Article

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

Division of Hematopoiesis and Gene Therapy Program, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Avenida Complutense 22, 28040 Madrid, Spain.
Molecular Cancer Therapeutics (Impact Factor: 5.6). 06/2008; 7(5):1309-18. DOI: 10.1158/1535-7163.MCT-07-2432
Source: PubMed

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 degrees 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 G2-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.

0 Bookmarks
 · 
123 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Radiotherapy is a chosen treatment option for prostate cancer patients and while some tumours respond well, up to 50% of patients may experience tumour recurrence. Identification of functionally relevant predictive biomarkers for radioresponse in prostate cancer would enable radioresistant patients to be directed to more appropriate treatment options, avoiding the side-effects of radiotherapy.
    BMC Cancer 11/2014; 14(1):808. · 3.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Breast cancer is a heterogeneous disease defined by both germline and somatic abnormalities. In preclinical models, tumors carrying homologous recombination defects are highly sensitive to trabectedin. This phase II trial evaluated the efficacy and safety of trabectedin in BRCA1/2 germline mutation carriers with pretreated metastatic breast cancer (MBC). Trabectedin 1.3 mg/m(2) as a 3-hour intravenous infusion was administered every 3 weeks until progression or intolerance. The primary efficacy endpoint was the objective response rate (ORR) as per RECIST. Secondary efficacy endpoints comprised time-to-event endpoints, and changes in tumor volume and expression of tumor marker CA15.3. Safety was evaluated using the NCI-CTCAE. Forty BRCA1/2 germline mutation carriers with MBC were included. Confirmed partial response (PR) occurred in 6 of 35 evaluable patients (ORR=17%; 95% CI: 7%-34%) and lasted 1.4-6.8 months. Median PFS was 3.9 months (95% CI, 1.6-5.5 months). Eight patients (21%) showed changes in tumor volume, and 14 (40%) a clinical benefit. Trabectedin-related adverse events were generally mild/moderate, the most common being fatigue, nausea, constipation and anorexia. Severe laboratory abnormalities (neutropenia, transaminase increases) were mostly transient and non-cumulative, and were managed by dose adjustments. With the caveat of the limited patient number, trabectedin monotherapy showed activity and was well tolerated in heavily pretreated metastatic breast cancer patients selected for germline BRCA mutation. These results prompt further evaluation of trabectedin alone or combined with other specific drugs in this indication. ClinicalTrials.gov identifier: NCT00580112.
    Annals of Oncology 04/2014; · 7.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PM01183 is a new synthetic tetrahydroisoquinoline alkaloid that is currently in phase I clinical development for the treatment of solid tumours. In this study we have characterized the interactions of PM01183 with selected DNA molecules of defined sequence and its in vitro and in vivo cytotoxicity. DNA binding characteristics of PM01183 were studied using electrophoretic mobility shift assays, fluorescence-based melting kinetic experiments and computational modelling methods. Its mechanism of action was investigated using flow cytometry, Western blot analysis and fluorescent microscopy. In vitro anti-tumour activity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and the in vivo activity utilized several human cancer models. Electrophoretic mobility shift assays demonstrated that PM01183 bound to DNA. Fluorescence-based thermal denaturation experiments showed that the most favourable DNA triplets providing a central guanine for covalent adduct formation are AGC, CGG, AGG and TGG. These binding preferences could be rationalized using molecular modelling. PM01183-DNA adducts in living cells give rise to double-strand breaks, triggering S-phase accumulation and apoptosis. The potent cytotoxic activity of PM01183 was ascertained in a 23-cell line panel with a mean GI(50) value of 2.7 nM. In four murine xenograft models of human cancer, PM01183 inhibited tumour growth significantly with no weight loss of treated animals. PM01183 is shown to bind to selected DNA sequences and promoted apoptosis by inducing double-strand breaks at nanomolar concentrations. The potent anti-tumour activity of PM01183 in several murine models of human cancer supports its development as a novel anti-neoplastic agent.
    British Journal of Pharmacology 11/2010; 161(5):1099-110. · 5.07 Impact Factor

Full-text (2 Sources)

Download
69 Downloads
Available from
May 28, 2014