Breast cancer is the leading cause of
cancer death among women.
Paclitaxel, a mitotic inhibitor, is highly effective in the treatment of
breast cancer. However, development of resistance to
paclitaxel limits its clinical use. Identifying new compounds and new strategies that are effective against
breast cancer, in particular
drug-resistant
cancer, is of great importance. the aim of the present study was to explore the potential of a next-generation
taxoid,
SB-T-121205, in modulating the proliferation, migration and invasion of
paclitaxel-resistant human
breast cancer cells (MCF-7/PTX) and further evaluate the underlying molecular mechanisms. The results of MTT assay showed that
SB-T-121205 has much higher potency to human
breast cancer cells (MCF-7/S, MCF-7/PTX and MDA-MB-453 cells) than
paclitaxel, while that the non-tumorigenic human bronchial epithelial cells (BEAS-2B) were slightly less sensitive to
SB-T-121205 than
paclitaxel. Flow cytometry and western blot methods revealed that
SB-T-121205 induced cell cycle arrest at the G2/M phase and apoptosis in MCF-7/PTX cells through accelerating mitochondrial apoptotic pathway, resulting in reduction of Bcl-2/Bax ratio, as well as elevation of
caspase-3,
caspase-9, and
poly(ADP-ribose) polymerase (PARP) levels. Moreover,
SB-T-121205 changed epithelial-mesenchymal transition (EMT) property, and suppressed migration and invasion abilities of MCF-7/PTX cells. Additionally,
SB-T-121205 exerted antitumor activity by inhibiting the
transgelin 2 and PI3K/Akt pathway. These findings indicate that
SB-T-121205 is a potent
antitumor agent that promotes apoptosis and also recedes migration/invasion abilities of MCF-7/PTX cells by restraining the activity of
transgelin 2 and PI3K/Akt, as well as mitochondrial apoptotic pathway. Such results suggest a potential clinical value of
SB-T-121205 in
breast cancer treatment.