Evaluation of the antitumoral effect of dihydrocucurbitacin-B in both in vitro and in vivo models.
OBJECTIVE
We evaluated both in vitro and in vivo antitumoral properties of an isolated compound from Wilbrandia ebracteata, dihydrocucurbitacin-B (DHCB), using B16F10 cells (murine melanoma).


METHODS
We made use of MTT and (3)H-Thymidine assays to investigate the cell viability and cell proliferation, flow cytometry analysis to monitor cell cycle and apoptosis, western blot analysis to evaluate the expression of cell cycle proteins, imunofluorescence analysis and in vivo tumor growth and metastasis.


RESULTS
Dihydrocucurbitacin-B significantly reduced cell proliferation without important effects on cells viability. DHCB lead cells to accumulate in G2/M phases accompanied by the appearance of polyploid cells, confirmed by fluorescence assays that demonstrated a remarkable alteration in the cell cytoskeleton and formation of binuclear cells. Annexin-V-FITC incorporation demonstrated that DHCB did not induce apoptosis. About 10 microg/mL DHCB was found to decrease cyclin-A, and especially in cyclin-B1. The in vivo experiments showed that DHCB treatment (once a day up to 12 days; p.o.) was able to reduce the tumor growth and lung metastasis up to 83.5 and 50.3%, respectively.


CONCLUSIONS
Dihydrocucurbitacin-B reduces cell proliferation due to a decrease in the expression of cyclins, mainly cyclin-B1 and disruption of the actin cytoskeleton, arresting B16F10 cells in G2/M phase. Taken together, the in vitro and in vivo experiments suggest that DHCB was effective against cancer, however, it remains to be proved if DHCB will be a good candidate for drug development.
Siqueira
Jarbas Mota
JM
Department of Pharmacology, CCB, Bloco D, Federal University of Santa Catarina, Florianópolis, SC, Brazil. jarbasms@farmaco.ufsc.br
Gazola
Andressa Córneo
AC
Farias
Mareni Rocha
MR
Volkov
Lëonid
L
Rivard
Nathalie
N
de Brum-Fernandes
Artur José
AJ
Ribeiro-do-Valle
Rosa Maria
RM
D000199:Actins / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019662:Cucurbitaceae / Q000737:chemistry*; D016213:Cyclins / Q000187:drug effects / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D008297:Male; D008546:Melanoma, Experimental / Q000188:drug therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*
D000199:Actins; D000972:Antineoplastic Agents, Phytogenic; D016213:Cyclins; D014315:Triterpenes; C523469:dihydrocucurbitacin B