FIGURE 6.

Ectopic connexin expression in melanomas does not establish heterocellular GJIC with keratinocytes. Melanomas were co-cultured with keratinocytes at a 1:10 ratio, respectively. Under phase contrast, melanoma clusters were identified (dashed lines), and their melanoma phenotypes were confirmed, where possible, by the expression of GFP. In all cases, injected melanomas (arrows) failed to pass Alexa350 to adjacent keratinocytes, and only Cx-expressing melanomas exhibited sufficient dye transfer among each other (n = 18). Similarly, keratinocytes injected with Alexa350 (arrowheads) were highly coupled with neighboring keratinocytes, but in all cases, failed to pass dye to adjacent melanomas (n = 18). Bar, 50 μm.