Figure 5.

Localization of CA IX in nascent focal adhesions in lamellipodia. (A) Immunofluorescence analysis of SiHa cells grown into cell islands in hypoxia (2% O₂), induced into migration with HGF (40 ng/ml) for 3 h. CA IX (stained red) was massively relocalized to the leading edge where it was co-stained with paxillin, a marker of focal contacts (green). The inset of a magnified lamellipodial area shows that small nascent focal adhesions were formed in the region with accumulated CA IX (arrows), whilst paxillin-stained contacts were more elongated and mature in the neighboring CA IX-free regions (arrowheads). Scale bars: 10 μm (5 μm for the inset). (B) Numerical analysis of area and length of focal contacts in lamellipodia from 20 cells dissected into CA IX containing regions and CA IX-free regions. Results confirmed that CA IX containing areas displayed significantly smaller and less elongated focal contacts (compared by t-test, ^**p < 0.01).