Lanreotide-Induced Modulation of 5-Fluorouracil or Mitomycin C Cytotoxicity in Human Colon Cancer Cell Lines: a Preclinical Study

Abstract

The effect on growth of the long-acting somatostatin analogue lanreotide (LAN), alone or in combination with 5-fluorouracil (5-FU) and mitomycin C (MIT), was investigated in three human colon cancer lines. Cell survival inhibition induced by LAN alone, as evaluated by sulforhodamine B assay, ranged from 20% to 40% as a function of cell line and concentration. The IC₅₀, the concentration inhibiting cell survival by 50%, was never reached. The antipro-liferative effect produced by a 48h exposure to 5-FU or MIT was synergistically enhanced in all cell lines by a subsequent 48h exposure to LAN. The synergis-tic interaction was not related to specific cell cycle perturbations or to the somatostatin receptor 2 (sst2) mRNA abundance. In conclusion, our study seems to indicate that LAN is a potentially useful modulating agent for enhancing 5-FU and MIT activity in colorectal cancer patients.