Abstract
Background14-3-3epsilon regulates a wide range of biological processes, including cell cycle control, proliferation, and apoptosis, and plays a significant role in neurogenesis and the formation of malignant tumours. However, the exact function and regulatory mechanism of 14-3-3epsilon in carcinogenesis have not been elucidated.MethodsThe expression of 14-3-3epsilon was assessed by RT-PCR and western blotting. The invasiveness and viability of Hep-2 cells were determined by the transwell migration assay and MTT assay, respectively. Cell cycle and apoptosis of Hep-2 cells were detected by flow cytometry.ResultsThe mRNA and protein expression of 14-3-3epsilon in larynx squamous cell carcinoma (LSCC) tissues were significantly lower than those in clear surgical margin tissues. Statistical analysis showed that the 14-3-3epsilon protein level in metastatic lymph nodes was lower than that in paired tumour tissues. In addition, the protein level of 14-3-3epsilon in stage III or IV tumours was significantly lower than that in stage I or II tumours. Compared with control Hep-2 cells, the percentages of viable cells in the 14-3-3epsilon-GFP and negative control GFP groups were 36.68 ± 14.09% and 71.68 ± 12.10%, respectively. The proportions of S phase were 22.47 ± 3.36%, 28.17 ± 3.97% and 46.15 ± 6.82%, and the apoptotic sub-G1 populations were 1.23 ± 1.02%, 2.92 ± 1.59% and 13.72 ± 3.89% in the control, negative control GFP and 14-3-3epsilon-GFP groups, respectively. The percentages of the apoptotic cells were 0.84 ± 0.25%, 1.08 ± 0.24% and 2.93 ± 0.13% in the control, negative control GFP and 14-3-3epsilon-GFP groups, respectively. The numbers of cells that penetrated the filter membrane in the control, negative control GFP and 14-3-3epsilon-GFP groups were 20.65 ± 1.94, 17.63 ± 1.04 and 9.1 ± 0.24, respectively, indicating significant differences among the different groups.ConclusionsDecreased expression of 14-3-3epsilon in LSCC tissues contributes to the initiation and progression of LSCC. 14-3-3epsilon can promote apoptosis and inhibit the invasiveness of LSCC.
Highlights
Squamous cell carcinoma of the head and neck (SCCHN) is considered the sixth most common cancer in the world [1]
Total laryngectomy or laryngopharyngectomy remains the procedure of choice for advanced stage laryngeal carcinoma around the world [7]
Reduced expression of 14-3-3epsilon in Larynx squamous cell carcinoma (LSCC) 14-3-3epsilon mRNA levels in 72 of the 101 cases of LSCC and matched clear surgical margin tissues were evaluated by reverse transcription-polymerase chain reaction (RT-PCR)
Summary
14-3-3epsilon-GFP vectors and pEGFP-C1 vectors (as a negative control) were transfected into Hep-2 cells using Lipofectamine 2000 (Invitrogen, USA) following the manufacturer's instructions. Staining was performed according to the manufacturer's instructions, and flow cytometry was conducted on a FACSCalibur (Becton Dickinson, Mountain View, NJ, USA) Cells that were both annexin V-PE and 7-AAD negative were considered viable cells. Hep-2 cells transfected with negative control GFP and 14-3-3epsilon-GFP were detached from the tissue culture plates, washed, resuspended in conditioned medium (2 × 105 cells/ml), and added to the upper compartment of the invasion chamber. The comparisons between mRNA and protein expression levels in one group between tumour and matched clear surgical margin tissues and in the other group between tumour and metastatic lymph nodes were made by the paired sample t-test for parametric analysis or Wilcoxon signed rank test for nonparametric analysis. Statistical significance was assumed for a two-tailed p < 0.05
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
