PARP1 is a hot target, and its inhibitors have been approved for cancer therapy. However, some undesirable properties restrict the application of PARP1 inhibitors, including drug resistance, side e... Graphical abstract
23 October 2024 in Organic & Biomolecular Chemistry
BRD4 inhibitors have demonstrated promising potential in cancer therapy. However, their therapeutic efficacy in breast cancer varies depending on the breast cancer subtype, particularly in the treatment of TNBC. In this study, we designed and synthesized 94 derivatives of 4-(3-(3,5-dimethylisoxazol-4-yl)benzyl)phthalazin-1(2H)-one to evaluate their inhibitory activities against BRD4. Notably, compound DDT26 exhibited the most potent inhibitory effect on BRD4, with an IC50 value of 0.237 ± 0.093 μM. DDT26 demonstrated significant anti-proliferative activity against both TNBC cell lines and MCF-7 cells. Intriguingly, the phthalazinone moiety of DDT26 mimicked the PAPR1 substrate, resulting in DDT26 displaying a moderate inhibitory effect on PARP1 with an IC50 value of 4.289 ± 1.807 μM. Further, DDT26 was shown to modulate the expression of c-MYC and γ-H2AX, induce DNA damage, inhibit cell migration and colony formation, and arrest the cell cycle at the G1 phase in MCF-7 cells. Our findings present potential lead compounds for the development of potent anti-breast cancer agents targeting BRD4.
The malignancy of breast cancer poses a global challenge, with existing treatments often falling short of desired efficacy. Extensive research has underscored the effectiveness of targeting the metabolism of nicotinamide adenine dinucleotide (NAD), a pivotal molecule crucial for cancer cell survival and growth, as a promising anticancer strategy. Within mammalian cells, sustaining optimal NAD concentrations relies on two key enzymes, namely nicotinamide phosphoribosyltransferase (NAMPT) and poly(ADP-ribose) polymer 1 (PARP1). Recent studies have accentuated the potential benefits of combining NAMPT inhibitors and PARP1 inhibitors to enhance therapeutic outcomes, particularly in breast cancer. In this study, we designed and synthesized eleven novel NAMPT/PARP1 dual-target inhibitors. Among them, compound DDY02 exhibited acceptable inhibitory activities against both NAMPT and PARP1, with IC50 values of 0.01 and 0.05 µM, respectively. Moreover, in vitro evaluations revealed that treatment with DDY02 resulted in proliferation inhibition, NAD depletion, DNA damage, apoptosis, and migration inhibition in MDA-MB-468 cells. These results posit DDY02, by targeting NAD metabolism through inhibiting both NAMPT and PARP1, as a promising lead compound for the development of breast cancer therapy.