• Title/Summary/Keyword: Topoisomerase I and II

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Cloning and Characterization of Replication Origins from Misgurnus mizolepis (미꾸라지로부터의 복제원점 클로닝 및 그 특성에 관한 연구)

  • Lim Hak-Seob;Kim Moo-Sang;Lee Hyung-Ho
    • Journal of Aquaculture
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    • v.8 no.3
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    • pp.209-220
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    • 1995
  • The nuclear matrix was isolated from Misgumus mizolepis liver nuclei by low salt extraction and restriction enzyme treatment. The structure was digested with proteinase K. After centrifugation, matrix attachment regions (MARs) were obtained by RNase treatment and phenol-chloroform extraction. The result leads to the appearance of smeared bands in the range of about 0.3-15 kb. pURY19 vector was constructed by inserting 2.13 kb Eco47 III fragment of the yeast uracil 3 gene into the unique Ssp I site of pUC19 plasmid vector as a selection marker. This vector is unable to be maintained in Sacrharomyces cerevisiae by itself since it cannot replicate as an extrachromosomal element. Using this system, we attempted cloning the ARS (autonomously replicating sequence) from M. mizelepis to develop an efficient expression vector for the transgenic fish. pURY19N_{l-62}$ were constructed by inserting MARs in pURY19 plasmid vector and transformation of E. coli $DH5\alpha$. Replication origins (ARS) of M. mizolepis were isolated, which enabled the vector to replicate autonomously in S. cerevisiae. The cloned DNA fragments were sequenced by Sanger's dideoxy-chain termination method. All clones were AT-rich. $pURY19N_6$, one of the clones, expecially contained ARS consensus sequence, Topoisomerase II consensus, near A-box and T-box.

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Phase II Study of Induction Irinotecan + Cisplatin Chemotherapy Followed by Concurrent Irinotecan + Cisplatin Plus Twice-Daily Thoracic Radiotherapy (유제한성 병기의 소세포 폐암에서 3주 간격으로 시행된 irinotecan과 cisplatin을 이용한 과다분할 방사선 동시 요법)

  • Lee, Jeong Eun;Park, Hee Sun;Jung, Sung Soo;Kim, Ju Ock;Cho, Moon June;Kim, Jin Hwan;Lee, Choong Sik;Kim, Sun Young
    • Tuberculosis and Respiratory Diseases
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    • v.63 no.2
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    • pp.154-164
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    • 2007
  • Background: Irinotecan hydrochloride, a topoisomerase I inhibitor, is effective against small-cell lung cancer. Irinotecan also can act as a potential radiation sensitizer along with cisplatin. To evaluate efficacy and toxicity of irinotecan plus cisplatin (IP) with concurrent thoracic radiotherapy, we conducted a phase II study of IP followed by concurrent IP plus hyperfractionated thoracic radiotherapy in patients with previously untreated limited-stage small-cell lung cancer. Methods: Twenty-four patients with previously untreated small-cell lung cancer were enrolled onto the study since November 2004. Irinotecan $60mg/m^2$ was administered intravenously on days 1 and 8 in combination with cisplatin $60mg/m^2$ on day1 every 21 days. From the first day of third cycle, twice-daily thoracic irradiation (total 45 Gy) was given. Prophylactic cranial irradiation was given to the patients who showed complete remission after concurrent chemoradiotherapy. Restaging was done after second and sixth cycle with chest CT and/or bronchosocpy. Results: Up to November 2004, 19 patients were assessable. The median follow-up time was 12.5 months. A total of 99 cycles (median 5.2 cycles per patient) were administered. The actual dose intensity values were cisplatin $19.6mg/m^2$/week and irinotecan $38.2mg/m^2$/week. Among the 19 patients, the objective response rate was 95% (19 patients), with 9 patients (47%) having a complete response (CR). The major grade 3/4 hematological toxicities were neutropenia (35% of cycles), anemia (7% of cycles), thrombocytopenia (7% of cycles). Febrile neutropenia was 4% of cycles. The predominant grade 3/4 non-hematological toxicities was diarrhea (5% of cycles). Toxicities was not significantly different with concurrent administration of irinotecan and cisplatin with radiotherapy, except grade 3/4 radiation esophagitis (10% of patients). No treatment-related deaths were observed. The 1-year and 2-year survival rate of eligible patients was 89% (16/18) and 47% (9/18), respectively. Conclusion: Three-week schedule of irinotecan plus cisplatin followed by concurrent IP plus hyperfractionated thoracic radiotherapy is an effective treatment for limited disease small-cell lung cancer, with acceptable toxicity.

Phase II Study of Irinotecan Plus Cisplatin as First Line therapy in Extensive Small-Cell Lung Cancer (확장기 소세포폐암에서 1차 치료로서 Irinotecan + Cisplatin 복합요법의 임상적 결과)

  • Hwang, Ki Eun;Kim, So Young;Jung, Jong Hoon;Park, Seong Hoon;Park, Jung Hyun;Kim, Hwi Jung;Kim, Hak Ryul;Yang, Sei Hoon;Jeong, Eun Taik
    • Tuberculosis and Respiratory Diseases
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    • v.61 no.2
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    • pp.143-149
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    • 2006
  • Background: Irinotecan (topoisomerase I inhibitor) is effective as a monotherapy against small-cell lung cancer(SCLC). Cisplatin is also an important drug against SCLC. A phase II study of irinotecan combined with cisplatin was carried out to evaluate the efficacy and toxicity of this combined regimen as a first line treatment in patients with extensive SCLC. Methods: Thirty-nine patients with previously untreated extensive SCLC were enrolled in this study. Irinotecan $60mg/m^2$ was administered intravenously on days 1, 8 and 15, and in combination with cisplatin $60mg/m^2$ on day 1 and every 28 days thereafter. Four cycles of chemotherapy were given to the patients. Results: The overall response rate was 77% with a complete response (CR) rate of 8%. The median survival time, 1- and 2-year survival rate were 14.8 months, 60.9% and 27.6%, respectively. The median progression free survival time, 6-and 12-month progression free survival rate were 8.4 months, 75% and 18.8%, respectively. The WHO grade 3 or more toxicity encountered were leukopenia (23%), diarrhea (26%). Two patients changed their chemotherapeutic regimen and one patient died from severe diarrhea. Conclusion: The combination of irinotecan and cisplatin is effective as a first line therapy in extensive SCLC is effective, but has severe or fatal diarrhea as toxicity.

Phase II Trial of Irinotecan plus Cisplatin Combination as First Line Therapy for Patients with Small cell Lung Cancer (소세포폐암 환자에서 1차 항암 치료제로서 Irinotecan 과 Cisplatin 병합요법에 관한 2상 연구)

  • Jeong, Hye Cheol;Lee, Sang Yeub;Kim, Jung Ha;Ha, Eun Sil;Jung, Jin Yong;Lee, Kyung Ju;Lee, Seung Hyeun;Kim, Se Joong;Lee, Eun Joo;Hur, Gyu Young;Lee, Sung Yong;Kim, Je Hyeong;Shin, Chol;Shim, Jae Jeong;In, Kwang Ho;Kang, Kyung Ho;Yoo, Se Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.60 no.1
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    • pp.57-64
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    • 2006
  • Background : Recently, there have been several studies showing that irinotecan hydrochloride, a topoisomerase I inhibitor, is effective against extensive disease(ED) small cell lung cancer (SCLC). We conducted a phase II trial to evaluate the efficacy and toxicity of irinotecan plus cisplatin as a 1st line therapy for both limited and extensive disease SCLC. Methods : The study was conducted between January 2002 and June 2004. Patients were treated with $60mg/m^2$ irinotecan on day 1, 8, 15 and $60mg/m^2$ cisplatin on day 1, every 4 weeks. During concurrent thoracic irradiation for limited disease (LD)-SCLC patients, dose of irinotecan was reduced to $40mg/m^2$. Prophylactic cranial irradiation was given to patients with complete remission (CR) after chemotherapy. Results : Median ages of LD- and ED- SCLC were 64 years and performance status (PS) was 0-2. In patients with LD-SCLC, the response rate after concurrent chemoradiotherapy was 85% (CR, 6; Partial response [PR], 11). The median survival was 20 months (95% CIs, 15.6 to 24.4) with 1-and 2-year survival rates of 85% and 35%, respectively. Median progression free survival (PFS) was 12 months (95% CIs, 6.2 to 18.1) with 1- year PFS of 36%. In ED-SCLC, the response rate was 83.4% (CR, 1; PR, 14). The median survival was 14.5 months (95% CIs, 8.8 to 20.1) with 1-year survival rates of 75%. Median PFS was 6.3 months (95% CIs, 5.6 to 7.1) with 1- year PFS of 20%. The major toxicities (grade 3 or 4) of this regimen included leukopenia, anemia, thrombocytopenia, nausea/vomiting, and diarrhea without life threatening complication. Conclusion : Our data shows that the combination of irinotecan plus cisplatin as a first line therapy is effective and tolerable in the treatment of both LD- and ED- SCLC.