Antineoplastic activity of 2-methoxyestradiol in human pancreatic and gastric cancer cells with different multidrug-resistant phenotypes.

Background and Aim: Chemoresistance often leads to loss of the last treatment option for cancer. 2-Methoxyestradiol (2-ME2) has been shown to inhibit tumor growth. The aim was to examine the efficacy of 2-ME2 on multidrug-resistant human cells from pancreatic and gastric cancer.
Methods: We investigated the impact of 2-ME2 on multidrug-resistant cells derived from human pancreatic and gastric cancer cells that were positive or negative for the MDR1-gene.
Results: In pancreatic cancer cells, growth inhibition was 57% in parental, 72% in MDR1-negative and 87% in MDR1-positive cells after 1 micromol/L 2-ME2. In gastric cancer cells we found a growth inhibition of 75% in parental, 82% in MDR1-positive and 95% in MDR1-negative cells. Strong induction of apoptosis was induced after a low dose of 2-ME2. No significant difference in the amount of apoptotic cells was observed between parental and multidrug-resistant cells of both tumor types. The number of apoptotic cells after 2-ME2 ranged from 7.5% in parental gastric cancer cells to 20.1% in MDR1-negative gastric cancer cells.
Conclusion: 2-ME2 may therefore have clinical application for chemoresistant cancer.