0 2 An an DT 3 12 essential essential JJ 13 17 role role NN 18 21 for for IN 22 31 NF-kappaB NF-kappaB NNP 32 34 in in IN 35 40 human human JJ 41 48 CD34(+) cd34(+) JJ 49 53 bone bone NN 54 60 marrow marrow NN 61 65 cell cell NN 66 74 survival survival NN 74 75 . . . 77 80 The the DT 81 94 transcription transcription NN 95 101 factor factor NN 101 102 , , , 103 112 NF-kappaB NF-kappaB NNP 112 113 , , , 114 116 is be VBZ 117 126 important important JJ 127 130 for for IN 131 137 T-cell t-cell NN 138 148 activation activation NN 148 149 , , , 150 156 B-cell b-cell NN 157 167 maturation maturation NN 167 168 , , , 169 172 and and CC 173 178 human human JJ 179 195 immunodeficiency immunodeficiency NN 196 201 virus virus NN 202 215 transcription transcription NN 216 219 and and CC 220 225 plays play VBZ 226 227 a a DT 228 232 role role NN 233 235 in in IN 236 249 alternatively alternatively RB 250 259 mediating mediate VBG 260 263 and and CC 264 274 protecting protect VBG 275 282 against against IN 283 292 apoptosis apoptosis NN 293 295 in in IN 296 297 a a DT 298 305 variety variety NN 306 308 of of IN 309 313 cell cell NN 314 319 types type NNS 319 320 . . . 321 328 However however RB 328 329 , , , 330 331 a a DT 332 336 role role NN 337 340 for for IN 341 350 NF-kappaB NF-kappaB NNP 351 353 in in IN 354 359 human human JJ 360 367 CD34(+) cd34(+) JJ 368 372 bone bone NN 373 379 marrow marrow NN 380 385 cells cell NNS 386 389 has have VBZ 390 393 not not RB 394 398 been be VBN 399 408 described describe VBN 408 409 . . . 410 412 We we PRP 413 420 provide provide VBP 421 429 evidence evidence NN 430 434 here here RB 435 439 that that IN 440 449 virtually virtually RB 450 453 all all DT 454 459 human human JJ 460 467 CD34(+) cd34(+) JJ 468 472 bone bone NN 473 479 marrow marrow NN 480 485 cells cell NNS 486 493 express express VBP 494 503 NF-kappaB NF-kappaB NNP 504 508 that that WDT 509 512 can can MD 513 515 be be VB 516 525 activated activate VBN 526 528 by by IN 529 537 exposure exposure NN 538 540 to to TO 541 548 phorbol phorbol NN 549 561 12-myristate 12-myristate NN 562 572 13-acetate 13-acetate NN 573 576 and and CC 577 578 a a DT 579 586 variety variety NN 587 589 of of IN 590 599 cytokines cytokine NNS 599 600 , , , 601 603 eg eg FW 603 604 , , , 605 610 tumor tumor NN 611 619 necrosis necrosis NN 620 626 factor factor NN 627 632 alpha alpha NN 632 633 , , , 634 647 interleukin-3 interleukin-3 NN 647 648 , , , 649 652 and and CC 653 675 granulocyte-macrophage granulocyte-macrophage JJ 676 694 colony-stimulating colony-stimulating JJ 695 701 factor factor NN 701 702 . . . 703 705 In in IN 706 714 addition addition NN 714 715 , , , 716 718 we we PRP 719 730 demonstrate demonstrate VBP 731 735 that that IN 736 745 NF-kappaB NF-kappaB NNP 746 749 may may MD 750 752 be be VB 753 761 required require VBN 762 765 for for IN 766 771 human human JJ 772 779 CD34(+) cd34(+) JJ 780 784 bone bone NN 785 791 marrow marrow NN 792 796 cell cell NN 797 807 clonogenic clonogenic JJ 808 816 function function NN 817 820 and and CC 821 829 survival survival NN 829 830 . . . 831 836 These these DT 837 844 results result NNS 845 850 offer offer VBP 851 858 insight insight NN 859 863 into into IN 864 865 a a DT 866 869 new new JJ 870 874 role role NN 875 878 for for IN 879 888 NF-kappaB NF-kappaB NNP 889 891 in in IN 892 903 maintaining maintain VBG 904 912 survival survival NN 913 916 and and CC 917 925 function function NN 926 928 in in IN 929 942 hematopoietic hematopoietic JJ 943 947 stem stem NN 948 951 and and CC 952 962 progenitor progenitor NN 963 968 cells cell NNS 969 972 and and CC 973 980 suggest suggest VBP 981 985 that that IN 986 994 proposed propose VBN 995 1005 strategies strategy NNS 1006 1015 involving involve VBG 1016 1026 inhibition inhibition NN 1027 1029 of of IN 1030 1039 NF-kappaB NF-kappaB NNP 1040 1050 activation activation NN 1051 1053 as as IN 1054 1056 an an DT 1057 1064 adjunct adjunct NN 1065 1067 to to TO 1068 1074 cancer cancer NN 1075 1087 chemotherapy chemotherapy NN 1088 1094 should should MD 1095 1097 be be VB 1098 1108 approached approach VBN 1109 1113 with with IN 1114 1121 caution caution NN 1121 1122 . . .