Study of thermal effect on breast tumor metabolism and growth using metabonomics.

In this study, the biological effects of long-term mild hyperthermia treatment on tumor metabolism and growth were investigated using 4T1 murine mammary carcinoma, a common animal model of metastatic breast cancer. Periodic thermal treatment (12 hours per day) was applied to tumors and carried out for 3 days, 7 days, 14 days, and 21 days, respectively. The metabolites of tumor tissues were analyzed by gas chromatography-mass spectrometry. The results showed that the growth rate of thermally treated tumors was inversely related to the abundance of long chain fatty acids and acyl glycerols identified in tumor tissues. In the first two weeks, the growth of thermally treated tumors was significantly inhibited, while there was an obvious accumulation of long chain fatty acids and acyl glycerols in tumor tissues. In the third week, the thermally treated tumors adapted to the thermal environment and started to regrow, while the abundance of long chain fatty acids and acyl glycerols decreased in the tumor tissues. These observations suggested that the blockade of long chain fatty acid synthesis during mild hyperthermia treatment of tumors could improve the long-term treatment effect by limiting the supply of substance and energy for tumor re-growth.