Colonocytes in Barrett's metaplasia?

Multifocal heterogeneity in villin and Ep-CAM expression in Barrett's esophagus

Barrett's esophagus (BE) is a metaplastic change of the squamous esophageal epithelium to columnar gastric or intestinal-like epithelium. BE is associated with long-standing gastroesophageal reflux disease and carries an increased risk for dysplasia and adenocarcinoma. Little if any is known regarding the differentiation state of esophageal metaplasia and its relationship to carcinogenesis. In this study, we investigated the potential of villin, a cytoskeletal protein, and Ep-CAM, a glandular epithelial glycoprotein, to serve as markers for enterocytic differentiation in BE at the molecular level. Endoscopic mucosal biopsy samples of normal esophagus, BE, stomach and duodenum were collected from 23 patients with BE. Biopsies were analyzed for villin and Ep-CAM expression by immunoblotting, and in some cases for the presence of microvilli by electron microscopy. By mapping of BE segments in 6 patients, correlations were also made between the histologic evidence of metaplasia and villin expression. Villin was uniformly expressed in all duodenal samples but was not detected in normal esophagus and stomach. In BE biopsies, villin expression was limited to the subset of patients whose adjacent biopsies showed microvilli by electron microscopy. In several patients studied, however, the expression of villin and the epithelial glycoprotein Ep-CAM differed among various regions of esophageal metaplasia within the same patient. Mapping studies failed to reveal any correlation among histologic evidence of metaplasia, dysplasia and villin expression and confirmed the multifocal heterogeneity of villin expression in BE. Preliminary data of 4 adenocarcinoma patients studied showed that villin expression was absent in 3 and very low in 1 patient. Ep-CAM was highly expressed in all adenocarcinoma patients. Our results show that BE represents a complex epithelium with significant heterogeneity in antigen expression and ultrastructural morphologic features. This molecular heterogeneity supports the presence of different stages of differentiation within the same epithelium.

Breast Cancer: A Revolutionary Concept

In this paper we trace the evolution of paradigms concerning the nature of breast cancer and their therapeutic consequences. There is no doubt that the conceptual revolution of about 20 years ago has led to modest gains in survival following the use of adjuvant systemic therapy and the quality of survival by demonstrating the safety of conservative surgical regimens. At the same time, there seems to be a plateau in progress. The results of adjuvant systemic therapy are not as good as anticipated and there are a number of other inconsistencies within the conventional model of biological predeterminism that remain to be explained. We offer up an alternative paradigm that suggests that not all metastases are due to cellular dissemination with late onset local and distant recurrence resulting from a transfection phenomenon, whereby subcellular particles shed by the primary cancer cell are taken up by wandering cells of the monocyte macrophage system and transported to distant sites where the local mesenchymal cells are transfected with the genetic information that activates components of the genome to instruct these plastic cells to express the phenotypic picture of a dedifferentiated breast duct epithelial cell. Such a conceptual revolution will open up the way for a new program of research and the development of therapies based on anti-viral rather than cytotoxic drugs.