title: Combined effects of lonidamine and tamoxifen in human breast-cancer cell-lines.
abstract: The antiproliferative activity of lonidamine, alone or in combination with the antiestrogen tamoxifen, was studied on estrogen receptor-positive and estrogen receptor-negative human breast cancer cell lines. Lonidamine by itself induced an appreciable cytotoxic effect on all five cell lines, with 50% inhibitory concentrations (IC50) ranging from 19.5 to 54 mu M. The combination of lonidamine and tamoxifen, simultaneously administered or in sequence, provided additive effects on the estrogen receptor-negative MCF/DX cell line and a sub-additive interaction in the estrogen receptor-positive MCF7 cells. The negative interference between the two drugs could be ascribed to the marked reduction induced by lonidamine in the expression of estrogen receptor in the MCF7 cells.
authors.affiliation: IST NAZL STUDIO & CURA TUMORI,DIV ONCOL SPERIMENTALE C,I-20133 MILAN,ITALY.
authors.forename: D
authors.initials: D
authors.lastname: Gornati
authors.forename: N
authors.initials: N
authors.lastname: Zaffaroni
authors.forename: L
authors.initials: L
authors.lastname: Orlandi
authors.forename: G
authors.initials: G
authors.lastname: Difronzo
authors.forename: R
authors.initials: R
authors.lastname: Silvestrini