In vivo effects of dexamethasone on the tumor growth of glucocorticoid-sensitive Fu5-derived rat hepatoma cells.

We have previously demonstrated that BDS.1 cells are a minimal deviation rat hepatoma cell line that is hypersensitive to the anti-proliferative effects of glucocorticoids in vitro. When transplanted into athymic mice, exposure to dexamethasone reduced the initial growth rate and increased the latency time before detection of palpable BDS.1-derived tumors but did not affect the maximal growth rate, size and histology of the tumor. After collagenase dissociation, the in vitro growth of BDS.1-derived tumor cells was fully suppressed by dexamethasone. Exposure to insulin prevented the glucocorticoid inhibition of anchorage-independent growth of BDS.1 cell colonies in vitro and may therefore be one of the systemic factors that masks the long term in vivo growth response of glucocorticoids.