Objective To investigate the apoptotic effect of the transmembrane form vaccine of human blood group A mimotope on malignant melanoma cell line B16. Methods B16 cells were transfected with different recombinant plasmid through Lipofectamine 2000 and incubated with different concentration of monoclonal anti-A antibody at 2.5 μg/ml, 5 μg/ml,10 μg/ml and 20 μg/ml. Apoptosis rate of cells was determined with Annexin Ⅴ/PI double staining by flow cytometry. Results Apoptosis rate to P/F-M-pIRES group B16 cells was 74.74% when anti-A monoclonal antibody concentration was 10 μg/ml; apoptosis rate of plasmids carrying peptide/Fas fusion gene such as P/F-M-pIRES group and P/F-pIRES group were significantly higher than M-pIRES group and pIRES group. The apoptosis rate was statistically significantly different between different recombinated plasmid groups (F＝669.707,P＜0.01). The apoptosis rate was statistically significantly different between different antibody groups (F＝106.596,P＜0.01). The interaction between recombinated plasmid groups and antibody groups was statistically significant (F＝34.806,P＜0.01). Conclusions The transmembrane form vaccine of human blood group A mimotope could induce B16 cell apoptosis in vitro. This vaccine may be a promising candidate for potential malignant melanoma therapy.

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.