Figure 2
Prostate cancer cases showing variable PTEN protein expression with hemizygous PTEN gene deletion. Case #3: PTEN immunohistochemistry demonstrates intact PTEN protein (left), with four-color FISH image from an adjacent section showing a hemizygous PTEN deletion with loss of one PTEN gene (see enlarged inset-one red signal). As both centromeres (pink) and the WAPAL (green) and FAS (aqua) probes that flank either side of PTEN are retained, it is likely that this hemizygous deletion is interstitial and restricted to the PTEN region. Case #4: PTEN immunohistochemistry image shows homogeneous loss of PTEN protein (left) while FISH image from an adjacent section (right) shows a hemizygous PTEN deletion (see enlarged inset–one red signal). Concurrent hemizygous deletion of the adjacent FAS gene probe (one aqua signal missing) but retention of two copies of the centromere and WAPAL gene probes indicates the deletion includes both the PTEN and FAS genes. Case #5: PTEN immunohistochemistry image shows somewhat light, but intact immunostaining for PTEN protein (left) while the FISH image from an adjacent section (right) shows a hemizygous PTEN deletion (see enlarged inset–one red signal). Because there was concurrent loss of the WAPAL, PTEN, and FAS gene probes (green, red, and aqua, respectively), but retention of both centromeres (pink), this hemizygous deletion extends outside the PTEN region in both directions.
