W. Bielke et al., APOPTOSIS IN THE RAT MAMMARY GLAND AND VENTRAL PROSTATE - DETECTION OF CELL DEATH-ASSOCIATED GENES USING A COINCIDENT-EXPRESSION CLONING APPROACH, Cell death and differentiation, 4(2), 1997, pp. 114-124
Apoptosis plays a striking role in the hormone-dependent involution of
the mammary gland, but it has proved difficult to distinguish between
the 'cell death' associated genes and the 'tissue remodelling' genes
which are expressed concurrently. To identify cell death-associated ge
nes, we have established a 'coincidence analysis', based on the previo
usly described 'RNA differential display' method of Liang and Pardee (
1992). Coincidence analysis allows the detection of genes expressed du
ring related processes in different organs and was employed here to id
entify transcripts in which expression patterns are seen to be associa
ted with apoptosis during involution of both rat mammary- and the vent
ral prostate glands. That the coincidence analysis is a promising appr
oach can be seen from the fact that while widely accepted apoptosis ma
rkers such as transglutaminase (Fesus et al, 1987; Strange et al, 1992
) and sulfated glycoprotein-2 (Buttyan et al, 1989; Strange et al, 199
2; Guenette et al, 1994) exhibited similar expression in both regressi
ng tissues, transcription of tissue remodelling enzymes was minimal in
the involuting prostate. We describe here the characteristics of five
clones isolated which show coincident expression during programmed ce
ll death in mammary and prostate tissues. Partial sequence analysis re
vealed for three clones high homologies with previously described gene
s; the putative rat homolog of the growth arrest gene gas-1 (Schneider
et al, 1988; Del Sat et al, 1992), a homolog of the mouse 'Integrin A
ssociated Protein' (IAP) (Brown et al, 1990; Lindberg et al, 1993) and
the sequence encoding for the 'Allograft inflammatory Factor' AIF-1 (
Autieri et al, 1995; Utans et al, 1995). One clone displayed homology
with an expressed human sequence tag and one clone unrelated to any kn
own DNA sequence was isolated. The expression of these genes in involu
ting rat mammary and ventral prostate, was correlated with that in oth
er organs and in situ hybridization was applied to establish that the
secretary epithelial cells which undergo programmed cell death are the
site of elevated expression during the course of involution. Furtherm
ore, we conclude that the coincidence analysis approach described here
could be easily applied to facilitate the characterization of gene ex
pression i.e. for the detection and comparison of hormonally regulated
genes in different organs.