Figure 4

(A) Diagrammatic illustration of DAG-1 and C4.4a proteins showing the extracellular hAG-2 and hAG-3 minimum binding domains identified by yeast two-hybrid analyses. Although both structures are shown attached to the same cell, it is likely that the interactions of the hAG proteins are autocrine in nature for C4.4a and paracrine for DAG-1. (B) Real-time quantitative RT–PCR analysis of C4.4a mRNA expression in seven donor-matched adjacent normal (N) and tumour (T) breast samples (indicated 1–7) and four human breast cancer-derived cell lines. C4.4a is upregulated in all of the tumour samples, relative to their matched normal tissue, and expressed in all the breast cancer cell lines used to create the yeast two-hybrid prey library. Expression values are described as copies per nanogram of cDNA derived from a standard curve of known dilutions of C4.4a DNA.