Effect of difluoromethylornithine and methotrexate on proliferation of human breast carcinoma cells

Abstract

Introduction: In human colon cancer cells, the combination of difluoromethylornithine (DFMO) and methotrexate (MTX) has been shown to inhibit cellular proliferation. Objectives: To determine if the combination of DFMO and MTX inhibit proliferation of human breast cancer cells. Materials and methods: Sterile cell culture techniques, including harvesting and subculturing, were used in performing these experiments. Human breast carcinoma cells were treated alone and in combination with DFMO and MTX for 72hours. Vehicle control for MTX was dimethylsulfoxide at equivalent concentration. Results: Cell viability was inhibited with DFMO and MTX treatment alone. However, the combination treatment had no inhibitory effect. Conclusions: In human breast carcinoma cells, DFMO and MTX each inhibited cell growth by approximately 35% compared with untreated cells. However, in combination, DFMO and MTX resulted in no inhibition of cell growth. This drug combination is antagonistic and does not seem to be beneficial for therapeutic use. Other drug agents could be tested in combination to indicate inhibition of proliferation. Acknowledgements: Special thanks to our Dean, Dr Khaled Algumizi, our supervisor, Dr Sami Aldham, Dr Fahad Alateeq, Professor Patricia Thompson and her laboratory members: Julie Bickmeier, Ashley Vargas, Christina Preece and Manuel Snyder for all their help and effort.