Silibinin, a natural compound extracted from
milk thistle, has demonstrated antitumor properties in
urinary bladder cancer cells; however, the
role of
TP53 gene in these effects is unclear. In order to better understand the molecular and antiproliferative mechanisms of this compound,
urinary bladder cancer cells with different
TP53 gene status, RT4 (low-grade
tumor, wild
TP53 gene), 5637 (high-grade
tumor, Grade 2, mutated
TP53 gene), and T24 (high-grade
tumor, Grade 3, mutated
TP53 gene) were treated with several concentrations of
silibinin (1, 5, 10, 50, 100, and 150 µM). Cytotoxicity, prooxidant effect, morphological changes,
cell migration,
cell cycle progression, global
methylation profile, and relative expression of HOXB3, c-MYC, PLK1, SMAD4, SRC, HAT, HDAC, and RASSF1A
genes were evaluated. The
silibinin presented cytotoxic and prooxidant effects in the three
cell lines. In mutated TP53
cells, significant interference in
cell migration and
cell cycle arrest at the G2/
M phase was observed. Additionally,
silibinin induced global
DNA hypomethylation in the highest grade
tumor cells. For wild-type TP53
cells, a sub-G1 apoptotic
population was present. Furthermore, there was modulation of
gene expression responsible for
cell growth (SMAD and c-MYC), migration (SRC),
cell cycle kinetics (PLK1), angiogenesis (HOXB3), and of
genes associated with
epigenetic events such as
DNA acetylation (HAT) and deacetylation (HDAC). In conclusion, the
silibinin inhibited the
urinary bladder tumor cell proliferation independently of TP53 status; however,
cell cycle effects,
gene expression changes, and alteration of
cell migration are dependent on TP53 status. © 2020 Wiley Periodicals, Inc.