Downregulation of iASPP Expression Suppresses Proliferation, Invasion and Increases Chemosensitivity to Paclitaxel of Head and Neck Squamous Cell Carcinoma In Vitro.

Objective Our previous study has revealed that iASPP is elevated in human head and neck squamous cell carcinoma (HNSCC) and iASPP overexpression signifcantly correlates with tumor malignant progression and poor survival of HNSCC. This study investigated the function of iASPP playing in proliferation and invasion of HNSCC in vitro. Methods HNSCC cell line Tu686 transfected with Lentiviral vector-mediated iASPP-specific shRNA and control shRNA were named the shRNA-iASPP group and shRNA-NC group, respectively. The non-infected Tu686 cells were named the CON group. CCK-8 assay, flow cytometry, transwell invasion assay were performed to detect the effects of iASPP inhibition in vitro. Results Our results demonstrated that the proliferation of shRNA-iASPP cells at the time of 72 h (F=32.459, P=0.000), 96 h (F=51.407, P=0.000), 120 h (F=35.125, P=0.000) post-transfection, was significantly lower than that of shRNA-NC cells and CON cells. The apoptosis ratio of shRNA-iASPP cells was 9.42% ± 0.39% (F=299.490, P=0.000), which was significantly higher than that of CON cells (2.80% ± 0.42%) and shRNA-NC cells (3.18% ± 0.28%). The percentage of shRNA-iASPP cells in G0/G1 phase was 74.65% ± 1.09% (F=388.901, P=0.000), which was strikingly increased, compared with that of CON cells (55.19% ± 1.02%) and shRNA-NC cells (54.62% ± 0.88%). The number of invading cells was 56 ± 4 in the shRNA-iASPP group (F=84.965, P=0.000), which decreased significantly, compared with the CON group (111 ± 3) and the shRNA-NC group (105 ± 8). The survival rate of shRNA-iASPP cells administrated with paclitaxel was highly decreased, compared with CON cells and shRNA-NC cells (F=634.841, P=0.000). Conclusion These results suggest iASPP may play an important role in progression and aggressive behavior of HNSCC and may be an efficient chemotherapeutic target for the treatment of HNSCC.

Water-soluble photoluminescent fullerene capped mesoporous silica for pH-responsive drug delivery and bioimaging.

In this paper, a biocompatible and water-soluble fluorescent fullerene (C60-TEG-COOH) coated mesoporous silica nanoparticle (MSN) was successfully fabricated for pH-sensitive drug release and fluorescent cell imaging. The MSN was first reacted with 3-aminopropyltriethoxysilane to obtain an amino-modified MSN, and then the water-soluble C60 with a carboxyl group was used to cover the surface of the MSN through electrostatic interaction with the amino group in PBS solution (pH = 7.4). The release of doxorubicin hydrochloride (DOX) could be triggered under a mild acidic environment (lysosome, pH = 5.0) due to the protonation of C60-TEG-COO-, which induced the dissociation of the C60-TEG-COOH modified MSN (MSN@C60). Furthermore, the uptake of nanoparticles by cells could be tracked because of the green fluorescent property of the C60-modified MSN. In an in vitro study, the prepared materials showed excellent biocompatibility and the DOX-loaded nanocarrier exhibited efficient anticancer ability. This work offered a simple method for designing a simultaneous pH-responsive drug delivery and bioimaging system.

Endoscopic surgery of cavernous sinus tumors originating from the extradura.

In the present study, we explored the effects of various endoscopic approaches in patients with cavernous sinus (CS) tumors. Five endoscopic approaches, including the endoscopic transseptal transsphenoidal approach, extended endoscopic transseptal transsphenoidal approach, extended transnasal transmaxillary approach, extranasal extended maxillary sinus approach, and endoscopic transnasal transpterygoid approach, were selected for the resection of CS tumors from 36 patients. Thirty gross total tumors and 6 subtotal tumors were removed. After a follow-up period of 6 months to 3 years, 30 patients were determined to be recurrence-free, and 2 patients had unchanged residual tumors. One patient with a recurrent pituitary adenoma underwent a second surgery, and 1 patient with chordoma died because of an intracavernous carotid artery rupture 18 months after the operation. Various endoscopic approaches tailored to the origin and extent of the CS tumor were proven efficacious for the maximal and precise removal of CS tumors while avoiding vital structures.

[Expression of HMGB1 protein in laryngeal squamous cell carcinoma and its clinical significance].

OBJECTIVE: To evaluate the expression of HMGB1 protein in tissue specimens of laryngeal squamous cell carcinoma (LSCC) and adjacent normal mucosa, and explore the correlation of HMGB1 protein expression with clinicopathologic features and prognosis in LSCC. METHODS: Ninty-three cases of LSCC and 5 cases of adjcent mucosal tissue samples were included in this study. Immunohistochemical staining was performed on paraffin-embedded tissue specimens to examine the HMGB1 protein expression. The data were futher correlated with the clinicopathological features and prognosis of the LSCC patients. RESULTS: The positive rates of HMGB1 expression in LSCC specimens was 87.1%, significantly higher than that in the adjcent normal mucosa samples (46.7%, P = 0.001), and its overexpresion was closely correlated with T stage (Chi2 = 10.878, P = 0.004), clinical stage (Chi2 = 21.115, P < 0.01), metastasis (Chi2 = 28.298, P < 0.01) and recurrence (Chi2 = 14. 923, P = 0.001) in patients with LSCC. Patients with HMGB1 overexpression had both poorer disease-free survival and poorer overall survival compared with that in patients with low HMGB1 expression (Chi2 = 13.815, Chi2 = 11.912; Both P < 0.01). Univariate and multivariate Cox regression analyses revealed that HMGBI expression is an independent prognostic factor for patients with LSCC. CONCLUSIONS: The results of this study demonstrate that HMGB1 protein expression is significantly increased in LSCC tissues, and HMGB1 protein overexpression is associated with a poorer prognosis in patients with LSCC. These results suggest that HMGB1 may play a critical role in the initiation and progression of LSCC, implicating HMGB1 may become a valuable marker for the prediction of prognosis in patients with LSCC.

[Correlation of EphA2 protein expression with clinicopathological characteristics and prognosis in laryngeal squamous cell carcinoma].

OBJECTIVE: To evaluate the expression of EphA2 protein in tissue specimens and cell lines of laryngeal squamous cell carcinoma (LSCC), and to further study the correlation of EphA2 protein expression with clinicopathological characteristics and prognosis in LSCC. METHODS: Western blot was applied to assess the EphA2 protein expression in LSCC cell line Hep-2 cells and the head and neck immortalized epithelial cell line NP-69 cells. Immunohistochemical staining was performed on paraffin sections of 88 cases of LSCC specimens and 16 cases of adjcent normal tissue samples to investigate the EphA2 protein expression, and to futher elucidate its correlation with clinicopathological characteristics. RESULTS: Compared with the NP-69 cells, EphA2 expression in LSCC cell line Hep-2 cells was upregulated. The positive rates of EphA2 expression in LSCC and adjcent normal tissues samples were 80.7% and 43.8%, respectively, with a significant difference between the two groups (P < 0.001). EphA2 overexpresion was closely correlated with clinical stage (I + II/III + IV, P = 0.005), metastasis (P = 0.025) and recurrence (P = 0.021) in LSCC. Furthermore, patients with EphA2 overexpression had poorer tumor-free survival and 5-year overall survival compared with that in patients with low EphA2 expression (33.3% vs. 63.2%, P = 0.003; 46.7% vs. 81.6%, P = 0.002). EphA2 expression combined with clinical stage provided a better predictive value in prognosis. Univariate and multivariate Cox regression analysis revealed that EphA2 expression is an independent prognostic factor for patients with LSCC (P = 0.019). CONCLUSIONS: The results of this study demonstrate that EphA2 protein expression is significantly increased in LSCC tissues and cell lines, and EphA2 protein overexpression is associated with tumor recurrence, metastasis and poorer prognosis in LSCC patients. These results suggest that EphA2 may play a critical role in the initiation and progression of LSCC, implicating EphA2 as a valuable marker for the prediction of recurrence, metastasis and prognosis in LSCC.

Resection of extensive sellar tumors with extended endoscopic transseptal transsphenoidal approach.

The endoscope has recently been used to extensive sellar lesions, but the extended areas of the lesions and operative techniques vary from each study. Here we present our experience with extended endoscopic transseptal transsphenoidal (EETT) approach to 16 patients with extensive sellar lesion and evaluate the feasibility of EETT in different extensive sellar tumor resection. Sixteen patients with extensive sellar lesion were operated by EETT approach in this study. The approach included unilateral posterior septum mucosa resection, posterior septectomy, extended ethmoidectomy and sphenoidoctomy, four tumoral circumferences (bilateral, superior, inferior aspects) isolated and subsequently tumoral removal from outside to inside of the tumors obtained. This surgical procedure is satisfactory for sellar lesion with different juxtasellar extension. After surgery, CT scan and MR image showed that total removal of the tumor was achieved in 10 patients. Six patients who received subtotal resection were treated with postoperative radiation therapy or gamma knife surgery. Two patients developed postoperative cerebrospinal fluid leak that was successfully managed by conservative treatment within 6 days after surgery. No other new postoperative endocrinological or neurological defects occurred. Six months to 5 years follow up indicated that all 16 patients with the visual disturbances and 4 patients with endocrine impairments have recovered or improved. One patient with malignant meningioma died due to recurrence of the tumor 2 years postoperation. Another one patient with malignant inverted papilloma recurred 1 year postoperation and underwent operation and radiation therapy again. The EETT approach might better facilitate the removal of different extensive sellar lesions with maximal preservation of important anatomical structures and nasal function.

[A preliminary study of endoscopic transoral trans-posteriorwall pharynx resection of hypo-clivus chordoma].

OBJECTIVE: To introduce a endoscopic surgical approach for hypo-clivus chordoma, and to explore the clinical value of the endoscopic resection of hypo-clivus chordoma. METHODS: Three hypo-clivus chordoma were resected by endoscopic transoral tans-posteriorwall pharynx approach. RESULTS: The MR image showed that total removal of the tumor was achieved in 2 patients and subtotal resection was received in one patient. No severe postoperative complications and sequelae occurred. In 6 months to 2 years' follow-up, the MRI showed that 2 patients had no residue tumor, and one patient died due to recurrence of the tumor 1 year after operation. CONCLUSION: The endoscopic transoral tans-posteriorwall pharynx approach might be valuable in the treatment of the hypo-clivus chordoma. The use of the endoscope allows for direct access to the hypo-clivus lesions while minimizing the chances of surrounding anatomic structure injury. In addition, this approach has the advantages of quick recovery, avoidance of catastrophic complications and sequelae. Especially, various angle view of the endoscope provides a panoramic view of the hypo-clivus, thus exposing and resecting hide lesion which can not be exposed by other approaches. This approach might facilitate complete resection of the chordoma with maximal preservation of normal tissues.

[Combining FCU/5-FU suicide gene/prodrug system and radiation in treating nasopharyngeal carcinoma: an experimental study].

OBJECTIVE: To explore the in vitro, in situ and in vivo killing effects to CNE-2 cells of human nasopharyngeal carcinoma (NPC) by FCU/5-FC system combined with gamma irradiation for predicting the treatment effect on NPC. METHODS: Plasmid pcDNA3.1(-)CMVe.Egr-1. FCU was introduced into CNE-2 cells by electroporation. The transfected cells were selected by G418 (600 microg/ml) for 14 days to yield cells expressing FCU stably. The FCU protein in transfected CNE-2 cells was tested by Western blotting. In vitro response of FCU-expressing CNE-2 cells to 5-FC or gamma irradiation, alone or in combination was detected by MTT assay. Furthermore, A NPC model was employed by inoculating CNE-2 cells in the right flank of nude mice for in situ gene therapy, and after 12 days of inoculation, those rats were randomized to seven groups, then the suppression of NPC growth in model was observed after giving different treatments. Finally, FCU-expressing CNE-2 cells were inoculating in the right flank of nude mice to generate NPC xenografts for in vivo gene therapy, and after 5-day of implantation, those rats were randomized to seven groups, then the delaying of tumour growth was observed in xenografts treated with different conditions. RESULTS: A anticipated relative molecular quality 42,000 protein was obtained from total protein of FCU-expressing CNE-2 cells. The growth of FCU-positive CNE-2 cells were inhibited by 5-FC or gamma irradiation, alone or in combination, but cells treated with both 5-FC and gamma irradiation resulted in enhanced cell killing when compared with cells treated with gamma irradiation or 5-FC alone. In vitro study showed that the relative survival rates of FCU-expressing CNE-2 cells treated with gamma irradiation were 15.85% - 97.88%, while that of gamma irradiation + 5-FC (100 microg/ml) group were 6.58% - 50.00%, and there was a significant difference (P < 0.01). The MTT results also demonstrated that the relative survival rate has a striking different (P < 0.01) between 5-FC group (12.11% - 99.51%) and 5-FC + gamma irradiation (1.0 Gy) group (2.37% - 35.87%). Not only in situ but also in vivo, potent growth inhibition on the explanted NPC tumours was observed in mice treated with 5-FC or gamma irradiation, alone or in combination, among which interference of both 5-FC and gamma irradiation leaded to most distinct suppression of tumour growth. Tumour volumes in groups interfered by 5-FC and or gamma irradiation were extinctly different with the control group and PBS treatment group (P < 0.05). CONCLUSION: CNE-2 cells or nasopharyngeal carcinoma venograph could be killed by FCU/5-FC suicide gene prodrug system or gamma irradiation, and there is a synergistic therapeutic effect on NPC between FCU/5-FC and gamma irradiation.

[Clinical analysis of 170 cases head and neck lymphoma].

OBJECTIVE: To study the characteristics of head and neck lymphoma in order to improve its diagnose rate. METHODS: Review and analysis 170 patients with head and neck lymphoma in department of otolaryngology of Xiangya hospital from 1997 to 2005. RESULTS: Nasal cavity and nasal sinuses, neck, tonsil were the common place of the origin of head and neck lymphoma. There are 9 cases Hodgkin disease and 161 cases non-Hodgkin lymphoma (NHL). T cellularity, B cellularity lymphoma, the mixed pattern and nullityping accounted for 60.9%, 36.0% and 3.1% of these patients with NHL, respectively. CHOP and radiotherapy were the main treatment method. CONCLUSION: The clinical and imageology manifestation of head and neck lymphoma were of diversification and no specificity, whose final diagnosis depended on immunohistochemistry.

[Clinical analysis of pneumomediastinum or pneumothorax during the removal of brochial foreign bodies].

OBJECTIVE: To discuss the etiology, diagnosis, treatment, and prevention of pneumomediastinum or pneumothorax during the removal of bronchial foreign bodies in children. METHODS: We analyzed the clinical data of 10 cases of pneumomediastinum or pneumothorax during the removal of bronchial foreign bodies in children. RESULTS: Two patients died and the other 8 were cured. CONCLUSION: Pneumomediastinum or pneumothorax is mainly caused by the intrapulmonary hyper-pressure and fracture of pulmonary bubbles. The prognosis of pneumomediastinum or pneumothorax is closely related to such factors as correct and punctual diagnosis and quick removal of the airway obstruction.

Glucose- and pH-responsive nanogated ensemble based on polymeric network capped mesoporous silica.

In this paper, a glucose and pH-responsive release system based on polymeric network capped mesoporous silica nanoparticles (MSN) has been presented. The poly(acrylic acid) (PAA) brush on MSN was obtained through the surface-initiated atom transfer radical polymerization (SI-ATRP) of t-butyl acrylate and the subsequent hydrolysis of the ester bond. Then the PAA was glycosylated with glucosamine to obtain P(AA-AGA). To block the pore of silica, the P(AA-AGA) chains were cross-linked through the formation of boronate esters between 4,4-(ethylenedicarbamoyl)phenylboronic acid (EPBA) and the hydroxyl groups of P(AA-AGA). The boronate esters disassociated in the presence of glucose or in acidic conditions, which lead to opening of the mesoporous channels and the release of loaded guest molecules. The rate of release could be tuned by varying the pH or the concentration of glucose in the environment. The combination of two stimuli exhibited an obvious enhanced release capacity in mild acidic conditions (pH 6.0).

Highly efficient antibacterial surface grafted with a triclosan-decorated poly(N-hydroxyethylacrylamide) brush.

This work presented a highly efficient antibacterial Ti-surface which was grafted with poly(N-hydroxyethylacrylamide) (PHEAA) brush and further decorated with triclosan (TCS). The modified surfaces were characterized using contact angle measurements, X-ray photoelectron spectroscopy, and attenuated total reflectance Fourier transform infrared. The antibacterial performance of the modified surfaces was evaluated using the Streptococcus mutans and Actinomyces naeslundii attachment test. The Ti surface with PHEAA brush (Ti-PHEAA) was able to resist the adhesion of the bacteria, while the TCS-decorated Ti surface (Ti-TCS) showed the capability of killing the bacteria adhered on the surface. As we coupled the TCS to the PHEAA brush, the surface showed highly efficient antibacterial performance due to the combination of the resistance to the bacteria adhesion and its activity of killing bacteria.

Association between high initial tissue levels of cyclin d1 and recurrence of nasopharyngeal carcinoma.

OBJECTIVES/HYPOTHESIS: Cyclin D1 expression and the rate of apoptosis have been reported to serve as important prognostic indicators in human cancers. The purpose of the present study was to determine the prognostic significance of both initial cyclin D1 expression and the apoptotic index in nasopharyngeal carcinoma. STUDY DESIGN: Cohort study. METHODS: Cyclin D1 protein levels and apoptosis in tumors and their corresponding adjacent, histologically normal tissues were determined at the time of initial diagnosis using immunohistochemical staining, Western blot analysis, and in situ end labeling, respectively, in 64 patients with T1-T4/N0-N2, poorly differentiated squamous cell carcinoma of the nasopharynx. All cases were treated by routine radiation therapy with a total median dose of 70 Gy and followed up for 10 years. RESULTS: High levels of cyclin D1 were found in 35 of 64 tumor specimens (54.7%); no cyclin D1--positive cells were determinable in normal epithelium of the nasopharynx. Rates of early local recurrence (within 5 y) were significantly higher (P <.01) for patients with high levels of cyclin D1 before radiation therapy (24 of 35 patients [68.6%]) as compared with patients with low or no expression (3 of 29 [10.3%]). Furthermore, patients bearing high levels of cyclin D1 had a poorer prognosis concerning 10-year survival than the others (P <.001), whereas overexpression of cyclin D1 did not correlate with the initial TMN classification (P >.05). According to the rate of spontaneous apoptosis in tumors below or above the median, patients were divided into two groups. There was no statistically significant difference for the overall survival between the two groups (P >.05). CONCLUSIONS: The present study demonstrates that cyclin D1 can be used as an indicator of recurrence and subsequent prognosis in nasopharyngeal carcinoma after radiation therapy. At the same time, the apoptotic state before radiation therapy is of no value in predicting the prognosis of patients with nasopharyngeal carcinoma.

[Primary functional analysis of CK13 gene 5' flanking region].

OBJECTIVE: To investigate the mechanism of cytokeratin 13 (CK13) gene expression control and the effects of different motifs of CK13 gene 5' flanking region on its transcriptional activity. METHODS: The molecular clone technique and reporter gene analysis were used to assay the effects of different motifs of 513 bp of CK13 gene 5' flanking region on its transcriptional activity. The pCAT enhancer vectors with different motifs of CK13 gene 5' flanking region were constructed and transferred to HeLa cells with the help of lipofectin. The instant CAT expression of different clones was detected and the effects of different motifs of the CK13 gene 5' flanking region on its transcriptional activity were evaluated. RESULTS: 119 bp from -nt.325 to -nt.207 upstream of the first ATG of CK13 gene 5' flanking region included a silent element. 113 bp region from -nt.206 to -nt.94 included an enhanced element. CONCLUSION: 513 bp of CK13 gene 5' flanking region includes a silent element and an enhanced element. Further locating these cis elements and detecting the related trans reaction factors may unveil some important clues to the details of the mechanisms for the CK13 gene expression and tissue-specific expression.

[Telomere shortening in the pathogenesis of nasopharyngeal carcinoma].

OBJECTIVE: To explore the role of telomere shortening in the pathogenesis of nasopharyngeal carcinoma (NPC). METHODS: Southern blotting was employed to determine the mean telomere length (MTL) in 42 tumor samples and 15 samples of the tissues adjacent to the tumors obtained from 42 NPC patients, along with the tissue specimens from 17 patients with chronic nasopharyngitis. RESULTS: In NPC tissues, the length of the MTL was 4.5+/-2.3 kb, obviously shorter than those of the MTL in tissues adjacent to the tumor 14.6+/-2.8 kb and in chronic nasopharyngitis 15.8+/-3.1 kb. CONCLUSION: Telomere shortening may play an important role in the pathogenesis of nasopharyngeal epithelium cell malignancies.

[Resection of parapharyngeal neoplasms via styloid diaphragm approach].

OBJECTIVE: To evaluate the surgical technique and efficacy of the resection of parapharyngeal space neoplasm via styloid diaphragm approach. METHODS: Thirty-three cases underwent the resection of parapharyngeal space tumors via styloid diaphragm approach from Jan 2005 to Jan 2011 were reviewed. Of the cases, 28 were with benign tumors treated by surgery alone, and 5 were malignant tumors treated by surgery plus postoperative radical radiotherapy. RESULTS: The parapharyngeal neoplasms in all cases were completely resected via styloid diaphragm approach. The postoperative follow-up ranged from 13 months to 7 years (median = 4.6 years). No tumor recurrence was found in 30 cases, but 3 cases experienced tumor recurrence, including 1 chondrosarcoma (3 years after surgery and chemoradiotherapy), 1 chordoma and 1 adenoid cystic carcinoma (5 years after surgery and radiotherapy). Severe postoperative complications were not observed, but 2 cases showed mild mouth askew and fully recovered after 3 months, and 1 case was complicated with hoarseness and cough symptoms that disappeared after heteropathy. CONCLUSION: Resection of parapharyngeal neoplasms via styloid diaphragm approach is an ideal surgical technique, with well-exposed surgical field, less tissue injury, and less postoperative complication.

[EphA2 promotes angiogenesis and metastasis of head and neck squamous cell carcinoma in vivo].

OBJECTIVE: To investigate the effects of EphA2 on the angiogenesis and cervical lymph node metastasis of squamous cell carcinoma of the head and neck (SCCHN) in vivo. METHODS: EphA2 short hairpin (shRNA) lentiviral particles were used to knockdown the expression of EphA2 in SCCHN cell line M2 with high lymph nodes metastasis rate. Stable clones, obtained by puromycin screening, were assayed by RT-PCR and Western blot to validate the gene silencing efficiency and were used to establish SCCHN metastatic xenograft mouse model. Hematoxylin-eosin staining was applied to identify cervical lymph node metastasis of SCCHN in xenografted tumors. Immunohistochemistry was used to observe microvessel density. Western blot was used to investigate the protein expressions of EphA2 and vascular endothelial, growth factor (VEGF). RESULTS: EphA2 shRNA lentiviral particles efficiently decreased the mRNA and protein expressions of EphA2 in SCCHN cell line M2, which were further successfully utilized to establish SCCHN metastatic xenograft mouse model. Compared with xenografted tumors in control group, xenografted tumors in M2EphA2RNAi(+) group decreased significantly tumor volume [(430.7 ± 190.0) mm(3) (x(-) ± s) vs (1179.0 ± 289.4) mm(3)] and weight [(0.26 ± 0.10) g vs (0.54 ± 0.12) g] (both P < 0.05). More importantly, bilateral cervical lymph node metastasis rate in M2EphA2RNAi(+) was also greatly declined (Mann-Whitney U = 10.0, P < 0.05). Decreased protein expressions of EphA2 and VEGF and microvessel density were observed in M2EphA2RNAi(+) group (t = 26.751, P < 0.01). CONCLUSIONS: Knockdown of EphA2 expression led to the inhibition of tumor growth and metastasis in SCCHN nude mouse model. More importantly, SCCHN angiogenesis was also impeded, which might be associated with the decreased expression of VEGF.

[Endoscopic posterior septectomy for patients with nasopharyngeal tumor].

OBJECTIVE: To explore the techniques, advantages and disadvantages, indications and cautions of a surgical approach for the resection of nasopharyngeal tumor. METHODS: Ten cases with nasopharyngeal tumors were recruited in this study, of them, 3 cases with residual nasopharyngeal carcinoma after chemoradiotherapy, 2 cases with cavernous angioma, 2 cases with benign mixed tumor, 1 malignant mixed tumor, 1 adenoid cystic carcinoma, and 1 chordoma. All patients underwent endoscopic resection of posteroinferior quarter part of nasal septum, and then the removal of nasopharyngeal tumors through bilateral transnasal approach. RESULTS: Total resection of the tumor was achieved for all cases without severe surgical complications. All cases with benign tumors, with following-up of 6-18 months, showed no recurrence. Of 6 cases with malignant tumors, with following-up of 12-48 months, 5 cases showed no recurrence, and 1 case was suspected to relapse one year postoperatively, but not with any lesion enlargement after another 6 month follow-up. CONCLUSIONS: Posteroinferior quarter part of nasal septectomy is preferred for endoscopic resection of nasopharyngeal tumors because it can provide a panoramic view on nasopharyngeal cavity and tumors, thus, facilitating the removal of nasopharyngeal tumors.

[Tumor-targeted human telomerase reverse transcriptase promoter/tk gene therapy against human nasopharyngeal carcinoma cells in vitro].

OBJECTIVE: To investigate the targeted killing effect of human telomerase reverse transcriptase promoter (hTERTp)/tk gene on human nasopharyngeal carcinoma (NPC) cells. METHODS: The recombinant plasmid hTERTp/tk/pGL3 was transfected into human NPC HNE1 cells and the expressions of TK and telomerase were investigated. The targeted killing effect induced by hTERTp/tk on HNE1 cells was assessed using RT-PCR and MTT assay. RESULTS: TK gene expression was detected in HNE1 cells transfected by hTERTp/tk/pGL3, and the cells showed reduced telomerase and hTERT expression as compared with the control cells. hTERTp/tk/pGL3 resulted in target killing of HNE1 cells but not of the normal control cells. The tumor cell-killing effect of hTERTp/tk/pGL3 was slightly milder than that of the positive control CMV/tk/pGL3 that produced nonselective cell killing. CONCLUSION: hTERTp/tk, a tumor-specific expression system, allows targeted tumor cell killing and reduces the activity of telomerase in NPC cells in vitro.