Analysis of downstream effects of endogenous WNT signaling during cardiac differentiation of human ES cells

WNT signaling inhibition at an intermediate stage of differentiation is a key requirement for cardiac induction of human ES cells, suggesting that endogenous WNT activity interferes with cardiomyocyte formation. Two downstream genes of endogenous WNT signaling, MSX1 and CDX2, were induced during cardiac differentiation to reveal whether they may account for the global negative effects played by endogenous WNT signaling in this process. Total RNA isolated from day 5 differentiating in-vitro samples: (i) Cells treated with a WNT inhibitor during differentiation to promote cardiac induction, (ii) cells not treated with the WNT inhibitor, (iii) cells treated with a WNT inhibitor and overexpressing MSX1 at the same time, and (iv) cells treated with a WNT inhibitor and overexpressing CDX2 at the same time