Breast Carcinoma Cells in Primary Tumors and Effusions Have Different Gene Array Profiles

Abstract

The detection of breast carcinoma cells in effusions is associated with rapidly fatal outcome, but these cells are poorly characterized at the molecular level. This study compared the gene array signatures of breast carcinoma cells in primary carcinomas and effusions. The genetic signature of 10 primary tumors and 10 effusions was analyzed using the Array-Ready Oligo set for the Human Genome platform. Results for selected genes were validated using PCR, Western blotting, and immunohistochemistry. Array analysis identified 255 significantly downregulated and 96 upregulated genes in the effusion samples. The majority of differentially expressed genes were part of pathways involved in focal adhesion, extracellular matrix-cell interaction, and the regulation of the actin cytoskeleton. Genes that were upregulated in effusions included KRT8, BCAR1, CLDN4, VIL2, while DCN, CLDN19, ITGA7, and ITGA5 were downregulated at this anatomic site. PCR, Western blotting, and immunohistochemistry confirmed the array findings for BCAR1, CLDN4, VIL2, and DCN. Our data show that breast carcinoma cells in primary carcinomas and effusions have different gene expression signatures, and differentially express a large number of molecules related to adhesion, motility, and metastasis. These differences may have a critical role in designing therapy and in prognostication for patients with metastatic disease localized to the serosal cavities.

Regenerative Therapy and Cancer: In Vitro and In Vivo Studies of the Interaction Between Adipose-Derived Stem Cells and Breast Cancer Cells from Clinical Isolates

“…Despite this heterogeneity, MPE consistently express high levels of metastasis-related proteins, such as ezrin and claudin-4, compared to primary tumors. 34 Culture of MPE cells in the presence of low-passage ASC unequivocally promoted the growth of MPE cells (5.1-fold increase, p ¼ 0.0005) ( Fig. 1; Table 1).…”

Ezrin and BCAR1/p130Cas mediate breast cancer growth as 3-D spheroids

“…However, although recurrence as metastatic disease is the major cause of tumor-related mortality, the processes which lead to metastasis formation in general and effusion formation in particular, are still incompletely understood. We recently reported that breast carcinoma cells in effusions differ from their counterparts in primary carcinomas mainly in expression of molecules involved in cell-ECM interactions [11]. These molecules may have regulatory effect on cell-cell interactions, survival in the absence of substrate and enhanced cell motility of carcinoma cells, leading to effusion formation.…”

“…In a recently performed gene array analysis [11], we found that two metastasis-associated genes, the BCAR1 gene encoding p130cas protein and the EZR/VIL2 gene encoding ezrin, are significantly upregulated in breast carcinoma effusions compared to primary carcinomas. We hypothesized that if the upregulation of p130cas and Ezrin is critical for tumor progression, then silencing of their expression in MDA-MB-231 cells will result in a less invasive phenotype and induce differentiation on Matrigel.…”

“…Negative controls consisted of sections that underwent similar staining procedures with isotype-matched mouse antibody. Positive controls consisted of a breast carcinoma biopsy that demonstrated immunoreactivity for the studied antigens in our previous study [11].…”

“…Recently, we compared the global expression profiles of primary breast carcinomas and breast carcinoma effusions and identified 255 significantly downregulated and 96 upregulated genes in the effusion samples [11]. The majority of differentially expressed genes belonged to cellular pathways involved in adhesion and motility, and may thus have an important role in metastasis.…”