Prostate Tissue Arrays

Tissue arrays constructed by
Prof Colin Cooper csc@icr.ac.uk, A Fletcher fletcher@icr.ac.uk,
Dr A Falconer falconer@icr.ac.uk, Dr Ros Eeles ros@icr.ac.uk
Institute of Cancer Research
and Prof Chris Foster, University of Liverpool

Tissue arrays are being constructed as part of the Collaboratives’ Molecular Pathology programme. An H&E stained section of the formalin fixed tumour is first examined by a histopathologist who marks the location of the tumour and normal tissue.

To make tissue arrays a block of Lambwax is first placed in the recipient block holder in the Tissue Arrayer (Fig 1).

Fig 1

A core is taken of wax and is then removed (Fig 2a). A bridge is then placed over the recipient wax block. The block containing the formalin preserved prostate specimen together with the H&E stained section aligned on top is then placed on the bridge (Fig 2b).

Fig 2a taking core from recipient block	Fig 2b bridge and block and slide

Their position is then adjusted so that the coring needle is aligned with the region of the tumour to be sampled. The core is then taken (Fig 2c). Following removal of the bridge the core is then placed in the hole in the recipient block (Figure 2d). The procedure is repeated to construct the entire array. For each cancer six 0.6mm cores are taken from the formalin preserved specimens two from each of the two major areas contributing to the Gleason score and two from regions of normal tissue. Finally, sections from the tissue array are mounted on slides and used for immunohistochemical, DNA and RNA analyses.

Fig 2c taking core from block	Fig 2d placing core in recipient block

The NCRI Collaborative have currently constructed tissue arrays form 100 prostate cancers. Construction of arrays from a further 100 specimens is underway. The Core Tissue Array Facility is also being used by Professor Jack Cuzick to construct tissue arrays from 2000 prostate cancers.

The benefits of tissues arrays are numerous. They include the analysis of multiple markers over a large number of tumours in a relatively short space of time, generating large data sets very quickly. Tissue arrays are very economical, instead of hundreds of experiments on hundreds of different slides. Only a few experiments on a few slides containing arrays would be needed, reducing costs in the reagents and manual labour departments.

To use the Collaboratives’ prostate tissue array please email:- fletcher@icr.ac.uk.