Figure 3
Prostate cancer cases showing absence of PTEN protein expression with homozygous PTEN gene deletion. Case #6: PTEN immunohistochemistry image (left) shows loss of PTEN protein in tumor glands. Intraductal spread of tumor is present in this case and retention of PTEN protein is seen in benign basal and luminal cells of duct containing tumor (arrowhead). Four-color FISH image from an adjacent section (right) shows a homozygous deletion with loss of both PTEN genes (see enlarged inset–no red signals). The retention of the centromeres (pink) and both WAPAL genes (green), but the presence of only one copy of the FAS gene (aqua) indicates that one of the deletions involved both the PTEN and FAS genes. Case #7: PTEN immunohistochemistry image (left) shows loss of PTEN protein in tumor glands, with retention in entrapped benign gland (B). FISH image from an adjacent section (right) shows a homozygous PTEN deletion (see enlarged inset–no red signals). The retention of the centromeres (pink) but concurrent loss of one WAPAL (green) and one FAS gene (blue) indicates the deletions extend outside the PTEN region. Case #8: PTEN immunohistochemistry image (left) shows loss of PTEN protein in tumor glands, with retention in adjacent benign gland (B) and nearby endothelial cells (arrowhead). (FISH image from an adjacent section (right) shows a homozygous PTEN deletion (see enlarged inset–no red signals). The retention of the centromeres and both the WAPAL genes (green), but the concurrent loss of both FAS (blue) and PTEN (red), indicates that both copies of chromosome 10 have deletions involving these genes.
