[Development of cell cultures in basic research on renal carcinoma]

The development of in vitro cell tissue culture techniques has provided most of the current knowledge on the physiology of both normal and tumor cells. The results of cell culture studies using nephrectomy specimens are presented.

Surgical specimens from 7 patients (3 males, 42.9%; 4 females, 57.1%) aged 43-79 years (mean 62.14), who had undergone nephrectomy for renal adenocarcinoma between April 1997 and February 1998 were utilized. The tumor cell samples were obtained during surgery, after the kidney had been excised. The samples were cut, washed in a balanced saline solution and enzymatically dissociated in a trypsin solution (0.1% Hank's solution) for 30 minutes at 37 degrees, centrifuged, placed in Multiwell plates, covered with 0.1 mg/ml polylysine (ICN) or 3 mg/ml collagen S (Boehringer) and cultured in RPMI 1640 (Sigma) supplemented with 5% fetal calf serum (reagent), which was changed every 2-3 days for one month. After the culture had developed, samples were fixed in 70% ethanol and stained with hematoxylin-eosin for cell identification. Cell types were identified by cytokeratin analysis.

The histological types were: clear cell renal adenocarcinoma in three cases (42.9%), renal oncocytoma in two (28.6%), mixed cells renal adenocarcinoma in one (14.3%) and papillary carcinoma in one case (14.3%). Polylysine and collagen were found to be good substrates for normal and tumor cell culture. Polylysine was found to be a better substrate for epithelial cells; there were less epithelial and more mesangial cells in the collagen substate. The positive cytokeratin expression (a marker for intermediate filaments) corroborates the well-known epithelial origin of renal cell carcinoma. Epithelial cells from normal kidney grew well in the culture medium. Mean cell survival was 30.83 days (range 15-50). To evaluate the viability of the culture, positivity for a neutral red stain was used as marker for good metabolic activity after one month. All cultures that survived for more than one month (5 of 7) stained positively.

The study and development of human cell lines is useful to analyze the metabolic aspects of renal carcinoma. Cell cultures permit conducting genetic and molecular studies and investigating the radio and chemosensitivity of renal carcinoma in vitro.