1.
Curcumin Suppresses Proliferation and Migration of MDA-MB-231 Breast Cancer Cells through Autophagy-Dependent Akt Degradation.
Guan, F, Ding, Y, Zhang, Y, Zhou, Y, Li, M, Wang, C
PloS one. 2016;(1):e0146553
Abstract
Previous studies have evidenced that the anticancer potential of curcumin (diferuloylmethane), a main yellow bioactive compound from plant turmeric was mediated by interfering with PI3K/Akt signaling. However, the underlying molecular mechanism is still poorly understood. This study experimentally revealed that curcumin treatment reduced Akt protein expression in a dose- and time-dependent manner in MDA-MB-231 breast cancer cells, along with an activation of autophagy and suppression of ubiquitin-proteasome system (UPS) function. The curcumin-reduced Akt expression, cell proliferation, and migration were prevented by genetic and pharmacological inhibition of autophagy but not by UPS inhibition. Additionally, inactivation of AMPK by its specific inhibitor compound C or by target shRNA-mediated silencing attenuated curcumin-activated autophagy. Thus, these results indicate that curcumin-stimulated AMPK activity induces activation of the autophagy-lysosomal protein degradation pathway leading to Akt degradation and the subsequent suppression of proliferation and migration in breast cancer cell.
2.
Vitamin D receptor gene ApaI polymorphism and breast cancer susceptibility: a meta-analysis.
Luo, S, Guo, L, Li, Y, Wang, S
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine. 2014;(1):785-90
Abstract
Vitamin D receptor (VDR) principally mediates the anticancer activities of vitamin D. Many studies investigated the association between VDR gene ApaI polymorphism and breast cancer, but the results were inconclusive. We performed this meta-analysis to evaluate the association between VDR gene ApaI polymorphism and breast cancer. Twelve studies with a total of 8,254 subjects were identified from PubMed and Wanfang databases. The pooled odds ratio (OR) and confidence intervals (95% CI) were used to assess the association. The meta-analysis indicated that VDR gene ApaI polymorphism was not associated with risk of breast cancer (a vs. A: OR = 0.97, 95% CI 0.91-1.04, P = 0.378; aa vs. AA: OR = 0.97, 95% CI 0.85-1.10, P = 0.618; aa vs. AA + Aa: OR = 1.00, 95% CI 0.89-1.12, P = 0.972; aa + Aa vs. AA: OR = 0.95, 95% CI 0.82-1.11, P = 0.550). Subgroup analysis by ethnicity further showed that VDR gene ApaI polymorphism was not associated with risk of breast cancer in both Asians and Caucasians. These data from the meta-analysis indicate that VDR gene ApaI polymorphism is not associated with breast cancer susceptibility.