Optimizing the lower limit of detection of proteins for use in a novel diagnostic device for cancer

Abstract

Cancer is a major health concern throughout the United States and around the world. It is the second most common cause of death in the United States. However, since the 1970's survivorship has increased for many types of cancer. Cancer diagnostics, in addition to better and more targeted treatment, have been critical to this success. Current gold standard methods have significant limitations which can lead to delays in treatment or require more invasive procedures that need a significant amount of tissue for accurate diagnosis. One approach to improve current diagnostic methods is to use proteomics and microfluidic devices to create an integrated diagnostic device. A microfluidic device, built as a porous polymer monolith, can be utilized for solid phase extraction for protein biomarkers that are indicative of cancer. Microfluidic devices have already been used to extract RNA from bacteria, viruses and, in a previous study, for extracting miRNA from human cancer cells in large enough quantities to be useful as a diagnostic assay and require a significant amount of tissue. The aim of this study is to validate the presence of select protein biomarkers, to determine the lower limit of detection of these biomarkers and to quantify them from two cancer cell lines. This study is being conducted in support of a larger project's goal to design a cheap, disposable, plastic microfluidic chip for the analysis of protein biomarkers that are indicative of cancer and intended for use in a bench top machine. Ultimately, the chip's utility will be validated by analyzing small volume human specimens. BCPAP, a thyroid cancer cell line, and MCF-7, a breast cancer cell line, will be used to demonstrate the chips ability to extract, from whole cell lysates, the following protein biomarkers: Estrogen Receptor-alpha, Estrogen Receptor-beta, Thyroid Transcription Factor-1, Thyroglobulin, Human Epidermal Growth Factor Receptor-2, and E-cadherin from whole celllysates.