Fig. 4. Identification of TrkA and p75^NTR receptors on SW480 cells. (A) RT-PCR analysis of β-actin, TrkA and p75^NTR mRNA; the first lane shows markers of a DNA ladder. (B) Comparison of the intensity of bands from the RT-PCR gel in relation to the intensity of β-actin. Bands that are visualized in A were scanned into Uni-Scan-It software and digitalized to obtain the pixel numbers. The relative presence of mRNA of analyzed receptors was calculated relative to β-actin mRNA. Filled bars, TrkA; open bars, p75^NTR. Error bars indicate s.d. from five measurements. (C) Binding of ¹²⁵I-NGF to three cell lines in the presence or absence of VLO5. VLO5 (1 µM) was added to the cell suspension and experiments were performed as described in Materials and Methods. Filled bars, specific binding of NGF in the absence of VLO5; open bars, in the presence of VLO5. Error bars indicate s.d. from three experiments, each performed in triplicate. (D) Western blot analysis of cell lysates obtained from PC12 (lane a), 9SW480 (lane b), mock-SW480 (lane c), and SY-SY5Y (lane d) using anti-TrkA polyclonal serum. The bands were visualized using a chemiluminescent western detection kit. The numbers above the bands represent the value of the average pixels, reflecting intensity of the bands, digitalized using Un-Scan-It gel software.