Abstract
Fifteen tumor-containing specimens were obtained directly from patients with small cell carcinoma of the lung and tested for their ability to grow in serum-supplemented medium and in serum-free medium supplemented with hydrocortisone, insulin, transferrin, estrogen, and selenium (HITES). The tumor cells replicated in 14 of 15 cases (93%) in the HITES medium and in 10 of 15 cases (67%) in the serum-supplemented medium. The neoplastic origin of the cells growing in the HITES medium was confirmed by standard cytologic criteria, by DNA content analysis using flow cytometry, and by their ability to form colonies in agarose and tumors in athymic nude mice. While the tumor cells had very similar morphologies in both media, the serum-free medium did not support the growth of nonmalignant stromal cells, and essentially pure cultures of replicating tumor cells were obtained 7-10 days after plating. The selectivity of the HITES medium was demonstrated by the failure of cells to grow in 20 specimens cytologically negative for small cell carcinoma and in 9 of 10 specimens containing other tumor types (including other types of lung cancer). The results demonstrate that a chemically defined medium, determined by work on tissue culture-adapted human tumor lines, can support the selective growth of tumor specimens obtained directly from patients. Such selective formulas are probably specific for different tumor types and thus could be used for diagnosis, drug sensitivity testing in vitro, and identification of factors regulating tumor growth. All of these have direct application to patient treatment.