Histone deacetylases (HDACs) are clinically validated epigenetic drug targets for cancer treatment.

There is a strong rationale to therapeutically target the PI3K/Akt/mTOR and MAPK/ERK pathways in cervical carcinoma since they are highly deregulated in this disease. Previous study by our group have demonstrated that Zeylenone (Zey) exhibited strong suppressive activity on PI3K/AKT/mTOR and MAPK/ERK signaling, providing a foundation to investigate its antitumor activity in cervical carcinoma. Herein, the present study aimed to investigate suppressive effect of Zey on HeLa and CaSki cells, and further explore the underlying mechanisms. Cells were treated with Zey for indicated time, followed by measuring its effects on cell viability, colony formation, cell cycle, cell apoptosis, and signal pathways. In vivo antitumor activity of Zey was then assessed with nude xenografts. We found that Zey substantially suppressed cell proliferation, induced cell cycle arrest, and increased cell apoptosis, accompanied by increased production of ROS, decreased mitochondrial membrane potential, activated caspase apoptotic cascade, and attenuated PI3K/Akt/mTOR and MAPK/ERK pathways. Additionally, in vivo experiments showed that Zey exerted good antitumor efficacy against HeLa bearing mice models via decreasing levels of p-PI3K and p-ERK. Collectively, these data clearly demonstrated the antitumor activity of Zey in cervical carcinoma cells, which is most likely via the regulation of PI3K/Akt/mTOR and MAPK/ERK pathways.

Colorectal cancer (CRC), the third most common cancer worldwide, remains highly lethal as the disease only becomes symptomatic at an advanced stage. Growing evidence suggests that histone deacetylases (HDACs), a group of epigenetic enzymes overexpressed in precancerous lesions of CRC, may represent promising molecular targets for CRC treatment. Histone deacetylase inhibitors (HDACis) have gradually become powerful anti-cancer agents targeting epigenetic modulation and have been widely used in the clinical treatment of hematologic malignancies, while only few studies on the benefit of HDACis in the treatment of CRC. In the present study, we designed a series of small-molecule Thiazole-based HDACis, among which HR488B bound to HDAC1 with a high affinity and exerted effective anti-CRC activity both in vitro and in vivo. Moreover, we revealed that HR488B specifically suppressed the growth of CRC cells by inducing cell cycle G0/G1 arrest and apoptosis via causing mitochondrial dysfunction, reactive oxygen species (ROS) generation, and DNA damage accumulation. Importantly, we noticed that HR488B significantly decreased the expression of the E2F transcription factor 1 (E2F1), which was crucial for the inhibitory effect of HR488B on CRC. Mechanistically, HR488B obviously decreased the phosphorylation level of the retinoblastoma protein (Rb), and subsequently prevented the release of E2F1 from the E2F1/Rb/HDAC1 complex, which ultimately suppressed the growth of CRC cells. Overall, our study suggests that HR488B, a novel and efficient HDAC1 inhibitor, may be a potential candidate for CRC therapy in the future. Furthermore, targeting the E2F1/Rb/HDAC1 axis with HR488B provides a promising therapeutic avenue for CRC.

A series of novel coumarin-based hydroxamate derivatives were designed and synthesized as histone deacetylase inhibitors (HDACis). Selective compounds showed a potent HDAC inhibition with nM IC₅₀ values, with the best compound (10e) being nearly 90 times more active than vorinostat (SAHA) against HDAC1. Compounds 10e and 11d also increased the levels of acetylated histone H3 and H4, which is consistent with their strong HDAC inhibition. In addition, 10e and 11d displayed a higher potency toward human A549 and Hela cancer cell lines compared with SAHA. Moreover, 10e and 11d significantly arrested A549 cells at the G2/M phase and enhanced apoptosis. Molecular docking studies revealed the possible mode of interaction of compounds 10e and 12a with HDAC1. Our findings suggest that these novel coumarin-based HDAC inhibitors provide a promising scaffold for the development of new potential cancer chemotherapies.

Aim: Histone deacetylases (HDACs) are one of the validated targets for cancer treatments. In our previous work, we designed a series of bis-substituted aromatic amide HDAC inhibitors (HDACis), am... Graphical abstract