EFFECT OF ELAIDIC ACID ON ANTI-TUMORAL EFFECT OF 5-FLUOROURACIL

We studied the effects of elaidic acid (EA) has on the anti-tumor effect of 5-fluorouracil (FU). Examining the 5-FU sensitivity in mouse lung cancer cell line LL2, and mouse colorectal cancer cell lines CT26 and CMT93, CMT93 showed low sensitivity. The increased growth inhibitory effects in CT26, CMT93, and LL2 cells were 1.0-, 1.2-, and 1.1-times, respectively, on concurrent treatment with EA at an apoptosis-inducing concentration and 5-FU at a concentration of IC50. On examining aldehyde dehydrogenase (ALDH) activity changes in the cancer stem cells in this case, it was found to have been increased 3.8-fold by simultaneous treatment with 5-FU and EA in CT26 and LL2 cells, but 1.5-fold in CMT93 cells. In addition, considering the expression of nucleostemin as a stem cell marker, in simultaneous treatment with 5-FU and EA, and treatment with EA alone, the expression was increased in CT26 and LL2 cells, whereas the expression level did not change in CMT93 cells. The foregoing suggests that, rather than altering the 5-FU sensitivity of cancer cells, EA might promote the survival of cancer stem cells. The results suggest that the content of the diet during chemotherapy is a relevant issue