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Background New evidence suggests that histidine triad nucleotide-binding protein 1 (Hint1) exerts a tumor suppressor effect in various human tumors, such as colorectal cancer and gastric cancer. However, it has not been reported whether Hint1 is involved in the occurrence and development of osteosarcoma (OS). Materials and methods The present study investigated the role of Hint1 in human OS cells by using cell lines, including 143B, U2OS, KHOS-240S, Saos-2 and MG-63. Cell proliferation and apoptosis were detected by flow cytometry. Results The present result revealed that Hint1 is downregulated in these cell lines. The overexpression of Hint1 by adenovirus transfection in 143B and MG63 cell lines suppressed the proliferation and cell cycle, and increased the cell apoptosis. Mechanically, it was found that Hint1 downregulated the cyclin D1 expression via FOXO1 inhibition. Furthermore, FOXO1 overexpression in the 143B and MG63 cell lines significantly blurred the effects of Hint1 on cellular proliferation and apoptosis. Conclusion The present study indicates that Hint1 inhibits the development of OS by regulating FoxO1-cyclin D1, suggesting that Hint1 may be a new method for the treatment of OS.

Background/purpose Heavy alcohol drinking is associated with pancreatitis. Pancreatitis is initiated by the damage to the pancreatic acinar cells. The endoplasmic reticulum (ER) stress has been shown to play an important role in alcohol-induced pancreatic damage. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-inducible protein. The aim of the study was to determine whether MANF can ameliorate alcohol-induced ER stress and cellular damages to pancreatic acinar cells. Methods Alcohol-induced damage to mouse pancreatic 266-6 acinar cells was determined by MTT and flow cytometry. MANF expression was down-regulated by MANF siRNA using a Neon Transfection System. The over-expression of MANF was performed by the infection with the adenoviral vector carrying mouse MANF gene. The expression of ER stress markers was determined by immunoblotting and immunofluorescence. Results Alcohol caused ER stress, oxidative stress and induced apoptosis of 266-6 acinar cells. Recombinant human MANF alleviated alcohol-induced ER stress and cell death by inhibiting IRE1-caspase 12-caspase 3 apoptotic pathway. Overexpression of mouse MANF also protected cells against alcohol-induced apoptosis. In contrast, inhibiting MANF by siRNA exacerbated alcohol-induced cellular damage. Conclusions MANF was protective against alcohol-induced ER stress and cellular injury in pancreatic acinar cells. The findings suggest a potential therapeutic value of MANF for alcoholic pancreatitis.

The aim of the present study was to investigate the cytotoxic effects of bufalin on SCC-4 human tongue cancer cells. Cell morphological changes and viability were examined using phase contrast microscopy and flow cytometry, respectively. The results indicated that bufalin induced morphological changes and reduced total viable cells. Apoptotic cell death was analyzed by DAPI staining and DNA gel electrophoresis; the results revealed that bufalin induced cell apoptosis. Levels of reactive oxygen species (ROS), Ca2+, nitric oxide (NO) and mitochondrial membrane potential (ΔΨm) were measured by flow cytometry, and bufalin was observed to increase Ca2+ and NO production, decrease the ΔΨm and reduce ROS production in SCC-4 cells. In addition, western blotting was performed to detect apoptosis-associated protein expression. The results demonstrated that bufalin reduced the expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) and increased the expression of the pro-apoptotic protein, Bcl-2-associated X protein. However, bufalin treatment also increased the expression of other apoptosis-associated proteins such as apoptosis-inducing factor and endonuclease G in SCC-4 cells. Based on these findings, bufalin may induce apoptotic cell death via mitochondria-dependent pathways in human tongue cancer SCC-4 cells.

(-)-Epigallocatechin-3-gallate (EGCG) is a major constituent of green tea and has been identified as an excellent anticancer agent. Nevertheless, there are no reports to date about the molecular mechanisms and signal pathways of EGCG on the induction of apoptosis in human adrenal NCI-H295 cancer cells. The purpose of this study was to investigate the anticancer effect and molecular mechanisms of EGCG on human adrenal NCI-H295 cancer cells. The results showed that EGCG induced growth inhibition in a dose- and time-dependent manner. Moreover, it exerted low cytotoxicity on Detroit 551 normal human embryonic skin cell. When NCI-H295 cells were treated with 20 microM EGCG, the mitochondrial membrane potential decreased and intracellular free Ca(2+) increased in a time-dependent manner as analysed by flow cytometry. EGCG decreased the protein levels of Bcl-2, Bcl-xl, xIAP, cIAP, Hsp70 and Hsp90, but increased the protein expression of Bad, Bax, Fas/CD95, cytochrome c, Apaf-1, AIF, GADD153, GRP78, and caspase-3, -7,-8 and -9 as observed by Western blotting examination. EGCG promoted caspase-8, -9 and -3 activities in a time-dependent manner. However, pretreatment of cells with inhibitors of caspase-8, -9 and -3 led to a decrease in caspase-8, -9 and -3 activities and an increase in the percentage of viable cells. Based on the above findings, it was confirmed that EGCG may be a drug candidate for the treatment of human adrenal cancer in the future.

Salivary adenoid cystic carcinoma is an epithelial tumor in the head and neck region. Despite its slow growth, patients with salivary adenoid cystic carcinoma exhibit poor long term survival because of a high rate of distant metastasis. Lung and bone are common distant metastasis sites. Zoledronic acid, a third generation bisphosphonate, has been used for tumor-induced osteolysis due to bone metastasis and has direct antitumor activity in several human neoplasms. Here, we observed that zoledronic acid inhibited salivary adenoid cystic carcinoma cell line SACC-83 xenograft tumor growth in nude mice. In vitro, zoledronic acid induced apoptosis and reduced clonogenic survival in SACC-83. Flow cytometry and western blotting indicated that the cell cycle was arrested at G0/G1. Zoledronic acid treatment upregulated reactive oxygen species as well as the autophagy marker protein LC-3B. Reactive oxygen species scavenger N-acetylcysteine and autophagy antagonist 3-methyladenine decreased zoledronic acid-induced apoptosis and increased clonogenic survival. Silencing of the autophagy related gene Beclin-1 also decreased zoledronic acid-induced apoptosis and inhibition of clonogenic formation. In addition, isobolographic analysis revealed synergistic effects on apoptosis when zoledronic acid and paclitaxel/cisplatin were combined. Taken together, our results suggest that zoledronic acid induced apoptosis and reduced clonogenic survival via upregulation of reactive oxygen species and autophagy in the SACC-83 cell line. Thus, zoledronic acid should be considered a promising drug for the treatment of salivary adenoid cystic carcinoma.