• Biomolecules & Therapeutics
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• 제25권5호
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• pp.490-496
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• 2017

Imatinib resistance has become a major clinical problem for chronic myeloid leukemia. The aim of the present study was to investigate the involvement of MEG3, a lncRNA, in imatinib resistance and demonstrate its underlying mechanisms. RNAs were extracted from CML patients' peripheral blood cells and human leukemic K562 cells, and the expression of MEG3 was measured by RT-qPCR. Cell proliferation and cell apoptosis were evaluated. Western blotting was used to measure the protein expression of several multidrug resistant transporters. Luciferase reporter assay was performed to determine the binding between MEG3 and miR-21. Our results showed that MEG3 was significantly decreased in imatinib-resistant CML patients and imatinib-resistant K562 cells. Overexpression of MEG3 in imatinib-resistant K562 cells markedly decreased cell proliferation, increased cell apoptosis, reversed imatinib resistance, and reduced the expression of MRP1, MDR1, and ABCG2. Interestingly, MEG3 binds to miR-21. MEG3 and miR-21 were negatively correlated in CML patients. In addition, miR-21 mimics reversed the phenotype of MEG3-overexpression in imatinib-resistant K562 cells. Taken together, MEG3 is involved in imatinib resistance in CML and possibly contributes to imatinib resistance through regulating miR-21, and subsequent cell proliferation, apoptosis and expression of multidrug resistant transporters.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.311-317
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• 1999

Human T-cell leukemia virus Type-I (HTLV-I) is etiologically associated with rare adult T-cell leukemia, a malignant T-cell disorder. cDNAs encoding p24 (gag), gp21(env), and pXII of HTLV-I were amplified by polymerase chain reaction (PCR) using the genomic DNA extracted from HUT102 cell line as a template. The amplified cDNAs were cloned into the Escherichia coli expression vectors and over-expression of the recombinant proteins were achieved by adding IPTG into the culture media in order to induce the promoter. The molecular weights of the recombinant p24, gp21, and pXII, determined by SDS-PAGE, were found to be approximately 28 kDa, 23 kDa, and 15 kDa, respectively. Reactivity of the recombinant proteins with human sera was tested by the immunoblot assay. The gp21 and p24 reacted against the sera obtained from HTLV-I-infected individuals but not against the sera obtained from normal persons. These results suggest that the recombinant proteins expressed in E. coli were recognized by antibodies in sera from HTLV-I infected patients. These recombinant proteins would be applicable for detecting the presence of antibodies against HTLV-I in human blood samples.

• Toxicological Research
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• 제25권3호
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• pp.113-118
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• 2009

Cell death induced by menadione (vitamin K-3,2-methyl-1,4-naphthoquinone) has been investigated in human promyelocytic leukemia HL-60 cells. Menadione was found to induce both apoptosis and necrosis in HL-60 cells. Low concentration ($1{\sim}$50 ${\mu}$M) of menadione induced apoptotic cell death, which was demonstrated by typical DNA ladder patterns on agarose gel electrophoresis and flow cytometry analysis. In contrast, a high concentration of menadione (100 ${\mu}$M) induced necrotic cell death, which was demonstrated by DNA smear pattern in agarose gel electrophoresis. Necrotic cell death was accompanied with a great reduction of cell viability. Menadione activated caspase-3, as evidenced by both increased protease activity and proteolytic cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) into 85 kDa cleavage product. Caspase-3 activity was maximum at 50 ${\mu}$M of menadione, and very low at 100 ${\mu}$M of menadione. Taken together, our results showed that menadione induced mixed types of cell death, apoptosis at low concentrations and necrosis at high concentrations in HL-60 cells.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6423-6428
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• 2015

The present study was designed to evaluate in vitro anti-proliferative potential of extracts from four Indian medicinal plants, namely Anogeissus latifolia, Terminalia bellerica, Acacia catechu and Moringa oleiferna. Their cytotoxicity was tested in nine human cancer cell lines, including cancers of lung (A549), prostate (PC-3), breast (T47D and MCF-7), colon (HCT-16 and Colo-205) and leukemia (THP-1, HL-60 and K562) by using SRB and MTT assays. The findings showed that the selected plant extracts inhibited the cell proliferation of nine human cancer cell lines in a concentration dependent manner. The extracts inhibited cell viability of leukemia HL-60 and K562 cells by blocking G0/G1 phase of the cell cycle. Interestingly, A. catechu extract at $100{\mu}g/mL$ induced G2/M arrest in K562 cells. DNA fragmentation analysis displayed the appearance of a smear pattern of cell necrosis upon agarose gel electrophoresis after incubation of HL-60 cells with these extracts for 24h.

• 생약학회지
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• 제33권1호통권128호
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• pp.29-34
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• 2002

Albizzia julibrissin belonging to the family Leguminosae has been used for the treatment of contusion, sore throat, amnesia, and insomnia in Oriental traditional medicine. The water extract of A. julibrissin induced apoptosis in Jurkat T-acute lymphoblastic leukemia (ALL) cells as measured by cell morphology. The capability of this herb medicine to induce apoptosis was associated with proteolytic cleavage of specific target protein such as beta-catenin protein suggesting the possible involvement of caspases. The purpose of the present study is also to investigate the effect of A. julibrissin on cell cycle progression. Our results showed that GI checkpoint related gene products (cyclin D1, cyclin dependent kinase 4, retinoblastoma, E2F1) were decreased in their protein levels in a dose-dependent manners after treatment of the extract. These results indicate that the increase of apoptotic cell death by A. julibrissin may be due to the inhibition of cell cycle progression in wild type p53-lacking Jurkat cells.

• 대한골관절종양학회지
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• 제6권2호
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• pp.98-105
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• 2000

골육종 환자에서 항암 화학요법 후 후기 합병증으로 발생하는 이차성 급성 골수성 백혈병은 드물지만 본 교실에서 한 증례를 경험하였기에 이를 보고하고자 한다. 1995년부터 1999년까지 골육종 진단후 항암 화학요법을 받은 77명의 환자중에서 이차적으로 발생한 급성 골수성 백혈병 1례를 경험하였고 이를 다른 문헌과 비교하여 원인 및 결과를 분석하였다. 17세 남자로 대퇴골 원위부의 골육종으로 진단받고 항암 화학요법 완료 후 28개월만에 환자의 혈액화학 검사상 백혈구의 심한 증가(20만개 이상)와 혈소판 감소를 보였고 골수 흡인생검 및 말초 혈액 도말 검사에서 단구양 미성숙 세포(monocytoid immature cell) 와 아세포(blast) 및 전단구 세포(promonocyte)의 심한 증가를 보여 항암 화학요법 후 이차적으로 발생한 급성 골수성 백혈병(AML M4)으로 진단하게 되었다. 항암화학 요법후 이차적으로 발생하는 급성 골수성 백혈병은 그 발생빈도는 미미하지만 조기 진단 및 치료가 이뤄지지 않으면 높은 이환률과 치사율을 보이는 치명적인 질환이며 발생가능성을 충분히 인식하고 항암 화학요법후 주기적 추시 관찰 및 적절한 검사 그리고 발병시 신속한 치료가 필요할 것으로 판단 된다.

• 보험의학회지
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• 제18권
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• pp.67-76
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• 1999

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2221-2224
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• 2013

The glutathione S-transferases (GSTs) are a family of enzymes involved in the detoxification of a wide range of chemicals, including important environmental carcinogens, as well as chemotherapeutic agents. In the present study 294 acute leukemia cases, comprising 152 of acute lymphocytic leukemia (ALL) and 142 of acute myeloid leukemia, and 251 control samples were analyzed for GSTM1 and GSTT1 polymorphisms through multiplex PCR methods. Significantly increased frequencies of GSTM1 null genotype (M0), GSTT1 null genotype (T0) and GST double null genotype (T0M0) were observed in the both ALL and AML cases as compared to controls. When data were analyzed with respect to clinical variables, increased mean levels of WBC, Blast %, LDH and significant reduction in DFS were observed in both ALL and AML cases with T0 genotype. In conclusion, absence of both GST M & GST T might confer increased risk of developing ALL or AML. The absence of GST enzyme might lead to oxidative stress and subsequent DNA damage resulting in genomic instability, a hallmark of acute leukemia. The GST enzyme deficiency might also exert impact on clinical prognosis leading to poorer DFS. Hence GST genotyping can be made mandatory in management of acute leukemia so that more aggressive therapy such as allogenic stem cell transplantation may be planned in the case of patients with a null genotype.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.347-350
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• 2012

TP53 is the mostly commonly mutated gene in many cancers and the P53 tumor suppressor protein is involved in multiple cellular processes, including transcription, DNA repair, genomic stability, senescence, cell cycle control and apoptosis. A common single nucleotide polymorphism located within the proline rich region of TP53 gene at codon 72 in exon 4 encodes either proline or arginine. TP53 Arg 72 is more active than TP53 Pro 72 in inducing apoptosis. The aim of this study was to understand the association of the 72 codon polymorphism with acute leukemia development and prognosis. A total of 288 acute leukemia cases comprising 147 acute lymphocytic leukemia (ALL) and 141 acute myeloid leukemia (AML), as well as 245 controls were recruited for analysis of the TP53 72 polymorphism using PCR-RFLP method. Significant association of homozygous arginine genotype with AML was observed (${\chi}^2$- 133.53; df-2, p < 0.001. When data were analyzed with respect to clinical variables, elevation in mean WBC, blast %, LDH levels and slight reduction in DFS in ALL cases with the arginine genotype was observed. In contrast, AML patients with Pro/Pro had elevated WBC, Blast%, LDH levels with slightly reduced DFS. Our study indicates that Arg/Arg genotype might confer increased risk to development of acute myeloid leukemia.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권6호
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• pp.535-540
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• 2009

Proliferation of abnormal hematopoietic cells with impaired differentiation, regulation and programmed cell death leads to leukemia. AML(acute myeloid leukemia) is a malignancy with malfunction of myeloid hematopoietic cells with acute behavior. The oral manifestations of the disease are posterior palate hemorrhage, gingival bleeding and gingival ulceration as a result of infection by normal oral flora and gingival infiltration by leukemic cells. A 49-year-old male patient was referred from local dental clinic. The patient was diagnosed with AML FAB M1 (acute myeloid leukemia French-American-British classification M1 myeloblastic leukemia without maturation). The oral infection focus was removed by a conservative treatment. 2 days after the dental treatment, the patient underwent chemotherapy. At 8-month follow-up, the overall outcome was excellent. Oral manifestations of AML are often the first indications of the malignancy. Therefore it is essential for dentists, especially oral and maxillofacial surgeons, to be aware of the diagnostic signs and complications associated with leukemia for better diagnosis and subsequent treatment and management.