One-Two Punch Therapy for the Treatment of T-Cell Malignancies Involving p53-Dependent Cellular Senescence.

T-cell malignancies are still difficult to treat due to a paucity of plans that target critical dependencies. Drug-induced cellular senescence provides a permanent cell cycle arrest during tumorigenesis and cancer development, particularly when combined with senolytics to promote apoptosis of senescent cells, which is an innovation for cancer therapy. Here, our research found that wogonin, a well-known natural flavonoid compound, not only had a potential to inhibit cell growth and proliferation but also induced cellular senescence in T-cell malignancies with nonlethal concentration. Transcription activity of senescence-suppression human telomerase reverse transcriptase (hTERT) and oncogenic C-MYC was suppressed in wogonin-induced senescent cells, resulting in the inhibition of telomerase activity. We also substantiated the occurrence of DNA damage during the wogonin-induced aging process. Results showed that wogonin increased the activity of senescence-associated ß-galactosidase (SA-ß-Gal) and activated the DNA damage response pathway mediated by p53. In addition, we found the upregulated expression of BCL-2 in senescent T-cell malignancies because of the antiapoptotic properties of senescent cells. Following up this result, we identified a BCL-2 inhibitor Navitoclax (ABT-263), which was highly effective in decreasing cell viability and inducing apoptotic cell death in wogonin-induced senescent cells. Thus, the "one-two punch" approach increased the sensibility of T-cell malignancies with low expression of BCL-2 to Navitoclax. In conclusion, our research revealed that wogonin possesses potential antitumor effects based on senescence induction, offering a better insight into the development of novel therapeutic methods for T-cell malignancies.

Effect of Jiajian Guishen Formula on the senescence-associated heterochromatic foci in mouse ovaria after induction of premature ovarian aging by the endocrine-disrupting agent 4-vinylcyclohexene diepoxide.

ETHNOPHARMACOLOGICAL RELEVANCE: Jiajian Guishen Formula (JJGSF), which is a prescription of Traditional Chinese Medicine (TCM), has been reported to be useful in the treatment of premature ovarian insufficiency (POI). AIM OF THE STUDY: To investigate the therapeutic effects of JJGSF on the treatment of POI induced by 4-vinylcyclohexene diep-oxide (VCD), an endocrine-disrupting chemical (EDC), and to elucidate the potential mechanism. MATERIALS AND METHODS: Female 8-week-old ICR mice (N = 72) were randomized into six groups, containing the Model group, Control group, three JJGSF groups, and Progynova group which was served as a positive control. After model establishment by VCD, the Progynova group were given a daily intragastric administration of Progynova, and the three JJGSF groups (high dose group, medium dose group and low dose group) received a daily intragastric administration of JJGSF at doses of 9, 4.5 and 2.25 g/kg for four weeks. The general growth of the mice was observed and the estrous cycles were examined. The serum hormone concentrations were measured by enzyme-linked immunosorbent assay (ELISA). To explore the potential mechanism of effect, the protein expressions of H3K9me3, HP1, and HMGA1/HMGA2 related to senescence-associated heterochromatic foci (SAHF), were determined by Immunofluorescence and Western blot analysis, respectively. RESULTS: After treating with JJGSF, the estrous cycles were improved significantly. The level of estrogen (E2) and anti-müllerian hormone (AMH) was increased and the ratio of follicle-stimulating hormone (FSH) to luteinizing hormone (LH) in serum was decreased significantly. Furthermore, a significant down-regulation of HMGA1/HMGA2 on protein level, a reduction distribution of HP1 and H3K9me3 in ovarian, and a lower fraction of SAHF-positive cells were observed after the administration with JJGSF, additionally effects showed a positive correlation with dosages. CONCLUSIONS: JJGSF could treat POI by the mechanism of inhibiting SAHF.

Putative Epimutagens in Maternal Peripheral and Cord Blood Samples Identified Using Human Induced Pluripotent Stem Cells.

The regulation of transcription and genome stability by epigenetic systems are crucial for the proper development of mammalian embryos. Chemicals that disturb epigenetic systems are termed epimutagens. We previously performed chemical screening that focused on heterochromatin formation and DNA methylation status in mouse embryonic stem cells and identified five epimutagens: diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se), and octachlorodipropyl ether (S-421). Here, we used human induced pluripotent stem cells (hiPSCs) to confirm the effects of 20 chemicals, including the five epimutagens, detected at low concentrations in maternal peripheral and cord blood samples. Of note, these individual chemicals did not exhibit epimutagenic activity in hiPSCs. However, because the fetal environment contains various chemicals, we evaluated the effects of combined exposure to chemicals (DEP, Hg, cotinine, Se, and S-421) on hiPSCs. The combined exposure caused a decrease in the number of heterochromatin signals and aberrant DNA methylation status at multiple gene loci in hiPSCs. The combined exposure also affected embryoid body formation and neural differentiation from hiPSCs. Therefore, DEP, Hg, cotinine, Se, and S-421 were defined as an "epimutagen combination" that is effective at low concentrations as detected in maternal peripheral and cord blood.