Fas labeling status does not correlate with apoptosis of renal cell carcinoma in vivo
Koga, F.; Arai, K.; Kamai, T.; Abe, H.; Yoshida, K.
Anticancer Research 21(5): 3193-3197
2001
ISSN/ISBN: 0250-7005 PMID: 11848472 Document Number: 527664
Contribution of the Fas system to apoptosis of renal cell carcinoma (RCC) was investigated in vivo. Tissues from 30 RCC cases were immunostained for Fas and Fas ligand (FasL) to assess associations between Fas labeling status of RCC, indices of FasL-positive tumor-infiltrating mononuclear cells (FasL-TIM) and apoptotic indices (AI) of RCC. In all cases, tumor cells co-expressed Fas and FasL; strongly and diffusely in 13 cases (43%) and weakly in 17 (57%). Despite the constitutive co-expression of Fas and FasL, AI was low in most cases (median, 7 per 1,000 tumor cells; range, 1 to 257). The Fas labeling status did not significantly associate with AI while FasL-TIM index positively correlated with AI. These results suggest that the Fas system is not the principal mechanism of apoptosis of RCC while activated tumor-infiltrating mononuclear cells induce apoptosis via mechanisms other than the Fas system.