The effect of butyric acid and retinoic acid on invasion and experimental metastasis of murine melanoma cells.

The effect of butyric acid (BA) and all trans-retinoic acid (RA) on murine melanoma cells was investigated in vitro and in vivo. The in vitro assays included 3H-IdUR incorporation, adhesion, migration and invasion experiments. Butyric acid decreased 3H-IdUR cellular incorporation within 24 h and increased adhesion as measured by trypsin release of 3H-IdUR labelled cells from either polycarbonate (p.c.) or Matrigel-coated p.c. membranes. Migration and invasion rates after 72 h were quantified by scanning electron microscopy (SEM). The invasion barrier consisted of Matrigel-coated p.c. membranes. Butyric acid significantly enhanced migration and invasion of B16a cells, while RA significantly decreased migration and invasion of B16a and K-1735 cells. Subcutaneous administration of either BA or RA pellets significantly decreased the number of lung nodules in the experimental metastatic assay. The experimental metastatic assay is defined as a tail vein inoculation protocol followed by subsequent lung evaluation.