0 1 A a DT 2 7 newly newly RB 8 19 established establish VBN 20 46 megakaryoblastic/erythroid megakaryoblastic/erythroid JJ 47 51 cell cell NN 52 56 line line NN 57 61 that that WDT 62 76 differentiates differentiate VBZ 77 79 to to TO 80 83 red red JJ 84 89 cells cell NNS 90 92 in in IN 93 96 the the DT 97 105 presence presence NN 106 108 of of IN 109 123 erythropoietin erythropoietin NN 124 127 and and CC 128 136 produces produce VBZ 137 150 platelet-like platelet-like JJ 151 160 particles particle NNS 160 161 . . . 163 165 In in IN 166 172 August August NNP 172 173 , , , 174 178 1992 1992 CD 178 179 , , , 180 182 we we PRP 183 194 established establish VBD 195 196 a a DT 197 205 leukemic leukemic JJ 206 210 cell cell NN 211 215 line line NN 216 217 ( ( ( 217 223 NS-Meg NS-Meg NNP 223 224 ) ) ) 225 229 from from IN 230 231 a a DT 232 239 patient patient NN 240 242 in in IN 243 259 megakaryoblastic megakaryoblastic JJ 260 274 transformation transformation NN 275 277 of of IN 278 290 Philadelphia Philadelphia NNP 291 310 chromosome-positive chromosome-positive JJ 311 318 chronic chronic JJ 319 326 myeloid myeloid JJ 327 335 leukemia leukemia NN 335 336 . . . 337 340 The the DT 341 347 NS-Meg NS-Meg NNP 348 353 cells cell NNS 354 358 were be VBD 359 367 positive positive JJ 368 371 for for IN 372 386 alpha-naphthyl alpha-naphthyl NN 387 394 acetate acetate NN 395 403 esterase esterase NN 404 407 and and CC 408 416 periodic periodic JJ 417 428 acid-Schiff acid-schiff NN 429 430 ( ( ( 430 433 PAS PAS NNP 433 434 ) ) ) 435 443 staining staining NN 444 447 and and CC 448 451 for for IN 452 459 surface surface NN 460 463 CD4 cd4 NN 463 464 , , , 465 468 CD7 CD7 NNP 468 469 , , , 470 474 CD13 CD13 NNP 474 475 , , , 476 480 CD34 CD34 NNP 480 481 , , , 482 487 CD41a CD41a NNP 487 488 , , , 489 492 and and CC 493 504 glycophorin glycophorin NN 505 506 A a NN 507 515 antigens antigen NNS 515 516 . . . 517 534 Ultrastructurally ultrastructurally RB 534 535 , , , 536 539 the the DT 540 545 cells cell NNS 546 549 had have VBD 550 564 alpha-granules alpha-granule NNS 564 565 , , , 566 577 demarcation demarcation NN 578 587 membranes membrane NNS 587 588 , , , 589 592 and and CC 593 601 platelet platelet NN 602 612 peroxidase peroxidase NN 613 621 activity activity NN 621 622 . . . 623 626 The the DT 627 633 NS-Meg NS-Meg NNP 634 639 cells cell NNS 640 653 spontaneously spontaneously RB 654 662 produced produce VBD 663 676 platelet-like platelet-like JJ 677 686 particles particle NNS 687 692 which which WDT 693 702 contained contain VBD 703 717 alpha-granules alpha-granule NNS 717 718 , , , 719 731 mitochondria mitochondrion NNS 732 735 and and CC 736 741 dense dense JJ 742 748 bodies body NNS 748 749 , , , 750 758 strongly strongly RB 759 769 suggesting suggest VBG 770 778 platelet platelet NN 779 789 production production NN 789 790 . . . 791 805 Erythropoietin erythropoietin NN 806 807 ( ( ( 807 810 Epo Epo NNP 810 811 ) ) ) 811 812 , , , 813 835 granulocyte/macrophage granulocyte/macrophage JJ 836 842 colony colony NN 843 854 stimulating stimulate VBG 855 869 factor(GM-CSF) factor(gm-csf) NN 869 870 , , , 871 874 and and CC 875 886 interleukin interleukin NN 887 888 3 3 CD 889 890 ( ( ( 890 894 IL-3 IL-3 NNP 894 895 ) ) ) 896 904 promoted promote VBD 905 908 the the DT 909 915 growth growth NN 916 918 of of IN 919 925 NS-Meg ns-meg NN 926 931 cells cell NNS 931 932 . . . 933 964 Phorbol-12-myristate-13-acetate Phorbol-12-myristate-13-acetate NNP 965 974 increased increase VBD 975 978 the the DT 979 989 expression expression NN 990 992 of of IN 993 997 both both CC 998 1003 CD41a CD41a NNP 1004 1007 and and CC 1008 1012 CD61 cd61 NN 1013 1021 antigens antigen NNS 1021 1022 . . . 1023 1030 Ten-day ten-day JJ 1031 1039 exposure exposure NN 1040 1042 to to TO 1043 1046 Epo Epo NNP 1047 1054 induced induce VBD 1055 1061 mature mature JJ 1062 1075 erythroblasts erythroblast NNS 1076 1079 and and CC 1080 1083 red red JJ 1084 1089 cells cell NNS 1089 1090 . . . 1091 1096 These these DT 1097 1115 benzidine-positive benzidine-positive JJ 1116 1121 cells cell NNS 1122 1126 were be VBD 1127 1135 positive positive JJ 1136 1139 for for IN 1140 1150 hemoglobin hemoglobin NN 1151 1152 F f NN 1153 1161 staining staining NN 1161 1162 . . . 1163 1172 Untreated untreated JJ 1173 1179 NS-Meg NS-Meg NNP 1180 1185 cells cell NNS 1186 1195 expressed express VBD 1196 1200 mRNA mrna NN 1201 1204 for for IN 1205 1208 the the DT 1209 1212 Epo Epo NNP 1213 1221 receptor receptor NN 1222 1223 ( ( ( 1223 1227 EpoR EpoR NNP 1227 1228 ) ) ) 1228 1229 , , , 1230 1233 for for IN 1234 1240 GATA-1 gata-1 NN 1240 1241 , , , 1242 1245 and and CC 1246 1249 for for IN 1250 1255 alpha alpha NN 1256 1257 1 1 CD 1257 1258 , , , 1259 1264 alpha alpha NN 1265 1266 2 2 CD 1267 1270 and and CC 1271 1276 gamma gamma NN 1277 1283 globin globin NN 1284 1289 genes gene NNS 1289 1290 . . . 1291 1296 These these DT 1297 1304 results result NNS 1305 1313 indicate indicate VBP 1314 1318 that that IN 1319 1325 NS-Meg ns-meg NN 1326 1331 cells cell NNS 1332 1339 undergo undergo VBP 1340 1348 terminal terminal JJ 1349 1364 differentiation differentiation NN 1365 1367 of of IN 1368 1372 both both CC 1373 1387 megakaryocytic megakaryocytic JJ 1388 1391 and and CC 1392 1401 erythroid erythroid JJ 1402 1410 lineages lineage NNS 1410 1411 . . . 1412 1416 This this DT 1417 1421 cell cell NN 1422 1426 line line NN 1427 1433 should should MD 1434 1436 be be VB 1437 1438 a a DT 1439 1443 very very RB 1444 1450 useful useful JJ 1451 1455 tool tool NN 1456 1459 for for IN 1460 1463 the the DT 1464 1477 investigation investigation NN 1478 1480 of of IN 1481 1485 both both CC 1486 1500 megakaryocytic megakaryocytic JJ 1501 1504 and and CC 1505 1514 erythroid erythroid JJ 1515 1525 maturation maturation NN 1525 1526 . . .