Effect of RNA interference mediated gene silencing of DJ-1 on proliferation of laryngeal carcinoma cell line Hep-2 / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To assess the effect of small interfering RNA (siRNA)-mediated gene silencing of DJ-1 on the proliferation of human laryngeal carcinoma cell line Hep-2.</p><p><b>METHODS</b>Three siRNA sequences specific to DJ-1 gene were synthesized according to GenBank. Human laryngeal carcinoma cell line Hep-2 was cultured and divided into 4 groups: non-specific group (siRNA control) and 3 RNAi groups, transfected with specific DJ-1 siRNA (siRNA1, siRNA2, siRNA3). The mRNA and protein levels of DJ-1 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot respectively. Cell apoptosis were analyzed by flow cytometry. The proliferation of Hep-2 cells was assessed by MTT assay.</p><p><b>RESULTS</b>DJ-1 siRNA down-regulated the mRNA and protein levels of DJ-1 in Hep-2 cells. After transfection, the expression of DJ-1 mRNA and protein levels in Hep-2 cells of the DJ-1 siRNA1 group were significantly lower than those of non-specific siRNA control group. MTT assay showed that DJ-1 siRNA1 group inhibited proliferation of Hep-2 cells. Flow cytometry showed that apoptosis rate of the DJ-1 siRNA1 group (15.7%) was significantly higher than that of non-specific siRNA control group (4.5%) or untransfected group (3.5%), t = 4.736, P < 0.01.</p><p><b>CONCLUSIONS</b>Specific siRNA targeting DJ-1 can effectively inhibit DJ-1 expression, resulting in the reduced proliferation and the enhanced apoptosis in Hep-2 cells.</p>

Effect of chemotherapy with cisplatin and rapamycin against Hep-2 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of combined use of rapamycin and cisplatin in the chemotherapy of Hep-2 cells in vitro.</p><p><b>METHODS</b>The inhibitory effects of rapamycin and cisplatin, used alone or in combination, on the proliferation of Hep-2 cells were measured with MTT assay and median-effect plot analysis. The cell cycle changes after the treatment were analyzed using flow cytometry and Hoechst 33258 immunofluorescence staining.</p><p><b>RESULTS</b>The IC50 of rapamycin and cisplatin for inducing growth arrest of Hep-2 cells was 11.03 nmol/L and 8.81 micromol/L, respectively. Rapamycin alone caused cell cycle arrest of the Hep-2 cells in G1 phase. Rapamycin and cisplatin showed synergistic effects in the chemotherapy of Hep-2 cells (q > 1.15, King's Formula), causing significantly increased apoptosis ratio and growth inhibition rate of Hep-2 cells.</p><p><b>CONCLUSION</b>Combined use of rapamycin and cisplatin significantly improves the chemotherapeutic effect against Hep-2 cells.</p>

Transient receptor potential melastatin 7 channel protein in human head and neck carcinoma cells and role in cell proliferation / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To detect the presence of ion channel protein and its role in cell growth and proliferation in human head and neck squamous carcinoma cells (SCC).</p><p><b>METHODS</b>Human head and neck squamous carcinoma SCC-25 cell line was tested with transient receptor potential melastatin 7 (TRPM7) antibody using the method of immunocytochemistry. The role of TRPM7 in cell growth and proliferation was evaluated through its blockade by ion channel blockers and specific siRNA using lactate dehydrogenase (LDH) assay technique.</p><p><b>RESULTS</b>Clear immunoreactivity against TRPM7 was detected in almost all SCC-25 cells tested, whereas no immunoreactivity was observed in negative control. The inhibitory effect of Gd3+, a non-specific ion channel blocker, on cell growth and proliferation was potent. Addition of 10 micromol/L Gd3+ (n = 16) and 100 micromol/L Gd3+ (n = 16) in the culture medium significantly inhibited the growth of SCC-25 cells, as compared with control cells growing in normal medium (t was 4.1414 and 6.2661, P was 0.0256 and 0.0082 respectively). However, the effect of 2-APB was striking. Cell proliferation was almost totally suppressed in the presence of 100 micromol/L 2-APB (t = 13.4493, P = 0.0008, n = 16) compared with cells growing in normal medium. Suppression of TRPM7 expression by siRNA also significantly inhibited the growth and proliferation of these cells (t = 4.3446, P = 0.0002, n = 32, compared with nontransfected cells),whereas cells transfected with negative control siRNA showed no difference in cell proliferation compared with nontransfected cells.</p><p><b>CONCLUSIONS</b>All of those results strongly suggest the existence of TRPM7 channel in human head and neck squamous carcinoma cells. Ion channel blockers serve as a potent inhibitor of SCC-25 cell proliferation. The striking inhibitory effect of 2-APB on cell growth and proliferation may promise clinical workers an inspiring remedy for fighting against carcinoma.</p>

Analysis of the risk factors causing tracheal stenosis after tracheotomy for mechanical ventilation in 560 patients / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the risk factors causing tracheal stenosis after tracheotomy for mechanical ventilation.</p><p><b>METHODS</b>A retrospective study was carried out to review the clinical data of 560 patients who had been tracheotomy for mechanical ventilation in the First Affiliated Hospital of Sun Yat-sen University from 1990 to 2006. The clinical relevant factors causing tracheal stenosis included age, sex, preoperative intubation, preoperative intubation time, postoperative mechanical ventilation duration, airway infection, multiple changes of intubation tube, cricothyroidotomy, previous tracheotomy, gastroesophageal reflux, diabetes, etc. Multivariate stepwise logistic regression model was used for the analysis.</p><p><b>RESULTS</b>Fifty-four cases (9.6%) presented tracheal stenosis in 560 patients after tracheotomy. With multivariate analysis, it was confirmed that the following variable correlated to tracheal stenosis. i.e, preoperative intubation time (chi2 = 4.323, P = 0.038), postoperative mechanical ventilation duration (chi2 = 14.062, P = 0.000), airway infection (chi2 = 8.604, P = 0.004), diabetes (chi2 = 5.237, P = 0.014). The effect degree of these risk factors was as below, postoperative mechanical ventilation duration (OR = 10.818), airway infection (OR = 6.349), diabetes (OR = 3.019), intubation time preoperative (OR = 2.156).</p><p><b>CONCLUSIONS</b>Among patients who received tracheotomy for mechanical ventilation, the clinical relevant factors causing tracheal stenosis were various. Statistical analysis showed that preoperative intubation time, postoperative mechanical ventilation duration, diabetes, airway infection were main risky factors which may cause tracheal stenosis.</p>

Postoperative diabetes insipidus after transsphenoidal resection of pituitary tumor / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the prevention and treatment of postoperative diabetes insipidus after removal of pituitary tumor through transsphenoidal operation, to decrease the incidence of postoperative complications and improve the treatment of pituitary tumor.</p><p><b>METHODS</b>The clinical data of 86 cases of transsphenoidal resection of pituitary tumor in recent 8 years were retrospectively reviewed, including 35 endoscopic operation and 51 microscopic operation. The incidence, prevention and treatment of diabetes insipidus were statistically analysed.</p><p><b>RESULTS</b>There were 18 cases of postoperative diabetes insipidus in total of 86 operations, including 15 acute cases, 3 delayed cases. Twelve were temporary , which recovered within 1 week. After prompt treatment, 14 recovered within 1 week, 4 recovered within 2 weeks. No persistent diabetes insipidus was found.</p><p><b>CONCLUSIONS</b>The key points to prevent postoperative diabetes insipidus lay in the improvement of operative skills, careful protection during operation and avoidance of unnecessary injury. In case of diabetes insipidus occurred, rational use of antidiuretics and correction of electrolyte balance were effective in the treatment of postoperative diabetes insipidus.</p>

Analysis of relevant factors causing laryngeal stenosis after partial laryngectomy / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical relevant factors causing laryngeal stenosis after partial laryngectomy.</p><p><b>METHODS</b>A retrospective study was carried out to review the history clinical data from 138 patients of partial laryngectomy in the First Affiliated Hospital of Sun Yat-Sen University between January 1994 to October 2004. The clinical relevant factors causing laryngeal stenosis were included as follows: age, sex, TNM stage, tumor site, extension of thyroid cartilage defect, extension of larynx parenchyma defect, reconstruction method, laryngeal dilator, duration of using antibiotics, postoperative radiotherapy, lung infection, gastroesophageal reflux, diabetes. Multivariate stepwise logistic regression model was used for the analysis.</p><p><b>RESULTS</b>Of 138 cases after partial laryngectomy, stenosis developed in 25 cases. The occurrence rate was 18.1%. In multivariate analysis, it was confirmed that the following factors correlated to laryngeal stenosis, i. e, extension of thyroid cartilage defect (chi2 = 4.323, P = 0.038), postoperative radiotherapy (chi2 = 6.002, P = 0.014), lung infection (chi2 = 4.220, P = 0.040), and gastroesophageal reflux (chi2 = 5.614, P = 0.018).</p><p><b>CONCLUSIONS</b>The clinical relevant factors causing laryngeal stenosis after partial laryngectomy were multiple. Statistical analysis showed that extension of thyroid cartilage defect, postoperative radiotherapy, lung infection and gastroesophageal reflux were the risk factors which may cause laryngeal stenosis.</p>