Expression of Rb2/p130 in breast and endometrial cancer: correlations with hormone receptor status.

TY - JOUR

T1 - Expression of Rb2/p130 in breast and endometrial cancer: correlations with hormone receptor status.

AU - Milde-Langosch, K

AU - Goemann, C

AU - Methner, C

AU - Rieck, G

AU - Bamberger, A M

AU - Löning, T

N1 - Copyright 2001 Cancer Research Campaign.

PY - 2001/8/17

Y1 - 2001/8/17

N2 - Rb2/p130 is a member of the retinoblastoma family of proteins, consisting of Rb, Rb2 and p107, which are important negative regulators of cell cycle progression and differentiation. While Rb2 downregulation was observed in several malignant tumours including endometrial cancer, the role of p130 in breast carcinomas is still unknown. We investigated Rb2 protein expression in tumour tissue from 68 mammary and 41 endometrial carcinomas, 4 mammary cell lines, and normal tissue samples. Therefore, we performed Western blot experiments for Rb2, Rb, and the oestrogen and progesterone receptors (ER, PR-A, PR-B). Weak or absent Rb2 expression was more often found in endometrial (59%) than in mammary carcinomas (24%). We found significant positive correlations of Rb2 expression with Rb, ER, and PR-B in breast cancer samples, and of Rb2 with Rb, PR-A, PR-B, and younger age in endometrial carcinomas. No significant associations with histological grading, stage, nodal involvement, or Ki67 staining were detected. Rb2 mRNA expression was studied by semi-quantitative RT-PCR in 56 endometrial or mammary tissue samples and correlated significantly with Western blot results. Our results indicate that loss of Rb2 expression, mostly by transcriptional down-regulation, may be associated with the development and dedifferentiation of most endometrial and a subset of mammary carcinomas.

AB - Rb2/p130 is a member of the retinoblastoma family of proteins, consisting of Rb, Rb2 and p107, which are important negative regulators of cell cycle progression and differentiation. While Rb2 downregulation was observed in several malignant tumours including endometrial cancer, the role of p130 in breast carcinomas is still unknown. We investigated Rb2 protein expression in tumour tissue from 68 mammary and 41 endometrial carcinomas, 4 mammary cell lines, and normal tissue samples. Therefore, we performed Western blot experiments for Rb2, Rb, and the oestrogen and progesterone receptors (ER, PR-A, PR-B). Weak or absent Rb2 expression was more often found in endometrial (59%) than in mammary carcinomas (24%). We found significant positive correlations of Rb2 expression with Rb, ER, and PR-B in breast cancer samples, and of Rb2 with Rb, PR-A, PR-B, and younger age in endometrial carcinomas. No significant associations with histological grading, stage, nodal involvement, or Ki67 staining were detected. Rb2 mRNA expression was studied by semi-quantitative RT-PCR in 56 endometrial or mammary tissue samples and correlated significantly with Western blot results. Our results indicate that loss of Rb2 expression, mostly by transcriptional down-regulation, may be associated with the development and dedifferentiation of most endometrial and a subset of mammary carcinomas.

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Blotting, Western

KW - Breast Neoplasms

KW - Carcinoma

KW - Endometrial Neoplasms

KW - Female

KW - Gene Expression Regulation, Neoplastic

KW - Humans

KW - Middle Aged

KW - Phosphoproteins

KW - Proteins

KW - Receptors, Estrogen

KW - Receptors, Progesterone

KW - Retinoblastoma Protein

KW - Retinoblastoma-Like Protein p130

KW - Reverse Transcriptase Polymerase Chain Reaction

U2 - 10.1054/bjoc.2001.1923

DO - 10.1054/bjoc.2001.1923

M3 - SCORING: Journal article

C2 - 11506494

VL - 85

SP - 546

EP - 551

JO - BRIT J CANCER

JF - BRIT J CANCER

SN - 0007-0920

IS - 4

M1 - 4

ER -