SV40 전이 포유동물세포에 있어 복제기구의 크기와 자외선 감수성

박상대 ( Sang Dai Park ) 생화학분자생물학회 1982 BMB Reports Vol.15 No.2

The molecular weights of pulse labeled DNA at various times after UV-irradiation declined and then recovered. The rate recovery at which their ability to synthesize control size DNA was a function of replicon size; normal human cells with small replicons recovered more rapidly than SV40 transformed cells with large replicons At low numbers of UV-lesions per replicon in normal cells, inhibition of replicon initiation was the predominant response; at higher numbers of lesions per replicons in SV40 transformed cells, blockage of chain growth was the predominant response. These results indicate that replicon size determines, in part, the response of DNA replication to UV damage.

Replicon Sizes and UV-Sensitivities in SV40-Transformed Mammalian Cells

박상대,Park, Sang-Dai 생화학분자생물학회 1982 한국생화학회지 Vol.15 No.2

자외선조사후 시간간격에 따라 표지한 DNA의 분자량은 감소후 회복됨을 보여 준다. 이같이 정상 크기의 DNA를 합성하는 능력인 회복율은 복제기구의 크기에 따라 다름을 알 수 있다. 즉 작은 크기의 복제기구를 갖는 정상세포에서는 큰 복제기구를 갖는 SV40 전이 세포에 비해 빨리 회복된다. 또 정상 세포에서와 같이 복제기구당 자외선의 상해수가 적을 경우에는 복제 기구에 의한 복제개시가 억제되는 것이 그 주된 영향이며, 복제기구당 상해수가 많은 SV40 전이 세포에서는 DNA사의 생장이 주로 억제된다. 이같은 결과는 복제기구가 자외선 상해에 대한 DNA 복제의 반응을 결정하는 것임을 시사하는 것이다. The molecular weights of pulse labeled DNA at various times after UV-irradiation declined and then recovered. The rate recovery at which their ability to synthesize control size DNA was a function of replicon size; normal human cells with small replicons recovered more rapidly than SV40 transformed cells with large replicons At low numbers of UV-lesions per replicon in normal cells, inhibition of replicon initiation was the predominant response; at higher numbers of lesions per replicons in SV40 transformed cells, blockage of chain growth was the predominant response. These results indicate that replicon size determines, in part, the response of DNA replication to UV damage.

자외선과 카페인을 처리한 사람의 정상 및 색소 건피증 세포에 있어 DNA 복제와 회복과의 연관성에 관한 연구

박상대,엄경일,최경희 ( Sang Dai Park,Kyung Il Um,Kyung Hee Choi ) 생화학분자생물학회 1979 BMB Reports Vol.12 No.3

Human normal (GM 637) and excision-defective (XP 12 RO) and variant (XP 4 BE) xeroderma pigmentosum cells irradiated with UV-light and pulselabeled with ³H-thymidine underwent transient decline and recovery of molecular weights of newly synthesized DNA and rates of DNA synthesis per cell. The ability to synthesize normal sized DNA recovered more rapidly than the rate of DNA synthesis in normal and XP-variant cells, but not in excision-defective XP cells. This effect might be due to breaks induced in parental DNA during excision repair that inhibit the initiation of clusters of replication. The changes in molecular weights appear due to DNA chain growth being blocked by DNA damage. During recovery cells steadily increased in their ability to replicate normal sized DNA on those replicons whose initiation was not inhibited by excision breaks. Caffeine added during the post-irradiation period eliminated the recovery of molecular weights in all cell types. This effect may be explained by competition between the DNA binding properties of caffeine and constitutive replication proteins.

Coupling of DNA Replication and Repair in Ultraviolet Light and Caffeine Treated Human Normal and Xeroderma Pigmentosum Fibroblasts

박상대,엄경일,최경희,Park, Sang-Dai,Um, Kyung-Il,Choi, Kyung-Hee 생화학분자생물학회 1979 한국생화학회지 Vol.12 No.3

Human normal (GM637) and excision-defective (XP 12RO) and variant (XP 4 BE) xeroderma pigmentosum cells irradiated with UV-light and pulse-labeled with $^3H$-thymidine underwent transient decline and recovery of molecular weights of newly synthesized DNA and rates of DNA synthesis per cell. The ability to synthesize normal sized DNA recovered more rapidly than the rate of DNA synthesis in normal and XP-variant cells, but not in excision-defective XP cells. This effect might be due to breaks induced in parental DNA during excision repair that inhibit the initiation of clusters of replication. The changes in molecular weights appear due to DNA chain growth being blocked by DNA damage. During recovery cells steadily increased in their ability to replicate normal sized DNA on those replicons whose initiation was not inhibited by excision breaks. Caffeine added during the post-irradiation period eliminated the recovery of molecular weights in all cell types. This effect may be explained by competition between the DNA binding properties of caffeine and constitutive replication proteins. 자외선 조사후 $^3H$-thymidine으로 표지한 사랑의 정상 세포(GM 637)와 결제결함(XP 12RO) 및 변형(XP 4BE)의 색소건피증 세포는 새로 합성하는 DNA 분자량과 세포당 DNA 합성율이 일시 감소했다 회복하는 것을 보여준다. 이때 정상크기의 DNA로 합성하는 능력(정상 DNA분자량)은 정상과 변형 세포의 경우 DNA 합성율의 회복보다 더욱 빨리 일어나나, 절제결함 세포에서는 그렇지 못하다. 이와 같이 DNA 합성율의 회복이 늦어지는 것은 정제회복 중에 유발된 DNA 절단이 상해로 인해 DNA 나선사의 생장이 억제되기 때문으로 생각된다. 그러나 회복이 진행되면 세포는 절제절단으로 복제 시작이 억제되지 않았던 이들 복제 기구들이 정상 크기의 DNA로 복제하는 능력을 점차 증가시켜 나가게 된다. 카페인을 처리하연 분자량의 회복이 모든 세포에서 중단 된다. 이는 카페인의 DNA 결함특성과 복제에 관하여는 단백질과의 경쟁으로 설명될 수 있다.

Studies on the Effects of Steroids on DNA Synthesis of Chromosmoes in Synchronized Human Cells

강영선,박상대,류정희,Kang, Yung Sun,Park, Sang Dai,Ryu, Chung Hee The Korean Society for Integrative Biology 1969 동물학회지 Vol.12 No.3

5-AU에 의해 同時分裂促進된 사람의 胎兒 賢臟細胞를 材料로 steroid 에 의한 染色體 異常率 時間經過에 따른 染色體異常率, DNA 合成樣相을 調査한 結果는 다음과 같다. 1. 5-AU 處理區에서 細胞當 染色體 異常率은 0.131로 對照區에 比해 3倍 이상이나 된다. 또한 5-AU + progesterone 과 5-AU + testosterone 處理區에서는 細胞當 染色體異常率이 각각 0.340과 0.452이다. 2. 5-AU 處理區에서 異常染色體를 지니는 細胞는 0.8%로 時間變化에 무관하게 전체 其間에 걸쳐 존재한다. 5-AU + progesterone과 5-AU + testosterone 處理區에서는 2.2%, 4.3%의 異常染色體數가 觀察되고, 時間이 지남에 따라 增加한다. 또한 染色體 異常率은 5-AU + progesterone 處理區에서는 12時間과 18時間에 가장 높았고, 5-AU + testosterone 處理區에서는 時間變化에 따라 감소하고 5-AU 處理區에서는 유의한 차이가 없다. 3. 5-AU 는 標識分裂像의 出現頻度와 標識强度를 增加시키는데, 이는 5-AU에 의해 S-stage의 細胞가 축적되는 결과로 생각된다. 그러나 steroid는 標識分裂像의 出現頻度를 감소시키고 DNA 合成時期를 지연시키고 있다. 또한 性染色體의 DNA 合成樣相이 細胞週期의 각 段階에 따라 다르며, 이는 5-AU와 steroid의 二重處理로 DNA 合成時期를 不規則하게 만든 때문이다. The frequencies of chromosomal aberrations, unmerical variations at various time intervals and DNA synthetic patterns after the treatment with steroids in synchronized human kidney cells treated with 5-AU were investigated in the present experiment. 1. In 5-AU treated group, the frequency of chromosomal aberrations per cell was 0.131, 3 times of control group. In 5-AU + progesterone and 5-AU + testosterone groups, the frequency of chromosomal aberrations per cell was 0.340 and 0.452 respectively. 2. In 5-AU treated group, the frequency of cells with abnormal chromosome number was 0.8%, which was distributed throughout the time regardless of time interval. In 5-AU + progesterone and 5-AU + testosterone groups, the frequencies of cells with abnormal chromosome number were 2.2% and 4.3% respectively and they increased with the time. In 5-AU + progesterone group, the frequency of chromosomal aberrations exhiited the peaks at 12 and 18 hour stage after the treatment with steroids and, in 5-AU + testosterone group, it decreased with the time and in 5-AU treated group no significant difference was observed 3. The increase of labeled metaphases and labelling intensities in 5-AU treated cells are the result of the accumulation of cells at S stage by 5-AU. The decrease of labeled metaphases, labelling intensities and the delay of DNA synthetic time were observed in steroid groups. DNA synthetic pattern of sex chromosomes differs according to the step of cell cycle and DNA synthetic time is irregular because of double treatments with 5-AU and steroids.

사람의 배양세포에 있어 자외선 및 MMS 에 의한 비동시 (非同時) DNA 합성과 염색체 이상에 미치는 감기상사체의 (監基相似體) 영향

엄경일,박상대 ( Kyung Il Um,Sang Dai Park ) 한국유전학회 1981 Genes & Genomics Vol.3 No.1

The effects of base analogs on UV-light and MMS-induced unscheduled DNA synthesis and chromosome aberrations were investigated in human cells and the results obtained were as follows: BUdR and IUdR were found to be both potent sensitizers enhancing UV-induced unscheduled DNA synthesis and chromosome aberrations. The sensitization effects of these base analogs were different in these two different repair processes. BUdR and IUdR did not seem to act as sensitizers for both unscheduled DNA synthesis and chromosome aberrations induced by MMS. These results suggest that excision repair may not be related to chromosome aberrations in human cells.

Enhancing Effects of Inhibitors of Poly(ADP-ribose) Polymerase on Alkylating Agents-Induced DNA Strand Breaks, Excision Repair and sister Chromatid Exchanges

김철근,박종군,박상대,Kim, Chul-Geun,Park, Jong-Kun,Park, Sang-Dai 생화학분자생물학회 1983 한국생화학회지 Vol.16 No.2

CHO 세포에 있어서 강력한 poly(ADP-ribose) polymerase 저해제인 benzamide와 3-aminobenzmide는 MMS와 MNNG에 의한 DNA 단사절단을 증가시켰으며 단사절단의 재결합을 유의성 있게 억제하였다. 이들 저해제는 또한 MNNG에 의한 비주기성 DNA 합성(UDS)과 자매염색분체 교환(SCE)에 상승 효과를 나타내었다. MMS와 MNNG의 복합처리에 의한 UDS와 단사절단은 상가효과를 보이나 저해제 처리에 의해 이의 효과는 상승되었다. 이들 결과로 보아 poly(ADP-ribose)는 DNA에 단사절단이 일어날때마다 염색사구초를 안정화 시킴으로서 DNA 손상에 대한 회복에 조절작용을 나타낸다고 사료된다. Benzamide and 3-aminobenzamide, potent inhibitors of poly (ADP-ribose) polymerase, increased MMS or MNNG-induced DNA strand breaks and significantly retarded the rejoining of strand breaks in CHO cells. These inhibitors also synergistically enhanced the frequencies of unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCE) induced by MNNG. Amounts of UDS and strand breaks induced by the combined treatment with MMS and MNNG were found to be additive but these amount were enhanced in the presence of inhibitors. These results suggest that poly (ADP-ribose) functions a regulatory role in the repair of DNA damage by virtue of stabilizing chromatin structure whenever strand breaks occur in DNA.

알킬화제에 의한 DNA 단사절단 , 절제회복 및 자매염색분체 교환에 미치는 Poly ( ADP - ribose ) polymerase 저해제의 상승효과

김철근,박종군,박상대 ( Chul Geun Kim,Jong Kun Park,Sang Dai Park ) 생화학분자생물학회 1983 BMB Reports Vol.16 No.2

Benzamide and 3-aminobenzamide, potent inhibitors of poly (ADP-ribose) polymerase, increased MMS or MNNG-induced DNA strand breaks and significantly retarded the rejoining of strand breaks in CHO cells. These inhibitors also synergistically enhanced the frequencies of unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCE) induced by MNNG. Amounts of UDS and strand breaks induced by the combined treatment with MMS and MNNG were found to be additive but these amount were enhanced in the presence of inhibitors. These results suggest that poly (ADP-ribose) functions a regulatory role in the repair of DNA damage by virtue of stabilizing chromatin structure whenever strand breaks occur in DNA.

Effects of 3 - Aminobenzamide on Polymerase α - dependent DNA Repair

박종근,변미경,박상대 ( Jong Kun Park,Mee Kyeong Byeon,Sang Dai Pak ) 한국유전학회 1986 Genes & Genomics Vol.8 No.1

The action of 3-aminobenzamide (3AB), an inhibitor of poly (ADP-ribose) polymerase, synergistically enhanced the amount of unscheduled DNA synthesis and DNA strand breaks in asynchronous CHO (Chinese hamster ovay)-K 1 cells exposed to methylmethane sulfonate (MMS). In this system, the time dependent decrease in the strand breaks was inhibited by 3AB. In synchronous CHO-K 1 cells, however, the sensitivity of exonuclease II on the repair patches blocked by aphidicolin, the inhibitor of DNA polymerase showed nonsignificant difference between normal-and 3AB-chased groups. Similarly, the rate of removal of exo II-sensitive sites was not altered by 3AB in WIL-2 (human lymphoid) cells. These results, therefore, suggest that poly (ADP-ribose) polymerization does not exert any significant role in the ligation of polymerase-dependent repair synthesis induced by MMS.

DNA 상해와 복제억제에 미치는 3 - methylcholanthrene 의 영향

박기현,이정섭,이형호,박상대 ( Ki Hyun Park,Jung Sup Lee,Hyung Ho Lee,Sang Dai Park ) 생화학분자생물학회 1985 BMB Reports Vol.18 No.2

DNA strand breaks and replication inhibition by 3-methylcholanthrene (3-MC) were determined in the presence or absence of metabolic activation in CHO-Kl cells. DNA strand breaks were induced in a small extent by 3-MC for 24 hr treatment. However, the single strand breaks were effectively induced by 3-MC for 1 hr treatment with the metabolic activation system. The production of strand breaks were remarkably increased by post-incubation with hydorxyurea and ara-C. At low doses below 10^(-6) M, inhibition of replicon initiation was observed, at higher doses non-specific inhibition of both replicon initiation and chain growth was shown.