Abstract 1265: Tissue is alive: Preserving phosphoproteins and tissue morphology in clinical trial samples

Abstract

Abstract An urgent clinical goal is to identify subpopulations of cancer patients that may respond to targeted kinase inhibitors and/or their phosphorylated substrates. Consequently, phosphorylated signal pathway proteins have emerged as a critical class of analytes for therapeutic stratification. Technologies now exist that can measure protein phosphorylations and map cell signaling pathways in a single core-needle biopsy, thus relying on the inhibition of any kinase/phosphatase activity within the sample immediately following excision. Unfortunately applying these technologies to clinical samples has been hindered because phosphoprotein epitopes are not adequately preserved by formalin fixation and paraffin embedding, while freezing tissue samples may not be feasible in multi-center clinical trial sites and cannot adequately preserve morphology. To facilitate clinical trial molecular profiling, where immediate snap-freezing of tumor biopsies is not feasible, we have created a novel, one-step, room temperature preservative that stabilizes proteins/phosphoproteins equivalent to snap-freezing and tissue/cell morphology equivalent to neutral buffered formalin fixation. In addition, our preservative solution simultaneously fixes and decalcifies bony tissue, thus permitting molecular profiling of bony tissues that was never before possible. We have utilized our Biomarker and Histology Preservative (BHP-Cell and/or BHP-Tissue) in a breast cancer multi-site clinical trial (US Oncology 05-074/GSK LPT109096) and a clinical research multiple myeloma trial. BHP has been validated to a) function as a transport medium while preserving histomorphology, b) maintain full antigenicity for clinical immunohistochemistry (such as Ki-67, ER, PR, Her2, p63, and phosphorylated epitopes), c) preserve phosphoprotein epitopes for cell signaling pathway profiling by reverse phase protein microarray (RPMA), d) be compatible with frozen sections or paraffin embedding, and e) obviate the need for additional decalcification. Preservation of tissue morphology has been demonstrated in 25 mouse, feline, and human tissues with enhanced immunohistochemical properties for >20 antigens using standard IHC protocols. RPMA data from LPT10906 shows differentially deranged signaling networks in the pre-treatment biopsies for patients that did not have a pathologic complete response compared to responders. Our multiple myeloma trial quantifies cell signaling pathway expression pre/post kinase inhibitor treatment, in an ex vivo treatment model, on both myeloma and bone marrow cells, preserved in BHP. We are currently evaluating the integrity of nucleic acid preservation in parallel with proteins to provide a universal one step biospecimen tissue fixative for clinical trials. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1265. doi:1538-7445.AM2012-1265