title: The anticancer agent prodigiosin induces p21WAF1/CIP1 expression via transforming growth factor-beta receptor pathway.
abstract: The anticancer agent prodigiosin has been shown to act as an efficient immunosuppressant, eliciting cell cycle arrest at non-cytotoxic concentrations, and potent proapoptotic and antimetastatic effects at higher concentrations. Gene expression profiling of MCF-7 cells after treatment with a non-cytotoxic concentration of prodigiosin showed that expression of the p21WAF1/CIP1 gene, a negative cell cycle regulator was induced. In this study, we show that prodigiosin induces p21 expression leading to cell cycle blockade. Subsequently, we attempted to elucidate the molecular mechanisms involved in prodigiosin-mediated p21 gene expression. We demonstrate that prodigiosin induces p21 in a p53-independent manner as prodigiosin induced p21 in cells with both mutated and dominant negative p53. Conversely, the transforming growth factor-beta (TGF-beta) pathway has been found to be necessary for p21 induction. Prodigiosin-mediated p21 expression was blocked by SB431542, a TGF-beta receptor inhibitor. Nevertheless, this pathway alone is not enough to induce p21 expression. The TGF-beta family member (nonsteroidal anti-inflammatory drug)-activated gene 1/growth differentiation factor 15 (NAG-1) may activate this pathway, as it has previously been suggested to signal through the TGF-beta pathway and is overexpressed in response to prodigiosin treatment. We show that NAG-1 colocalizes with TGF-beta receptor type I, suggesting a possible interaction between them. Taken together, these results suggest the TGF-beta pathway is required for induction of p21 expression after prodigiosin treatment of MCF-7 cells.
authors.affiliation: Department of Pathology and Experimental Therapeutics, Cancer Cell Biology Research Group, Universitat de Barcelona, and Laboratori de Recerca Translacional, ICO-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Soto-Cerrato
authors.forename: Francesc
authors.initials: F
authors.lastname: Viñals
authors.forename: James R
authors.initials: JR
authors.lastname: Lambert
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pérez-Tomás
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001549:Benzamides / Q000494:pharmacology; D015153:Blotting, Western; D001943:Breast Neoplasms; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000096:biosynthesis*; D004149:Dioxoles / Q000494:pharmacology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D011353:Prodigiosin / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: C459179:4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D000970:Antineoplastic Agents; D001549:Benzamides; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004149:Dioxoles; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D016159:Tumor Suppressor Protein p53; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D011353:Prodigiosin