New NSAID-Pt(IV) prodrugs to suppress metastasis and invasion of tumor cells and enhance anti-tumor effect in vitro and in vivo.

The great interest in epithelial-to-mesenchymal transition (EMT) programme lies in its association with process of metastasis and invasion, which is a crucial cause of cancer-related death. Herein, we designed and reported three new NSAID-Pt(IV) prodrugs, taking Non-Steroid Anti-Inflammatory Drugs (NSAIDs) to disrupt EMT programme and assist genotoxic platinum-based drugs as a cytotoxicity booster, to offer a class of potential anticarcinogens with a multi-functional action mechanism. The NSAID-Pt(IV) prodrugs, especially Eto-Pt(IV), highly enhanced cellular uptake with amount up to 42-fold at 3 h compared with CDDP, and greatly increased DNA damage and cell apoptosis, showing much higher cytotoxicity than cisplatin in the tested cancer cells even in A549/cis cells. Among of them, Eto-Pt(IV) and Car-Pt(IV) exhibited more excellent activity than Sul-Pt(IV), arising from their reduction-labile and favorable lipophilicity. Most strikingly, Eto-Pt(IV) markedly inhibited metastasis and invasion of MCF-7 cells, owing to its COX-2 suppression that down-regulated active MMP-2, vimentin protein and up-regulated E-cadherin. In vivo, Eto-Pt(IV) displayed potent antitumor activity and no observable toxicity in BALB/c nude mice bearing MCF-7 tumors.

Chlorambucil-conjugated platinum(IV) prodrugs to treat triple-negative breast cancer in vitro and in vivo.

Modification of platinum (II) into lipophilic platinum (IV) compounds by introducing biologically active molecules were widely employed to develop new platinum-based prodrugs in the past decade. In this paper, two chlorambucil platinum (IV) complexes, CLB-Pt and CLB-Pt-CLB, were synthesized and displayed very potent antiproliferative activity against all the tested cancer cell lines, such as A549, HeLa and MCF-7, especially to treat the well-known refractory triple-negative breast cancer. CLB-Pt-CLB significantly improved cell-killing effect in triple-negative subtype MDA-MB-231 cells, and showed much stronger cytotoxicity than either monotherapy or combination of cisplatin and chlorambucil. CLB-Pt-CLB prodrug entered cells in dramatically increased amount compared with cisplatin and enhanced DNA damage, inducing cancer cell apoptosis. It exhibited high anticancer activity and no observable toxicity in BALB/c nude mice bearing MDA-MB-231 tumors. The chlorambucil moiety not only greatly assisted the passive diffusion of CLB-Pt-CLB into cells, but also produced the synergism with cisplatin in targeting DNA.