External Qi of Yan Xin Qigong Induces Apoptosis and Inhibits Migration and Invasion of Estrogen-Independent Breast Cancer Cells Through Suppression of Akt/NF-ĸB Signaling

The antitumor effects of external Qi of Yan Xin Qigong (YXQ-EQ) have been widely described over the past three decades. To gain a better understanding of the mechanisms underlying YXQ-EQ's antitumor effects, in the present study we investigated its effects on growth, migration, invasion and apoptosis of breast cancer cells and the underlying molecular mechanisms. We show that YXQ-EQ treatment caused a time-dependent reduction in viability, blocked clonogenic growth and induced apoptosis in estrogen-independent breast cancer MDA-MB-231 cells. Furthermore, YXQ-EQ treatment blocked migration and invasion of MDA-MB-231 cells. Biochemically, YXQ-EQ treatment markedly inhibited constitutive and EGF-induced Akt phosphorylation. YXQ-EQ also substantially repressed NF-kappaB activity, resulting in decreased expression of anti-apoptotic Bcl-2, Bcl-X(L), XIAP and survivin proteins. These findings suggest that YXQ-EQ may induce apoptosis and inhibition of migration and invasion of MDA-MB-231 cells through the repression of Akt/NF-kappaB signaling.