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The cell-adhesion and signaling molecule PECAM-1 is a molecular mediator of resistance to genotoxic chemotherapy. Cancer Biol Ther 2006 Dec;5(12):1699-707



Pubmed ID




Scopus ID

2-s2.0-33846947172 (requires institutional sign-in at Scopus site)   27 Citations


Defects in the regulation of apoptotic pathways have been implicated in the emergence of cancers resistant to chemotherapy-induced cell death. Identification of novel signaling molecules that influence cell survival has the potential to facilitate the development of new cancer therapies. The cell adhesion and signaling molecule, PECAM-1, is expressed in many hematopoietic and endothelial cell malignancies, and has previously been shown to suppress mitochondrial-dependent, Bax-mediated apoptosis. The ability of PECAM-1 to influence tumor cell survival following exposure to chemotherapeutic agents, however, is not known. Here we show that, when overexpressed in HEK293 and REN mesothelioma cells, PECAM-1 confers resistance to apoptosis induced by the DNA-damaging chemotherapeutic agent, etoposide. Surprisingly, PECAM-1-mediated cytoprotection was found to be largely independent of its ability to form a signaling complex with the protein-tyrosine phosphatase SHP-2, as virtually no tyrosine phosphorylation of, or SHP-2 association with, PECAM-1 could be detected after etoposide treatment. Furthermore, PECAM-1 retained its ability to protect against chemotherapy-induced apoptosis in cells with SHP-2 levels significantly reduced using SHP-2-specific siRNA, and in cells in which Erk1/2--a downstream effector of SHP-2--had been inhibited. Finally, to determine whether endogenous PECAM-1 confers resistance to chemotherapy-induced apoptosis in lymphoid malignancies and endothelial cells, we used a lentiviral vector to stably express PECAM-1-specific siRNA in the Jurkat leukemia cell line and human umbilical vein endothelial cells (HUVECs). siRNA-expressing Jurkat cells with a 70% reduction of PECAM-1 expression were significantly more sensitive to chemotherapy-induced apoptosis. HUVECs with PECAM-1 expression reduced 75% were also markedly more sensitive to chemotherapy-induced cell death. Taken together, these data demonstrate that endogenous PECAM-1 expression on lymphoid cancers confers resistance to apoptosis, and that lowering PECAM-1 expression in lymphoid malignancies can render them more susceptible to chemotherapy-induced apoptosis. In addition, reducing PECAM-1 levels in the tumor endothelium may aid in low-dose, anti-angiogenic therapy.

Author List

Bergom C, Goel R, Paddock C, Gao C, Newman DK, Matsuyama S, Newman PJ


Debra K. Newman PhD Investigator in the Blood Research Institute department at BloodCenter of Wisconsin
Debra K. Newman PhD Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cell Adhesion
Cell Line
Cell Line, Tumor
Cells, Cultured
Drug Resistance, Neoplasm
Endothelium, Vascular
Gene Deletion
Intracellular Signaling Peptides and Proteins
Jurkat Cells
Platelet Endothelial Cell Adhesion Molecule-1
Protein Tyrosine Phosphatase, Non-Receptor Type 11
Protein Tyrosine Phosphatases
Recombinant Proteins
Signal Transduction
Umbilical Cord