FIGURE 2.

Wound closure of the human-derived primary skin fibroblast (HPF) cell line occurs during 12 h with a constant speed (A); the healing curve shows a good fit to linear and normalized curves (C). HaCaT cell line shows non-linear closure (B); however, piecewise analysis shows that there is a 6-h interval with good linearity (D). Within this 6-h long interval, all cell lines show a good linear fit, compared to a 12-h long period (F). Within this time interval, we determined the speed is to be dependent on the cell line, and values are similar for normal and cancer cells, except for the HT1080 and U2OS cell lines (E).