Accumulation of beta-amyloid (Abeta) peptides in senile plaques is one of the pathological hallmarks in Alzheimer's disease (AD), which can trigger apoptosis. We have previously demonstrated that Abeta triggered calcium release from the ER. Depletion of ER Ca(2+) ions has been reported leading to unfolded protein responses (UPR). While hypothesis has been made about UPR and neurodegeneration in AD, little is known about the effects of extracellular accumulation of Abeta on UPR. We have shown previously that activation of PKR in Abeta-triggered apoptosis. Since UPR can trigger PKR, our study aims to elucidate whether extracellular accumulation of Abeta peptides induce UPR in cultured neurons. Our results showed that Abeta could not trigger UPR signalings including phosphorylation of PERK, alternative cleavage of xbp-1 mRNA and induction of transcription of xbp-1 and Gadd153. Taken together, our results suggest that extracellular accumulation of Abeta peptides induce apoptosis via a mechanism independent of UPR.

Prostate carcinoma and metastasis are common among male subjects worldwide. CKBM is a drug product targeting prostate cancer in multiple ways. Prostate cancer cell lines PC3 and DU145 were treated with CKBM. The effect of CKBM on the cell's viability, cell cycle, adhesive and invasive properties and its growth in an animal model were assessed. Results indicated that CKBM inhibited PC3 and DU145 cell growth in vitro at IC(50 )values 3.923 and 4.697% respectively, and it brought about cell cycle arrest at G2/M phase. CKBM also attenuated DU145 cells to invade and adhere to extracellular matrices including Matrigel, laminin, fibronectin and collagen IV. Moreover, PC3 tumor xenograft growth was inhibited by over 60% after 28-day of 0.2, 0.4 or 0.8 ml/day CKBM treatment. The present study indicates that CKBM is effective against prostate cancer cell growth in vitro and in vivo. Further studies are required to elucidate its mechanism of action.