A Useful Guide for Analysis of Biomarkers in Cancer by Fluorochrome (Luminex) Technique

Remarkable progress in basic, translational, and clinical cancer research has been observed during the last decade. This has opened possibilities for the development of novel diagnostics and therapeutic approaches and created opportunities for personalized medicine. Cancer biomarkers are key players in human cancer progression, both peripheral and at the site of tumor. Through reliable techniques detecting biomarkers, cancer can thus be predicted, diagnosed and progression and response to therapy can be followed. Multiplex analysis of biomarkers in small blood volumes allows for rapid quantification of large number of circulating analytes. The Luminex technique allows multiple biomarkers to be measured simultaneously in small volumes and provides a convenient and sensitive tool for the detection of large number of extracellular secreted biomarkers to be used in prediction and therapy prognosis in cancer. The technique is based on so-called microspheres (beads) that serve as a solid phase for molecular detection. These individually dyed microbeads have monoclonal antibodies directed against the biomarker of interest and allow simultaneous detection of up to hundreds of biomarkers in a dual-laser flow analyzer. Biomarkers can be detected in serum- and plasma samples as well as in cell culture supernatants from in vitro cultured and stimulated cells, e.g., peripheral blood mononuclear cells (PBMC) or cancer cell lines.The need for robust detection of biomarkers for prediction as well as outcome of cancer therapy progression is of great importance. This chapter describes the Luminex technique for detection of biomarkers associated with cancer by magnetic bead sandwich immunoassay, with focus on some important pre-analytic factors, e.g., cell separation and cryopreservation and thawing of PBMC that may affect the outcome of detection of biomarkers. The Luminex technique is thus one way to discover biomarkers to predict, prognose, and improve clinical outcome of cancer.