PDF file - 1140K, Supplementary material and methods: including Cell proliferation assay, Colony formation assay, Cell viability assay, Western blot analysis, Gas chromatography analysis of fatty acids compositions Supplementary Tables (including 5 Tables): Table S1,n-3 and n-6 PUFAs content in experimental diet; Table S2,Primer sequences for PCR amplification; Table S3, Fatty acids composition in mice tumors; Table S4, Fatty acids composition in SCID or fat-1-SCID mouse tails; Table S5, Fatty acids composition in mice uteri. Supplementary figures (including 10 figures): Fig. S1, Arachidonic acid (AA) stimulates endometrial cancer cell growth; Fig. S2, DHA inhibits endometrial cancer cell colony formation; Fig. S3, n-3 PUFAs promote the inhibitory effect of cisplatin on endometrial tumor growth in xenograft models; Fig. S4, Ectopic expression of fat-1 in endometrial cancer cell lines; Fig. S5, Endogenously produced n-3 PUFAs inhibit endometrial cancer cell colony formation; Fig. S6, n-3 PUFAs prevent endometrial cancer cell migration; Fig. S7, n-3 PUFAs promote endometrial cancer cell apoptosis; Fig. S8, n-3 PUFAs promote cisplatin-induced endometrial cancer cell apoptosis; Fig. S9, n-3 PUFAs inhibits mTORC1/2 in HEC-1-B cells; Fig. S10, n-3 PUFAs prevent tamoxifen-stimulated endometrial growth in the mouse model.
ARTICLE ABSTRACT
Although preclinical and epidemiologic studies have shown the importance of n-3 polyunsaturated fatty acids (PUFA) in the prevention of hormone-responsive cancers such as breast cancer, evidence of the association between n-3 PUFAs and endometrial cancer risk is limited and no previous study has examined the effect of n-3 PUFAs on endometrial cancer in cellular and animal models. In this study, we demonstrated that docosahexenoic acid (DHA) dose- and time-dependently inhibited endometrial cancer cell proliferation, colony formation, and migration and promoted apoptosis. Dietary n-3 PUFAs efficiently prevented endometrial cancer cell growth in xenograft models. Moreover, ectopic expression of fat-1, a desaturase, catalyzed the conversion of n-6 to n-3 PUFAs and produced n-3 PUFAs endogenously, also suppressed endometrial tumor cell growth and migration, and potentiated apoptosis in endometrial cancer cell lines. Interestingly, implanted endometrial cancer cells were unable to grow in fat-1 transgenic SCID mice. Further study revealed that mTOR signaling, which plays an essential role in cell proliferation and endometrial tumorigenesis, is a target of n-3 PUFAs. Exogenous or endogenous n-3 PUFAs efficiently suppressed both mTOR complex 1 (mTORC1) and mTORC2 in vitro and in vivo. Moreover, both dietary n-3 PUFAs and transgenic expression of fat-1 in mice effectively repressed mTORC1/2 signaling and endometrial growth elicited by unopposed estrogen. Taken together, our findings provide comprehensive preclinical evidences that n-3 PUFAs efficiently prevent endometrial cancer and establish mTORC1/2 as a target of n-3 PUFAs. Cancer Prev Res; 7(8); 824–34. ©2014 AACR.
