anthricin and Glioblastoma

Deoxypodophyllotoxin (DPT) is a natural chemical that has been demonstrated to inhibit cellular viability and motility in various cancer cell types. Although previous studies have indicated that programmed cell death and cell cycle arrest are involved in the suppression of glioma development by DPT, the underlying mechanism has not been fully explored. Different methods were used to the elucidate the mechanisms of DPT that inhibit the malignant behavior of glioma cells. Cellular viability was assessed by MTT assay. Relative protein and mRNA expression levels were detected by western blot analysis and reverse transcription‑quantitative polymerase chain reaction analyses, respectively. Cell cycle distribution and the apoptosis rate were detected by flow cytometry. Hochest 33258 staining was also performed to detect apoptosis. Transwell assays without and with Matrigel were used to assess migration and invasion abilities, respectively. It was determined that DPT suppressed cellular viability by inducing cell cycle arrest at the G1/S phase by targeting the phosphatidylinositol 4,5‑bisphosphate 3‑kinase (PI3K)/RAC‑α serine/threonine‑protein kinase (Akt)‑cyclin‑dependent kinase inhibitor 1‑cyclin‑dependent kinase 2/cyclin E signaling cascades. Additionally, DPT significantly enhanced apoptosis by attenuating the PI3K/Akt‑mediated suppression of Bcl‑2‑associated agonist of cell death expression, which was accompanied by an increased apoptosis regulator BAX/apoptosis regulator Bcl‑2 ratio. Furthermore, DPT downregulated the invasiveness of glioma cells by hindering PI3K/Akt‑matrix metalloproteinase (MMP)9/MMP2 signaling pathways. In conclusion, DPT effectively inhibited the expression of PI3K and downregulated PI3K/Akt‑mediated signaling pathways to prevent glioblastoma progression.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Astrocytes; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Podophyllotoxin; Proto-Oncogene Proteins c-akt; Sequiviridae; Signal Transduction

Deoxypodophyllotoxin (DPT) is a semi-synthetic compound derived from the extract of Dysosma versipellis (Hance) M. Cheng, one of the most popular Chinese herbal medicines. The present study evaluates the in vitro cytotoxicity of DPT on a wide panel of human cancer cell lines and investigates its molecular mechanism of action on high grade glioma U-87 MG and SF126 cells.. The growth inhibitory effect of DPT on different types of human cancer cells was measured by the Cell Counting Kit-8 (CCK-8) assay. For the elucidation of the nature of the cellular response to DPT-treatment; flow cytometry-based assays, light and fluorescent microscopy, caspase colorimetric and inhibition assays, and Western blot analysis were performed.. Our data show that DPT possesses a potent growth-inhibitory action, with IC50 values in nanomolar ranges. Cell cycle analysis revealed G2/M phase arrest in a dose- and time-dependent manner before cell death occurred. Additional studies indicated that DPT induced G2 arrest in U-87 MG cells by decreasing the expression of Cdc2, cyclin B1, and Cdc25C proteins. In contrast, DPT failed to down-regulate these cell cycle regulatory molecules in SF126 glioblastoma cells and stopped the cell cycle at M phase. Interestingly, morphological changes and biochemical markers such as phosphatydylserine externalization, DNA fragmentation, and caspase activation, confirmed that DPT-treatment resulted in an induction of apoptosis in both examined cell lines via caspase-dependent pathways.. Taken together, our data demonstrated that DPT possesses a potent in vitro cytotoxic activity and exerts its effect via G2/M arrest and apoptosis.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Caspases; CDC2 Protein Kinase; cdc25 Phosphatases; Cell Count; Cell Cycle; Cell Line, Tumor; Cyclin B1; Cyclin-Dependent Kinases; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; Glioblastoma; Humans; Membrane Potential, Mitochondrial; Podophyllotoxin