Effects of enhancer of zeste homolog (EZH2) downregulation on the proliferation and invasion of nasopharyngeal carcinoma cell and the possible mechanisms / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of the enhancer of zeste homolog 2 (EZH2) gene on cell growth and invasion of the nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Recombinant lentivirus vector for shRNA delivery of EZH2 was constructed and transfected into 293FT cells. After collecting the viral particles, the NPC cell line 5-8F cells were transfected. The effects of EZH2 silence on cell proliferation and cell cycle were detected using MTT assay, plate colony formation assay and flow cytometry. The migration and invasion of 5-8F cells were determined by wound healing assay and matrigel invasion assay, respectively. The expressions of EZH2 and epithelial-mesenchymal transition (EMT)-related markers at mRNA and protein levels were examined by real-time PCR and Western blot respectively.</p><p><b>RESULTS</b>The expressions of EZH2 mRNA and protein in the transfected 5-8F cells were obviously reduced. MTT assay showed that EZH2 downregulation significantly inhibited the growth of 5-8F/shEZH2 cells (P < 0.001). Colony formation rate (84.44%) of 5-8F/shEZH2 cells was lower than control (31.56%, P = 0.001). Cell cycle analysis showed that most 5-8F/shEZH2 cells were arrested in G0/G1 phase, with a very low ratio of cells in S phase. Wound healing assay indicated that the migration ability of cells silencing EZH2 decreased significantly, and the 48-hour relative migration distance of 5-8F/ShEZH2 cells and control cells was 0.58 ± 0.05, and 0.81 ± 0.02, respectively (P < 0.000). Matrigel invasion assay, showed the invasive capacity of cells silencing EZH2 was significantly inhibited, with less penetrating cells (72.23 ± 4.08) compared to control (150.95 ± 16.27), P < 0.000. The mRNA expressions of epithelial markers E-cadherin and Keratin 18 in the cells silencing EZH2 increased by 177% and 158% respectively, and the mRNA expressions of mesenchymal markers β-catenin and N-cadherin decreased by 18.04% and 41.18% respectively. Similar results also were obtained with Western blot analysis.</p><p><b>CONCLUSION</b>EZH2 significantly enhanced the proliferation and invasion of nasopharyngeal carcinoma cells in vitro, which might be mediated by inducing EMT.</p>

Enhancement of target gene expression by recombinant adeno-associated virus combined with recombinant adenovirus in vivo / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes in the intensity and temporal pattern of target gene expression in the tumor tissue of nude mice bearing human nasopharyngeal carcinoma (NPC) following injection of recombinant adeno-associated virus (rAAV) and recombinant adenovirus (AdV) in vivo.</p><p><b>METHODS</b>EBV-positive human NPC cell line C666-1 was inoculated subcutaneouly in nude mice. After the tumor mass reached 3 mm in diameter, 1.5 × 10(11) v.g (virus genome) rAAV-EGFP, 2.5 × 10(8) pfu rAdV-EGFP or their balanced mixture was injected intratumorally. At 5 and 10 days after the injection, the tumor tissues were harvested for immunohistochemical staining of GFP, and the ratio of the GFP-positive cells and the intensity of GFP expression was determined.</p><p><b>RESULTS</b>Immunohistochemistry for GFP showed that 5 days after the injection, GFP expression was detected (1.70 ∓ 0.48) in the tumor tissue in rAAV group, and the peak expression levels was seen in rAdV group (6.00∓1.94); the expression level was comparable between the combination group (6.90 ∓ 1.92) and rAdV group. At 10 days, GFP expression was considerably lowered to 2.00 ∓ 0.67 in rAdV group but increased to 8.00∓1.15 in rAAV group. The expression in the combination group maintained a high level at 10 days (10.10∓1.63), which was significantly higher than that in rAAV group (P%0.001).</p><p><b>CONCLUSION</b>Transfection with rAAV combined with rAdV allows instant, sustained and significantly enhanced expression of the target gene in the tumor tissue. This approach takes advantages of the two viruses and can be ideal for exogenous gene delivery into the tumor tissues.</p>

Application of SELDI-TOF-MS in establishing a model for predicting radiotherapy response of hypopharyngeal cancers / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect the serum proteomic fingerprints in patients with hypopharyngeal squamous cell carcinoma (HPSCC) by surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) protein chip array technique.</p><p><b>METHODS</b>The serum samples were obtained from 58 HPSCC patients for protein expression analysis using SELDI-TOF Protein Chip technique and cation-exchange (CM10) protein array. All the spectra were compared and the qualified mass peaks with mass-to-charge ratios (m/z) between 1 and 70 kD were autotimatically detected. The tree analysis pattern was generated using Biomarker Patterns Software.</p><p><b>RESULTS</b>The protein profiles of HPSCC serum were analyzed according to the clinical and pathological features of the patients and their treatment response. No significant difference was noted in the serum proteins between HPSCC patients with different statuses of cervical lympha node metastasis (P>0.05), and the difference between well differentiated and poorly differentiated HPSCC was only minor. No significant difference was found in the serum proteins between chemotherapy-sensitive patients and the insensitive patients (P>0.05), but 5 proteins were identified to be overexpressed in the sensitive patients (P < / = 0.05). Radiotherapy-sensitive HPSCC patients were segregated from the insensitive group with a sensitivity of 86.67% and specificity of 100%.</p><p><b>CONCLUSION</b>The serum protein at the m/z value of 6115.74 is overexpressed in radiotherapy-sensitive HPSCC patients. Serum protein profiling allows the prediction of radiotherapy response in HPSCC patients, and the identified proteins may serve as candidate biomarkers for predicting the radiotherapy sensitivity of HPSCC.</p>

Analysis of clinical characteristics of chronic rhinosinusitis in patients with postirradiated nasopharyngeal carcinoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the characters of chronic rhinosinusitis in patients with irradiated nasopharyngeal carcinoma.</p><p><b>METHODS</b>There were 65 cases of chronic rhinosinusitis after irradiated nasopharyngeal carcinoma (NPC, experimental group) and 65 cases of common chronic rhinosinusitis (CRS, control group) in the study. The visual analogue scale (VAS) was used to evaluate the intensity of subjective symptoms. Endoscopic finding was recorded and CT results were evaluated by Lund-Mackay scoring system.</p><p><b>RESULTS</b>As to the VAS, nasal secretion was significantly more severe in experimental group (7.86+/-1.62), compared with control group (5.12+/-1.32, t=10.541, P<0.01). As to endoscopic finding, middle nasal meatus were clean in 35 (53.8%) cases in experimental group, and 23 cases (35.4%) in control group (chi2=4.483, P<0.05). CT score was (7.03+/-4.63) in experiment group, and (11.42+/-3.32) in control group (t=-6.207, P<0.05). The main reason lays in lower CT score and lower involved rate of ostiomeatal complex, frontal sinus, maxillary sinus, anterior ethmoid sinus.</p><p><b>CONCLUSIONS</b>The characters of chronic rhinosinusitis in patients with irradiated nasopharyngeal carcinoma is quite different from the common CRS and different therapeutic measures should be taken.</p>