Figure 4.

Analysis of the integrity and expression of the Klf4 gene in gastric tumors. (A) DNA was isolated from matched gastric tumor specimens (T) and nontumorous corpus mucosa specimens (N) obtained from Villin-Cre⁻;Klf4^fl/fl (A1) and Villin-Cre⁺;Klf4^fl/fl (A2) mice. PCR analysis was performed for genotyping of Klf4 alleles. (B) An individual antral tumor was obtained immediately after surgery (B1) and divided into two parts: one for primary culture (CC, B2) and one for DNA extraction (TT). DNA was also extracted from a nontumorous corpus mucosa specimen (NT). PCR analysis was performed for genotyping of Klf4 alleles (B3). (C) Klf4 mRNA expression and genetic integrity in corpus tumors. Real-time PCR analysis was performed using total RNA extracted from corpus tumors and adjacent nontumorous tissue specimens from Klf4^+/+ and Klf4^−/− mice. Total RNA obtained from colonic mucosa in Klf4^+/+ and Klf4^−/− mice was used as a control (C1). DNA was extracted from Klf4^−/− corpus tumors, and PCR analysis was performed for genotyping of Klf4 alleles using DNA from TT and CC as a control (C2).