CorrectionsArai, and Glenn D. Prestwich, which appeared in number 1, January 7, 2003, of Proc. Natl. Acad. Sci. USA (100, 131-136; First Published December 26, 2002; 10.1073͞pnas.0135855100), Fig. 4 should have appeared in color. The correct figure and its legend appear below.
Fig. 4.LPA stimulates lipid accumulation, CD36 expression, and oxidized LDL uptake through a PPAR-responsive element. (a) LPA stimulates monocyte uptake of oxidized LDL. Freshly elutriated human monocytes were allowed to interact with an anti-ICAM3-coated well, which leads to rapid PPAR␥ expression (13), and then stimulated, or not (negative, oxLDL), with oleoyl LPA. Some cells were then briefly exposed to oxidized LDL before intracellular lipid stores were visualized with oil red O stain. (b) LPA increases the expression of CD36 on the surface of primary human monocytes. Monocytes engaging anti-ICAM3 were treated or not with LPA, and then recovered by gentle scraping and washing by centrifugation before their surface CD36 was assessed by flow cytometry. (c) LPA and the LPA analogs XY4 and XY8 stimulate CD36 promoter function only when the PPRE is present. RAW264.7 cells were transfected with the human CD36 promoter containing the PPRE (CD36 Ϫ273 ) or a reporter that lacks only this element (CD36 Ϫ261 ) and then stimulated with oleoyl LPA, azPC, XY4, or XY8. Expression of luciferase normalized to -galactosidase was determined as above. (d) Anti-CD36 blocks LPA-stimulated accumulation of cholesterol from oxidized LDL. Freshly isolated human monocytes were treated as in a, but after being preincubated with a blocking anti-CD36 antibody before exposure to oxidized LDL. G rowth factor receptors are promising targets for antibodybased cancer therapies. Because of their cell-surface location, they are readily accessible, and therapeutic antibodies can exert their inhibitory effects by either interfering with cellular signaling or targeting toxic molecules or biological effectors to the tumor site (1).The epidermal growth factor receptor (EGFR) is expressed in normal tissues and neoplastic lesions of most organs, and its expression level has been associated with biological characteristics of tumors (2). Elevated levels of EGFR have been demonstrated in many different types of cancer including glioblastoma, and EGFR overexpression seems to be associated with poor prognosis in several neoplasms (3). EGFR overexpression is often associated with gene amplification (4-8). In glioblastoma, EGFR amplification has been shown to be accompanied by gene rearrangement (9-11), frequently with deletions in the coding region. Several mutant forms have been found (12, 13), and among these the most common mutation is the ⌬2-7 deletion (⌬EGFR), which lacks exons 2-7 of the external EGFR domain, resulting in the loss of an 801-bp fragment of the wild-type (wt) gene (14). Several studies have indicated that the presence of ⌬EGFR enhances the tumorigenic behavior of cancer cells (15-17). ⌬EGFR has only been found in neoplastic lesions and not in any normal tissue. ...