Gastric cancer (GC) is a primary epithelial malignancy originating in the stomach. This research explored the influence and mechanism of Orientin on cellular senescence in GC. Orientin was predicted to regulate multiple cell cycle-related pathways, including cyclin-dependent protein kinase activity. Orientin docked with cyclin dependent kinase 2 (CDK2), cyclin A2 (CCNA2), cyclin E1 (CCNE1), and cyclin E2 (CCNE2) with binding energies of -9.1, -7.5, -7.2, and -8.3 kcal/mol, respectively. The IC 50 values of Orientin for AGS and HGC-27 cells were 24.33 μM and 39.28 μM, respectively. Orientin dose-dependently inhibited GC cell proliferation, promoted G0/G1 phase arrest, as well as downregulated CDK2, CCNA2, CCNE1, and CCNE2 expression. It enhanced senescence-associated β-galactosidase staining intensity, upregulated p16 and p21, and downregulated phosphorylated retinoblastoma (p-Rb). In vivo , Orientin also suppressed tumor progression, promoted p16 and p21 expression, and inhibited CCNE/CCNA-CDK2 signaling. Orientin exerts anti-cancer effects in GC through triggering cellular senescence and cell cycle arrest, likely via activating p16/p21-Rb signaling axis and inhibiting the CCNE/CCNA-CDK2 pathway. Download: Download high-res image (282KB) Download: Download full-size image
This study aimed to evaluate the anti-cervical cancer activity of chondroitin sulfate–functionalized selenium nanoparticles (SeCS) and to elucidate their action mechanism. Cytotoxic effect of SeCS on HeLa cells was assessed by MTT assay. Further molecular mechanism of SeCS was analyzed by flow cytometric assay and western blotting. The results showed that treatment with SeCS resulted in a dose- and time-dependent inhibition in the proliferation of HeLa cells. The data obtained from flow cytometry demonstrated that SeCS inhibited HeLa cell growth via the induction of S-phase arrest and cell apoptosis. Further mechanism analysis found that SeCS down-regulated expression levels of cyclin A and CDK2 and up-regulated p21 expression, which contributed to S arrest. Moreover, SeCS increased the level of Bax and decreased the expression of Bcl-2, resulting in the release of cytochrome C from mitochondria and activating caspase-3/8/9 for caspase-dependent apoptosis. Meanwhile, intracellular reactive oxygen species (ROS) levels were elevated after SeCS treatment, suggesting that ROS might be upstream of SeCS-induced S-phase arrest and cell apoptosis. These data show that SeCS has anti-tumor effects and possesses the potential to become a new therapeutic agent or adjuvant therapy for cancer patients. Practical Application In our previous study, we used chondroitin sulfate to stabilize nano-selenium to obtain SeCS to improve the bioactivity and stability of nano-selenium. We found that it possessed an inhibitory effect on HeLa cells. However, the molecular mechanism remains unclear. This study elucidated the mechanism of SeCS damage to HeLa cells. SeCS has the potential to become a new therapeutic agent or adjuvant therapy for cancer patients.