Metabolic Alterations Induced by Kudingcha Lead to Cancer Cell Apoptosis and Metastasis Inhibition.

Kudingcha is implicated in alleviating metabolic disorders in traditional Chinese medicine. However, the role of Kudingcha, one of the Ligustrum robustum species, in metabolic regulations and its antitumor activity in triple-negative breast cancer (TNBC) remains to be determined. Two breast cancer cell lines and immunocompetent and immunodeficient mice were used to evaluate the therapeutic effects of Kudingcha treatment. The production of reactive oxygen species (ROS) and glucose uptake were examined by flow cytometry. Metabolic shift was examined by metabonomics and western blot analysis. In this study, we found that aqueous extract of Kudingcha dose dependently inhibited cell growth and induced apoptosis in vitro and in vivo. Moreover, Kudingcha supplementation significantly reduced cancer metastasis. Kudingcha significantly inhibited glycolysis and glutamine metabolism. In addition, we demonstrated that the antitumor effects of Kudingcha were dependent on ROS production, which was increased by ß-oxidation and oxidative phosphorylation. These findings provide a novel potential benefit of Kudingcha from targeting the cancer metabolism.

Metabolic Shift Induced by ω -3 PUFAs and Rapamycin Lead to Cancer Cell Death.

BACKGROUND/AIMS: Rapamycin (Rp), the main mammalian target of rapamycin complex inhibitor, is a promising therapeutic agent for breast cancer. However, metabolic disorders and drug resistance reduce its efficacy. Epidemiological, clinical, and experimental studies have demonstrated that omega-3 polyunsaturated fatty acids (ω-3 PUFAs) significantly reduce the incidence and mortality of breast cancer and improve metabolic disorders. METHODS: Three breast cancer cell lines and immunocompetent and immunodeficient mice were used to evaluate the therapeutic effects of Rp plus ω-3 PUFA treatment. The production of reactive oxygen species (ROS) and glucose uptake were examined by flow cytometry. Metabolic shift was examined by metabonomics, seahorse experiments, and western blot analysis. RESULTS: We found that ω-3 PUFAs and Rp synergistically induced cell cycle arrest and apoptosis in vitro and in vivo, accompanied by autophagy blockage. In addition, Rp-induced hypertriglyceridemia and hypercholesterolemia were completely abolished by ω-3 PUFA supplementation. Moreover, the combined treatment of ω-3 PUFA and Rp significantly inhibited glycolysis and glutamine metabolism. The anti-tumor effects of this combination treatment were dependent on ROS production, which was increased by ß-oxidation and oxidative phosphorylation. CONCLUSION: Our study revealed that ω-3 PUFA enhanced the anti-tumor activity of Rp while minimizing its side effects in vitro and in vivo. These results provide novel insights into the mechanisms underlying the potential beneficial effects of Rp combined with ω-3 PUFAs on the prevention of breast cancer.

GPR120 is not required for ω-3 PUFAs-induced cell growth inhibition and apoptosis in breast cancer cells.

Intake of ω-3 PUFAs reduces the frequency of breast cancer, and GPR120 receptor transduces ω-3 PUFAs signaling to increase insulin sensitivity in mice, but whether GPR120 mediates ω-3 PUFAs signaling to inhibit breast carcinogenesis is currently unknown. In the present study, we found that GPR120 is highly expressed in human breast cancerous tissues but not adjacent normal tissue. Knockdown of GPR120 by siRNA in breast cancer cells significantly reduced cell growth, and dramatically increased ω-3 FFA-induced cell growth inhibition and apoptosis. Thus, these observations indicated that GPR120 promotes breast cancer cell growth, whereas ω-3 PUFA-induce breast cancer cell apoptosis independently of GPR120.

Vitamin D enhances omega-3 polyunsaturated fatty acids-induced apoptosis in breast cancer cells.

Breast cancer is a leading type of cancer in women and generally classified into three subtypes of ER+ /PR+ , HER2+ and triple negative. Both omega-3 polyunsaturated fatty acids and vitamin D3 play positive role in the reduction of breast cancer incidence. However, whether combination of omega-3 polyunsaturated fatty acids and vitamin D3 has stronger protective effect on breast carcinogenesis still remains unknown. In this study, we show that the combination of ω-3 free fatty acids (ω-3 FFAs) and 1α, 25-dihydroxy-vitamin D3 (VD3 ) dramatically enhances cell apoptosis among three subtypes of breast cancer cell lines. Bcl-2 and total PARP protein levels are decreased in combined treatment MCF-7 and SK-BR-3 cells. Caspase signals play a vital role in cell apoptosis induced by combination. Moreover, Raf-MAPK signaling pathway is involved in the apoptosis induction by combination of ω-3 FFAs+VD3 . These results demonstrate that the induction of cell apoptosis by combined treatment is dependent on different signaling pathways in three subtypes of breast cancer cell lines.

RA and ω-3 PUFA co-treatment activates autophagy in cancer cells.

Retinoic acid (RA), is a promising therapeutic agent for the treatment of breast cancer. However, metabolic disorders and drug resistance reduce the efficacy of RA. In this study, we found that RA and ω-3 polyunsaturated fatty acids (ω-3 PUFAs) synergistically induced cell death in vitro and in vivo and autophagy activation. Moreover, RA-induced hypercholesterolemia was completely corrected by ω-3 PUFA supplementation. In addition, we demonstrated that the effects of this combination on the autophagic flux were independent of the two major canonic regulatory complexes controlling autophagic vesicle formation. The treatment activated Gαq-p38 MAPK signaling pathways, which resulted in autophagy of breast cancer cells. Knockdown of Gαq or P38 expression prevented RA and ω-3 PUFAs from inducing autophagy. Data indicated that Gαq-p38activation was mediated by the co-activation of GPR40 and RARα in lipid rafts, rather than by the activation of GPR120, RARß, or RARγ. The results of this study suggest that hyperlipidemic drug side effects may be ameliorated by the administration of ω-3 PUFAs. Thus, the therapeutic indexes of the corresponding drugs may be increased.