0 12 STAT-related stat-related JJ 13 26 transcription transcription NN 27 34 factors factor NNS 35 38 are be VBP 39 53 constitutively constitutively RB 54 63 activated activate VBN 64 66 in in IN 67 77 peripheral peripheral JJ 78 83 blood blood NN 84 89 cells cell NNS 90 94 from from IN 95 100 acute acute JJ 101 109 leukemia leukemia NN 110 118 patients patient NNS 118 119 . . . 121 122 A a DT 123 129 signal signal NN 130 142 transduction transduction NN 143 150 pathway pathway NN 151 160 activated activate VBN 161 163 by by IN 164 168 many many JJ 169 178 cytokines cytokine NNS 179 182 has have VBZ 183 191 recently recently RB 192 196 been be VBN 197 207 elaborated elaborate VBN 207 208 . . . 209 212 The the DT 213 216 JAK jak NN 217 224 kinases kinase NNS 225 228 and and CC 229 232 the the DT 233 239 signal signal NN 240 251 transducers transducer NNS 252 255 and and CC 256 266 activators activator NNS 267 269 of of IN 270 283 transcription transcription NN 284 285 ( ( ( 285 289 STAT STAT NNP 289 290 ) ) ) 291 298 factors factor NNS 299 303 have have VBP 304 308 been be VBN 309 314 found find VBN 315 317 to to TO 318 320 be be VB 321 330 essential essential JJ 331 341 components component NNS 341 342 . . . 343 345 In in IN 346 350 this this DT 351 357 report report NN 357 358 , , , 359 361 we we PRP 362 370 describe describe VBP 371 374 the the DT 375 383 presence presence NN 384 386 of of IN 387 401 constitutively constitutively RB 402 411 activated activate VBN 412 416 STAT stat NN 417 424 factors factor NNS 425 427 in in IN 428 438 peripheral peripheral JJ 439 444 blood blood NN 445 450 cells cell NNS 451 455 from from IN 456 464 patients patient NNS 465 469 with with IN 470 475 acute acute JJ 476 484 leukemia leukemia NN 484 485 . . . 486 488 We we PRP 489 493 used use VBD 494 509 oligonucleotide oligonucleotide NN 510 516 probes probe NNS 517 521 from from IN 522 525 the the DT 526 537 beta-casein beta-casein NN 538 541 and and CC 542 547 IRF-1 irf-1 NN 548 552 gene gene NN 553 562 promoters promoter NNS 563 566 and and CC 567 570 the the DT 571 575 ISRE ISRE NNP 576 581 probe probe NN 582 584 to to TO 585 591 detect detect VB 592 596 STAT stat NN 597 605 proteins protein NNS 606 608 in in IN 609 616 nuclear nuclear JJ 617 625 extracts extract NNS 626 630 from from IN 631 636 acute acute JJ 637 645 leukemia leukemia NN 646 651 cells cell NNS 652 654 in in IN 655 664 bandshift bandshift NN 665 671 assays assay NNS 671 672 . . . 673 681 Specific specific JJ 682 685 DNA dna NN 686 693 protein protein NN 694 701 complex complex NN 702 711 formation formation NN 712 715 was be VBD 716 724 observed observe VBN 725 729 with with IN 730 733 the the DT 734 740 probes probe NNS 741 745 from from IN 746 749 the the DT 750 761 beta-casein beta-casein NN 762 765 and and CC 766 771 IRF-1 irf-1 NN 772 776 gene gene NN 777 786 promoters promoter NNS 786 787 , , , 788 791 but but CC 792 795 not not RB 796 800 with with IN 801 804 the the DT 805 809 ISRE ISRE NNP 810 825 oligonucleotide oligonucleotide NN 826 831 probe probe NN 831 832 , , , 833 837 when when WRB 838 842 cell cell NN 843 851 extracts extract NNS 852 856 from from IN 857 862 acute acute JJ 863 876 lymphoblastic lymphoblastic JJ 877 885 leukemia leukemia NN 886 887 ( ( ( 887 890 ALL ALL NNP 890 891 ) ) ) 892 895 and and CC 896 901 acute acute JJ 902 909 myeloid myeloid JJ 910 918 leukemia leukemia NN 919 920 ( ( ( 920 923 AML AML NNP 923 924 ) ) ) 925 929 were be VBD 930 942 investigated investigate VBN 942 943 . . . 944 946 We we PRP 947 951 used use VBD 952 966 nonradioactive nonradioactive JJ 967 983 oligonucleotides oligonucleotide NNS 984 986 as as IN 987 998 competitors competitor NNS 999 1001 to to TO 1002 1006 show show VB 1007 1010 the the DT 1011 1022 specificity specificity NN 1023 1025 of of IN 1026 1029 the the DT 1030 1037 complex complex NN 1038 1047 formation formation NN 1047 1048 . . . 1049 1057 Specific specific JJ 1058 1068 antibodies antibody NNS 1069 1077 directed direct VBN 1078 1085 against against IN 1086 1089 the the DT 1090 1100 individual individual JJ 1101 1105 STAT stat NN 1106 1114 proteins protein NNS 1115 1119 were be VBD 1120 1124 used use VBN 1125 1127 in in IN 1128 1138 supershift supershift NN 1139 1150 experiments experiment NNS 1150 1151 . . . 1152 1158 STAT5- stat5- NN 1159 1162 and and CC 1163 1176 STAT1-related stat1-related JJ 1177 1184 factors factor NNS 1185 1189 were be VBD 1190 1198 detected detect VBN 1199 1201 in in IN 1202 1205 ALL ALL NNP 1206 1209 and and CC 1210 1216 STAT1- STAT1- NNP 1216 1217 , , , 1218 1224 STAT3- stat3- NN 1224 1225 , , , 1226 1229 and and CC 1230 1243 STAT5-related stat5-related JJ 1244 1252 proteins protein NNS 1253 1257 were be VBD 1258 1265 present present JJ 1266 1268 in in IN 1269 1276 nuclear nuclear JJ 1277 1281 cell cell NN 1282 1290 extracts extract NNS 1291 1295 from from IN 1296 1299 AML AML NNP 1299 1300 . . . 1301 1306 Since since IN 1307 1310 the the DT 1311 1316 cells cell NNS 1317 1321 were be VBD 1322 1325 not not RB 1326 1333 treated treat VBN 1334 1338 with with IN 1339 1348 cytokines cytokine NNS 1349 1355 before before IN 1356 1359 the the DT 1360 1367 nuclear nuclear JJ 1368 1376 proteins protein NNS 1377 1381 were be VBD 1382 1391 extracted extract VBN 1391 1392 , , , 1393 1395 we we PRP 1396 1404 conclude conclude VBP 1405 1409 that that IN 1410 1415 these these DT 1416 1423 factors factor NNS 1424 1427 are be VBP 1428 1442 constitutively constitutively RB 1443 1452 activated activate VBN 1453 1455 in in FW 1456 1460 vivo vivo FW 1460 1461 . . . 1462 1464 It it PRP 1465 1467 is be VBZ 1468 1474 likely likely JJ 1475 1479 that that IN 1480 1483 the the DT 1484 1496 constitutive constitutive JJ 1497 1507 activation activation NN 1508 1510 of of IN 1511 1515 STAT STAT NNP 1516 1524 proteins protein NNS 1525 1527 is be VBZ 1528 1529 a a DT 1530 1534 part part NN 1535 1537 of of IN 1538 1541 the the DT 1542 1548 events event NNS 1549 1551 of of IN 1552 1566 leukemogenesis leukemogenesis NN 1566 1567 . . .