[Establishment of a new human renal cancer cell line (TC-1) and its productivity of interleukin-6 (IL-6)].

We established a new cell line (TC-1) from primary site of a renal cell carcinoma (RCC) patient. Its doubling time in tissue culture was 20 hours at 45th passage and mycoplasma contamination test was negative. The karyotypic analysis demonstrated a human karyotype with a modal number of 70. A consistent chromosomal abnormality was noted such as No. 4 monosomy, No. 7 trisomy and a loss of Y chromosome. Electron microscopic examination showed a brush border, vacuoles and abundant glycogen granules in the cytoplasm, which was compatible with RCC cells. This cell line was transplantable to nude mice and the grown tumor closely resembled the original tumor, i.e. clear cell type and hypervascularity. High titer of interleukin-6 (IL-6) was detected in the supernatant of TC-1 cell culture (approximately 5 ng/ml) as well as in sera of nude mice bearing this tumor (260 pg/ml). Exogenous IL-6 did not enhance the TC-1 cell proliferation as determined by cell count. Flow cytometric analysis could not demonstrate the existence of IL-6 receptor on the cell surface. These results suggested the produced IL-6 did not act as an autocrine growth factor in the cell line. Additional IL-1 alpha to the culture medium induced 3-4 times higher concentration of IL-6 in the culture supernatant compared with that of non-stimulating cells, while exogenous TNF alpha did not stimulate IL-6 production.