Effects of Manipulation of CRABP1 Expression on p75NTR Expression and Fenretinide Efficacy in Neuroblastoid Human Neuroblastoma Cell Lines.
Induction of expression of CRABP1 in SH-SY5Y cells did not alter expression of p75NTR (Figure 5).
CRABP1 binds to retinoids and thereby sequesters them in the cytoplasm and prevents their shuttling to the nucleus.
Our results demonstrate neuroblastoma cell line-dependence of the effects of manipulation of p75NTR expression on CRABP1 expression and the effects of CRABP1 expression on fenretinide-induced cell death.
The fact that p75NTR and CRABP1 expression differentially affect one another and the impact of treatment with fenretinide in different neuroblastomas makes p75NTR or CRABP1, at best, complex biomarkers for likely responsiveness to that drug.
hHPRT: human hypoxanthine-guanine phosphoribosyltransferase; open bars, p75NTR; solid bars, CRABP1.
Caption: Figure 2: (a) Western blot for CRABP1 in SH-EP1 cells transfected with an expression construct for p75NTR (OE) or the analogous empty vector (OE Ctrl).
Caption: Figure 3: Metabolic viability and cell number of SH-EP1 cells transfected with CRABP1 siRNA or a scrambled control construct after treatment with fenretinide.