Pleiotropic anti-myeloma activity of ITF2357: inhibition of interleukin-6 receptor signaling and repression of miR-19a and miR-19b.
BACKGROUND
The histone deacetylase inhibitor ITF2357 has potent cytotoxic activity in multiple myeloma in vitro and has entered clinical trials for this disease.


METHODS
In order to gain an overall view of the activity of ITF2357 and identify specific pathways that may be modulated by the drug, we performed gene expression profiling of the KMS18 multiple myeloma cell line treated with the drug. The modulation of several genes and their biological consequence were verified in a panel of multiple myeloma cell lines and cells freshly isolated from patients by using polymerase chain reaction analysis and western blotting.


RESULTS
Out of 38,500 human genes, we identified 140 and 574 up-regulated genes and 102 and 556 down-modulated genes at 2 and 6 h, respectively, with a significant presence of genes related to transcription regulation at 2 h and to cell cycling and apoptosis at 6 h. Several of the identified genes are particularly relevant to the biology of multiple myeloma and it was confirmed that ITF2357 also modulated their encoded proteins in different multiple myeloma cell lines. In particular, ITF2357 down-modulated the interleukin-6 receptor alpha (CD126) transcript and protein in both cell lines and freshly isolated patients' cells, whereas it did not significantly modify interleukin-6 receptor beta (CD130) expression. The decrease in CD126 expression was accompanied by decreased signaling by interleukin-6 receptor, as measured by STAT3 phosphorylation in the presence and absence of inter-leukin-6. Finally, the drug significantly down-modulated the MIRHG1 transcript and its associated microRNA, miR-19a and miR-19b, known to have oncogenic activity in multiple myeloma.


CONCLUSIONS
ITF2357 inhibits several signaling pathways involved in myeloma cell growth and survival.
Todoerti
Katia
K
Department of Medical Sciences, University of Milan, Fondazione IRCCS Policlinico, Milano, Italy.
Barbui
Valentina
V
Pedrini
Olga
O
Lionetti
Marta
M
Fossati
Gianluca
G
Mascagni
Paolo
P
Rambaldi
Alessandro
A
Neri
Antonino
A
Introna
Martino
M
Lombardi
Luigia
L
Golay
Josée
J
D045744:Cell Line, Tumor; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology / Q000627:therapeutic use*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000473:pathology; D035683:MicroRNAs / Q000235:genetics; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000235:genetics; D019947:Receptors, Interleukin-6 / Q000037:antagonists & inhibitors* / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects
D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D035683:MicroRNAs; D019947:Receptors, Interleukin-6; C113250:interleukin-6 receptor alpha; C502418:givinostat hydrochloride