The Indole-3-carbinol cyclic tetrameric derivative CTet synergizes with cisplatin and doxorubicin in triple-negative breast cancer cell lines.

OBJECTIVE

The indole-3-carbinol cyclic tetrameric derivative (CTet) inhibits breast cancer cell proliferation by endoplasmic reticulum stress and autophagy-related cell death induction, AKT/PKB (protein kinase B) activity inhibition and p53-independent overexpression of cyclin-dependent kinase inhibitor-1A (p21/CDKN1A). In the present study we evaluated the synergistic activity of CTet in combination with cisplatin and doxorubicin in triple-negative breast cancer cell lines.

METHODS

Synergisms were evaluated in terms of cell viability, induction of autophagy and overexpression of microtubule-associated protein-1 light chain-3 beta (MAP1LC3B) autophagy-related gene in MDA-MB-231 and BT-20 triple-negative breast cancer cells.

RESULTS

We demonstrated that CTet in combination with both cisplatin and doxorubicin synergistically inhibits cell viability and induces autophay. The MAP1LC3B gene was synergistically overexpressed in MDA-MB-231 cells treated with CTet-cisplatin combination. Moreover, the cytotoxic activity of CTet was improved in cells pre-treated with cisplatin and doxorubicin.

CONCLUSIONS

This preliminary in vitro study confirms the potential of CTet as a chemopreventive agent or chemotherapeutic in combination with standard approaches for triple-negative breast cancer.