Journal Article

Intracellular Fas ligand in normal and malignant breast epithelium does not induce apoptosis in Fas-sensitive cells

Jónasson, J G, Ólafsdóttir, K, Rafnar, T, Vidarsson, H, Kristjánsdóttir, K, Ögmundsdóttir, H M, Kjartansson, J, Mikaelsdottir, E K, Ragnarsson, G B

2000

Overview

Fas ligand (FasL) is expressed on some cancers and may play a role in the immune evasion of the tumour. We used immuno-histochemistry to study the expression of Fas and FasL in tissue samples from breast cancer patients, as well as normal breast tissue. Our results show that Fas and FasL are co-expressed both in normal tissue and in breast tumours. Fas and FasL mRNA were expressed in fresh normal and malignant breast tissue, as well as cultured breast epithelium and breast cancer cell lines. Flow cytometry analysis of live cells failed to detect FasL on the surface of normal or malignant breast cells; however, both stained positive for FasL after permeabilization. Fas was detected on the surface of normal breast cells and T47D and MCF-10A cell lines but only intracellularly in other breast cell lines tested. Neither normal breast epithelium nor breast cell lines induced Fas-dependent apoptosis in Jurkat cells. Finally, 20 tumour samples were stained for apoptosis. Few apoptotic cells were detected and there was no increase in apoptotic cells on the borders between tumour cells and lymphocytes. We conclude that FasL is expressed intracellularly in both normal and malignant breast epithelium and unlikely to be important for the immune evasion of breast tumours. © 2000 Cancer Research Campaign http://www.bjcancer.com

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: Animals / Apoptosis / Biological and medical sciences / Biomedical and Life Sciences / Biomedicine / Blotting, Western / Breast - metabolism / Breast - pathology / Breast cancer / Breast Neoplasms - genetics / Breast Neoplasms - metabolism / Breast Neoplasms - pathology / Cancer Research / Cells / Cells, Cultured / Drug Resistance / Epidemiology / Epithelium - metabolism / Epithelium - pathology / Fas Ligand Protein / fas Receptor - genetics / fas Receptor - metabolism / Female / Flow Cytometry / Gene Expression Regulation / Gynecology. Andrology. Obstetrics / Humans / Immune system / Immunohistochemistry / Jurkat Cells / Ligands / Mammary gland diseases / Medical research / Medical sciences / Membrane Glycoproteins - genetics / Membrane Glycoproteins - metabolism / Molecular Medicine / Oncology / Regular / regular-article / Reverse Transcriptase Polymerase Chain Reaction / RNA - genetics / RNA - metabolism / Tumor Cells, Cultured / Tumor necrosis factor-TNF / Tumors