Tip cell overtaking occurs as a side effect of sprouting in computational models of angiogenesis

BMC Systems Biology

Table 1 Sprout tip occupancy by WT cells. Overview of the percentile sprout tip occupancy by WT cells

		Differential adhesion		Differential sensitivity to chemoattractant
WT percentage	Experiment	Contact	Long	Contact	Long
50	87	93 (p = 6.7∙10^-16)	48 (p = 0.73)	87 (p < 1∙10^-16)	64 (p = 6.2∙10^-4)
20	60	49 (p = 7.7∙10^-16)	18 (p = 0.75)	53 (p < 1∙10^-16)	25 (p = 3.6∙10^-2)
10	40	27 (p = 6.9∙10^-9)	11 (p = 0.33)	34 (p < 1∙10^-16)	22 (p = 7.2∙10^-8)

WT occupancy was quantified for different initial WT:Vegfr2 ^+/− mixing ratios in experiments [5] (Experiment), in the contact inhibition model (Contact) and in the cell elongation model (Long). The WT:Vegfr2 ^+/− mixing ratios were 1:1, 1:4 and 1:9, resulting in a WT percentage of 50, 20 and 10 respectively. Two different mechanisms are tested in the models: differential adhesion between tip and stalk cells and differential sensitivity to an auto-secreted chemoattractant between tip and stalk cells. The p-values represent the probability that the total number of simulated sprouts were occupied by at least the indicated percentage of WT cells when assuming only random motion (calculated with a binomial distribution, with n the number of sprouts, k the number of sprouts occupied by WT cells, and p the mixing ratio)

ISSN: 1752-0509