Morphological and biochemical basis of centchroman as a novel antineoplastic agent in MCF-7 human breast cancer cells

OBJECTIVE: To investigate the antineoplastic potential of a novel antiestrogen (AE) centchroman (CENT) using cell morphology, viability and cathepsin-D (Cath-D) gene expression as indices in MCF-7 human breast cancer cell line. MATERIAL AND METHODS: MCF-7 cells were incubated with CENT (1 μM, 10 μM) in the absence and presence of 17-β estradiol (E₂, 10 nM) for 4 days. Investigations were carried out on alterations in cell morphology, number, Cath-D gene expression using Phase Contrast Microscopy, Trypan-blue dye exclusion and spectrophotometric assay. A standard antiestrogen and antibreast cancer agent tamoxifen (TAM -1 μM, 10 μM) was used as a positive control.
RESULTS: E₂ (10 nM) alone significantly up-regulated the cells morphologically, numerically and biochemically thus establishing their hormonal responsiveness. TAM and CENT at 1 μM each enhanced and reduced the viable cell number respectively whereas both elevated the Cath-D activity. However, 35mm photographic evidence did not indicate any cytotoxic effect with either drug as compared to control. Addition of E₂ to the two ligands separately affected the three parameters similar to that in E₂ alone. With 10 μM TAM and CENT individually, the cells were visually devastated and so were the viable cell numbers and Cath-D gene expression. Supplementation of E₂ under similar conditions failed to undo the damage to the cells morphologically and quantitatively. However, disparate results were observed with regards to the enzyme activity where TAM+E₂ caused inhibition and CENT+E₂ resulted in an induction.
CONCLUSION: It can be concluded that both the AEs TAM and CENT displayed similarities in their antineoplastic action on MCF-7 cells as observed by morphological and viability studies except that the latter proved cytotoxic even at 1μM concentration. TAM and CENT showed a similar effect on Cath-D gene expression except at the higher dose (10 μM). These results suggest that the antiestrogen CENT has better antineoplastic potential as opposed to TAM.