401. Evaluation of HO-1 expression, cellular ROS production, cellular proliferation and cellular apoptosis in human esophageal squamous cell carcinoma tumors and cell lines.
- Author
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Ren QG, Yang SL, Hu JL, Li PD, Chen YS, and Wang QS
- Subjects
- Adult, Aged, Aged, 80 and over, Apoptosis, Carcinoma, Squamous Cell genetics, Carcinoma, Squamous Cell metabolism, Cell Line, Tumor, Cell Proliferation, Cytoplasm metabolism, Esophageal Neoplasms genetics, Esophageal Neoplasms metabolism, Esophageal Squamous Cell Carcinoma, Gene Expression Regulation, Neoplastic, Humans, Male, Neoplasm Grading, Prognosis, Carcinoma, Squamous Cell pathology, Esophageal Neoplasms pathology, Heme Oxygenase-1 genetics, Heme Oxygenase-1 metabolism, Reactive Oxygen Species metabolism
- Abstract
Patients with esophageal squamous cell carcinoma (ESCC) have a poor prognosis. However, the related mechanisms are unclear, thus we investigated the expression of HO-1 in ESCC tissue and explored possible mechanisms of tumor progression. Expression of HO-1 was examined by immunohistochemistry in 143 ESCC tumors. The correlation of HO-1 with clinicopathological characteristics was also examined. Two human ESCC cell lines, TE-13 and Eca109 were studied. Silencing of cell line HO-1 by specific small interfering RNA (siRNA) was evaluated using real-time quantitative PCR. Cell line viability, apoptosis and intracellular levels of reactive oxygen species (ROS) after transfection were determined using MTT and flow cytometry, respectively. HO-1, Bax, Bcl-2 and A-caspase-3/-9 expression was evaluated using western blot analyses. We found that HO-1 was expressed in 58 of 143 ESCC tumors, mainly in the cytoplasm. There was a significant association between HO-1 expression and tumor grade (P<0.001). Knockdown of HO-1 expression in cell lines was associated with significantly decreased cellular proliferation (P<0.05) and a higher rate of apoptosis (P<0.001) 48 h after treatment. Treatment of the cell lines with the ROS inhibitor N-acetylcysteine abrogated this effect. Knockdown of HO-1 was associated with increased A-caspase-3 and -9 expression, but no change in Bax or Bcl-2 expression or Bax/Bcl-2 ratio was observed. Thus, the present study identified that ESCC tumors frequently expressed HO-1. Knockdown of HO-1 promoted apoptosis through activation of a ROS-mediated caspase apoptosis pathway.
- Published
- 2016
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