Synthesis and evaluation of novel α-substituted chalcones with potent anti-cancer activities and ability to overcome multidrug resistance

A series of forty a-substituted chalcones were synthesized and screened for their antiproliferative activities against HCT116 (colorectal) and HCC1954 (breast) cancer cell lines. Compounds 5a and 5e were found to be the most potent compounds with GI(50) values of 0.63 mu M and 0.725 mu M in HCC1954 cell line and 0.69 mu M and 1.59 mu M in HCT116 cell line, respectively. Both compounds induced a G2/M cell cycle arrest and caused apoptotic cell death in HCT116 cells as shown by the induction of PARP cleavage. The compounds also stabilized p53 in a dose-dependent manner in HCT116 cells following 24-hour treatment. Furthermore, both 5a and 5e were able to overcome multidrug resistance in two MDR-1 overexpressing multidrug resistant cell lines.