Tissue-print and print-phoresis as platform technologies for the molecular analysis of human surgical specimens: mapping tumor invasion of the prostate capsule

Abstract

Molecular profiling of human biopsies and surgical specimens is frequently complicated by their inherent biological heterogeneity and by the need to conserve tissue for clinical diagnosis. We have developed a set of novel 'tissue print' and 'print-phoresis' technologies to facilitate tissue and tumor-marker profiling under these circumstances. Tissue printing transfers cells and extracellular matrix components from a tissue surface onto nitrocellulose membranes, generating a two-dimensional anatomical image on which molecular markers can be visualized by specific protein and RNA- and DNA-detection techniques. Print-phoresis is a complementary new electrophoresis method in which thin strips from the print are subjected to polyacrylamide gel electrophoresis, providing a straightforward interface between the tissue-print image and gel-based proteomic techniques. Here we have utilized these technologies to identify and characterize markers of tumor invasion of the prostate capsule, an event generally not apparent to the naked eye that may result in tumor at the surgical margins ('positive margins'). We have also shown that tissue-print technologies can provide a general platform for the generation of marker maps that can be superimposed directly onto histopathological and radiological images, permitting molecular identification and classification of individual malignant lesions.

DNA Degradation Test Predicts Success in Whole-Genome Amplification from Diverse Clinical Samples

“…4 Prostate tissue prints were snap-frozen immediately on collection and stored at Ϫ80°C before processing; each tissue print was sliced into a set of 5 ϫ 5-mm tiles for biomarker extraction. Print collection and processing was performed in an oriented manner (with fiduciary markers) so that FFPE samples from corresponding tumor sites could be identified for DNA analysis.…”

“…These archived samples contain a wealth of genetic information and offer a great potential for discovery and analysis of biomarkers with diagnostic and therapeutic significance. 1,2 Laser capture microdissected (LCM) samples, 3 tissue print micropeels, 4 and plasmacirculating DNA 5 are additional sources of valuable clinical material with major potential for discovery and evaluation of cancer biomarkers.…”

“…21 However, the investment required for performing such procedures is not justified if there is no guarantee on the suitability of the starting DNA. A simple assay that predicts success of WGA as well as downstream assays for small amounts of starting DNA such as that obtained via LCM, tissue print micropeels, 4 or plasma-circulating DNA would be very useful because it would prevent wasting time, effort, and resources.…”

Correlation of gene methylation in surgical margin imprints with locoregional recurrence in head and neck squamous cell carcinoma

“…In order to effectively collect margin specimens from the wider area of an irregular deep margin surface, we employed an innovative margin imprint procedure using nitrocellulose membrane to harvest DNA. Gaston, et al, first reported this approach for prostate specimens and extracted RNA from the cells collected on the membrane surface 18 . Our group adapted the procedure to collect DNA from imprint samples 19 .…”

Meeting report on the 12th International Congress of Histochemistry and Cytochemistry (ICHC)

“…In the Symposium: ''Discovery and Development of TissueBased Biomarkers in Prostate Cancer,'' B.S. Knudsen (USA) introduced this topic based on novel technological advances of analysis of genomic and proteomic expression in prostate tumors (Chen et al, 2004;Yu et al, 2004); P. Nelson (USA) focused on the fact that molecular correlates of pathological and clinical observations may provide resources for studies designed to determine mechanisms of cancer behavior; A.M. DeMarzo (USA) showed that the earliest phase of human prostate carcinogenesis may proceed as a consequence of chromosomal instability mediated by shortened, dysfunctional telomeres (Lapointe et al, 2004); M. Rubin (USA) provided an approach to validation of candidate genes to use as biomarkers for prostate cancer progression using tissue microarrays (Gaston et al, 2005); and C.C. Collins (USA) showed the use of array Comparative Genomic Hybridation (aCGH) to analyze a cohort of patients indicating that aCGH profiles revealed numerous recurrent copy number aberrations associated to different stages of this cancer.…”