• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.107-107
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• 2003

The activation of protooncogenes or the inactivation of their gene products may be a specific and effective functional study for human neoplasia. To examine this possibility, we have used the tetracycline regulatory system to generate transgenic mice that conditionally express the HccR-2 protooncogene in vivo. The new human cervical cancer protooncogene (HccR-2) was detected from cervical cancer cell line. To elucidate its biological functions, we generated transgenic mice that expressed the HccR-2 gene. The sustained expression of the HccR-2 transgene culminated chronic neutrophilic leukemia (CNL). CNL is a rare chronic myeloproliferative disorder that presents as a sustained, mature neutrophilic leukocytosis with few or no circulating immature granulocytes, the absence of peripheral blood monocytosis, basophilia, or eosinophilia, and infiltration of neutrophils at the liver, spleen and kidney. Mice expressing the HccR-2 and tetracycline-transactivating protein (tTa) transgene were found to have altered myeloid development that was characterized by increased percentages of mature neutrophil and band form neutrophil in the peripheral blood, liver and spleen. Activation of the transgene causes CNL. In our model, expression of HccR-2 transgene mice was similar in many respects to the human CNL. This model will be valuable not only for investigating the biological properties of the HccR-2 and other protooncogenes in vivo but also for analyzing the mechanism involved in the progression of CNL.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4773-4780
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• 2014

Background: To investigate the effects of small interference RNA (siRNA) targeting BCR/ABL mRNA on proliferation and apoptosis in the K562 human chronic myeloid leukemia (CML) cell line and to provide a theoretical rationale and experimental evidence for its potential clinical application for anti-CML treatment. Materials and Methods: The gene sequence for BCR/ABL mRNA was found from the GeneBank. The target gene site on the BCR/ABL mRNA were selected according to Max-Planck-Institute (MPI) and rational siRNA design rules, the secondary structure of the candidate targeted mRNA was predicted, the relevant thermodynamic parameters were analyzed, and the targeted gene sequences were compared with BLAST to eliminate any sequences with significant homology. Inhibition of proliferation was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry (FCM) and the morphology of apoptotic cells was identified by Giemsa-Wright staining. Western blotting was used to analyze the expression of BCR/ABL fusion protein in K562 cells after siRNA treatment. Results: The mRNA local secondary structure calculated by RNA structure software, and the optimal design of specific siRNA were contributed by bioinformatics rules. Five sequences of BCR/ABL siRNAs were designed and synthesized in vitro. Three sequences, siRNA1384, siRNA1276 and siRNA1786, which showed the most effective inhibition of K562 cell growth, were identified among the five candidate siRNAs, with a cell proliferative inhibitory rate nearly 50% after exposure to 12.5nmol/L~50nmol/L siRNA1384 for 24,48 and 72 hours. The 50% inhibitory concentrations ($IC_{50}$) of siRNA1384, siRNA1276 and siRNA1786 for 24hours were 46.6 nmol/L, 59.3 nmol/L and 62.6 nmol/L, respectively, and 65.668 nmol/L, 76.6 nmol/L, 74.4 nmol/L for 72 hours. The colony-formation inhibiting test also indicated that, compared with control, cell growth of siRNA treated group was inhibited. FCM results showed that the rate of cell apoptosis increased 24 hours after transfecting siRNA. The results of annexinV/PI staining indicated that the rate of apoptosis imcreased (1.53%, 15.3%, 64.5%, 57.5% and 21.5%) following treamtne with siRNAs (siRNA34, siRNA372, siRNA1384, siRNA1276 and siRNA1786). Morphological analysis showed td typical morphologic changes of apoptosis such as shrunken, fragmentation nucleus as well as "apoptotic bodies" after K562 cell exposure to siRNA. Western blot analysis showed that BCR/ABL protein was reduced sharply after a single dose of 50nmol/L siRNA transfection. Conclusions: Proliferation of K562 cells was remarkbly inhibited by siRNAs (siRNA1384, siRNA1276 and siRNA1786) in a concentration-dependent manner in vitro, with effective induction of apoptosis at a concentration of 50 nmol/L. One anti-leukemia mechanism in K562 cells appeared that BCR/ABL targeted protein was highly down-regulated. The siRNAs (siRNA1384, siRNA1276 and siRNA1786) may prove valuable in the treatment of CML.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2159-2164
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• 2016

Background: A diagnosis of chronic myeloid leukemia (CML) is made on discovery of the presence of a Philadelphia (Ph) chromosome. The success of the treatment of this form of leukemia with tyrosine kinase inhibitor (TKI) is monitored by reduction of the Ph chromosome. Objective: To compare the role of conventional cytogenetic (CC) methods with a real time quantitative polymerase chain reaction (RQ-PCR) and fluorescence in situ hybridization (FISH) for diagnosis and treatment monitoring of CML patients. The secondary outcome was to analyze the treatment responses to TKI in CML patients. Materials and Methods: This was a retrospective study of CML patients who attended the Hematology clinic at Chiang Mai University Hospital from 2005-2010. Medical records were reviewed for demographic data, risk score, treatment response and the results of CC methods, FISH and RQ-PCR. Results: One hundred and twenty three cases were included in the study, 57.7% of whom were male with a mean age of 46.9 years. Most of the patients registered as intermediate to high risk on the Sokal score. At diagnosis, 121 patients were tested using the CC method and 118 (95.9%) were identified as positive. Five patients failed to be diagnosed by CC methods but were positive for BCR-ABL1 using the FISH method. Imatinib was the first-line treatment used in 120 patients (97.6%). In most patients (108 out of 122, 88.5%), a complete cytogenetic response (CCyR) was achieved after TKI therapy and in 86 patients (70.5%) CCyR was achieved long term by the CC method. Five out of the 35 analyzed patients in which CCyR was achieved by the CC method had a positive FISH result. Out of the 76 patients in which CCyR was achieved, RQ-PCR classified patients to only CCyR in 17 patients (22.4%) with a deeper major molecular response (MMR) in 4 patients (5.3%) and complete molecular response (CMR) in 55 patients (72.4%). In the case of initial therapy, CCyR was achieved in 95 patients (79.1%) who received imatinib and in both patients who received dasatinib (100%). For the second line treatment, nilotinib were used in 30 patients and in 19 of them (63.3%) CCyR was achieved. In half of the 6 patients (50%) who received dasatinib as second line or third line treatment CCyR was also achieved. Conclusions: CML patients had a good response to TKI treatment. FISH could be useful for diagnosis in cases where CC analysis failed to detect the Ph chromosome. RQ-PCR was helpful in detecting any residual disease and determining the depth of the treatment response at levels greater than the CC methods.

• Archives of Pharmacal Research
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• v.29 no.1
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• pp.80-87
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• 2006

Leukemias are common worldwide. Wilms'tumor1 (WT1) protein is highly expressed in leukemic blast cells of myeloid and lymphoid origin. Thus, WT1 mRNA serves as a tumor marker for leukemias detection and monitoring disease progression. Curcumin is well known for its anticancer property. The objective of this study was to investigate the effect of curcumin on WT1 gene expression in patient leukemic cells. The leukemic cells were collected from 70 childhood leukemia patients admitted at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand, in the period July 2003 to February 2005. There were 58 cases of acute lymphoblastic leukemia (ALL), 10 cases of acute myeloblastic leukemia (AML), and 2 cases of chronic myelocytic leukemia (CML). There were 41 males and 29 females ranging from 1 to 15 years old. Leukemic cells were cultured in the presence or absence of 10 mM curcumin for 48 h. WT1 mRNA levels were determined by RT-PCR. The result showed that curcumin reduced WT1 gene expression in the cells from 35 patients (50%). It affected the WT1 gene expression in 4 of 8 relapsed cases (50%), 12 of 24 cases of drug maintenance (50%), 7 of 16 cases of completed treatment (44%), and 12 of 22 cases of new patients (54%). The basal expression levels of WT1 gene in leukemic patient cells as compared to that of K562 cells were classified as low level (1-20%) in 6 of 20 cases (30%), medium level (21-60%) in 12 of 21 cases (57%), and high level (61-100%) in 17 of 23 cases (74%). In summary, curcumin decreased WT1 mRNA in patient leukemic cells. Thus, curcumin treatment may provide a lead for clinical treatment in leukemic patients in the future.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4555-4561
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• 2014

Background: Silencing due to methylation of suppressor of cytokine signaling-3 (SOCS-3), a negative regulator gene for the JAK/STAT signaling pathway has been reported to play important roles in leukemogenesis. Imatinib mesylate is a tyrosine kinase inhibitor that specifically targets the BCR-ABL protein and induces hematological remission in patients with chronic myeloid leukemia (CML). Unfortunately, the majority of CML patients treated with imatinib develop resistance under prolonged therapy. We here investigated the methylation profile of SOCS-3 gene and its downstream effects in a BCR-ABL positive CML cells resistant to imatinib. Materials and Methods: BCR-ABL positive CML cells resistant to imatinib (K562-R) were developed by overexposure of K562 cell lines to the drug. Cytotoxicity was determined by MTS assays and $IC_{50}$ values calculated. Apoptosis assays were performed using annexin V-FITC binding assays and analyzed by flow cytometry. Methylation profiles were investigated using methylation specific PCR and sequencing analysis of SOCS-1 and SOCS-3 genes. Gene expression was assessed by quantitative real-time PCR, and protein expression and phosphorylation of STAT1, 2 and 3 were examined by Western blotting. Results: The $IC_{50}$ for imatinib on K562 was 362nM compared to 3,952nM for K562-R (p=0.001). Percentage of apoptotic cells in K562 increased upto 50% by increasing the concentration of imatinib, in contrast to only 20% in K562-R (p<0.001). A change from non-methylation of the SOCS-3 gene in K562 to complete methylation in K562-R was observed. Gene expression revealed down-regulation of both SOCS-1 and SOCS-3 genes in resistant cells. STAT3 was phosphorylated in K562-R but not K562. Conclusions: Development of cells resistant to imatinib is feasible by overexposure of the drug to the cells. Activation of STAT3 protein leads to uncontrolled cell proliferation in imatinib resistant BCR-ABL due to DNA methylation of the SOCS-3 gene. Thus SOCS-3 provides a suitable candidate for mechanisms underlying the development of imatinib resistant in CML patients.

• Journal of Yeungnam Medical Science
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• v.40 no.3
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• pp.283-288
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• 2023

Severe chronic neutropenia is classified as severe congenital, cyclic, autoimmune, or idiopathic. However, there is a lot of uncertainty regarding the diagnosis of severe congenital neutropenia (SCN) and chronic idiopathic neutropenia, and this uncertainty affects further evaluations and treatments. A 20-year-old man presented with fever and knee abrasions after a bicycle accident. On admission, his initial absolute neutrophil count (ANC) was 30/µL. He had no medical history of persistent severe neutropenia with periodic oscillation of ANC. Although his fever resolved after appropriate antibiotic therapy, ANC remained at 80/µL. Bone marrow (BM) aspiration and biopsy were performed, and a BM smear showed myeloid maturation arrest. Moreover, genetic mutation test results showed a heterozygous missense variant in exon 4 of the neutrophil elastase ELANE: c597+1G>C (pV190-F199del). The patient was diagnosed with SCN. After discharge, we routinely checked his ANC level and monitored any signs of infection with minimum use of granulocyte colony-stimulating factor (G-CSF), considering its potential risk of leukemic transformation. Considering that SCN can be fatal, timely diagnosis and appropriate management with G-CSF are essential. We report the case of a patient with SCN caused by ELANE mutation who had atypical clinical manifestations. For a more accurate diagnosis and treatment of severe chronic neutropenia, further studies are needed to elucidate the various clinical features of ELANE.

• Journal of Gastric Cancer
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• v.7 no.4
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• pp.237-241
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• 2007

Purpose: Patients with hematologic diseases such as chronic myeloid leukemia (CML) or chronic lymphoid leukemia (CLL) are known to have an increased chance of acquiring a secondary neoplasm. Stomach cancer is one of the most common malignant diseases in Korea, and we investigated whether the incidence of secondary stomach cancer in patients with a hematologic disease increases, in order to determine if a more intensive screening program for detecting secondary gastric cancer was required. We also investigated the safety of performing a gastrectomy in hematologic disease patients. Materials and Methods: From 1992 to 2006, the medical records of 8376 patients diagnosed with one of the six common hematologic diseases were reviewed. Results: Nine secondary stomach cancers were found among the 8376 patients during the 15-year observation period. No surgical-related complications occurred, and there was no recurrence of stomach cancer if detected early. Conclusion: It seems that a more intensive screening program for detecting secondary gastric cancer in hematologic disease patients is not required, and surgery is not risky in these patients.

• Development and Reproduction
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• v.21 no.2
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• pp.139-150
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• 2017

Metformin is the most commonly prescribed anti-diabetic drug with relatively minor side effect. Substantial evidence has suggested that metformin is associated with decreased cancer risk and anticancer activity against diverse cancer cells. The tyrosine kinase inhibitor imatinib has shown powerful activity for treatment of chronic myeloid leukemia and also induces growth arrest and apoptosis in colorectal cancer cells. In this study, we tested the combination of imatinib and metformin against HCT15 colorectal cancer cells for effects on cell viability, cell cycle and autophagy. Our data show that metformin synergistically enhances the imatinib cytotoxicity in HCT15 cells as indicated by combination and drug reduction indices. We also demonstrate that the combination causes synergistic down-regulation of pERK, cell cycle arrest in S and $G_2/M$ phases via reduction of cyclin B1 level. Moreover, the combination resulted in autophagy induction as revealed by increased acidic vesicular organelles and cleaved form of LC3-II. Inhibition of autophagic process by chloroquine led to decreased cell viability, suggesting that induction of autophagy seems to play a cell protective role that may act against anticancer effects. In conclusion, our present data suggest that metformin in combination with imatinib might be a promising therapeutic option in colorectal cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3375-3376
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• 2013

• Korean journal of aerospace and environmental medicine
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• v.31 no.3
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• pp.61-63
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• 2021

In Vol. 31, No. 3, our journal prepared three review articles, an original paper, and two case reports. First, as COVID-19 continues for a long time, aviation workers, including pilots, are also experiencing mental problems such as depression. Therefore, we have compiled the basic principles for improving the mental health of pilots. Next, it is difficult to properly perform cardio-pulmonary resuscitation (CPR) when a cardiac arrest situation occurs in an aircraft. Moreover, in the context of the COVID-19 pandemic, CPR is more difficult because medical staff and other passengers may also be exposed to infections. Therefore, we have summarized the principles of CPR on board and ways to perform CPR while keeping the safety of medical staff and other passengers in the COVID-19 situation. The sudden change of gravity caused by space travel has various effects on the human body, and among them, the effect on the immune system is profound. Therefore, we reviewed the research methods to study the effect of gravity on the immune system and the results. In addition, we analyzed the demographic characteristics and health status of immigrant visa applicants who intended to immigrate to the United States over the past five years. Next, through two case reports, we reported cases of determining physical fitness for aviation service in patients who recovered after receiving appropriate treatment for chronic myeloid leukemia or renal cell carcinoma.