H19Overexpression in Breast Adenocarcinoma Stromal Cells Is Associated with Tumor Values and Steroid Receptor Status but Independent of p53 and Ki-67 Expression

In a previous study we described the expression of theH19gene by in situhybridization (ISH) in normal breast and in benign or malignant breast tumors (Dugimont T, Curgy JJ, Wernert N, Delobelle A. Raes MB, Joubel A, Stéhelin D, Coll J: Biol Cell 1995, 85:117–124). In the present work, 1) we extend the previous one to a statistically useful number of adenocarcinomas, including 10 subclasses, 2) we provide information on the precise ISH localization of the H19RNA by using, on serial tissue sections, antibodies delineating specifically the stromal or the epithelial component of the breast, and 3) we consider relationships between theH19gene expression and various clinicopathological information as tumor values (T0 to T4), grades, steroid receptors, lymph node status, and molecular features as the p53 gene product and the Ki-67/MIB-1 protein, which is specific to proliferating cells. Data indicate that 1) in 72.5% of studied breast adenocarcinomas an overall H19gene expression is increased when compared with healthy tissues, 2) the H19gene is generally overexpressed in stromal cells (92.2%) and rarely in epithelial cells (2.9% only), 3) an up-regulation of the H19gene is significantly correlated with the tumor values and the presence of both estrogen and progesterone receptors, and 4) at the cellular level, the H19gene demonstrates an independent expressionversusaccumulation of both the p53 protein and the Ki-67/MIB-1 cell-cycle marker.