title: Bis-indols: a novel class of molecules enhancing the cytodifferentiating properties of retinoids in myeloid leukemia cells.
abstract: Enhancing the pharmacologic activity of all-trans retinoic acid (ATRA) is potentially useful in the management of acute promyelocytic leukemia (APL) and other types of myeloid leukemia. In this report, we identify a novel class of experimental agents selectively potentiating the cytodifferentiating activity of ATRA and synthetic retinoic acid receptor alpha agonists in APL and other myeloid leukemia cell lines. These agents have a bis-indolic structure (BISINDS), and ST1346 is the prototypical compound of the series. Gene-profiling experiments and determination of the level of expression of myeloid-associated markers indicate that ST1346 stimulates many aspects of the granulocytic maturation process set in motion by ATRA. Stimulation of the cytodifferentiating activity of ATRA by ST1346 enhances the efficacy of the retinoid in vivo, as demonstrated in the APL model of the severe combined immunodeficiency (SCID) mouse receiving transplants of NB4 cells. Although the molecular mechanisms underlying the ATRA-potentiating action of ST1346 and congeners have not been completely clarified, bis-indols are not ligands and do not exert any direct effect on the ATRA-dependent transactivation of nuclear receptors. However, ST1346 inhibits the down-regulation of cyclic adenosine monophosphate (cAMP)-dependent CREB transcriptional complexes and enhances the level of expression of signal transducers and activators of transcription-1 (STAT1), 2 putative molecular determinants of the differentiation process activated by ATRA in APL cells. More importantly, ST1346 relieves the down-regulation of Jun N-terminal kinases (JNK) afforded by ATRA. In addition, a specific JNK inhibitor blocks the enhancing effect of ST1346 on ATRA-induced maturation of NB4 cells. This demonstrates an important role for the mitogen-activated protein kinase in the molecular mechanisms underlying the pharmacologic activity of the bis-indol.
authors.affiliation: Istituto di Ricerche Farmacologiche Mario Negri, Laboratory of Molecular Biology, Centro Catullo e Daniela Borgomainerio, Milano, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Pisano
authors.forename: Peter
authors.initials: P
authors.lastname: Kollar
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gianní
authors.forename: Yesim
authors.initials: Y
authors.lastname: Kalac
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Giordano
authors.forename: Fabiana Fosca
authors.initials: FF
authors.lastname: Ferrara
authors.forename: Richard
authors.initials: R
authors.lastname: Tancredi
authors.forename: Antonio
authors.initials: A
authors.lastname: Devoto
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rinaldi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Rambaldi
authors.forename: Sergio
authors.initials: S
authors.lastname: Penco
authors.forename: Mauro
authors.initials: M
authors.lastname: Marzi
authors.forename: Giampiero
authors.initials: G
authors.lastname: Moretti
authors.forename: Loredana
authors.initials: L
authors.lastname: Vesci
authors.forename: Ornella
authors.initials: O
authors.lastname: Tinti
authors.forename: Paolo
authors.initials: P
authors.lastname: Carminati
authors.forename: Mineko
authors.initials: M
authors.lastname: Terao
authors.forename: Enrico
authors.initials: E
authors.lastname: Garattini
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D006801:Humans; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology*; D007951:Leukemia, Myeloid / Q000188:drug therapy / Q000473:pathology*; D018168:Receptors, Retinoic Acid / Q000187:drug effects / Q000235:genetics; D000072482:Retinoic Acid Receptor alpha; D047488:Retinoid X Receptors; D012176:Retinoids / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000187:drug effects / Q000235:genetics; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007211:Indoles; C000607071:RARA protein, human; C000607072:Rara protein, mouse; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D047488:Retinoid X Receptors; D012176:Retinoids; C471762:ST 1346; D014157:Transcription Factors; D014212:Tretinoin