Detection of apoptosis in renal cell carcinoma.

Apoptosis is a selective process of programmed cell death that plays an important role in both physiologic and malignant states. In neoplastic disease, the rate at which a tumor grows depends on cell deletion as well as cell proliferation. It has been shown in several types of tumors that more aggressive tumors usually have a higher proliferative activity as well as an increased rate of apoptosis. The same characteristics seem true of renal neoplasms, as the frequency of apoptosis has been positively correlated with tumor grade, stage, and size in renal cell carcinoma (RCC) (1). Apoptosis is closely related to proliferative activity, tumor differentiation, and depth of invasion in transitional-cell carcinoma of the renal pelvis and ureter (2). The mechanisms of cell-cycle control, proliferation, and apoptosis are key issues in the biology and prognosis of RCCs. The expression of bcl-2 and p53 has been implicated in the control of apoptosis in tumorigenesis, and as a possible pathway to which cancer treatments could be directed. A reciprocal correlation was found between apoptosis and p53 positivity in RCC suggesting that the presence of mutant p53 is a negative regulator of apoptosis (3).