[Studies on the interaction between interleukin-6 and human renal cell carcinoma cell line GRC-1]

To demonstrate the effects of IL-6 on the renal cell carcinoma cell line GRC-1.

Immunocytochemical staining and RT-PCR analysis indicated that this cell line could express IL-6 both on mRNA and protein levels. Secretion of IL-6 in this cell line was 465 pg/ml, which was identified by ELISA assay. By RT-PCR analysis, we found that GRC-1 expressed IL-6 receptor system including IL-6 mRNA and gp130 mRNA. The rhIL-6 did not stimulate the growth of GRC-1 while the neutralizing antibody did not inhibit its growth. For further identification of the effect of IL-6 on GRC-1 cells, we introduced an antisense IL-6 RNA into GRC-1 cells. Thereafter, the lowered expression of IL-6 mRNA was observed by Northern blot, and the secretion of IL-6 was reduced to 250 pg/ml. But there were no significant growth-inhibitory effects on GRC-1 cells.

Although GRC-1 could express IL-6, IL-6 R and gp130, the rhIL-6 and IL-6 neutralizing antibody or transducing antisense IL-6 RNA could not change the growth of GRC-1 cells significantly. These results suggest that it is not likely for IL-6 functioning as an autocrine growth factor for GRC-1.