BACKGROUND AND PURPOSEMarine sponges have evolved the capacity to produce a series of very efficient chemicals to combat viruses, bacteria, and eukaryotic organisms. It has been demonstrated that several of these compounds have anti-neoplastic activity. The highly toxic sponge Crambe crambe has been the source of several molecules named crambescidins. Of these, crambescidin-816 has been shown to be cytotoxic for colon carcinoma cells. To further investigate the potential anti-carcinogenic effect of crambescidin-816, we analysed its effect on the transcription of HepG2 cells by microarray analysis followed by experiments guided by the results obtained.
EXPERIMENTAL APPROACHAfter cytotoxicity determination, a transcriptomic analysis was performed to test the effect of crambescidin-816 on the liver-derived tumour cell HepG2. Based on the results obtained, we analysed the effect of crambescidin-816 on cell-cell adhesion, cell-matrix adhesion, and cell migration by Western blot, confocal microscopy, flow cytometry and transmission electron microscopy. Cytotoxicity and cell migration were also studied in a variety of other cell lines derived from human tumours.
KEY RESULTSCrambescidin-816 had a cytotoxic effect on all the cell lines studied. It inhibited cell-cell adhesion, interfered with the formation of tight junctions, and cell-matrix adhesion, negatively affecting focal adhesions. It also altered the cytoskeleton dynamics. As a consequence of all these effects on cells crambescidin-816 inhibited cell migration.
CONCLUSIONS AND IMPLICATIONSThe results indicate that crambescidin-816 is active against tumour cells and implicate a new mechanism for the anti-tumour effect of this compound.
AbbreviationsACTA, actin alpha; CDKN2A, cyclin-dependent kinase inhibitor 2A (p16); CDKN2D, cyclin-dependent kinase inhibitor 2D (p19); CDK2, cyclin-dependent kinase 2; CLDN, claudin; C816, crambescidin-816; DE, differentially expressed; MTT, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); OCLN, occludin; TUBB, tubulin beta; VCL, vinculin BJP British Journal of Pharmacology