Anti-CCK monoclonal antibody, clone IZC 456-13

Objectives Targeting the deubiquitinases (DUBs) has become a promising avenue for anti-cancer drug development. However, the effect and mechanism of pan-DUB inhibitor, PR-619, on oesophageal squamous cell carcinoma (ESCC) cells remain to be investigated. Materials and Methods The effect of PR-619 on ESCC cell growth and cell cycle was evaluated by CCK-8 and PI staining. Annexin V-FITC/PI double staining was performed to detect apoptosis. LC3 immunofluorescence and acridine orange staining were applied to examine autophagy. Intercellular Ca2+ concentration was monitored by Fluo-3AM fluorescence. The accumulation of ubi-proteins and the expression of the endoplasmic reticulum (ER) stress-related protein and CaMKK beta-AMPK signalling were determined by immunoblotting. Results PR-619 could inhibit ESCC cell growth and induce G2/M cell cycle arrest by downregulating cyclin B1 and upregulating p21. Meanwhile, PR-619 led to the accumulation of ubiquitylated proteins, induced ER stress and triggered apoptosis by the ATF4-Noxa axis. Moreover, the ER stress increased cytoplasmic Ca2+ and then stimulated autophagy through Ca2+-CaMKK beta-AMPK signalling pathway. Ubiquitin E1 inhibitor, PYR-41, could reduce the accumulation of ubi-proteins and alleviate ER stress, G2/M cell cycle arrest, apoptosis and autophagy in PR-619-treated ESCC cells. Furthermore, blocking autophagy by chloroquine or bafilomycin A1 enhanced the cell growth inhibition effect and apoptosis induced by PR-619. Conclusions Our findings reveal an unrecognized mechanism for the cytotoxic effects of general DUBs inhibitor (PR-619) and imply that targeting DUBs may be a potential anti-ESCC strategy.

Objective: This study was designed to explore the ability of cordycepin to disrupt human tongue cancer cell growth, and to assess the mechanistic basis for such anti-cancer activity. Methods: CAL-27 human tongue cancer cells were treated with cordycepin prior to analysis via CCK-8 assay in order to assess their proliferation. In addition, cell cycle progression and apoptotic death in these cells were measured via flow cytometry, while the expression of apoptosis-associated genes and proteins (caspase-3, caspase-9, caspase-12, Bcl-2, and Bax) were measured via real-time PCR and western blotting. We further measured the intracellular production of reactive oxygen species (ROS) and used a murine xenograft model system to explore the in vivo anti-tumor activity of cordycepin. Results: Cordycepin was able to significantly suppress the proliferation of CAL-27 cells in a dose-dependent fashion (IC50 = 40 mu g/mL at 24 h). Cordycepin further induced Bax, caspase-3, caspase-9, and caspase-12 upregulation at the mRNA and protein levels while simultaneously downregulating anti-apoptotic Bcl-2 expression. CAL-27 cells treated using cordycepin also exhibited elevated levels of intracellular ROS. Importantly, cordycepin was able to effectively suppress tongue cancer tumor growth in a murine xenograft model system and similar mRNA and protein levels were observed in vivo. Conclusions: Cordycepin can inhibit human tongue cancer cell growth and can drive their apoptotic death via the mitochondrial pathway. In addition, cordycepin can suppress tongue cancer growth in vivo in treated mice.