세포 내 섭취정도를 비교하고 다약제내성 극복제로 잘 알려진 verapamil 과 cyclosporin A 처리에 의한 두 방사성 의약품의 암세포 내 섭취정도를 비교해 보았다. 재료 및 방법: Doxorubicin으로 다약제내성이 유발된 HCT15/CL02 대장암 세포와 doxorubicin과 vincristine으로 다약제내성을 유발시킨 K562(Adr)과 K562(Vcr) 백혈병 세포를 사용하였다. 다약제내성의 발현은 RT-PCR로 증명하였으며, verapamil은 1, 10, 50, 100, 200 ${\mu}M$의 농도로, cyclosporin A는 0.1, 10, 50, 100 ${\mu}M$의 농도로 각각 사용하였다. MIBI와 tetrofosmin의 암세포내 섭취는 $37^{\circ}C$에서 $1{\times}10^{6}cells/ml$ 농도의 단일세포 부유상태에서 1, 15, 30, 45, 60분 간격으로 배양하여 각 시간대별로 상층액과 침전물을 분리하여 각각의 방사능을 감마 계수기로 측정하였다. 결과: 다약제내성이 발현된 암세포에서는 모세포에 비하여 MIBI와 tetrofosmin의 섭취가 감소되었다. 두 방사성약품의 섭취정도는 HCT15/CL02세포와 K562(Adr)세포에서는 유의한 차이가 없었으나, K562(Vcr)세포에서는 MIBI가 tetrofosmin보다 다소 높았다. Verapamil과 cyclosporin A를 처리하였을 때 MIBI와 tetrofosmin의 섭취율은 기저치보다 모두 증가하였고, verapamil 에 의한 MIBI와 tetrofosmin의 섭취율(30분)을 기저치(30분)와 비교해 본 결과 HCT15/CL02 세포에서($100{\mu}M$)는 각각 11.9배와 6.8배, K562(Adr) 세포에서($50{\mu}M$)는 각각 14.3배와 8배, K562(Vcr) 세포에서($10{\mu}M$)는 각각 7배와 5.7배 증가하였다. Cyclosporin A에 의한 MIBI와 tetrofosmin의 섭취율(30분)을 기저치(30분)와 비교해 본 결과 HCT15/CL02세포에서($50{\mu}M$)는 각각 10배와 2.4배, K562(Adr)세포에서($50{\mu}M$)는 각각 44배와 13배, K562(Vcr)세포에서($10{\mu}M$)는 각각 18.8배와 11.8배 증가하여, MIBI의 섭취율이 tetrofosmin보다 1.2배에서 4배정도 높게 나타났다. 결론: 이러한 결과로 보아 MIBI와 tetrofosmin은 다약제내성의 발현을 평가할 수 있는 방사성의약품으로 판단되며, 다약제내성 극복제의 효능평가에는 MIBI가 tetrofosmin보다 더 우수할 것으로 사료되나, 세포추에 따른 차이가 있을 수 있으므로 보다 많은 세포주에서의 추가적인 연구가 필요할 것이다.

• 대한임상검사과학회지
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• 제39권2호
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• pp.68-75
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• 2007

약 100년 전에 박테리아가 암을 억제한다는 보고를 바탕으로 다양한 미생물이 항암효과를 가지는 백신 개발에 이용되거나 또는 미생물의 세포 밖 독소 단백질을 찾아내고 있다. Psuedomonas aeruginosa exotoxin A(ETA)는 암세포에서 세포성장을 억제하고 세포 죽음을 유발하는 것으로 알려져 있다. 하지만 ETA가 세포 자멸사를 유도하는 정확한 기전은 아직 알려져 있지 않다. 따라서 본 연구에서는 세포자멸사의 유도를 확인하기 위해 K562 cell을 이용하여 세포의 형태학적 변화, 세포독성, Annexin-V binding assay 그리고 세포주기를 분석하였으며, 그 결과로 ETA는 K-562세포에서의 세포증식과 성장을 억제하였고, 세포자멸사 기작을 통한 K-562 암세포의 사멸을 일으켰음을 관찰하였다. 또한 flow cytometric analysis에서는 ETA가 세포주기 중 특히 sub-G1 기를 정지시키는 것으로 나타났다. 본 연구는 ETA가 인간 백혈병 K-562 암세포의 세포성장을 억제하고 sub-G1 기를 정지시킴으로서 세포자멸사를 유도하고 있음을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권11호
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• pp.4857-4861
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• 2016

Background: Imatinib mesylate, a tyrosine kinase inhibitor specifically targeting the BCR/ABL fusion protein, induces hematological remission in patients with chronic myeloid leukemia (CML). However, the majority of CML patients treated with imatinib develop resistance with prolonged therapy. Dendrophthoe pentandra (L.) Miq. is a Malaysian mistletoe species that has been used as a traditional treatment for several ailments such as smallpox, ulcers, and cancers. Methods: We developed a resistant cell line (designated as K562R) by long-term co-culture of a BCR/ABL positive CML cell line, K562, with imatinib mesylate. We then investigated the anti-proliferative effects of D. pentandra methanol extract on parental K562 and resistant K562R cells. Trypan blue exclusion assays were performed to determine the IC50 concentration; apoptosis and cell cycle analysis were conducted by flow cytometry. Results: D. pentandra extract had greater anti-proliferative effects towards K562R ($IC50=192{\mu}g/mL$) compared to K562 ($500{\mu}g/mL$) cells. Upon treatment with D. pentandra extract at the IC50. concentration: K562 but not K562R demonstrated increase in apoptosis and cell cycle arrest in the G2/M phase. Conclusion: D. pentandra methanol extract exerts potent anti-proliferative effect on BCR/ABL positive K562 cells.

• 대한수의학회지
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• 제29권2호
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• pp.51-57
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• 1989

This study was performed to investigate the toxicity of ochratoxin A (OA) to the chromosomes of $K_{562}$ tumor cell-line in vitro. The results of this experiment were as follows: 1) Chromosomes of $K_{562}$tumor cell-line resulted in pseudotriploidy on the control group. Chromosomes of $K_{562}$ tumor cell-line treated with OA resulted in heteroploidy compared with the control group. The mean number of chromosomes in the karyotype of the control group (60) were 7 in the A group, 5 in the B group, 20 in the C+X group, 7 in the D group, 9 in the E group, 6 in the F group, and 6 in the G+Y group respectively. The number of chromosomes were increased as follows: Treating with $0.7{\mu}M$ OA, the number of chromosomes were increased one in E and F group, two in G+Y group compared with control group. In treated with $1.5{\mu}M$ OA, the increasing number of chromosome was one in E and F group. In treated with $3{\mu}M$ OA, E and F group was increased one and G+Y group were increased two chromosomes compared with control group. But in treated with $6{\mu}M$ OA, the number of chromosome in G+Y group was decreased one. 2) $K_{562}$ tumor cell line treated with OA showed Philadelphia-Chromosome in the long arm of the G group karyotype chromosome. The rate of chromosome aberration in $K_{562}$ tumor cell-line treated with OA was 77% in $0.7{\mu}M$ OA group, 71% in $1.5{\mu}M$ OA group, 82% in $3{\mu}M$ OA group and 94% in $6{\mu}M$ OA group respectively. The rate of chromosome aberration of $K_{562}$ tumor cell-line treated with OA was high in the high dose level of OA, and chromosome aberration of $K_{562}$ tumor cell-line treated with OA showed deletion, minute, dicentric-chromosome and translocation in the long arm of the C-group karyotype. As a result of this study, the toxicity of OA showed deletion, minute, dicentric-chromosome and translocation in the long arm of the C-group karyotype, and then, the toxicity of OA resulted in the damage to RNA and protein synthesis in $K_{562}$ tumor cell-line, and the C-group karyotype of $K_{562}$ tumor cell-line was target of the toxicity of OA.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7501-7508
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• 2013

Background: Chronic myeloid leukemia (CML) is a myeloproliferative disorder of hematopoietic stem cell scarrying the Philadelphia (Ph) chromosome and an oncogenic BCR-ABL1 fusion gene. The tyrosine kinase inhibitor (TKI) of BCR-ABL1 kinase is a treatment of choice for control of CML. Objective: Recent studies have demonstrated that miRNAs within exosomes from cancer cells play crucial roles in initiation and progression. This study was performed to assess miRNAs within exosomes of K562 cells. Methods: miRNA microarray analysis of K562 cells and K562 cell-derived exosomes was conducted with the 6th generation miRCURYTM LNA Array (v.16.0). Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were also carried out. GO terms and signaling pathways were categorized into 66 classes (including homophilic cell adhesion, negative regulation of apoptotic process, cell adhesion) and 26 signaling pathways (such as Wnt). Results: In exosomes, 49 miRNAs were up regulated as compared to K562 cells, and two of them were further confirmed by quantitative real-time PCR. There are differentially expressed miRNAs between K562 cell derived-exosomes and K562 cells. Conclusion: Selectively expressed miRNAs in exosomes may promote the development of CML via effects on interactions (e.g. adhesion) of CML cells with their microenvironment.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9131-9136
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• 2014

ELDF15, homologous with AT2 receptor-interaction protein 1 (ATIP1), may play an important role in cell differentiation, proliferation, and carcinogenesis. We aimed to understand the biological function of ELDF15 via construction and transfection of a recombinant expression vector containing antisense ELDF15. Recombinant expression vectors were successfully constructed and transfected into K562 cells. A stable transfectant, known as pXJ41-asELDF15, stably produced antisense ELDF15. Compared with K562 and K562-zeo cells, K562-pXJ41-asELDF15 cells showed inhibition of cell proliferation. RT-PCR analysis showed that the expression and protein level of ELDF15 decreased significantly in K562 cells transfected with pXJ41-asELDF15. Expression of hemoglobin increased in K562 cells transfected with pXJ41-asELDF15 by benzidine staining. increases NBT reduction activity in K562 cells transfected with pXJ41-asELDF15.Colony forming efficiency in two-layer soft agar was clearly inhibited as assessed by electron microscopy. These results suggest that ELDF15 plays a potential role in cell differentiation, proliferation and carcinogenesis.

• 한국동물학회지
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• 제39권1호
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• pp.12-20
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• 1996

K562 적혈구암 세포는 phorbol 12-myristate 13-acetate(PMA)에 의해서 대핵세포로 분화되고 gpIlla의 증가, megakaryocyte와 유사한 형태학적 변화로 특징지워진다. 또한 K562 세포는 dimethy1 sulfoxide(DMSO)나 butyrate와 같은 화학적 유도원에 의해 적혈구로 분화가 유도되고 동시에 헤모글로빈이 축척된다. 본 연구에서는 K562 세포에 대한 단일클론 항체를 생성하고 이를 이용하고 61 KDa의 표면항원을 동정하였다. 단클론항체 EK-2에 의해 인지되는 61 KDa의 표면항원은 sialic acide가 풍부해 당단백질로 사료되고, 그 epitope는 neuraminidase 절단과 peroxidase oxidation에 민감하며, 열처리에는 안정하다. K562 세포의 대핵세포로 분화시에는 61 KDa 표면항원의 발현은 증가하며, 적혈구로 분회시에는 그 발현이 감소한다. EK-2 단클론항체는 조혈세포의 분화 및 암화과정의 분자적 수준을 연구하기 위한 면역학적 probe로 이용 가능할 것으로 기대된다.