Abnormal expression of p120 correlates with poor survival in patients with bladder cancer

p120 is a cytoplasmic molecule closely associated with the Ca 2+-dependent cell–cell adhesion molecule E-cadherin, by forming complexes between the cytoplasmic domain of E-cadherin and the cytoskeleton. Although it has been shown that loss or downregulation of E-cadherin is associated with an invasive and poorly differentiated phenotype in several tumours, there is very little information available concerning p120 expression in malignant disease. We used an avidin–biotin immunoperoxidase technique to examine the immunoreactivity and cellular localisation of p120 and E-cadherin in 68 transitional cell carcinomas (TCC) and 14 normal bladder biopsies and correlated these results with pathological and clinical parameters. E-cadherin and p120 were expressed in a normal membranous pattern in all normal bladder epithelium specimens. Loss of normal surface E-cadherin and p120 expression was found in 52/68 (76%) and 57/68 (84%) tumours, respectively. There was a significant correlation between the loss of normal membranous expression of p120 and increased grade ( P