Which of the following immunohistochemical features would be associated with an aggressive tumour in bladder cancer?
A. Low p53Answer D
Retinoblastoma (Rb) protein is a tumour suppressor protein, which is involved in preventing excessive cell growth by inhibiting the cell cycle until the point where the cell is ready to divide. At the point of cell division, it is phosphorylated rendering it inactive. p53 is a gene that codes for a protein that regulates the cell cycle and apoptosis. Defective p53 allows abnormal cells to proliferate and lead to cancer. Ki67 is a cellular marker for proliferation, which is associated with ribosomal RNA transcription. Inactivation of Ki67 leads to inhibition of ribosomal RNA synthesis. Increased expression is associated with aggressive pathological features. E-cadherin is a cell adhesion molecule that is involved in adherent junction formation, which allow cells to bind to one another. Decreased expression is associated with increased metastasis.