Biomarkers in Plucked Hair for Assessing Cancer Therapy
There is a need for a technology that can quantitatively assay multiple proteins from a single hair follicle while preserving the morphology of the follicle. For proteomic profiling, the technology should be less labor intensive, with a higher throughput, more quantitative and more reproducible than immunohistochemis- try. Layered expression scanning of hair (LES-hair) has been used to detect the levels and localization of proteins in plucked hair follicles. These proteins included cleaved caspase 3, Ki-67 and the phosphorylated forms of c-Kit, EGF receptor and VEGF receptor. LES-hair provides a research tool for studying the basic biology of plucked hair follicles and has potential clinical applications such as using plucked hair follicles as a surrogate tissue to monitor pharmacodynamic effects of targeted cancer therapies.
The “plucked hair” biomarker program (EpiStem Inc) has evolved from the discovery of the link between the stem cells in the small intestine and the hair follicle. This biomarker has been developed as a non-invasive tool to measure drug effects on adult epithelial stem cells and tissues. Plucked human hairs are analyzed for the corresponding changes in gene expression at various times during cancer treatment. Gene expression changes in hairs can provide pharmaceutical companies with a measure of drug exposure, toxicity, dose/schedule and patient selection in preclinical and clinical drug development. By comparing the gene sets linked to tumors as well as drug exposure and toxicity, it may be possible to eventually use the hair biomarker approach for evaluating the effectiveness of new cancer treatments. This approach also has the potential to offer oncologists a simple means to more effectively treat cancer patients.