Figure 8.

A, Transfection of Cx43 expression vectors dose responsively induces specific gap junction proteins. To optimize Cx43 transfection, dose-response experiments with increasing vector concentrations (0.1–2.0 μg per 6 cm dish) were performed. The EC₅₀ was determined to be approximately 1.0 μg per 6-cm dish, which yielded less Cx43 protein accumulation than that achieved after 7 days of E/P/c treatment (H). Note that neither Cx43 overexpression nor E/P/c treatment had any effect on Cx32 or β-actin expression. B, Transfection of Cx43 expression vectors dose responsively increases MET markers and decreases N-cadherin in the absence of hormone treatment. Transfection of 1.0 and 2.0 μg per 6 cm dish Cx43 vectors resulted in increases in Cx43. Western blots of MET markers (E-cadherin, GdA, and ZO1) also showed increases. By contrast, the stromal marker N-cadherin was reduced when Cx43 was overexpressed. All experiments were performed in the absence of hormones. No effects on Cx32 or β-actin were observed. C, control.