Immunohistochemical and survival analysis of SP1 expression in gastric cancer patients and SP1 expression in gastric cancer cell lines.

<p>A) The expression of SP1 increases with tumor progression from precancerous to malignant lesions. Positive staining is determined by a reddish-brown precipitate in the nuclei. B) The Kaplan-Meier survival probability with respect to SP1 expression levels in gastric carcinomas. Log-rank tests were performed to compare the survival of SP1 subgroups both within and between subtypes. C) The Kaplan-Meier survival probability with respect to SP1 expression levels in intestinal-type gastric carcinomas. Log-rank tests were performed to compare the survival of SP1 subgroups both within and between subtypes. <i>P</i><0.05 was considered to be statistically significant. D) The Kaplan-Meier survival probability with respect to SP1 expression levels in diffuse-type gastric carcinomas. Log-rank tests were performed to compare the survival of SP1 subgroups both within and between subtypes. <i>P</i><0.05 was considered to be statistically significant. E) The SP1 expression in 15 gastric cancer cell lines was measured by western blot analysis. The numbers indicate semi-quantified protein expression based on scanning densitometry normalized to GAPDH (a control). VEGF was also measured to compare its expression with SP1 in each cell type.