Loss of CSMD1 in the MCF10A three-dimensional model resulted in an increased number of acini (P = 0.001), which are also larger in size (40%, P = 0.02) and misshapen relative to the control. Although expressing a high level of active caspase 3, shCSMD1 acini failed to form lumen.
Loss of CSMD1 expression caused a 56% (P = 0.001) increase in proliferation and a 44% (P = 0.0006) decrease in adhesion. shCSMD1 cells migrate much faster than control cells and showed 33% (P < 0.001) increase in invasion. These results were confirmed in two other cell lines.
Loss of CSMD1 expression was identified in 79/275 (28.7%) of BC cases, which was associated with high tumour grade (P = 0.003) and low overall survival (HR = 0.607, 95% CI = 0.4 to 0.91, P = 0.018). Moreover, CSMD1 is an independent predictor of overall survival (HR = 0.607, 95% CI = 0.4 to 0.91, P = 0.018) .