Related Experiment Video
Updated: Aug 13, 2026
A Next-generation Tissue Microarray (ngTMA) Protocol for Biomarker Studies
Published on: September 23, 2014
A pilot evaluation of the use of tissue microarrays for quantitation of target distribution in drug discovery
Jennifer S McKay1, Alison Bigley, Alex Bell
1Department of Pathology, Safety Assessment, AstraZeneca, Alderley Park, Cheshire SK10 4TG, UK. jenny.mckay@astrazeneca.com
Abstract:
The use of tissue microarrays (TMAs) in the determination of novel target molecule distribution in organs is an expanding area of discovery pathology. This pilot study was carried out to assess the Chromavision automated cellular imaging system (ACIS) for quantitation of both mRNA and protein distribution in rat and dog TMAs. The targets chosen were a protein kinase, P-CIP2, for mRNA assessment and its downsteam target, peptidylglycine amidating monoxygenase (PAM), for immunohistochemistry (IHC). Oligonucleotide probes produced against P-CIP2, together with an antibody against PAM, were evaluated on rat and dog TMAs. A method for evaluation of target distribution using the ACIS was developed and involved a two-tier approach. Firstly, an initial scanning of the labelled slides identified which tissues expressed the target. Secondly, a more comprehensive analysis was made. This required operator interaction to select specific regions of interest within selected tissue cores and exclude any background labelling from the final assessment. This exacted the level of expression of P-CIP2 or PAM in different cellular populations in tissue cores. A comparative semi-quantitative analysis of the same arrays was concomitantly made by the pathologist in order to assess the relative benefits of a potentially time-consuming detailed morphological evaluation. This involved the histological identification by the pathologist of specific cell populations expressing P-CIP2 or PAM. In this study, we demonstrate the power of an image analysing system to provide quantitative data on target distribution by in situ hybridisation and IHC on normal TMAs. This methodology, together with detailed histological analysis by a pathologist, forms a guideline for future target distribution evaluation within discovery pathology.
Insights
This study validates the Chromavision automated cellular imaging system (ACIS) for quantifying mRNA and protein distribution in tissue microarrays (TMAs). The ACIS provides powerful quantitative data for target distribution evaluation in discovery pathology.
Area of Science:
- Pathology
- Molecular Biology
- Biotechnology
Background:
- Tissue microarrays (TMAs) are increasingly used for novel target molecule distribution studies in organs.
- Automated cellular imaging systems offer potential for efficient quantitation of molecular targets.
Purpose of the Study:
- To assess the Chromavision automated cellular imaging system (ACIS) for quantitating mRNA and protein distribution in rat and dog TMAs.
- To develop and evaluate a method for target distribution analysis using ACIS in conjunction with pathologist review.
Main Methods:
- Utilized TMAs from rat and dog tissues.
- Assessed messenger RNA (mRNA) distribution of P-CIP2 using oligonucleotide probes and protein distribution of peptidylglycine amidating monoxygenase (PAM) via immunohistochemistry (IHC).
- Employed a two-tier ACIS analysis: initial scanning for target expression and detailed analysis of selected regions of interest.
Main Results:
- The ACIS successfully provided quantitative data on P-CIP2 and PAM distribution in different cellular populations within tissue cores.
- A comparative semi-quantitative analysis by a pathologist validated the ACIS findings.
- The developed methodology demonstrated the system's power for in situ hybridization and IHC analysis on normal TMAs.
Conclusions:
- The ACIS is a powerful tool for quantitative analysis of target distribution in discovery pathology.
- The combination of ACIS imaging analysis and pathologist histological review provides a robust guideline for future target distribution evaluations.
