Anticancer and immunomodulatory activities of a novel water-soluble derivative of ellipticine

Cancer still remains a major public health concern around the world and the search for
new potential antitumor molecules is essential for fighting the disease. This study evaluated the
anticancer and immunomodulatory potential of the newly synthetized ellipticine derivate: sodium
bromo-5,11-dimethyl-6H-pyrido[4,3-b]carbazole-7-sulfonate (Br-Ell-SO3Na). It was prepared by the
chlorosulfonation of 9-bromoellipticine. The ellipticine-7-sulfonic acid itself is not soluble, but its
saponification with sodium hydroxide afforded a water-soluble sodium salt. The cytotoxicity of
Br-Ell-SO3Na was tested against cancerous (K562 cell line) and non-cancerous cells (Vero cell line and
human peripheral blood mononuclear cells (PBMC)) using a Methylthiazoletetrazolium (MTT) assay.
Cell cycle arrest was assessed by flow cytometry and the immunomodulatory activity was analyzed
through an enzyme-linked immunosorbent assay (ELISA). The results showed that the Br-Ell-SO3Na
molecule has specific anticancer activity (IC50 = 35 µM) against the K562 cell line, once no cytotoxicity
effect was verified against non-cancerous cells. Cell cycle analysis demonstrated that K562 cells
treated with Br-Ell-SO3Na were arrested in the phase S. Moreover, the production of IL-6 increased
and the expression of IL-8 was inhibited in the human PBMC treated with Br-Ell-SO3Na. The results
demonstrated that Br-Ell-SO3Na is a promising anticancer molecule attested by its noteworthy activity
against the K562 tumor cell line and immunomodulatory activity in human PBMC cells.