SERUM LEVELS AND GENE EXPRESSIONS OF INTERLEUKIN-1/β (IL-1β), INTERLEUKIN-6 (IL-6) AND TUMOR NECROSIS FACTOR-α (TNF-α) IN HUMAN RENAL CELL CARCINOMAS

Abstract

We examined serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in 32 patients with renal cell carcinoma. Serum IL-1β was elevated in only one patient (3.1%), IL-6 in 17 (53.1%) and TNF-α in 6 (18.8%). Positive rate of serum IL-6 increased with progression of the stage (stage I and II: stage III and IV=14.3%:88.9%, p<0.0001) and was higher for rapid growth type (slow and intermediate growth type: rapid growth type=36.4%:90.0%, p<0.005). However, increased serum levels of IL-1β and TNF-α were not correlated with stage, grade, or growth type.
Gene expressions of IL-1β, IL-6, IL-6 receptor and TNF-α in the tissues resected from 15 patients with renal cell carcinoma and 3 cell lines established from renal cancers were evaluated by Northern blot analysis. Gene expression of IL-1β and TNF-α were not detected in any of the tissues or cell cultures, but highly enhanced expressions of IL-6 were revealed in two tumor specimens (13.3%, 1 rapid and 1 slow growth type) and 2 of 3 cell lines. Expressions of IL-6 receptor in tissues and cells were weak.
These results suggest that IL-6 plays an important role in the progression of renal cell carcinoma, and that measurement of IL-6 in patients with renal cell carcinoma may be useful clinically.