An organotin indomethacin derivative inhibits cancer cell proliferation and synergizes the antiproliferative effects of lapatinib in breast cancer cells

It is known that an inflammatory condition in different types of cancer provides a sustained microenvironment that favors tumor growth, invasion, and metastasis. Non-steroidal anti-inflammatory drugs such as indomethacin have demonstrated chemo-preventive, anti-proliferative and cytotoxic effects in a variety of tumors. The aim of this study was to investigate the effects of an organotin indomethacin derivative (OID) on the proliferation of breast and prostate cancer cell lines and the possible mechanisms of action of this compound. Different cancer cell lines were treated in the presence of OID and cell proliferation was measured by quantification of the DNA content, changes in the cell cycle profile and the activation of caspase 3 were evaluated by flow cytometry, interleukin 6 (IL-6) gene expression was evaluated by qPCR and protein expression was analyzed by ELISA and Western blot assays. OID inhibited the cell proliferation of a panel of cancer cell lines in a concentration-dependent manner. Moreover, the addition of OID to lapatinib treatment, targeted therapy for breast cancer, significantly enhanced its antiproliferative response. The effects on cell proliferation of these compounds involved, among others, the induction of apoptosis, the downregulation of IL-6 and a decrease of the MAPK activation pathway. Our results suggest that the use of OID alone or in combination with tyrosine kinase inhibitors could be considered as adjuvants in the treatment of cancer.