6-Formylindolo(3,2-b)Carbazole (FICZ) Modulates the Signalsome Responsible for RA-Induced Differentiation of HL-60 Myeloblastic Leukemia Cells.
6-Formylindolo(3,2-b)carbazole (FICZ) is a photoproduct of tryptophan and an endogenous high affinity ligand for aryl hydrocarbon receptor (AhR). It was previously reported that, in patient-derived HL-60 myeloblastic leukemia cells, retinoic acid (RA)-induced differentiation is driven by a signalsome containing c-Cbl and AhR. FICZ enhances RA-induced differentiation, assessed by expression of the membrane differentiation markers CD38 and CD11b, cell cycle arrest and the functional differentiation marker, inducible oxidative metabolism. Moreover, FICZ augments the expression of a number of the members of the RA-induced signalsome, such as c-Cbl, Vav1, Slp76, PI3K, and the Src family kinases Fgr and Lyn. Pursuing the molecular signaling responsible for RA-induced differentiation, we characterized, using FRET and clustering analysis, associations of key molecules thought to drive differentiation. Here we report that, assayed by FRET, AhR interacts with c-Cbl upon FICZ plus RA-induced differentiation, whereas AhR constitutively interacts with Cbl-b. Moreover, correlation analysis based on the flow cytometric assessment of differentiation markers and western blot detection of signaling factors reveal that Cbl-b, p-p38α and pT390-GSK3β, are not correlated with other known RA-induced signaling components or with a phenotypic outcome. We note that FICZ plus RA elicited signaling responses that were not typical of RA alone, but may represent alternative differentiation-driving pathways. In clusters of signaling molecules seminal to cell differentiation, FICZ co-administered with RA augments type and intensity of the dynamic changes induced by RA. Our data suggest relevance for FICZ in differentiation-induction therapy. The mechanism of action includes modulation of a SFK and MAPK centered signalsome and c-Cbl-AhR association.
Department of Biomedical Sciences, Cornell University, Ithaca, New York, 14853, United States of America.
Rodica P
RP
Bunaciu
Department of Biomedical Sciences, Cornell University, Ithaca, New York, 14853, United States of America; School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York, 14853, United States of America.
Holly A
HA
Jensen
Department of Biomedical Sciences, Cornell University, Ithaca, New York, 14853, United States of America.
Robert J
RJ
MacDonald
Flow Cytometry Core Facility, Cornell University, Ithaca, New York, 14853, United States of America.
Dorian H
DH
LaTocha
School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York, 14853, United States of America.
Jeffrey D
JD
Varner
Department of Biomedical Sciences, Cornell University, Ithaca, New York, 14853, United States of America; Flow Cytometry Core Facility, Cornell University, Ithaca, New York, 14853, United States of America.
Andrew
A
Yen
D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D039481:CD11b Antigen / Q000378:metabolism; D002227:Carbazoles / Q000494:pharmacology*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D045744:Cell Line, Tumor; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D050721:Proto-Oncogene Proteins c-cbl / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014212:Tretinoin / Q000494:pharmacology*; D019061:src-Family Kinases / Q000378:metabolism
C111855:6-formylindolo(3,2-b)carbazole; D000970:Antineoplastic Agents; D015415:Biomarkers; D039481:CD11b Antigen; D002227:Carbazoles; D018336:Receptors, Aryl Hydrocarbon; D014212:Tretinoin; D050721:Proto-Oncogene Proteins c-cbl; D019061:src-Family Kinases; D020928:Mitogen-Activated Protein Kinases; D051997:ADP-ribosyl Cyclase 1