Regulation of the Soluble Amyloid Precursor Protein α (sAPPα) Levels by Acetylcholinesterase and Brain-Derived Neurotrophic Factor in Lung Cancer Cell Media.

In comparing two human lung cancer cells, we previously found lower levels of acetylcholinesterase (AChE) and intact amyloid-β40/42 (Aβ), and higher levels of mature brain-derived neurotrophic factor (mBDNF) in the media of H1299 cells as compared to A549 cell media. In this study, we hypothesized that the levels of soluble amyloid precursor protein α (sAPPα) are regulated by AChE and mBDNF in A549 and H1299 cell media. The levels of sAPPα were higher in the media of H1299 cells.

Differences in the Relative Abundance of ProBDNF and Mature BDNF in A549 and H1299 Human Lung Cancer Cell Media.

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has been linked to several human malignancies and shown to promote tumorigenesis. The purpose of this study was to explore the relative abundance of pro-brain-derived neurotrophic factor (proBDNF) and mature BDNF (mBDNF) in A549 (p53 wild-type) and H1299 (p53-null) lung cancer cell media. Higher levels of proBDNF were detected in the media of A549 cells than in H1299 cell media.

Regulation of amyloid-β levels by matrix metalloproteinase-2/9 (MMP2/9) in the media of lung cancer cells.

In this study, we set out to identify regulators of intact amyloid-β40/42 (Aβ) levels in A549 (p53 wild-type) and H1299 (p53-null) lung cancer cell media. Higher Aβ levels were detected in the media of A549 than H1299 cells without or with treatment with 4-methylumbelliferone (4-MU) and/or the anti-CD44 antibody (5F12). Using inhibitors, we found that PI3K, AKT, and NFκB are likely involved in regulating Aβ levels in the media.

Interaction of amyloid beta with humanin and acetylcholinesterase is modulated by ATP.

Humanin (HN) is known to bind amyloid beta (Aβ)-inducing cytoprotective effects, while binding of acetylcholinesterase (AChE) to Aβ increases its aggregation and cytotoxicity. Previously, we showed that binding of HN to Aβ blocks aggregation induced by AChE and that HN decreases but does not abolish Aβ-AChE interactions in A549 cell media. Here, we set out to shed light on factors that modulate the interactions of Aβ with HN and AChE.