Objective To investigate the expression of cystein rich 61 (Cyr61) and vascular endothelial growth factor (VEGF) in different stages of multiple myeloma (MM) patients,evaluate their relationship with angiogenesis and prognosis,and to determine the relationship between Cyr61 and VEGF.Methods Expression of Cyr61 and VEGF in BMMNC from 31 patients with different stages of MM and 10 cases of control were detected by RT-PCR.Results Expression of Cyr61 and VEGF in patients with MM (0.3652±1.5423,0.4815±1.3423) were significantly elevated in comparison to control (0.1862±0.7542,0.2012±1.2331) (P ＜ 0.05,P ＜ 0.01).Expression of Cyr61 and VEGF in stage Ⅲ (0.4632±0.1634,0.5356± 0.2342) was significantly higher than those in stage Ⅰ and stage Ⅱ (t =2.423,2.524,P ＜ 0.05),but there was no difference between stage Ⅰ and stage Ⅱ (0.2513±0.1365,0.3064±0.2124; 0.3084±0.2254,0.3653±0.1265) (t =1.782,1.824,P ＞ 0.05).The levels of Cyr61 and VEGF were significantly decreased after chemotherapy compared to before chemotherapy (P ＜ 0.01).Expression of Cyr61 and VEGF were positively correlated (r =0.8941,P ＜ 0.01).Conclusion Cyr61 and VEGF may play roles in the angiogenesis and pathophysiology of MM.It can be used to guide treatment and estimate prognosis by monitoring Cyr61 and VEGF.

Chaperone-mediated autophagy (CMA) is a lysosome-dependent selective degradation pathway implicated in the pathogenesis of cancer and neurodegenerative diseases. However, the mechanisms that regulate CMA are not fully understood. Here, using unbiased drug screening approaches, we discover Metformin, a drug that is commonly the first medication prescribed for type 2 diabetes, can induce CMA. We delineate the mechanism of CMA induction by Metformin to be via activation of TAK1-IKKα/β signaling that leads to phosphorylation of Ser85 of the key mediator of CMA, Hsc70, and its activation. Notably, we find that amyloid-beta precursor protein (APP) is a CMA substrate and that it binds to Hsc70 in an IKKα/β-dependent manner. The inhibition of CMA-mediated degradation of APP enhances its cytotoxicity. Importantly, we find that in the APP/PS1 mouse model of Alzheimer's disease (AD), activation of CMA by Hsc70 overexpression or Metformin potently reduces the accumulated brain Aβ plaque levels and reverses the molecular and behavioral AD phenotypes. Our study elucidates a novel mechanism of CMA regulation via Metformin-TAK1-IKKα/β-Hsc70 signaling and suggests Metformin as a new activator of CMA for diseases, such as AD, where such therapeutic intervention could be beneficial.