Over the last two decades, prognostic and predictive biomarker studies in clinical and translational research settings have become synonymous with tissue microarrays (TMAs). TMAs are essentially “tissue archives” created by repeated transfer of small tissue cores from formalin-fixed paraffin-embedded tissues (“donor” blocks) into empty paraffin blocks (“recipient” blocks). In this manner, more than 500 different tissue spots can be arrayed onto a single TMA. TMA applications include the investigation of morphology, protein and gene expression or chromosomal aberrations. These can be visualized using H&E stains, immunohistochemistry (IHC), fluorescence and chromogenic mRNA or miRNA in situ hybridization (ISH). Despite many advantages such as cost-effectiveness, conventional tissue microarraying has several major drawbacks: it is a laborious, time-consuming and does not allow for precise tissue regions/structures to be captured. For studies aiming to investigate specific histological regions (e.g. interface between tumor and stroma) or particular cell types, conventional TMAs fall short. Our Translational Research Unit at the Institute of Pathology, University of Bern has developed next-generation TMAs (ngTMAs). ngTMA represents a process of TMA consulting, followed by slide scanning and digital pathology, as well as rapid, precise and automated TMA construction. Briefly, consulting in all aspects of TMA design/construction is discussed including histopathology and statistical considerations. Next, case review is performed and the best slide and paraffin block for subsequent TMA annotation. The selected slides (H&E or other staining) of all cases are digitally scanned. Digital images of each slide are then uploaded onto the slide management platform (http//ngtma.path.unibe.ch/casecenter). The pathologist retrieves the slides. Then using a TMA tool of 0.6, 1.0, 1.5 or 2.0mm in diameter, the digital slide is marked in desired regions. Several annotations per tissue can be made. The donor blocks are loaded into the automated tissue microarrayer and punched exactly on the annotated regions producing an optimal ngTMA. The ngTMA blocks can then be sectioned for further staining including IHC, DNA silver ISH (SISH), mRNA ISH, miRNA ISH or a combination of these. Tissues can be heterogeneous and biomarkers may be relevant only in certain cell types of the same tissue, hence the quality of the selected regions for inclusion in TMAs is of the uttermost importance. ngTMA accomplishes this goal with precision, speed and high quality of TMA design and construction.
How to Cite:
Zlobec, I. et al., (2015). Next-generation tissue microarrays (ngTMA) in translational research. New Horizons in Translational Medicine. 2(2), pp.58–59. DOI: http://doi.org/10.5334/j.nhtm.2014.11.015
Zlobec I, Suter G, Perren A, Lugli A. Next-generation tissue microarrays (ngTMA) in translational research. New Horizons in Translational Medicine. 2015;2(2):58–9. DOI: http://doi.org/10.5334/j.nhtm.2014.11.015
Zlobec, I., Suter, G., Perren, A., & Lugli, A. (2015). Next-generation tissue microarrays (ngTMA) in translational research. New Horizons in Translational Medicine, 2(2), 58–59. DOI: http://doi.org/10.5334/j.nhtm.2014.11.015