ABSTRACT
Proteins with legume lectin domains are known to possess a wide
range of biological functions. The antitumor effects of Concanavalin-A
(ConA) lectin and Tamoxifen (potent antagonist of estrogen and induces
apoptosis in MCF-7 cells) on human breast carcinoma cells were
investigated in vitro. Human breast carcinoma MCF-7 cells were
examined, cell viability, proliferation and cytotoxicity of MCF cells
treated with ConA and Tamoxifen using morphological analysis and
MTT cytotoxicity assay. The effects of ConA compared to Tamoxifen on
the expression of the transcription factor Erα and the expression of antiapoptosis
gene (Bcl2) in breast cancer MCF7 cell line were evaluated by
RT-PCR. The microscopic examination of cells indicated that ConA
induced significant cellular alterations typical of apoptosis cell-death in a
comparable manner as Tamoxifen. ConA showed also proliferation
inhibition activity, however it was lower than tamoxifen, as indicated by
MTT growth inhibition assay. The IC50 of ConA is 7.55 μM and of
Tamoxifen is 2.75 μM. The expression of Erα and Bcl2 proteins after
treatment with ConA were significantly decreased. In conclusion: ConA
induced significant apoptosis and inhibited the proliferation of breast
cancer cells that may be through mechanism involve reduction in the
expression of ERα and anti-apoptotic gene BCl-2. Finally, our results
indicate that ConA exerts anti-tumor actions against human breast
carcinoma MCF-7 cells in vitro and confer support for more research to
unravel the potentials of using concanavalin-A as complementary
treatment of ER+ breast cancer.