• Journal of Microbiology and Biotechnology
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• v.32 no.5
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• pp.551-563
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• 2022

L-asparaginase (E.C. 3.5.1.1) purified from bacterial cells is widely used in the food industry, as well as in the treatment of childhood acute lymphoblastic leukemia. In the present study, the Burkholderia pseudomallei L-asparaginase gene was cloned into the pGEX-2T DNA plasmid, expressed in E. coli BL21 (DE3) pLysS, and purified to homogeneity using Glutathione Sepharose chromatography with 7.26 purification fold and 16.01% recovery. The purified enzyme exhibited a molecular weight of ~33.6 kDa with SDS-PAGE and showed maximal activity at 50℃ and pH 8.0. It retained 95.1, 89.6%, and 70.2% initial activity after 60 min at 30℃, 40℃, and 50℃, respectively. The enzyme reserved its activity at 30℃ and 37℃ up to 24 h. The enzyme had optimum pH of 8 and reserved 50% activity up to 24 h. The recombinant enzyme showed the highest substrate specificity towards L-asparaginase substrate, while no detectable specificity was observed for L-glutamine, urea, and acrylamide at 10 mM concentration. THP-1, a human leukemia cell line, displayed significant morphological alterations after being treated with recombinant L-asparaginase and the IC₅₀ of the purified enzyme was recorded as 0.8 IU. Furthermore, the purified recombinant Lasparaginase improved cytotoxicity in liver cancer HepG2 and breast cancer MCF-7 cell lines, with IC₅₀ values of 1.53 and 18 IU, respectively.

• Clinical and Experimental Vaccine Research
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• v.12 no.4
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• pp.319-327
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• 2023

Purpose: Patients with hematological malignancies are at an increased risk of severe infection with coronavirus disease 2019 (COVID-19). However, developing an adequate immune response after vaccination is difficult, especially in patients with lymphoid neoplasms. Since the long-term effects of the BNT162b2 vaccine are unclear, the humoral immune response 5 months after the two vaccinations in patients with hematological disorders was analyzed. Materials and Methods: Samples were collected from 96 patients vaccinated twice with BNT162b2 and treated with at least one line of an antitumor or immunosuppressive drug in our hospital from November 2021 to February 2022. Serum anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) spike (S) antibody titers were analyzed. Patients were age- and sex-matched using propensity matching and compared with a healthy control group. Patients with serum anti-SARS-CoV-2 S antibodies were defined as 'responder' if >50 U/mL. The patients had B-cell non-Hodgkin lymphoma (B-NHL), multiple myeloma, chronic myeloid leukemia, etc. Results: Patients had significantly low antibody levels (median, 55.3 U/mL vs. 809.8 U/mL; p<0.001) and a significantly low response rate (p<0.001). Multivariate analysis showed that patients with B-NHL, aged >72 years, were associated with a low response to vaccination. There were no significant differences between patients with chronic myeloid leukemia and healthy controls. Conclusion: Our study shows that patients with hematological disorders are at risk of developing severe COVID-19 infections because of low responsiveness to vaccination. Moreover, the rate of antibody positivity differed between the disease groups. Further studies are warranted to determine an appropriate preventive method for these patients, especially those with B-NHL.

• The Journal of Internal Korean Medicine
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• v.26 no.2
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• pp.291-301
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• 2005

Objective : Anticancerous and host safety effects of the combination of Astragali Radix and chlorambucil are studied when it is applied to leukemia cell(P388D1 cell) related disease. Methods : After 5 groups of mice are treated by respective procedures (HG, CHL, HG+CHL, etc), the quantitative analyses (cell proliferation assay, mutagenesis test, survival rate, weight shift observation, tissue and blood analyses, etc) are conducted. Results : While sole injection of Astragali Radix extends the survival period and deter the liver and marrow function deterioration, combined injection (HG+CHL) shows more strong anticancerous effect than sole injection of Astragali Radix or Cholrambucil, and also does not cause any mutation on the normal cells and virulence on marrow and liver caused by leukemia. Conclusions : The combined application of Astragali Radix and chlorambucil has more effective anticancerous and host safety effects than independent use of them.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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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.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.150-153
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• 2011

Betulinic acid (BA), a naturally occurring triterpene found in the bark of the white birch tree, has been investigated to induce apoptosis in various cancer cells and animal models. However, there is no report of the chemopreventive effect of BA in cervical cancer cells. Using KB human cervical cancer cells as a model, we currently show that BA decreases cell viability and induces apoptotic cell death. The mechanism of the BA-induced anti-growth response in KB cells is due to the down-regulation of specificity protein 1 (Sp 1) and its downstream targets, myeloid cell leukemia-1(Mcl-1) and survivin. Thus, BA acts as a novel chemopreventive agent through the regulation of Sp1 that is highly expressed in tumors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1408-1414
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• 2008

The anticancer properties of Scolopendra subspinipes mutilans extract were investigated. The extract from S. subspinipes mutilans by 80% EtOH was fractionated with n-hexane, dichloromethan ($CH_2Cl_2$), ethylacetate (EtOAc), and butanol (BuOH) in order. The EtOAc fraction showed the highest inhibitory activity (about 80%) against human leukemia (HL-60) cell growth at $50\;{\mu}g/mL$. To explore the mechanism of cytotoxicity, we used several measures of apoptosis to determine whether these processes were involved in EtOAc fraction-induced HL-60 cell death. Our results showed EtOAc fraction induced cell shrinkage, cell membrane blebbing, apoptotic body, and DNA fragmentation. The EtOAc fraction gradually decreased the expression of anti-apoptotic Bcl-xL and led to the activation of caspase-3, -9 and cleavage of PARP. These findings suggest that S. subspinipes mutilans exhibits potential anticancer properties.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.903-907
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• 2005

Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1399-1404
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• 2006

The roots of Aralia continentalis (AC) have been used traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we report that the ethyl acetate-soluble traction (ACE) of the methanolic extract of AC root inhibited the cell growth of various human cancer cell lines and induced apoptosis of HL-60, human promyelocytic leukemia cells. Its $IC_{50}$ values on growth inhibition were estimated to be $56.3{\mu}g/ml$ on HL-60, $87.2{\mu}g/ml$ on HepG2, $93.2{\mu}g/ml$ on HeLa, $135.5{\mu}g/ml$ on DU-145, and $135.8{\mu}g/ml$ on HT-29 cells. Interestingly, ACE showed no antiproliferative effect on normal lymphocyte cells used as control. Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HL-60 cells exposed to $80{\mu}g/ml$ ACE, and a flow cytometric analysis of the HL-60 cells using propidium iodide showed that the apoptotic cell population increased gradually from 5% at 0 h to 16% at 12 h and 20% at 24 h after treated with $50{\mu}g/ml$ of ACE. TUNEL assay also revealed the apoptotic induction of the HL-60 cells treated with ACE. To obtain further information on the ACE-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HL-60 cells with ACE resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). The above results confirmed that the apoptosis in the HL-60 cells was induced by ACE, and that caspase-3-mediated PARP cleavage was involved in the process.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.3
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• pp.395-401
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• 1998

We have synthesized new platinum(II) analogs containing 1,2-diaminocyclohexane (dach) as a carrier ligand, 1,3-bis(diphenylphosphino) propane (DPPP) /1,2-bis(diphenylphosphino)ethane (DPPE) as a leaving group and nitrates to improve solubility. In the present study, the cytotoxicity of $[Pt(trans-l-dach)(DPPP)]\;2NO_3$ (KHPC-001) and $[Pt(trans-l-dach)(DPPE)]\;2NO_3$ (KHPC-002) was evaluated and compared on various P-388 cancer cell lines and porcine kidney cell line ($LLC-PK_1$). The new platinum complexes demonstrated high efficacy on P-388 mouse leukemia cell line as well as cisplatin-resistant (P-388/CDDP) and adriamycin-resistant (P-388/ADR) P-388 cell lines. The intracellular platinum content was measured by a flame atomic absorption spectrophotometer (FAAS), and it was comparable to the results of $IC_{50}$ of the three complexes on $LLC-PK_1$ and P-388/S cells, while only DPPE compound was accumulated in high volume in P-388/ADR and P-388/CDDP cells. While the DNA-interstrand cross-links of KHPC-001, KHPC-002 and cisplatin were similar on P-388/S leukemia cells, these new platinum complexes were much less DNA cross-linking to a kidney derived cell line, $LLC-PK_1$. These results indicate that KHPC-001 and KHPC-002 are a third-generation platinum complexes with potent antitumor activity and low nephrotoxicity.

• The Journal of Traditional Korean Medicine
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• v.15 no.1
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• pp.83-89
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• 2006

Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer. Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-Inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly. The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.