0 2 An an DT 3 18 IRF-1-dependent irf-1-dependent JJ 19 26 pathway pathway NN 27 29 of of IN 30 33 DNA DNA NNP 34 48 damage-induced damage-induced JJ 49 58 apoptosis apoptosis NN 59 61 in in IN 62 79 mitogen-activated mitogen-activated JJ 80 81 T t NN 82 93 lymphocytes lymphocyte NNS 93 94 . . . 96 107 Lymphocytes lymphocyte NNS 108 111 are be VBP 112 124 particularly particularly RB 125 136 susceptible susceptible JJ 137 139 to to TO 140 143 DNA DNA NNP 144 158 damage-induced damage-induced JJ 159 168 apoptosis apoptosis NN 168 169 , , , 170 171 a a DT 172 180 response response NN 181 186 which which WDT 187 190 may may MD 191 196 serve serve VB 197 199 as as IN 200 201 a a DT 202 206 form form NN 207 209 of of IN 210 211 ‘ ` `` 211 221 altruistic altruistic JJ 222 229 suicide suicide NN 229 230 ’ ' '' 231 233 to to TO 234 241 counter counter VB 242 247 their their PRP$ 248 257 intrinsic intrinsic JJ 258 262 high high JJ 263 272 potential potential NN 273 276 for for IN 277 285 mutation mutation NN 286 289 and and CC 290 296 clonal clonal JJ 297 306 expansion expansion NN 306 307 . . . 308 311 The the DT 312 318 tumour tumour NN 319 329 suppressor suppressor NN 330 333 p53 p53 NN 334 337 has have VBZ 338 342 been be VBN 343 348 shown show VBN 349 351 to to TO 352 360 regulate regulate VB 361 365 this this DT 366 370 type type NN 371 373 of of IN 374 383 apoptosis apoptosis NN 384 386 in in IN 387 397 thymocytes thymocyte NNS 397 398 , , , 399 402 but but CC 403 405 an an DT 406 408 as as RB 409 412 yet yet RB 413 420 unknown unknown JJ 420 421 , , , 422 437 p53-independent p53-independent JJ 438 448 pathway(s) pathway(s) NN 449 456 appears appear VBZ 457 459 to to TO 460 467 mediate mediate VB 468 471 the the DT 472 476 same same JJ 477 482 event event NN 483 485 in in IN 486 503 mitogen-activated mitogen-activated JJ 504 510 mature mature JJ 511 512 T t NN 513 524 lymphocytes lymphocyte NNS 524 525 . . . 526 530 Here here RB 531 533 we we PRP 534 538 show show VBP 539 542 DNA DNA NNP 543 557 damage-induced damage-induced JJ 558 567 apoptosis apoptosis NN 568 570 in in IN 571 576 these these DT 577 578 T t NN 579 590 lymphocytes lymphocyte NNS 591 593 is be VBZ 594 603 dependent dependent JJ 604 606 on on IN 607 610 the the DT 611 624 antioncogenic antioncogenic JJ 625 638 transcription transcription NN 639 645 factor factor NN 646 656 interferon interferon NN 657 667 regulatory regulatory JJ 668 674 factor factor NN 675 676 ( ( ( 676 682 IRF)-1 irf)-1 NN 682 683 . . . 684 688 Thus thus RB 689 692 two two CD 693 702 different different JJ 703 718 anti-onco-genic anti-onco-genic JJ 719 732 transcription transcription NN 733 740 factors factor NNS 740 741 , , , 742 745 p53 p53 NN 746 749 and and CC 750 755 IRF-1 irf-1 NN 755 756 , , , 757 760 are be VBP 761 769 required require VBN 770 773 for for IN 774 782 distinct distinct JJ 783 792 apoptotic apoptotic JJ 793 801 pathways pathway NNS 802 804 in in IN 805 806 T t NN 807 818 lymphocytes lymphocyte NNS 818 819 . . . 820 822 We we PRP 823 827 also also RB 828 832 show show VBP 833 837 that that IN 838 845 mitogen mitogen NN 846 855 induction induction NN 856 858 of of IN 859 862 the the DT 863 876 interleukin-1 interleukin-1 NN 877 881 beta beta SYM 882 892 converting convert VBG 893 899 enzyme enzyme NN 900 901 ( ( ( 901 904 ICE ICE NNP 904 905 ) ) ) 906 910 gene gene NN 910 911 , , , 912 913 a a DT 914 923 mammalian mammalian JJ 924 933 homologue homologue NN 934 936 of of IN 937 940 the the DT 941 955 Caenorhabditis Caenorhabditis NNP 956 963 elegans elegan NNS 964 968 cell cell NN 969 974 death death NN 975 979 gene gene NN 980 985 ced-3 ced-3 NN 985 986 , , , 987 989 is be VBZ 990 1005 IRF-1-dependent irf-1-dependent JJ 1005 1006 . . . 1007 1014 Ectopic ectopic JJ 1015 1029 overexpression overexpression NN 1030 1032 of of IN 1033 1038 IRF-1 irf-1 NN 1039 1046 results result VBZ 1047 1049 in in IN 1050 1053 the the DT 1054 1064 activation activation NN 1065 1067 of of IN 1068 1071 the the DT 1072 1082 endogenous endogenous JJ 1083 1087 gene gene NN 1088 1091 for for IN 1092 1095 ICE ICE NNP 1096 1099 and and CC 1100 1108 enhances enhance VBZ 1109 1112 the the DT 1113 1124 sensitivity sensitivity NN 1125 1127 of of IN 1128 1133 cells cell NNS 1134 1136 to to TO 1137 1154 radiation-induced radiation-induced JJ 1155 1164 apoptosis apoptosis NN 1164 1165 . . .