0 12 Constitutive constitutive JJ 13 23 activation activation NN 24 26 of of IN 27 36 different different JJ 37 40 Jak Jak NNP 41 49 tyrosine tyrosine NN 50 57 kinases kinase NNS 58 60 in in IN 61 66 human human JJ 67 68 T t NN 69 73 cell cell NN 74 82 leukemia leukemia NN 83 88 virus virus NN 89 93 type type NN 94 95 1 1 CD 96 97 ( ( ( 97 103 HTLV-1 HTLV-1 NNP 103 104 ) ) ) 105 108 tax tax NN 109 116 protein protein NN 117 119 or or CC 120 137 virus-transformed virus-transformed JJ 138 143 cells cell NNS 143 144 . . . 146 152 HTLV-1 htlv-1 NN 153 162 infection infection NN 163 169 causes cause VBZ 170 172 an an DT 173 178 adult adult JJ 179 180 T t NN 181 185 cell cell NN 186 194 leukemia leukemia NN 195 197 in in IN 198 204 humans human NNS 204 205 . . . 206 209 The the DT 210 215 viral viral JJ 216 223 encoded encode VBN 224 231 protein protein NN 232 235 tax tax NN 235 236 , , , 237 239 is be VBZ 240 247 thought think VBN 248 250 to to TO 251 255 play play VB 256 258 an an DT 259 268 important important JJ 269 273 role role NN 274 276 in in IN 277 288 oncogenesis oncogenesis NN 288 289 . . . 290 293 Our our PRP$ 294 302 previous previous JJ 303 307 data datum NNS 308 316 obtained obtain VBN 317 321 from from IN 322 323 a a DT 324 327 tax tax NN 328 338 transgenic transgenic JJ 339 344 mouse mouse NN 345 350 model model NN 351 359 revealed reveal VBD 360 364 that that IN 365 368 tax tax NN 369 379 transforms transform VBZ 380 385 mouse mouse NN 386 397 fibroblasts fibroblast NNS 398 401 but but CC 402 405 not not RB 406 416 thymocytes thymocyte NNS 416 417 , , , 418 425 despite despite IN 426 436 comparable comparable JJ 437 443 levels level NNS 444 446 of of IN 447 450 tax tax NN 451 461 expression expression NN 462 464 in in IN 465 469 both both DT 470 477 tissues tissue NNS 477 478 . . . 479 491 Constitutive constitutive JJ 492 500 tyrosine tyrosine NN 501 516 phosphorylation phosphorylation NN 517 519 of of IN 520 521 a a DT 522 528 130-kD 130-kd JJ 529 539 protein(s) protein(s) NN 540 543 was be VBD 544 552 observed observe VBN 553 555 in in IN 556 559 the the DT 560 563 tax tax NN 564 575 transformed transformed JJ 576 586 fibroblast fibroblast NN 587 588 B B NNP 589 593 line line NN 594 597 and and CC 598 600 in in IN 601 607 HTLV-1 HTLV-1 NNP 608 619 transformed transform VBD 620 625 human human JJ 626 634 lymphoid lymphoid JJ 635 640 lines line NNS 640 641 , , , 642 645 but but CC 646 649 not not RB 650 652 in in IN 653 663 thymocytes thymocyte NNS 664 668 from from IN 669 676 Thy-tax thy-tax JJ 677 687 transgenic transgenic JJ 688 692 mice mouse NNS 692 693 . . . 694 709 Phosphotyrosine Phosphotyrosine NNP 710 729 immunoprecipitation immunoprecipitation NN 730 738 followed follow VBN 739 741 by by IN 742 749 Western western JJ 750 754 blot blot NN 755 763 analysis analysis NN 764 768 with with IN 769 770 a a DT 771 774 set set NN 775 777 of of IN 778 781 Jak Jak NNP 782 788 kinase kinase NNP 789 797 specific specific JJ 798 808 antibodies antibody NNS 808 809 , , , 810 820 identified identify VBD 821 825 p130 p130 NN 826 828 as as IN 829 833 Jak2 jak2 NN 834 836 in in IN 837 840 the the DT 841 844 tax tax NN 845 856 transformed transform VBN 857 862 mouse mouse NN 863 875 fibroblastic fibroblastic JJ 876 880 cell cell NN 881 885 line line NN 886 889 and and CC 890 894 Jak3 jak3 NN 895 897 in in IN 898 904 HTLV-1 HTLV-1 NNP 905 916 transformed transform VBD 917 922 human human JJ 923 924 T t NN 925 929 cell cell NN 930 935 lines line NNS 935 936 . . . 937 952 Phosphorylation phosphorylation NN 953 955 of of IN 956 960 Jak2 jak2 NN 961 963 in in IN 964 967 tax tax NN 968 979 transformed transform VBN 980 985 cells cell NNS 986 994 resulted result VBD 995 999 from from IN 1000 1004 high high JJ 1005 1015 expression expression NN 1016 1018 of of IN 1019 1023 IL-6 IL-6 NNP 1023 1024 . . . 1025 1033 Tyrosine Tyrosine NNP 1034 1049 phosphorylation phosphorylation NN 1050 1052 of of IN 1053 1057 this this DT 1058 1065 protein protein NN 1066 1071 could could MD 1072 1076 also also RB 1077 1079 be be VB 1080 1087 induced induce VBN 1088 1090 in in IN 1091 1100 Balb/c3T3 balb/c3t3 NN 1101 1106 cells cell NNS 1107 1112 using use VBG 1113 1114 a a DT 1115 1126 supernatant supernatant NN 1127 1131 from from IN 1132 1135 the the DT 1136 1137 B B NNP 1138 1142 line line NN 1142 1143 , , , 1144 1149 which which WDT 1150 1153 was be VBD 1154 1164 associated associate VBN 1165 1169 with with IN 1170 1179 induction induction NN 1180 1182 of of IN 1183 1187 cell cell NN 1188 1201 proliferation proliferation NN 1201 1202 . . . 1203 1207 Both both CC 1208 1223 phosphorylation phosphorylation NN 1224 1227 and and CC 1228 1241 proliferation proliferation NN 1242 1246 were be VBD 1247 1256 inhibited inhibit VBN 1257 1259 by by IN 1260 1264 IL-6 IL-6 NNP 1265 1277 neutralizing neutralize VBG 1278 1288 antibodies antibody NNS 1288 1289 . . . 1290 1302 Constitutive constitutive JJ 1303 1318 phosphorylation phosphorylation NN 1319 1321 of of IN 1322 1325 Jak Jak NNP 1326 1333 kinases kinase NNS 1334 1337 may may MD 1338 1348 facilitate facilitate VB 1349 1354 tumor tumor NN 1355 1361 growth growth NN 1362 1364 in in IN 1365 1369 both both CC 1370 1376 HTLV-1 htlv-1 NN 1377 1385 infected infected JJ 1386 1391 human human JJ 1392 1393 T t NN 1394 1399 cells cell NNS 1400 1403 and and CC 1404 1407 the the DT 1408 1418 transgenic transgenic JJ 1419 1424 mouse mouse NN 1425 1430 model model NN 1430 1431 . . .