Brief tamoxifen pretreatment enhances the chemosensitivity of gastric carcinoma cells to 5-fluorouracil in vitro.

BACKGROUND

Estrogen receptors (ERs) have been detected in gastric carcinoma cells in vivo and in vitro. Several in vitro and in vivo studies examining the potential beneficial effects of adjuvant Tamoxifen (Tmx) have shown contradictory experimental and clinical results.

MATERIALS AND METHODS

We examined the effects of a brief Tmx pretreatment on the chemosensitivity to 5-FU of two gastric carcinoma cell lines. One of these cell lines was ER(+) and the other ER(-). Tmx was administered for 24 hours before chemotherapy.

RESULTS

We observed a significant increase in the cytotoxic action of 5-FU in both gastric carcinoma cell lines in the order of 100-155%. This increase in 5-FU cytotoxicity was not mediated by either the ER cell status or through TGF-beta 1 secretion.

CONCLUSION

Brief Tmx pretreatment increases the chemosensitivity of gastric carcinoma cells to 5-FU in vitro.