We analyzed the presence of a regulation loop like that between MDA-9/Syntenin - NF-κB - RKIP in three
TNBC cell lines (SUM 149, SUM 159 and MDA-MB-231) and in three cell lines of human liver carcinoma
(HA22T/VGH, Hep3B and HepG2). Both these cancers are characterized by high aggressive phenotype,
poor prognosis and few therapeutic possibilities.
Transient transfection was performed with siRNA anti-MDA-9/Syntenin. Expression of different factors was
evaluated by Real time-PCR and Western blotting, while NF-κB activation by TransAM assay. Invasion
capacity was analyzed by Matrigel Invasion Assay.
We observed that silencing of MDA-9/Syntenin expression by anti-MDA-9/Syntenin siRNA induced NF-κB
downregulation and contemporary restored expression of an important metastasis suppressor like RKIP in all
cancer models; interestingly, RKIP increase in liver cancer models occured only at mRNA levels. Lastly, in
our cell models MDA-9/Syntenin downregulation caused a reduction of invasion ability.
Our data confirmed the key role of MDA-9/Syntenin in cancer biology and for the first time showed that is
part of a regulation loop among NF-κB and RKIP in TNBC and in liver cancer cell lines. This loop could
constitute a new potential pharmacological target and provide new therapeutic approaches
