Targeting TRAIL death receptors.

The natural occurring tumor necrosis factor related apoptosis-inducing ligand (TRAIL) induces apoptosis following binding to the two TRAIL death receptors (DRs). Its recombinant form and monoclonal antibodies against the TRAIL DRs induce cell death in a wide variety of tumor cell lines and xenografts without causing toxicity to normal cells and are therefore potential attractive anticancer agents. These agents are currently in early clinical development. The phase 1 and 2 studies showed until now limited toxicity and tumor responses have been observed. Ongoing studies focus especially on combination of these agents with other targeted therapies or cytotoxic therapies. In this review, we summarize current knowledge on these agents and highlight their potential role in the intrinsically chemotherapy-resistant glioblastomas. In addition, we discuss the mechanisms to sensitize tumors cells to rhTRAIL by combination with the proteasome inhibitor bortezomib.

Prognostic versus predictive value of biomarkers in oncology.

Numerous options are currently available for tumour typing. This has raised intense interest in the elucidation of prognostic and predictive markers. A prognostic biomarker provides information about the patients overall cancer outcome, regardless of therapy, whilst a predictive biomarker gives information about the effect of a therapeutic intervention. A predictive biomarker can be a target for therapy. Amongst the genes that have proven to be of relevance are well-known markers such as ER, PR and HER2/neu in breast cancer, BCR-ABL fusion protein in chronic myeloid leukaemia, c-KIT mutations in GIST tumours and EGFR1 mutations in NSCLC. Several reasons for the difficult elucidation of new markers will be addressed including the involvement of cellular pathways in tumour biology instead of single genes and interference in disease outcome as a result of anticancer therapies. Future perspectives for the development of prognostic and predictive markers will be given.