News Finding: The finding of the connection between low PTEN levels and reduced response to radiation therapy.
Paper Finding: These data, combined with the selective increase in EGF-specific ligands in PTEN-null fibroblasts, strongly support direct paracrine activation of epithelial EGFR as the primary signaling nexus resulting in the observed genomic instability; however, it is certainly likely that both EGFR/EGFR homo-and EGFR/ErbB2 hetero-dimers are involved given co-expression and the known importance of dimerization in ErbB signaling .
News Context: When the PTEN level is low in the breast cancer connective tissue cells, the tumor cells have a high degree of genetic instability. The finding of the connection between low PTEN levels and reduced response to radiation therapy. "This allows for a multi-pronged attack on the tumor, by predicting who will respond the best to radiation therapy in combination with chemotherapy and other targeted treatments" says Ostrowski.
Paper Context: In evaluating treatment efficacy, we observed a reduction in epithelial EGFR activity with both compounds, while ErbB2 was inhibited by CP-724,714, not erlotinib. These data, combined with the selective increase in EGF-specific ligands in PTEN-null fibroblasts, strongly support direct paracrine activation of epithelial EGFR as the primary signaling nexus resulting in the observed genomic instability; however, it is certainly likely that both EGFR/EGFR homo-and EGFR/ErbB2 hetero-dimers are involved given co-expression and the known importance of dimerization in ErbB signaling . While beyond the scope of our current work, we also cannot rule out the possible involvement of the other ErbB family members, ErbB and ErbB4.