Cytokine profiling uncovers protein patterns of chemoresistance in prostate cancer
A recent publication showcases the work APAF conducted in collaboration with Dr Lisa Horvath and colleagues from RPAH and Chris O’Brien’s Lifehouse (Mahon et al. Br. J. Cancer, 2015). This study investigated plasma cytokine levels in patients with docetaxel-resistant prostate cancer. APAF scientists used a multiplexed bead-based ELISA assay (BioPlex) to quantitate the levels of 27 human cytokines/chemokines in 55 patients pre/post docetaxel cycle 1. Our study identified that 7 cytokine/chemokines were significantly associated with progressive disease. Interestingly, a combination of MIC-1, IL-4 and IL-6 most strongly predicted PSA response. The study demonstrates that docetaxel-resistance is mediated in part by cytokines released from resistant tumour cells and macrophages and may have utility for detecting failed response to treatment.
During this study we discovered that the levels of 6 cytokines were below the detection level prescribed by the manufacturers’ software. APAF bioinformaticians have since developed a novel approach using fluorescence intensities to recover this data and overcome this problem for future studies. We describe our approach in Breen et al., Cytokine 2015.
This figure shows the distribution of the blank fluorescence readings obtained from 14 analytes. The purpose of this figure is to show that the blank from analyte to analyte can vary a lot and can have values well above zero. The other figure is a schematic of the capture and detector antibody complex that includes the analyte of interest (biomarker).
Mahon KL, Lin HM, Castillo L, Lee BY, Lee-Ng M, Chatfield MD, Chiam K, Breit SN, Brown DA, Molloy MP, Marx GM, Pavlakis N, Boyer MJ, Stockler MR, Daly RJ, Henshall SM, Horvath LG. Cytokine profiling of docetaxel-resistant castration-resistant prostate cancer. Br J Cancer. 2015 Apr 14;112(8):1340-8. doi: 10.1038/bjc.2015.74.
Br J Cancer. 2015 Apr 14;112(8):1340-8. doi: 10.1038/bjc.2015.74. Epub 2015 Mar 31
Breen EJ, Polaskova V, Khan A. Bead-based multiplex immuno-assays for cytokines, chemokines, growth factors and other analytes: median fluorescence intensities versus their derived absolute concentration values for statistical analysis. Cytokine. 2015 Feb;71(2):188-98. doi: 10.1016/j.cyto.2014.10.030.
Cytokine. 2015 Feb;71(2):188-98. doi: 10.1016/j.cyto.2014.10.030. Epub 2014 Nov 19.