2-Methyl 2-butanol suppresses human retinoblastoma cells through cell cycle arrest and autophagy

2-Methyl-2-butanol (MBT) is a chemical compound from the group of alcohols more specifically pentanols, which has shown an excellent anti-cancer activity in our previous study. However, its mechanism of action remains unclear. The present study was designed to investigate the anti-cancer effect of MBT on human retinoblastoma cells. The results showed that the use of MBT leads to HXO-RB44 cell death but is cytotoxic to normal cells at higher concentrations. It showed a dose- as well as a time-dependent inhibition of HXO-RB44 cells. P27 is a cell cycle inhibitory protein, which plays an important role in cell cycle regulation whereas cyclin-B1 is a regulatory protein involved in mitosis. MBT increased the cell cycle arrest in a dose-dependent manner by augmenting p27 and reducing cyclin B1 expression. Moreover, it also accelerated apoptosis, increased light chain-3 (LC-3) conversion in a dose-dependent manner, and helped to debulk cancerous cells. LC3 is a soluble protein, which helps to engulf cytoplasmic components, including cytosolic proteins and organelles during autophagy from autophagosomes. In order to verify the effect of MBT, bafilomycin A1, an autophagy inhibitor, was used to block the MTB-induced apoptosis and necrosis. Additionally, a specific Akt agonist, SC-79, reversed the MBT-induced cell cycle arrest and autophagy. Thus, from the present study, it was concluded that MBT induced cell cycle arrest, apoptosis and autophagy through the PI3K/Akt pathway in HXO-RB44 cells.

Effect of Ahmed glaucoma drainage valve implantation on corneal endothelial cell density and intraocular pressure in patients with neovascular glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the effect of Ahmed glaucoma drainage valve implantation on corneal endothelial cell density and intraocular pressure in patients with neovascular glaucoma.METHODS:Totally 200 cases (200 eyes) of patients with neovascular glaucoma in our hospital from June 2013 to June 2016 were enrolled in this study.All patients were treated with glaucoma drainage valve implantation.The medical records of the patients were retrospectively analyzed;the evaluation of operation completion was made;intraocular pressure at preoperative and postoperative 1wk,1mo,1a was detected using non-contact tonometry;the corneal endothelial cell density at preoperative and postoperative 1 wk,1mo and 1 a was tested by corneal endothelial microscopy,and visual acuity of patients before operation and at 1 a after operation was recorded.All patients' complications and intervention methods were followed-up and recorded.RESULTS:All patients' complete success rate was 81.0％,the conditional success rate was 92.0％.The proportion of preoperative and postoperative vision without light perception,hand moving to 0.01,0.02-0.05,0.06-＜0.10,≥0.10 had significant difference (P＞0.05).Intraocular pressure before treatment was 42.43±3.43mmHg,and were 13.45 ± 2.34mmHg,15.89 ± 2.67mmHg,16.34±2.88mmHg at 1wk,1mo and 1a after operation respectively,showing significant difference (F=4570.62,P＜ 0.001).Before treatment,corneal endothelial cell density was 2453.67± 342.34/mm2,and were 2216.67-± 332.32/mm2,2087.34 ± 326.45/mm2,1959.67±303.34/mm2 at 1wk,1mo and 1 a after operation respectively,holding significantly different (F=83.42,P＜0.001).There were macular degeneration 20 eyes of hyphema,13 eyes of low pressure,8 eyes of drainage valve displacement and 21 eyes of shallow anterior chamber.CONCLUSION:Ahmed glaucoma drainage valve implantation for neovascular glaucoma can effectively control intraocular pressure but the presence of corneal endothelial cell loss exists,can effectively protect and recover residual vision of patients,relief complications and recover it after simple intervention,it is an effective method for neovascular glaucoma.