OBJECTIVES: Pseudolaric acid B (PAB) has been shown to inhibit the growth of various tumor cells, but the molecular details of its function are still unknown. This study investigated the molecular mechanisms by which PAB induces apoptosis in HeLa cells. METHODS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to investigate the effect of PAB treatment in various cervical cancer cell lines. Annexin V/propidium iodide staining combined with flow cytometry and Hoechst 33258 staining were used to assess PAB-induced apoptosis. Additionally, we performed bioinformatics analyses and identified a paired box 2 (PAX2) binding site on the BAX promoter. We then validated the binding using luciferase and chromatin immunoprecipitation assays. Finally, western blotting assays were used to investigate PAB effect on the Wnt signaling and the involved signaling molecules. RESULTS: PAB promotes apoptosis and downregulates PAX2 expression in HeLa cells in a time- and concentration-dependent manner. PAX2 binds to the promoter of BAX and inhibits its expression; therefore, PAX2 inhibition is associated with increased levels of BAX, which induces apoptosis of HeLa cells via the mitochondrial pathway. Additionally, PAB inhibits classical Wnt signaling. CONCLUSION: PAB effectively inhibits Wnt signaling and PAX2 expression, and increases BAX levels, which induce apoptosis in HeLa cells. Therefore, PAB is a promising natural molecule for the treatment of cervical cancer.
Apoptosis ; Binding Sites ; Bisbenzimidazole ; Blotting, Western ; Cell Line ; Chromatin Immunoprecipitation ; Computational Biology ; Flow Cytometry ; HeLa Cells ; Humans ; Luciferases ; Mitochondria ; Uterine Cervical Neoplasms ; Wnt Signaling Pathway

Creating new germplasms and breeding new cultivars in peanut by radiation mutagenesis and tissue culture were conducted in this study, aiming to develop new breeding method of peanut. Mature seeds from Luhua 11, the most commonly grown peanut cultivar in Northern China, were treated by fast neutron irradiation. Then the embryo leaflets were separated from the irradiated seeds and inoculated on the media, and the regenerated seedlings were obtained through somatic embryogenesis pathway. The regenerated seedlings were grafted, acclimated and then transplanted into field and the selfed pods were harvested from 83 regenerated plants. The progenies were selected by the pedigree method, and 107 mutants were obtained from the progenies of the 83 regenerated plants. Different mutants showed obvious variation in many agronomic traits, including main stem height, branch number, pod shape and size, seed coat color, inner seed coat color, oil content and protein content etc. Yuhua 7, a new peanut variety with low oil content, early maturity and waterlogging tolerance was obtained. The yield of Yuhua 7 was over 14% higher than that of the mutagenic parent Luhua 11, and the oil content of kernels was 47.0%, lower than that of parent Luhua 11 with 52.1% oil content. Yuhua 7 had passed peanut variety regional multi-location trials in Liaoning Province in 2016 and its average yield was 13.8% higher than that of the control variety Baisha 1017. It had also passed national peanut variety registration, and the registration ID is "GPD peanut (2018) 370105". The results show that irradiation mutagenesis combined with tissue culture is an effective method for creating new germplasm and breeding new varieties of peanut.
Arachis ; Breeding ; China ; Fast Neutrons ; Plant Breeding ; Seeds