Recent developments in the literature have demonstrated that curcumin exhibit antioxidant properties
supporting its anti-inflammatory, chemopreventive and antitumoral activities against aggressive and
recurrent cancers. Despite the valuable findings of curcumin against different cancer cells, the clinical
use of curcumin in cancer treatment is limited due to its extremely low aqueous solubility and instability,
which lead to poor in vivo bioavailability and limited therapeutic effects. We therefore focused in the present
study to evaluate the anti-tumor potential of curcumin analogues on the human breast carcinoma
cell lines MDA-MB-231 and MCF-7, as well as their effects on non-tumorigenic normal breast epithelial
cells (MCF-10). The IC50 values of curcumin analogue J1 in these cancer cell lines were determined to be 5
ng/ml and 10 ng/ml, in MDA-MB-231 and MCF-7 cells respectively. Interestingly, at these concentrations,
the J1 did not affect the viability of non-tumorigenic normal breast epithelial cells MCF-10. Furthermore,
we found that J1 strongly induced growth arrest of these cancer cells by modulating the mitochondrial
membrane potentials without significant effect on normal MCF-10 cells using JC-1 staining and flow
cytometry analysis. Using annexin-V/PI double staining assay followed by flow cytometry analysis, we
found that J1 robustly enhanced the induction of apoptosis by increasing the activity of caspases in
MDA-MB-231 and MCF-7 cancer cells. In addition, treatment of breast cancer cells with J1 revealed that,
in contrast to the expression of cyclin B1, this curcumin analogue vigorously decreased the expression of
cyclin A, CDK2 and cyclin E and subsequently sensitized tumor cells to cell cycle arrest. Most importantly,
the phosphorylation of AKT, mTOR and PKC-theta in J1-treated cancer cells was markedly decreased and
hence affecting the survival of these cancer cells. Most interestingly, J1-treated cancer cells exhibited a
significant inhibition in the activation of RhoA followed by reduction in actin polymerization and
cytoskeletal rearrangement in response to CXCL12. Our data reveal the therapeutic potential of the
curcumin analogue J1 and the underlying mechanisms to fight breast cancer cells.