(HealthDay News) – Short cycles of starvation (fasting) sensitizes mammalian cancer cells to chemotherapeutic agents, and may increase the effectiveness of chemotherapy against cancer cells and in mouse models, according to an experimental study published online Feb. 8 in Science Translational Medicine.
Changhan Lee, from the University of Southern California in Los Angeles, and colleagues examined whether fasting had any effect on chemotherapy sensitivity in yeast cells expressing the oncogene-like RAS2val19, 17 mammalian cancer cell lines, and in mouse models of neuroblastoma.
The researchers found that fasting sensitized yeast cells and 15 of the mammalian cancer cell lines to chemotherapeutic agents. For specific tumors, fasting was as effective as chemotherapeutic agents in delaying progression, and fasting increased the effectiveness of chemotherapeutic agents against melanoma, glioma, and breast cancer cells. Fasting cycles plus chemotherapy, but neither treatment alone, resulted in long-term cancer-free survival in a mouse model of neuroblastoma. Short-term starvation was associated with increased phosphorylation of stress-sensitizing kinases, oxidative stress, cleavage of caspase-3, DNA damage, and apoptosis in 4T1 breast cancer cells.
“The previously described fasting-dependent differential stress resistance of normal and cancer cells and the tumor cell-specific sensitization to chemotherapeutic agents presented here suggest that short-term starvation conditions or modified diets that promote similar changes may be able to enhance standard cancer therapies,” Lee and colleagues write.