• Title/Summary/Keyword: G1 progression

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Radiation Therapy Combined with Cisplatin Based Chemotherapy for the Patients with Locally Advanced Nasopharyngeal Cancer (국소 진행된 비인강암의 방사선-항암제 병용요법)

  • Son, Seok-Hyun;Kim, Ji-Yoon;Kim, Sung-Whan;Mun, Seong-Kwon;Cho, Seung-Ho;Park, Young-Hak;Hong, Young-Seon;Kim, Yeon-Sil
    • Korean Journal of Head & Neck Oncology
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    • v.22 no.2
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    • pp.123-129
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    • 2006
  • Objective : This retrospective study was designed to evaluate the anti-tumor efficacy and toxicities of the radiation therapy(RT) combined with cisplatin-based chemotherapy in locally advanced nasopharyngeal cancer(NPC). Materials and Methods : Fifty three patients with locally advanced NPCs(AJCC stage II, III, IV) received curative RT and cisplatin-based chemotherapy. Duration of follow-up ranged from 5.5 to 201 months(median 50.8 months). Nineteen patients(35.8%) were treated with induction chemotherapy including cisplatin $100mg/m^2$ for 1 day and 5-fluorouracil $1g/m^2$ for 5 days followed by RT(Induction CTx-RT). Another 34 patients (64.2%) were treated with concurrent chemoradiation(CCRT) using cisplatin $100mg/m^2$(D1, 22, 43). Results : Thirty-six(67.9%) and 11(20.8%) patients achieved clinical complete response and partial response, respectively. The pattern of failure was as follows:14 locoregional recurrence(26.4%) and 7 distant metastasis(13.2%). Among them, two patients(3.8%) had both locoregional and distant failure. Median overall survival(OS) and progression-free survival(PFS) were 85.5 months and 87.5 months, respectively. Five-year OS rate was 57.1%. The stage(AJCC), tumor response to chemoradiation and T stage were significant prognostic factors for OS(p=0.0113, p=0.0362 and p=0.0469). The stage(AJCC), tumor response to chemoradiation were also significant prognostic factors for PFS(p=0.0329, p=0.0424). Compared to each treatment group(Induction CTx-RT vs. CCRT), there were no significant differences in OS and PFS(p=0.7000, p=0.8261). Grade 3-4 mucositis, nausea/vomiting and hematological toxicities were noticed in 35.8%, 11.3% and 13.2%, respectively. Delayed RT over 2 weeks was inevitable in 26.5%. Seventeen patients(50%) successfully completed planned 3 courses of cisplatin in CCRT group. Conclusions : RT combined with cisplatin-based chemotherapy in locally advanced NPC showed high response rate, good locoregional control, and survival rate. As expected, frequency of acute toxicities increased, and the patient's compliance to treatment was need to be improved. Although our data could not show additional survival benefit of CCRT compare to that of induction chemotherapy followed by RT, patients' accrual and further follow-up are required due to limitation of retrospective study.

The Expression of Oncogenes on the Radiation-induced Apoptosis in SCK Mammary Adenocarcinoma Cell Line (SCK 선암세포주에서 방사선 조사에 의해 유도되는 Apoptosis에 미치는 암유전자의 발현)

  • Lee Hyung Sik;Park Hong Kyu;Moon Chang Woo;Yoon Seon Min;Hur Won Joo;Jeong Su Jin;Jeong Min Ho;Lee Sang Hwa
    • Radiation Oncology Journal
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    • v.17 no.1
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    • pp.70-77
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    • 1999
  • Purpose : The expression of p53, P211WAF/CIP, Bcl-2, and Bax underlying the radiation-induced apoptosis in different pH environments using SCK mammary adenocarcinoma cell line was investigated. Materials and Methods Mammary adenocarcinoma cells of hi) mice (SCK cells) in exponential growth phase were irradiated with a linear accelerator at room temperature. The cells were irradiated with 12 Gy and one hour later, the media was replaced with fresh media at a different pHs. After Incubation at 37Microbioiogy, College of Medicine Dong A University for 0$\~$48 h, the extort of apoptosis was determined using agarose gel electrophoresis and flow cytometry. The progression of cells through the cell cycle after irradiation in different pHs was also determined with flow cytometry. Western blot analysis was used to monitor p53, p211WAFfCIP, Bcl-2, and Bu protein levels. Results : The induction of apoptosis by irradiation in pH 6.6 medium was markedly less than that in pH 7.5 medium. The radiation-induced G2IM arrest in pH 6.6 medium lasted markedly longer than that in pH 7.5 medium. Considerable amounts of p53 and p21 proteins already existed at pH 7.5 and increased the level of p53 and p21 significantly after 12 Gy X-irradiation. An incubation at pH 6.6 after 12 Gy X-irradiation did not change the level of p53 and p21 protein levels significantly. Bcl-2 proteins were not significantly affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis in different pHs. An exposure to 12 Gy of X-rays increased the level of Bax protein at pH 7.5 but at pH 6.6, it was slight. Conclusions : The molecular mechanism underlying radiation-induced apoptosis in dinerent pH environments using SCK mammary adenocarcinoma cell line was dependent of the expression p53 and P211YVAF/CIP proteins. We may propose following hypothesis that an acidic stress augments the radiation-induced G2iM arrest, which inhibiting the irradiated cells undergo post-mitotic apoptosis. The effects of environmental acidity on anti-apoptotic and pro-apoptotic function of Bcl-2 family was unclear in SCK mammary adenocarcinoma cell line.

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Radiation-induced Apoptosis is Differentially Modulated by PTK Inhibitors in K562 Cells (K562 백혈병 세포주에서 방사선에 의해 유도되는 Apoptosis에 미치는 PTK Inhibitors의 영향)

  • Lee Hyung Sik;Moon Chang Woo;Hur Won Joo;Jeong Su Jin;Jeong Min Ho;Lee Jeong Hyeon;Lim Young kin;Park Heon Joo
    • Radiation Oncology Journal
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    • v.18 no.1
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    • pp.51-58
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    • 2000
  • Purpose :The effect of PTK inhibitors (herbimycin A and genistein) on the induction of radiation-induced apoptosis in Ph-positive KS62 leukemia cell line was investigated. Materials and Methods :K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For 6 MV X-ray irradiation and drug treatment, cultures were initiated at 2×106 cells/mL. The cells were irradiated with 10 Gy. Stock solutions of herbimycin A and genistein were prepared in dimethyl sulphoxide (DMSO). After incubation at 37$^{\circ}C$ for 0$\~$48 h, the extent of apoptosis was determined using agarose gel electrophoresis and TUNEL assay. The progression of cells through the cell cycle after irradiation and drug treatment was also determined with flow cytometry. Western blot analysis was used to monitor bel-2, bel-X$_{L}$ and bax protein levels. Results :Treatment with 10 Gy X-irradiation did not result in the induction of apoptosis. The HMA alone (500 nM) also failed to induce apoptosis. By contrast, incubation of K562 cells with HMA after irradiation resulted in a substantial induction of nuclear condensation and fragmentation by agarose gel electro-phoresis and TUNEL assay. Genistein failed to enhance the ability of X-irradiation to induce DNA fragmentation. Enhancement of apoptosis by HMA was not attributable to downregulation of the bel-2 or bel-X$_{L}$ anti-apoptotic proteins. When the cells were irradiated and maintained with HMA, the percentage of cells in G2/M phase decreased to 30$\~$40$\%$ at 48 h. On the other hand, cells exposed to 10 Gy X-irradiation alone or maintained with genistein did not show marked cell cycle redistribution. Conclusion : We have shown that nanomolar concentrations of the PTK inhibitor HMA synergize with X-irradiation in inducing the apoptosis in Ph (+) K562 leukemia cell line. While, genistein, a PTK inhibitor which is not selective for p210$^{bcr/abl}$ failed to enhance the radiation induced apoptosis in KS62 cells. It is unlikely that the ability of HMA to enhance apoptosis in K562 cells is attributable to bel-2 family. It is plausible that the relationship between cell cycle delays and cell death is essential for drug development based on molecular targeting designed to modify radiation-induced apoptosis.

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Effects of miR-152 on Cell Growth Inhibition, Motility Suppression and Apoptosis Induction in Hepatocellular Carcinoma Cells

  • Dang, Yi-Wu;Zeng, Jing;He, Rong-Quan;Rong, Min-Hua;Luo, Dian-Zhong;Chen, Gang
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.4969-4976
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    • 2014
  • Background: miR-152 is involved in the genesis and development of several malignancies. However, its role in HCC has not been fully clarified. The aim of this study was to investigate the clinicopathological significance of miR-152 and its effect on the malignant phenotype of HCC cells. Methods: miR-152 expression was detected using real-time quantitative RT-PCR in 89 pairs of HCC formalin-fixed paraffin-embedded and their adjacent tissues. Functionally, in vitro effects and mechanisms of action of miR-152 on proliferation, viability, caspase activity, apoptosis and motility were explored in HepG2, HepB3 and SNU449 cells, as assessed by spectrophotometry, fluorimetry, fluorescence microscopy, wound-healing and Western blotting, respectively. Results: miR-152 expression in HCC was downregulated remarkably compared to that in adjacent hepatic tissues. miR-152 levels in groups of advanced clinical stage, larger tumor size and positive HBV infection, were significantly lower than in other groups. A miR-152 mimic could suppress cell growth, inhibit cell motility and increase caspase activity and apoptosis in HCC cell lines. Furthermore, Western blotting showed that the miR-152 mimic downregulated Wnt-1, DNMT1, ERK1/2, AKT and TNFRS6B signaling. Intriguingly, inverse correlation of TNFRF6B and miR-152 expression was found in HCC and bioinformatics confirmed that TNFRF6B might be a target of miR-152. Conclusions: Underexpression of miR-152 plays a vital role in hepatocarcinogenesis and lack of miR-152 is related to the progression of HCC through deregulation of cell proliferation, motility and apoptosis. miR-152 may act as a tumor suppressor miRNA by also targeting TNFRSF6B and is therefore a potential candidate biomarker for HCC diagnosis, prognosis and molecular therapy.

Autophagy Inhibition with Monensin Enhances Cell Cycle Arrest and Apoptosis Induced by mTOR or Epidermal Growth Factor Receptor Inhibitors in Lung Cancer Cells

  • Choi, Hyeong Sim;Jeong, Eun-Hui;Lee, Tae-Gul;Kim, Seo Yun;Kim, Hye-Ryoun;Kim, Cheol Hyeon
    • Tuberculosis and Respiratory Diseases
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    • v.75 no.1
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    • pp.9-17
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    • 2013
  • Background: In cancer cells, autophagy is generally induced as a pro-survival mechanism in response to treatment-associated genotoxic and metabolic stress. Thus, concurrent autophagy inhibition can be expected to have a synergistic effect with chemotherapy on cancer cell death. Monensin, a polyether antibiotic, is known as an autophagy inhibitor, which interferes with the fusion of autophagosome and lysosome. There have been a few reports of its effect in combination with anticancer drugs. We performed this study to investigate whether erlotinib, an epidermal growth factor receptor inhibitor, or rapamycin, an mammalian target of rapamycin (mTOR) inhibitor, is effective in combination therapy with monensin in non-small cell lung cancer cells. Methods: NCI-H1299 cells were treated with rapamycin or erlotinib, with or without monensin pretreatment, and then subjected to growth inhibition assay, apoptosis analysis by flow cytometry, and cell cycle analysis on the basis of the DNA contents histogram. Finally, a Western blot analysis was done to examine the changes of proteins related to apoptosis and cell cycle control. Results: Monensin synergistically increases growth inhibition and apoptosis induced by rapamycin or erlotinib. The number of cells in the sub-$G_1$ phase increases noticeably after the combination treatment. Increase of proapoptotic proteins, including bax, cleaved caspase 3, and cleaved poly(ADP-ribose) polymerase, and decrease of anti-apoptotic proteins, bcl-2 and bcl-xL, are augmented by the combination treatment with monensin. The promoters of cell cycle progression, notch3 and skp2, decrease and p21, a cyclin-dependent kinase inhibitor, accumulates within the cell during this process. Conclusion: Our findings suggest that concurrent autophagy inhibition could have a role in lung cancer treatment.

The Effect of Atorvastatin on the Development of Puromycin Aminonucleoside(PAN)-induced Nephrosis in Rats (Puromycin을 투여한 백서에서 지질 변화가 신증의 진행에 미치는 영향)

  • Choi Kwang-Hae;Chung Hyo-Seuk;Kim Yong-Jin;Ha Jeong-Hee;Kim Heung-Sik;Park Yong-Hoon
    • Childhood Kidney Diseases
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    • v.7 no.1
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    • pp.9-15
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    • 2003
  • Purpose : Several studies have suggested that hyperlipidemia might be a causative factor contributing to the progression of initial glomerular injury through the development of glomerulosclerosis. We examined the potential beneficial effect of atorvastatin - which blocks the rate limiting step of cholesterol synthesis by inhibiting HMG-CoA reductase - in PAN-induced nephrosis. Materials and Methods : Glomerulosclerosis was induced in Sprague-Dawley male rats by repeated administration of PAN. Sprague-Dawley male rats were divided into 3 groups : group I(control), group II(PAN 20 mg/kg, subcutaneous injection), group III(PAN 20 mg/kg subcutaneous injection and atorvastatin 50 mg/kg/day per oral). On the 11th week, upon sacrifice of the experimental animals, blood sampling, 24-hr urine collection and nephrectomy were performed. Results : Group III had significantly lower BUN and higher serum albumin($30.9{\pm}17.2\;vs.\;17.3{\pm}2.5\;mg/dL;\;2.3{\pm}0.1\;vs.\;2.5{\pm}0.2\;g/dL$, P<0.05) compared with group II. In the lipid profiles, group III was associated with a reduction in total cholesterol and LDL($291{\pm}173\;vs.\;167{\pm}72\;mg/dL:\;57{\pm}53\;vs.\;27{\pm}12\;mg/dL$, P>0.05) compared with group II. Atorvastatin administration lowered the glomerular sclerosing index significantly(26.2% vs. 13.3%, P<0.05). Conclusion : Puromycin-induced glomerulosclerosis could be ameliorated by the reduction of hyperlipidemia with atorvastatin. This suggests that hyperlipidemia contributes to the pathogenesis of glomerulosclerosis.

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Effects of an Extract from the Roots of Platycodon Grandiflorum on the Levels of p53 and pRB in NCI-H460 Human Lung Carcinoma Cells (길경 수용액 추출물에 의한 NCI-H460 인체 폐암세포의 p53 및 pRB의 발현에 미치는 영향)

  • Park, Bong-Kyu;Gam, Chul-Woo;Heo, Tae-Yool;Park, Dong-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.6
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    • pp.1530-1537
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    • 2006
  • Platycodi Radix, the root of Platycodon grandiflorum A. DC (Campanulaceae), commonly known as Doraji in Korea (Chinese name, 'Jiegeng', and Japanese name, 'Kikyo') has been used as an expectorant in traditional Oriental medicine. Extracts from the roots of P. grandiflorum have been reported to have wide ranging health benefits. In Korea, Platycodi Radix is also used as a food and employed as a folk remedy for adult diseases, such as bronchitis, asthma and pulmonary tuberculosis, hyperlipidemia, diabetes, and inflammatory diseases, and as a sedative. Several studies on its chemical and immunopharmacological effects including immunostimulation and antitumor activity have been performed. However, the relevant molecular mechanisms are poorly understood. Platycodi Radix, the root of Platycodon grandiflorum A. DC (Campanulaceae), commonly known as Doraji in Korea (Chinese name, 'Jiegeng', and Japanese name, 'Kikyo') has been used as an expectorant in traditional Oriental medicine. Extracts from the roots of P. grandiflorum have been reported to have wide ranging health bensfits. In Korea, Platycodi Radix is also used as a food and employed as a folk remedy for adult diseases, such as bronchitis, asthma and pulmonary tuberculosis, hyperlipidemia, diabetes, and inflammatory diseases, and as a sedative. Several studies on its chemical and immunopharmacological effects including immunostimulation and antitumor activity have been performed. However, the relevant molecular mechanisms are poorly understood. In the present study, we investigated the effects of an aqueous extract from the roots of P. grandiflorum AEPG) on the cell growth of human lung adenocarcinoma NCI-H460 cells in order to understand its anti-proliferative mechanism. AEPG treatment down-regulated the cyclin D1 expression in both transcriptional and translational levels without alteration of cyclin E. In AEPG-treated cells, the levels of cyclin-dependent kinase (C아) 6 mRNA and protein were significantly inhibited, but the levels of Cdk2 and Cdk4 were slightly inhibited by treatment of AEPG. AEPG treatment induced a marked accumulation of Cdk inhibitors, p16 and p27. However, AEPG treatment did not affect not only retinoblastoma protein (pRB) but also tumor suppressor p53 protein expression. The present results indicated that AEPG-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1 phase progression through induction of Cdk inhibitors such as p16 and p27, and inhibition of cyclin D1 and Cdk6. AEPG exposure, as offered by this study, provides cluse for the mechanism of AEPG action. Taken together, these findings suggest that P. grandiflorum has strong potential for development as an agent for prevention and treatiment against human lung cancer.

Effect of endothelin receptor blockade on monocrotaline-induced pulmonary hypertension in rats (Monocrotaline으로 유발한 백서 폐동맥 고혈압에서 Endothelin 수용체 차단제 투여의 효과)

  • Lim, Kyoung Ah;Shim, Jung Yun;Cho, Sang Ho;Kim, Kwan Chang;Han, Jae Jin;Hong, Young Mi
    • Clinical and Experimental Pediatrics
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    • v.52 no.6
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    • pp.689-695
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    • 2009
  • Purpose : To examine the effect of bosentan, a dual endothelin receptor (ER) antagonist, on the development of monocrotaline (MCT)-induced pulmonary hypertension in rats by especially focusing on the pulmonary vascular morphology changes. Methods : Sprague-Dawley rats were treated as follows: controls received a subcutaneous saline injection, MCT-treated rats received a subcutaneous MCT injection, and bosentan-treated rats received a MCT injection followed by treatment with bosentan (20 mg/kg/day). To assess the effects of ER blockade on the time course, the animals were exsanguinated, and their hearts and lungs were dissected after 7, 14, or 28 days. Results : The mean body weights of the MCT- and bosentan-treated rats were significantly lower than that of the control rats on days 7, 14, and 28. Bosentan administration significantly inhibited the progression of right ventricular hypertrophy on day 28 (right ventricle/[left ventricle+septum]: $0.71{\pm}0.10$ in MCT-treated rats vs. $0.49{\pm}0.09$ in bosentan-treated rats; P<0.05). Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan-treated rats on day 28 ($49.96{\pm}10.06%$ in MCT-treated rats vs. $47.09{\pm}10.48%$ in bosentan-treated rats; P<0.05). In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on days 14 and 28. Conclusion : Bosentan administration in intermediate doses exerts inhibitory effects on lung vascular hypertrophy and right ventricular hypertrophy during the development of MCT-induced pulmonary hypertension in rats.

Young Rabbit Model for Pathophysiologic Study of Acute Lung Injury in Early Childhood (유아기 급성폐손상 병태생리 연구를 위한 어린 토끼 실험모델)

  • 권영민;최석철;박종원;김양원;이양행;황윤호;조광현
    • Journal of Chest Surgery
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    • v.36 no.8
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    • pp.545-558
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    • 2003
  • Adult respiratory distress syndrome (ARDS) is of particular interest because of its severity of the associated lung injury and its high mortality. However, the pathophysiologies of ARDS in infant and childhood groups are still not well clarified inspite of many previous investigations. To investigate the time course of pathophysiology of ARDS in infant and childhood groups, this study was designed with experimental endotoxin-induced ARDS model using young rabbits (8 week-old). Material and Method: Rabbits were divided into the control group (n=8) and the endotoxin-treated group (n=32). The endotoxin group was subdivided into 4 groups by the sampling times as 3, 6, 12 and 24 hr-groups (G- $E_{3,6,12,24,}$ each n=8). The experimental ARDS was made by a bolus injection of endotoxin (Escherichia coli serotype 055 : B5, 0.50 mg/kg) via rabbit ear vein. For evaluation of the hematologic and inflammatory markers, and superoxide dismutase (SOD) concentrations, the blood samples were taken from the heart. The bronchoalveolar lavage fluid (BALF) were obtained for analysis of the leukocytes and protein concentration. With biopsy of the lung, histopathologic changes of the lung were also evaluated. Result: In the endotoxin groups, significant leukopenia (owing to pancytopenia) occurred in 3 and 6-hr groups, which was followed by significant leukocytosis (owing to neutrophilia) in the 12 and 24-hr groups (p<0.05). Serum levels of tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and interleukin-1 $\beta$ (IL-1 $\beta$) in the endotoxin groups were higher than those of control group (p<0.05). Serum levels of superoxide dismutase (SOD) of G- $E_{3}$ and G- $E_{6}$ were higher than those of control group, whereas those of G- $E_{12}$ were lower than those of control groups (p<0.05). Total leukocyte counts and protein con-centrations in BALF were significantly elevated in the endotoxin groups compared to the control group (p < 0.05). The hemorrhagic pattern of BALF showed occurred in the endotoxin groups. The endotoxin groups (in G- $E_{6}$) had severe infiltration of inflammatory cells (lymphocyte and monocyte) in the pulmonary interstitium and parenchyma, migrations of neutrophil and eosinophil into alveolar spaces and interstitial widening, which are the evidences of acute lung injury. In the endotoxin groups, there were significant positive correlations between the BALF findings and the immunologic markers (TNF-$\alpha$, IL-1$\beta$, SOD) (p<0.05). Conclusion: Severe acute lung injury occurred in all the endotoxin-treated rabbits. The pathophysiologic findings were so progressive until 6-hr by time dependant pattern, and then recovered slowly, Variable hematologic, immuno-logic, and pathologic factors were well correlated in the development and progression of endoxin-induced lung injury. The pathophysiologic responses were sensitive and rapid in young rabbit Young rabbit seemed to be a useful experimental animal model for infant and childhood groups.roups.

Regulatory Mechanism of Insulin-Like Growth Factor Binding Protein-3 in Non-Small Cell Lung Cancer (비소세포성 폐암에서 인슐린 양 성장 인자 결합 단백질-3의 발현 조절 기전)

  • Chang, Yoon Soo;Lee, Ho-Young;Kim, Young Sam;Kim, Hyung Jung;Chang, Joon;Ahn, Chul Min;Kim, Sung Kyu;Kim, Se Kyu
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.5
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    • pp.465-484
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    • 2004
  • Background : Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) inhibits the proliferation of non-small cell lung cancer (NSCLC) cells by inducing apoptosis. Methods : In this study, we investigated whether hypermethylation of IGFBP-3 promoter play an important role in the loss of IGFBP-3 expression in NSCLC. We also studied the mechanisms that mediate the silencing of IGFBP-3 expression in the cell lines which have hypermethylated IGFBP-3 promoter. Results : The IGFBP-3 promoter has hypermethylation in 7 of 15 (46.7%) NSCLC cell lines and 16 (69.7%) of 23, 7 (77.8%) of 9, 4 (80%) of 5, 4 (66.7 %) of 6, and 6 (100%) of 6 tumor specimens from patients with stage I, II, IIIA, IIIB, and IV NSCLC, respectively. The methylation status correlated with the level of protein and mRNA in NSCLC cell lines. Expression of IGFBP-3 was restored by the demethylating agent 5'-aza-2'-deoxycytidine (5'-aza-dC) in a subset of NSCLC cell lines. The Sp-1/ Sp-3 binding element in the IGFBP-3 promoter, important for promoter activity, was methylated in the NSCLC cell lines which have reduced IGFBP-3 expression and the methylation of this element suppressed the binding of the Sp-1 transcription factor. A ChIP assay showed that the methylation status of the IGFBP-3 promoter influenced the binding of Sp-1, methyl-CpG binding protein-2 (MeCP2), and histone deacetylase (HDAC) to Sp-1/Sp-3 binding element, which were reversed by by 5'-aza-dC. In vitro methylation of the IGFBP-3 promoter containing the Sp-1/Sp-3 binding element significantly reduced promoter activity, which was further suppressed by the overexpression of MeCP2. This reduction in activity was rescued by 5'-aza-dC. Conclusion : These findings indicate that hypermethylation of the IGFBP-3 promoter is one mechanism by which IGFBP-3 expression is silenced and MeCP2, with recruitment of HDAC, may play a role in silencing of IGFBP-3 expression. The frequency of this abnormality is also associated with advanced stages among the patients with NSCLC, suggesting that IGFBP-3 plays an important role in lung carcinogenesis/progression and that the promoter methylation status of IGFBP-3 may be a marker for early molecular detection and/or for monitoring chemoprevention efforts.