tachyplesin-peptide--tachypleus-tridentatus and Glioma

Tachyplesin I is a cationic peptide isolated from hemocytes of the horseshoe crab and its anti-tumor activity has been demonstrated in several tumor cells. However, there is limited information providing the global effects and mechanisms of tachyplesin I on glioblastoma multiforme (GBM). Here, by using two complementary proteomic strategies (2D-DIGE and dimethyl isotope labeling-based shotgun proteomics), we explored the effect of tachyplesin I on the proteome of gliomaspheres, a three-dimensional growth model formed by a GBM cell line U251. In total, the expression levels of 192 proteins were found to be significantly altered by tachyplesin I treatment. Gene ontology (GO) analysis revealed that many of them were cytoskeleton proteins and lysosomal acid hydrolases, and the mostly altered biological process was related to cellular metabolism, especially glycolysis. Moreover, we built protein-protein interaction network of these proteins and suggested the important role of DNA topoisomerase 2-alpha (TOP2A) in the signal-transduction cascade of tachyplesin I. In conclusion, we propose that tachyplesin I might down-regulate cathepsins in lysosomes and up-regulate TOP2A to inhibit migration and promote apoptosis in glioma, thus contribute to its anti-tumor function. Our results suggest tachyplesin I is a potential candidate for treatment of glioma.

Topics: Antigens, Neoplasm; Antimicrobial Cationic Peptides; Antineoplastic Agents; Apoptosis; Cathepsins; Cell Line, Tumor; Cell Movement; DNA Topoisomerases, Type II; DNA-Binding Proteins; Down-Regulation; Glioblastoma; Glioma; Glycolysis; Humans; Lysosomes; Peptides, Cyclic; Poly-ADP-Ribose Binding Proteins; Proteome; Proteomics; Up-Regulation

Glioblastoma, is one of the most malignant types of intracranial tumor with complex progressive cellular and underlying molecular events. The use of glioma stem cells (GSCs) offers a promising strategy for tumor therapy in the future. Tachyplesin I has been demonstrated to have potential anticancer activity and was first observed in leukocytes. In the present study, the GSC subset was isolated from U251 glioma cells and tachyplesin I was assessed for antitumor activity. As a result, the U251 cells exhibited certain GSC phenotypes, including the expression of stem cell biomarkers CD133 and nestin, when transferred into stem cell culture conditions. The GSCs were grown in an adherent manner in a medium containing serum, while the U251 glioma cells were suspended and cultured in serum‑free medium. Tachyplesin I damaged the structure of GSC and inhibited the culture of GSC spheres in a time and dose‑dependent manner. When tachyplesin I was administered at a concentration of 10‑40 µg/ml, GSC differentiation was induced. GSCs treated with a low dose of tachyplesin I disrupted the plasma membrane and led to a loss of cytoplasmic organelles. These findings indicated that tachyplesin I had an effect on inhibiting tumor stem cells and demonstrated that tachyplesin I inhibited GSCs by disrupting the plasma membranes and inducing GSC differentiation.

Topics: Antimicrobial Cationic Peptides; Cell Line, Tumor; Cell Proliferation; DNA-Binding Proteins; Dose-Response Relationship, Drug; Glioma; Humans; Neoplastic Stem Cells; Peptides, Cyclic; Spheroids, Cellular; Tumor Cells, Cultured