BACKGROUND: Methylsulfonylmethane (MSM) is a commonly used diet supplement 
believed to decrease the inflammation in joints and fastens recovery in 
osteoarthritis, gastric mucosal injury, or obesity-related disorders. It was 
also suggested that MSM might play a beneficial role in cancer treatment.
PURPOSE: So far, the MSM might have a potentially beneficial effect in 
endometrial cancer (EC) treatment.
STUDY DESIGN: This study evaluated the effect and usefulness of MSM in 
combinatory therapy with known drug doxorubicin (DOX).
METHODS: The effect of combinational treatment of MSM and DOX on the induction 
of apoptosis was evaluated in EC cell lines (ISHIKAWA, MFE-296, MFE-280).
RESULTS: We observed that MSM itself induces apoptosis in EC cell lines, and 
pre-treatment with MSM for 24 h increases the sensitivity of EC cells to 
DOX-induced apoptosis and DNA damage and that effect might be regulated by 
p42/44 (Erk1/2) MAPK and Akt (protein kinase B).
CONCLUSION: These results for the first time show that MSM might act as a 
sensitizer of EC cells to known drugs, for which EC cells quickly acquire 
resistance. Graphical abstract.