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䠄䠏䠅㻌 ཎᏊ⅔୰ᛶᏊ⥺䛻䜘䛳䛶⏕䛨䜛䠠䠪䠝ᦆയ✀䛾ゎ᫂
బ㈡Ꮫ⥲ྜศᯒᐇ㦂䝉䞁䝍䞊 ᑎᮾᏹ᫂
㏆␥ᏛཎᏊຊ◊✲ᡤ ᒣすᘯᇛ䚸ᯇ⏣እᚿᮁ
IIntroduction
㻌 㟁㞳ᨺᑕ⥺䠄௨ୗ䚸ᨺᑕ⥺䠅䛾⏕≀ຠᯝ䛿䚸㑇ఏ≀㉁DNA䛻യᐖ䜢䛘䜛䛣䛸䛻䜘䜚⾲ฟ䛩䜛䛜䚸ᨺ ᑕ⥺DNAᦆയ䛻㛵䛩䜛◊✲䛾ከ䛟䛿䚸䃒⥺䜔䠴⥺䛺䛹䛻䜘䜛䜒䛾䛻㞟୰䛧䚸䛭䜜௨እ䛾⥺㉁䛻䜘䜛ᦆ യ䛾ᵝែ䛿᫂䛺Ⅼ䛜ከ䛟ṧ䛥䜜䛶䛔䜛䚹⚾䛿䚸䛣䜜䜎䛷ᨺᑕ⥺་Ꮫ⥲ྜ◊✲ᡤ㔜⢏Ꮚ⥺↷ᑕ⨨
HIMACඹྠᐇ㦂䜢㏻䛨䛶䚸Ⅳ⣲⥺䜢䛿䛨䜑䛸䛩䜛㔜⢏Ꮚ⥺䛻䜘䛳䛶⏕䛨䜛DNAᦆയ䛾ศᯒ䜢⾜䛳䛶 䛝䛯䠷1, 2䠹䚹䛭䛾◊✲ᡂᯝ䛸䛧䛶䚸㔜⢏Ꮚ⥺䛾䜘䛖䛺㧗LETᨺᑕ⥺䛷䛿䚸䃒⥺䛾䜘䛖䛺పLETᨺᑕ⥺䛸
␗䛺䜛DNAᦆയ✀䜔⋡䛜ᚓ䜙䜜䜛䛣䛸䛜䜟䛛䛳䛯䚹ᅗ1䛻㧗LETᨺᑕ⥺䛻≉ᚩⓗ䛺DNAᦆയ䛾ᙧ
ែ䜢䛒䛢䛯䛜䚸䜽䝻䝇䝸䞁䜽DNAᦆയ䛿䚸䝍䞁䝟䜽㉁➼䛾ศᏊ䛜DNA䛸⤖ྜ䛩䜛䜒䛾䛷䚸䛭䛾ᔞ㧗䛥䛛 䜙DNAྜᡂ㜼ᐖ⬟䛜㧗䛟䚸䜎䛯ಟຠ⋡䜒ప䛔䚹䜒䛖୍䛴䛾≉ᚩⓗ䛺DNAᦆയ䛷䛒䜛䜽䝷䝇䝍䞊DNA ᦆയ䛿䚸ᨺᑕ⥺䛜䝡䞊䝮䛸䛧䛶ᶆⓗDNA䜢㏻㐣䛩䜛㝿䛻䚸䛭䛾㌶㊧䛻ἢ䛳䛶」ᩘ䛾ᦆയ䜢⏕䛨䛫䛧 䜑䜛䜒䛾䛷䛒䜛䚹䛣䜜䛿ᦆയ䝥䝻䝉䝇䛾㐣⛬䛷䚸DNAྜᡂ㜼ᐖ⬟䛜㧗䛟䚸䜎䛯ṇ☜䛺ಟ䛜䛥䜜䛻䛟䛔 DNAᮏ㙐ษ᩿䠄DSB䠅䜢⏕䛨䚸ᨺᑕ⥺⏕≀ຠᯝ䛾せᅉ䛸䛥䜜䜛䜒䛾䛷䛒䜛䚹䜽䝷䝇䝍䞊DNAᦆയ 䛿䚸ᨺᑕ⥺䛾LET䛜㧗䛟䛺䜛䜋䛹䚸ᦆയ䛾ᐦ㞟ᗘ䛜㧗䛟䛺䜚䚸⏕≀ຠᯝ䜒䛝䛟䛺䜛䚹
ᮏ◊✲䛷䛿䚸ཎᏊ⅔୰ᛶᏊ䛻䜘䛳䛶⏕䛨䜛DNAᦆയ䛾ศᯒ䜢⾜䛔䚸୰ᛶᏊ⥺䛻䜘䜛⏕≀ຠᯝ䛾ศᏊ ᶵᵓ䛾ゎ᫂䜢┠ⓗ䛻ᐇ㦂䜢⾜䛳䛯䛾䛷䚸䛣䛣䛻ሗ࿌䛩䜛䚹
ᅗ1 䠊㧗LETᨺᑕ⥺䛻䜘䛳䛶⏕䛨䜛≉ᚩⓗ䛺DNAᦆയᙧែ䚹A䠅䜽䝻䝇䝸䞁䜽DNAᦆയ䚸B䠅䜽 䝷䝇䝍䞊DNA ᦆയ䚹ᮏ◊✲䛷䛿䛻 B䠅䜽䝷䝇䝍䞊DNA ᦆയ䛻䝣䜷䞊䜹䝇䛧䛶ศᯒ䜢⾜䛳䛶䛔 䜛䚹
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Materials and Methods
㻌 ᮏ◊✲䛷䛿᭱⤊ⓗ䛻↷ᑕ⏕≀య䛻䛚䛡䜛DNAᦆയศᯒ䜢┠ⓗ䛸䛩䜛䛜䚸ᖺᗘ䛿ึᖺᗘ䛸䛔䛖䛣 䛸䜒䛒䜚䚸⢭〇䛧䛯 DNA ศᏊ䜢↷ᑕᑐ㇟䛸䛧䛶ᐇ㦂䜢⾜䛔䚸୰ᛶᏊ⥺ DNA ᦆയศᯒᡭἲ䛾☜❧䜢
┠ᣦ䛧䛯䚹ᑐ㇟DNAศᏊ䛿䚸䝥䝷䝇䝭䝗pUC19䠄2,686 bp䠅䛸䛧䚸⭠⳦⣽⬊䛷ቑṪ䛥䛫䛯ྠ䝥䝷䝇䝭 䝗 DNA 䜢 Qiagen Plasmid Plus Kit 䛻䛶ᢳฟ䞉⢭〇䛧䛯䜒䛾䜢 10 mM Tris-HCl, 1 mM ethylenediaminetetraacetic acid, pH7.5䠄TE䠅䛻5 ng/μL䛾⃰ᗘ䛻⁐ゎ䛧䚸㏆␥ᏛཎᏊ⅔䛻䛶
୰ᛶᏊ⥺↷ᑕ䜢⾜䛳䛯䚹↷ᑕ䛩䜛DNA⁐ᾮ䛻䛿0䚸0.1䚸1 M䛾dimethyl sulfoxide䠄DMSO䠅䜢ῧ ຍ䛧䚸䝷䝆䜹䝹䝇䜹䝧䞁䝆䝱䞊⬟䛾ᙉᙅ䛻䜘䜛 DNA ᦆയ⋡䜈䛾ᙳ㡪䜢᳨ウ䛧䛯䚹↷ᑕ⥺㔞䛿 0䚸 0.3䚸0.6䚸0.9 Gy䛷䚸⥺㔞䛿㔠⟩䜢⏝䛔䛯୰ᛶᏊ᮰ ᐃ䛻䜘䜚ィ 䛧䛯䚹↷ᑕᚋ䚸DNA䜢 1.2%䜰䜺 䝻䞊䝇䝀䝹㟁ẼὋື䛧䚸ᦆയศᯒ䜢⾜䛳䛯䠷3䠹䚹㟁ẼὋື๓䛻↷ᑕDNA䜢endonuclease III䠄Endo
III䠅䛚䜘䜃 Fpg 䛷ฎ⌮䛩䜛䛣䛸䛻䜘䜚䚸䛭䜜䛮䜜㓟䝢䝸䝭䝆䞁ᦆയ䚸㓟䝥䝸䞁ᦆയ䜢 DNA 㙐ษ᩿
䛻ኚ䛧䚸㟁ẼὋື䛻䜘䜛⛣ືᗘ䛾ኚ䛻䜘䜛ᦆയ᳨ฟ䜢ྍ⬟䛻䛧䛯䠷3䠹䚹ᑐ↷ᐇ㦂䛸䛧䛶䚸㧗⥺㔞
⋡䛾䜶䝑䜽䝇⥺↷ᑕᐇ㦂䠄150kVp, 15.2 Gy/min䚸బ㈡Ꮫ⥲ྜศᯒᐇ㦂䝉䞁䝍䞊䠅䛚䜘䜃㠀↷ᑕᐇ 㦂䜢⾜䛳䛯䠷4䠹䚹
R Results
㻌 ཎᏊ⅔୰ᛶᏊ䛻䜘䛳䛶⏕䛨䜛DNA㙐ษ᩿ᦆയ䛻䛴䛔䛶䛿䚸⥺㔞䛻ᛂ䛨䛶୍ᮏ㙐ษ᩿䛾⏕ᡂ䜢♧䛩 type II䛾㔞䛜ቑຍ䛧䚸0.9 Gy䛷䛿21%䛸䛺䛳䛯䚹䛣䛾㔞䛿䃒⥺䜔䠴⥺䛾㔞䜘䜚䛝䛟䚸㔜⢏Ꮚ⥺
䛾㔞䛻㢮ఝ䛧䛶䛔䜛䛣䛸䛛䜙䚸㧗LETᨺᑕ⥺䛻≉ᚩⓗ䛸⪃䛘䜙䜜䛯䠷1, 2, 3䠹䚹䜎䛯䚸㓝⣲ฎ⌮䛺䛧䛾 䜲䞁䜻䝳䝧䞊䝖䛻䜘䜚type II㔞䛜䜋䛸䜣䛹ቑຍ䛧䛺䛛䛳䛯䛣䛸䛛䜙䚸ளᦆയ䛸䜀䜜䜛DNA⬤ᙅ㒊
䛾Ⓨ⏕䛿䚸୰ᛶᏊ⥺䛷䛿䜋䛸䜣䛹㉳䛣䜙䛺䛔䛣䛸䛜♧၀䛥䜜䛯䚹DSB䛿0.9 Gy䜎䛷䛾↷ᑕ䛷䜋䛸䜣䛹
᳨ฟ䛥䜜䛺䛛䛳䛯䚹㓝⣲ฎ⌮䛻䜘䜛㓟ሷᇶᦆയ䛾ศᯒ⤖ᯝ䛿䚸⥺㔞䛻ᛂ䛨䛶䚸䜽䝷䝇䝍䞊DNAᦆയ 䛾⏕ᡂ䜢♧䛩type III䛾㔞䛜ቑຍ䛧䛯䛣䛸䛛䜙䚸୰ᛶᏊ⥺↷ᑕ䛻䜘䜚㓟ሷᇶᦆയ䜢ྵ䜐䜽䝷䝇䝍䞊 DNAᦆയ䛜⏕䛨䛶䛔䜛䛣䛸䛜䜟䛛䛳䛯䚹ᅗ2䛻↷ᑕDNA䛾㟁ẼὋືീ䜢♧䛩䚹
ᅗ 2. ୰ᛶᏊ⥺↷ᑕ䜢⾜䛳䛯 pUC19 䝥䝷䝇䝭䝗 DNA 䛾䜰䜺䝻䞊䝇䝀䝹㟁ẼὋືศᯒീ䚹䛣䛣䛷䛿 DMSO 䛺䛧䛷䛾↷ᑕ䝃䞁䝥䝹䜢Ὃື䛧䛶䛔䜛䚹M 䛿ศᏊ㔞䝬䞊䜹䞊lambda HindIII 䜢䚸I䚸 II䚸 III 䛿 type I (intact), type II (single damage), and type III (complex damage)䛾䝞䞁䝗⨨䜢
♧䛩䚹Control䛿䜲䞁䜻䝳䝧䞊䝖䛺䛧䚸No enzyme䛿䜲䞁䜻䝳䝧䞊䝖䛾䜏䚸Endo III 䞉Fpg digests䛿 䛭䜜䛮䜜㓟䝢䝸䝭䝆䞁ᦆയ䛚䜘䜃㓟䝥䝸䞁ᦆയ䛾ษ᩿㓝⣲ฎ⌮䛻䜘䜚䛭䜜䜙䜢㙐ษ᩿䛸䛧䛶᳨ฟ 䛩䜛䛯䜑䛾䜒䛾䛷䛒䜛䚹
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F
Future Work
㻌 ⌧ᅾ䚸DMSO䜢ຍ䛘䛶↷ᑕ䛧䛯DNA䝃䞁䝥䝹䛾ศᯒ䜢⾜䛳䛶䛚䜚䚸䝷䝆䜹䝹䝇䜹䝧䞁䝆䝱䞊⬟䛾ᙉ ᙅ䛜DNAᦆയ⋡䜈䛹䛾䜘䛖䛻ᙳ㡪䛩䜛䛛䛻䛴䛔䛶ᚋ᳨ウ䜢⾜䛳䛶䛔䛟䚹㐣ཤ䛾▱ぢ䛛䜙䚸⣽⬊
ෆ䛾䝷䝆䜹䝹䝇䜹䝧䞁䝆䝱䞊⬟䛾䝺䝧䝹䛿1 M DMSO䛸ྠ➼䛸⪃䛘䜙䜜䜛䛣䛸䛛䜙䚸⣽⬊ෆDNAᦆയ
⋡䛾䝺䝧䝹䛜䛣䜜䛷ศ䛛䜛䛸⪃䛘䜙䜜䜛䚹ᚋ䛿䚸䛥䜙䛻ᇵ㣴⣽⬊䜢⏝䛔䛶⣽⬊ෆDNAᦆയ䜢ศᯒ 䛧䚸୰ᛶᏊDNAᦆയ䛾ㇺ䜢᫂䜙䛛䛻䛧䛶䛔䛟䚹
R
References
[1] H. Terato et al., J. Radiat. Res., 49 (2008) 133-146.
[2] Y. Tokuyama et al., J. Radiat. Res., 56 (2015) 446-455.
[3] M. M. Ali et al., J. Radiat. Res., 45 (2004) 229-237.
[4] K. Kudo et al., J Electrostat 73 (2015) 131-139.
ᴗ⦼୍ぴ
ᑎᮾᏹ᫂䠈ᚨᒣ⏤ె䠈᳃ຍዉᜨ䠈ᯇ⏣እᚿᮁ䠈ᒣすᘯᇛ䠈䛂ཎᏊ⅔୰ᛶᏊ䛻䜘䛳䛶⏕䛨䜛 DNA ᦆയ ศᯒ䛃ி㒔ᏛཎᏊ⅔ᐇ㦂ᡤ➨52ᅇᏛ⾡ㅮ₇䠈2018ᖺ1᭶25-26᪥
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