Cytogenetic and molecular analysis of the acute monocytic leukemia cell line THP-1 with anMLL-AF9 translocation

Abstract

Cell lines derived from patients with leukemia are used in many molecular biology studies. Here we report the cytogenetic analysis of the THP‐1 cell line using G‐banding, fluorescence in situ hybridization (FISH), and spectral karyotyping (SKY), and the molecular characterization of the MLL‐AF9 rearrangement by RT‐PCR. The THP‐1 cell line was established from the peripheral blood of a 1‐year‐old boy with acute monocytic leukemia (AML‐M5). THP‐1 is near‐diploid and consists of two related subclones with a number of aberrations, including the t(9;11), associated with AML M5. The use of FISH allowed us to identify and characterize otherwise hidden cytogenetic rearrangements, which include duplication of the 3′ portion of MLL in the derivative 9 chromosome and a deletion of the 5′ portion of the AF9 gene involved in the translocation. In addition to confirming the FISH results, SKY allowed for a more precise characterization of the karyotype of THP‐1 and allowed us to identify other abnormalities in this cell line, including der(1)t(1;12), der(20)t(1;20), deletions 6p, 12p, and 17p, trisomy 8, and monosomy 10. Sequencing of the RT‐PCR product showed a direct in‐frame fusion product on the derivative chromosome 11 between exon 6 (exon 9) of MLL and exon 5 of AF9, which is most commonly involved in MLL‐AF9 translocations. This study demonstrates that combining different techniques to achieve a more precise characterization of the THP‐1 cell line provides important information that will be valuable for understanding the critical events required for leukemogenesis. © 2000 Wiley‐Liss, Inc.

Divergent cytotoxic effects of PKC412 in combination with conventional antileukemic agents in FLT3 mutation-positive versus -negative leukemia cell lines

“…The sensitivity is not related to the presence of MLL gene rearrangements, which are observed in MOLM13, MOLM14, MV4-11, KOPB-26 and THP-1 cells among the cell lines used in this study. 27,28,36 The concentration of PKC412 that inhibits the autophosphorylation of FLT3 to 50% of the baseline level has been reported to be approximately 10 nM, 16,37 suggesting that PKC412 inhibits the growth of MOLM13, MOLM14 and MV4-11 solely by FLT3 inhibitory activity. The concentration of PKC412 required to induce substantial levels of cell death for FLT3 mutation-negative cell lines is much higher than the concentration needed to completely inhibit FLT3 phosphorylation.…”

“…Experiments were conducted using eight human leukemia cell lines: MOLM13 and MOLM14 from a patient with acute monocytic leukemia (M5a) carrying t(9;11), 25 MV4-11 from a patient with AML carrying t(4;11), 26 KOPB-26 from a patient with AML carrying t(9;11), 27 THP-1 from a patient with acute monocytic leukemia (M5) carrying t(9;11) 28 and BALL-1, KG-1 and U937 from patients with B-cell acute lymphoblastic leukemia, AML and acute monocytic leukemia, respectively. MV4-11 and THP-1 were purchased from American Type Culture Collection (Manassas, VA, USA).…”

Induction of microRNAs, mir-155, mir-222, mir-424 and mir-503, promotes monocytic differentiation through combinatorial regulation

“…1 For this project we studied monocytic differentiation of the M5 acute myeloid leukemia (AML) cell line THP-1. 2 This cell line contains the MLL-MLLT3 leukemogenic gene fusion 3 and displays a monoblastic phenotype; however, on phorbol myristate acetate (PMA) treatment it differentiates into an adherent monocytic phenotype, 4 closely approximating monoblast to monocyte differentiation.…”

Down-regulation of MLL-AF9, MLL and MYC expression is not obligatory for monocyte-macrophage maturation in AML-M5 cell lines carrying t(9;11)(p22;q23)

“…We recently showed that MLL-AF9 expression is down-regulated during monocytemacrophage maturation induced by ATRA (all-trans-retinoicacid) or PMA/TPA (phorbol-12-myristate-13-acetate) in AML-M5 THP-1 cells (4) carrying t(9;11)(p22;q23) and expressing MLL-AF9 (5). Since then, we have been surprised to observe that in THP-1 cells that have already undergone some months of continuous culture, PMA-or ATRA-induced differentiation is not accompanied by MLL-AF9 down-regulation.…”

“…457,2000). The aim of the present study was to clarify the pattern of MLL-AF9, MLL and MYC expression after induction of monocyte-macrophage terminal differentiation in THP-1, MM6 and MOLM-13, all of which are AML-M5 cell lines carrying t(9;11)(p22;q23) and expressing MLL-AF9 (5,11,12).…”