Figure 4. Dlg1, Scrib, and Lgl1 mRNA and protein expressions in mouse whole eyes during tumor development and in control eyes. Semi-quantitative RT–PCR was used to determine the relative amounts of Dlg1 (A), Scrib (C), and Lgl1 (E) mRNA in mouse whole eye tissue at P25, P30, and three months in CB6 control and Trp1/Tag mice. Cyclophilin was used as an internal control. Relative levels were calculated as the ratio of the intensity of each PCR band to the cyclophilin band. B, D, and F shows means of the ratio of expression corresponding to A, C, and E, respectively. G shows corresponding western blot analysis. The blot was counterstained with anti-β-actin antibody as a loading control. Specific bands corresponding to Dlg1 (140 kDa), Scrib (210 kDa), Lgl1 (112 kDa), and β-actin (42 kDa) were detected in all extracts. H shows the relative levels of each protein, which were quantified and normalized using β-actin as the internal standard. I shows E-cadherin and N-cadherin expressions using RT–PCR in control and TRP1/Tag mice. Error bars indicate SEM. Asterisks indicate statistically significant results (p<0.001). Dlg1, Scrib, and Lgl1 protein levels were reduced in the whole eye from the adenocarcinoma model at P30 whereas only Dlg1 and Scrib protein were reduced at three months (G,H). E-cadherin expression in total RNA samples extracted from whole eyes was much lower in the Trp1/Tag model than in the control mice at the P30 and three month stages (H). An upregulation of N-cadherin expression was associated with E-cadherin downregulation at these stages (I).