mdm2 gene alterations and mdm2 protein expression in breast carcinomas.
This study investigates the mdm2 gene status and expression in 66 surgically resected human breast carcinomas, with correlations with clinico-pathological and biological data (histological type, grading, steroid receptor status, p53 expression, proliferative activity). Four (7.7 per cent) out of 52 informative cases bear mdm2 gene amplification (four-to ten-fold) and 8 (15.4 per cent) of 52 cases showed borderline amplification (three-fold). Nine (13.6 per cent) out of 66 cases showed strong mdm2 nuclear immunoreactivity. Twenty-seven (40.9 per cent) cases showed isolated mdm2 reactive nuclei. All cases with clear amplification showed a high percentage of mdm2 immunoreactive nuclei. The relationship between gene amplification and mdm2 protein expression is highly significant (P < 0.0001). No association was observed between mdm2 gene amplification and any of the considered clinico-pathological and biological parameters, while mdm2 immunoreactivity showed a significant association only with oestrogen receptor immunoreactivity (P = 0.009). p53 expression was associated neither with mdm2 gene amplification nor with mdm2 immunoreactivity. It could be tempting to hypothesize that the evaluation of the combined mdm2/p53 immunohistochemical phenotype in human breast carcinoma could give us better prognostic information than the evaluation of the expression of the p53 protein alone.
Marchetti
A
A
Institute of Pathological Anatomy and Histology, University of Pisa, Italy.
Buttitta
F
F
Girlando
S
S
Dalla Palma
P
P
Pellegrini
S
S
Fina
P
P
Doglioni
C
C
Bevilacqua
G
G
Barbareschi
M
M
D000230:Adenocarcinoma / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D001943:Breast Neoplasms / Q000235:genetics*; D002278:Carcinoma in Situ / Q000235:genetics; D018270:Carcinoma, Ductal, Breast / Q000235:genetics; D018275:Carcinoma, Lobular / Q000235:genetics; D017931:DNA Primers; D005260:Female; D005784:Gene Amplification; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000235:genetics*; D051736:Proto-Oncogene Proteins c-mdm2
D017931:DNA Primers; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2