Relevance of the Fanconi anemia pathway in the response of human cells to trabectedin

Abstract

Trabectedin (Yondelis; ET-743) is a potent anticancer drug that binds to DNA by forming a covalent bond with a guanine in one strand and one or more hydrogen bonds with the opposite strand. Using a fluorescence-based melting assay, we show that one single trabectedin-DNA adduct increases the thermal stability of the double helix by >20°C. As deduced from the analysis of phosphorylated H2AX and Rad51 foci, we observed that clinically relevant doses of trabectedin induce the formation of DNA double-strand breaks in human cells and activate homologous recombination repair in a manner similar to that evoked by the DNA interstrand cross-linking agent mitomycin C (MMC). Because one important characteristic of this drug is its marked cytotoxicity on cells lacking a functional Fanconi anemia (FA) pathway, we compared the response of different subtypes of FA cells to MMC and trabectedin. Our data clearly show that human cells with mutations in FANCA, FANCC, FANCF, FANCG, or FANCD1 genes are highly sensitive to both MMC and trabectedin. However, in marked contrast to MMC, trabectedin does not induce any significant accumulation of FA cells in G 2 -M. The critical relevance of FA proteins in the response of human cells to trabectedin reported herein, together with observations showing the role of the FA pathway in cancer suppression, strongly suggest that screening for mutations in FA genes may facilitate the identification of tumors displaying enhanced sensitivity to this novel anticancer drug.

A Review of Trabectedin (ET-743): A Unique Mechanism of Action

“…As mentioned above, the DNA monoadducts are stabilized by hydrogen bonds between trabectedin and nucleotides located in the same or in the opposite strand, resulting in a DNA lesion similar to interstrand crosslinks. This characteristic explains why human cells with mutations in Fanconi anemia genes such as FANCA, FANCC, FANCF, FANCG, or FANCD1 are highly sensitive to trabectedin (14).…”

Trabectedin and Its C Subunit Modified Analogue PM01183 Attenuate Nucleotide Excision Repair and Show Activity toward Platinum-Resistant Cells

“…3C, open triangles and open squares) with a half-life of 48 minutes in the absence of PM01183 or trabectedin and 110 minutes in their presence. Both PM01183 and trabectedin adducts modify the local structure of DNA (2,33), which could possibly influence the formation of UV adducts. Therefore, cellular levels of 6-4 PP adducts were compared immediately after UV irradiation for the different treatment conditions.…”

Lurbinectedin (PM01183), a New DNA Minor Groove Binder, Inhibits Growth of Orthotopic Primary Graft of Cisplatin-Resistant Epithelial Ovarian Cancer

“…One of the best examples is trabectedin (Yondelis), which reacts with certain guanines in the minor groove of DNA to form a covalent bond (19)(20)(21). The adduct is stabilized by van der Waals interactions with nucleotides in the opposite DNA strand, creating the equivalent of a functional interstrand crosslink (22). Lurbinectedin (PM01183) is a new synthetic alkaloid that is structurally related to ecteinascidins (23), which, with the exception of a module addition (ring C), confer important pharmacokinetic and pharmacodynamics properties benefits as well intrinsic activity (24)(25)(26).…”