Methylation status of insulin-like growth factor-binding protein 7 concurs with the malignance of oral tongue cancer.

BACKGROUND: Aberrant insulin-like growth factor-binding protein 7 (IGFBP-7) expression has been found in various cancers such as prostate, breast, and colon. IGFBP-7 induced the apoptosis of tumor and potentially predicted the clinical outcome in some cancers is further demonstrated. This study investigates the causes and underlying mechanisms of aberrant IGFBP-7 expression in unravelling head and neck squamous cell carcinoma (HNSCC). METHODS: A total of 47 oral tongue cancer patient samples were primarily analyzed for the methylation status in 5' region of IGFBP-7 by methylation-specific PCR (MS-PCR). Subsequently the invasion, overexpression, and knockdown of IGFBP-7 in the HNSCC A253 invasive subpopulation were employed to examine the effect of IGFBP-7. The epithelial-mesenchymal transition (EMT) marker genes and AKT/GSK3ß/ß-catenin signaling were further evaluated by Western blot for the understanding the role of aberrant IGFBP-7 expression and thereof putative mechanism. RESULTS: EMT expressed in the invasive subpopulation of HNSCC cell lines (A253 and RPMI 2650) was contemporary with the down-regulation of IGFBP-7. After treatment with 5-AZA-2' deoxycytidine, the de-methylated CpG sites in the 5' region of IGFBP-7 were observed and IGFBP-7 mRNA expression was also restored. Accordingly, re-expression IGFBP-7 in invasive subpopulation of A253 could induce the mesenchymal-epithelial transition (MET) and concurrently inhibited the cell invasion. Moreover, IGFBP-7 methylation status of 47 oral tongue tumors showed a positive correlation to invasive depth of the tumor, loco-regional recurrence, and cancer sequence. CONCLUSIONS: IGFBP-7 can alter EMT relative marker genes and suppress cell invasion in A253 cell through AKT/GSK3ß/ß-catenin signaling. The epigenetic control of IGFBP-7 in the invasion and metastasis of HNSCC was reported, suggesting that IGFBP-7 could be a prognostic factor for the probability of invasion and a therapeutic remedy.

Concomitant induction of apoptosis and autophagy by prostate apoptosis response-4 in hypopharyngeal carcinoma cells.

The tumor-suppressive activity of prostate apoptosis response-4 (Par-4) has been demonstrated in a variety of human cancers. In this study, for the first time to our knowledge, we demonstrated that a higher intensity of Par-4 was significantly correlated with a better response in patients with hypopharyngeal carcinoma undergoing radiotherapy alone or concurrent chemoradiotherapy. Mechanistically, an elevated expression of Par-4 induced apoptosis of hypopharyngeal carcinoma cells and sensitized cells toward chemotherapeutic agents or X-ray irradiation. Along with apoptotic incitation, intriguingly, autophagic flux also increased on Par-4 stimulation and contributed to cell death. Moreover, the expressions of multiple common regulators involved in apoptosis and autophagy were regulated by Par-4. Taken together, our results suggested a prognostic role of Par-4 in hypopharyngeal carcinoma and showed novel activity of Par-4 in apoptosis and autophagy induction.

Widespread expression of prostate apoptosis response-4 in nasopharyngeal carcinoma.

BACKGROUND: Prostate apoptosis response-4 (Par-4) augments apoptosis in various tumors, either during apoptotic insult or by ectopic overexpression. However, investigation of Par-4 expression in nasopharyngeal carcinoma (NPC) is lacking. METHODS: Specimens from patients with NPC, hypopharyngeal carcinoma (HPC), or oral cavity cancer were examined for Par-4 expression using immunohistochemistry. NPC cell proliferation and apoptosis were analyzed using immunohistochemical staining for Ki67, B-cell lymphoma 2 (Bcl-2), and in situ terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick end-labeling (TUNEL) assay, respectively. RESULTS: Par-4 was ubiquitously expressed in NPC biopsies (96.2%, 25/26) and was significantly higher than in HPC (47.6%, 50/105, p < .0001) and oral cavity cancers (38.7%, 12/31, p < .0001). Remarkably, apoptosis of NPC cells was absent and Par-4 expression was associated with obvious expression of Bcl-2 and Ki67 in all patients tested with NPC. CONCLUSIONS: Immunohistochemistry results showed widespread expression of Par-4 in NPC and revealed sustainable proliferation of NPC cells regardless of Par-4 expression.

Upregulated claudin-1 expression confers resistance to cell death of nasopharyngeal carcinoma cells.

Accumulating evidence reveals that aberrant expression of claudins manifests in various tumors; however, their biological functions are poorly understood. Here, we report on the elevated expression of claudin-1 in nasopharyngeal carcinoma (NPC) cell lines under serum deprivation or fluorouracil (5-FU) treatment. Interestingly, an increase in expression of claudin-1 considerably reduced apoptosis rather than enhancing cell proliferation. However, claudin-1 expression and activity were unaffected by external stimuli or Akt and NF-kappaB activation. Notably, predominant cytoplasmic and nuclear localization of claudin-1 in NPC cells reflected the aforementioned feature. On the other hand, loss of epithelial morphology and E-cadherin expression was associated with serum withdrawal in NPC cells. Interestingly, restoration of E-cadherin inhibited the protein elevation and antiapoptotic activity of claudin-1. In conclusion, our data demonstrate the regulation and novel biological function of claudin-1 and indicate the important role of claudin-1 in NPC tumorigenesis.

Predictors of locoregional recurrence in early stage oral cavity cancer with free surgical margins.

Locoregional recurrence in patients with early stage oral cavity squamous cell carcinoma (ESOSCC) after surgery remains a problem and can affect their survival. We sought to identify new high-risk factors in these patients, who need further adjuvant therapy. We retrospectively reviewed records for 148 patients who underwent surgery for ESOSCC between 2002 and 2006 with negative surgical margins. The primary endpoint was locoregional recurrence. Recurrence-free survival (RFS) and overall survival (OS) were calculated by the Kaplan-Meier method. Univariate and multivariate analyses were used to identify independent predictors of locoregional recurrence. All patients were grouped into the low- and high-risk groups according to the odds ratios (OR) of the predictors. Recurrence rates of the low- and high-risk groups were then predicted. Recurrence was observed in 17 of 148 (11.5%) patients at the end of this study. None of the patients received postoperative radiotherapy or chemotherapy. At 3 years, the RFS rate was 89.7% and the OS rate at 3 years was 84.1%. Univariate analysis of the RFS revealed three significant prognostic factors: lymphovascular permeation (LVP, p<0.001), perineural infiltration (PNI, p=0.08), and non-T4 muscular invasion (non-T4MI, p<0.005). Multivariate analysis demonstrated that LVP (p=0.007, OR=10.7) and non-T4 MI (p=0.001, OR=8.347) were independent predictors. The recurrence rate was 1.96% in patients without LVP or non-T4MI, and it increased to 26.47% in patients with non-T4MI, to 50% in patients with LVP, and to 50% in patients with both. According to the status of LVP and non-T4MI, patients were divided into two groups: low-risk (no factors present) and high-risk (one or both factors present) groups. The 2-year RFS was lower in the high-risk group (84.13%) than in the low-risk group (93.91%); the 3-year RFS was also lower in the high-risk group (70.49%) than in the low-risk group (91.99%) (p=0.008). Subgroup analysis revealed that elective neck dissections did not affect the outcome or change the pattern of failure. For patients with elective neck dissections, the RFS was lower in the high-risk group than in the low-risk group (p=0.03). In ESOSCC (pT1-2N0), LVP and non-T4MI significantly increased the recurrence rate. The presence of one or both factors (LVP and/or non-T4MI) should be considered as a high-risk condition for locoregional recurrence, and adjuvant therapy is needed in such cases.

Surgical outcome in patients with oral verrucous carcinoma: long-term follow-up in an endemic betel quid chewing area.

BACKGROUND/AIMS: To evaluate the clinical features and prognosis of patients with oral verrucous carcinoma (OVC) in an endemic betel quid chewing area. METHODS: A retrospective review was conducted in 39 patients with OVC treated surgically from 1991 to 2002. RESULTS: Thirty-seven patients (94.9%) were male. The median age at diagnosis was 53.8 years. All patients had been exposed to betel quid, cigarette smoking, and/or alcohol. The most common site of tumor origin was the buccal mucosa (64.1%). The tumor control rate was 97.4% after the first surgical procedure. Second/multiple primary tumors (SPTs/MPTs) were found in 21 patients. There were 13 deaths during the follow-up period, with SPTs/MPTs being the most common cause. The cancer-specific survival rate was 89.1% at 5 years, but continued to decrease thereafter. CONCLUSION: Surgery was effective for controlling OVC. However, long-term follow-up was necessary because of the high incidence of SPTs/MPTs and its impact on patient survival.

Income and the incidence of oral cavity cancer: cross-national study.

OBJECTIVE: To examine the relation between income and oral cancer incidence in countries at different stages of economic development. DESIGN: Descriptive study with regression analysis of oral cancer incidence in relation to real gross domestic product (GDP) per capita from 1970 to 2000 performed for 8 different countries. METHODS: GDP per capita was collected from the United States, Hong Kong, Singapore, Italy, Mexico, Philippines, Poland, and Romania. Correlation factor and Pearson values were compared. RESULTS: The association between income and the oral cavity cancer rate was significant in all the countries selected. Using linear regression analysis, the results showed high r2 value. The increase of real GDP correlated negatively with the rate of male oral cavity cancer in the United States, Italy, Hong Kong, and Singapore but not in Mexico, Philippines, Poland, and Romania. CONCLUSIONS: The association between incidence and income appears to depend on per capita GDP, being negative in countries with GDP above US$10,000 and positive in countries with GDP below US$10,000.

EBV LMP-1 negatively regulates expression and pro-apoptotic activity of Par-4 in nasopharyngeal carcinoma cells.

Latent membrane protein-1 (LMP-1) of the Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC), and in this study we sought to determine whether the pro-apoptotic activity of prostate apoptosis response-4 (Par-4) is modulated by LMP-1 in NPC cells. We found that LMP-1 diminished the pro-apoptotic activity of Par-4 and negatively regulated Par-4 protein by de novo synthesis; moreover, although LMP-1 accelerated a Par-4 activator, PKA, we demonstrated that LMP-1 also activated the PI3K/Akt pathway and increased Bcl-2 expression to suppress the activity of Par-4. Consequently, our results revealed a novel negative action of LMP-1 on the pro-apoptosis protein Par-4 by the coordination of multiple signaling pathways.

Protein expression and intracellular localization of prostate apoptosis response-4 (Par-4) are associated with apoptosis induction in nasopharyngeal carcinoma cell lines.

Prostate apoptosis response-4 (Par-4) is a proapoptotic gene that selectively induces cell death in most cancer cells. In addition to the increased percentage of apoptotic cells, caspase-3 activity, and poly (ADP-ribose) polymerase (PARP) cleavage, we demonstrate that elevated expression of Par-4 and nuclear entry resulted in apoptosis of nasopharyngeal carcinoma (NPC) cell lines either in serum deprivation or by ectopic overexpression of Par-4. Moreover, disassociation from the Par-4/Akt complex was correlated with the induced proapoptotic ability of Par-4. Therefore, our data suggest that the cytoplasmic localization and expression level of endogenous Par-4 in NPC cells are not sufficient to augment apoptosis.

Optimal graft thickness for different sizes of tympanic membrane perforation in cartilage myringoplasty: a finite element analysis.

OBJECTIVE: The purpose of this study was to determine, using finite element analysis, the optimal graft thickness for cartilage myringoplasty in patients with different sizes of tympanic membrane (TM) perforations. STUDY DESIGN: We developed a cartilage plate-TM-coupled model using high-resolution computed tomography and finite element analysis. The geometric models of the perforated TM were generated using Patran and ANSYS software. METHOD: Three different sizes of TM perforations (15%, 55%, and 85%, representing small, medium, and large perforations, respectively) were created in the pars tensa. A cartilage plate was used to repair the eardrum perforation, and the new TM-cartilage coupled complex was loaded into our three-dimensional biomechanical model for analysis. The frequency-amplitude responses for different cartilage thicknesses were compared with those for natural TM. RESULTS: Our results show that, first, in cases with 85% perforation, the frequency-amplitude responses that were most similar to natural TM at lower frequencies were for graft thicknesses of 0.2 mm and for 0.1 mm at higher frequencies. Second, in cases with 55% posterior perforation of the TM, assessment of the predicted vibration amplitude of different thicknesses of the cartilage plate showed that a cartilage plate of less than 0.2 mm had a frequency response function similar to that of a natural TM in umbo and stapes footplate displacement. Finally, for a central perforation involving 15% of the TM, a cartilage plate of less than 1.0 mm showed a frequency response function similar to that of TM in umbo and stapes-footplate displacement. CONCLUSIONS: On the basis of our biomechanical analysis, the optimal thickness of a cartilage graft for myringoplasty appears to be 0.1 to 0.2 mm for medium and large TM perforations. For small perforations, a cartilage of less than 1.0 mm is a good compromise between mechanical stability and low acoustic transfer loss.

Tracheal incision for elective tracheotomy in oral cavity cancer.

The aim of this prospective study was to compare operative procedure and postoperative complications between horizontal tracheal incision and window-type tracheal excision for elective tracheotomy in patients with oral cavity cancer. Between February 2003 and April 2004, 40 patients with advanced-stage oral cavity cancer were consecutively seen at our tumor clinic. All patients underwent elective tracheotomy before wide excision of the tumor and free flap reconstruction. Either horizontal tracheal incision (H group) or window-type tracheal excision (W group) was randomly carried out in two groups comprising 20 patients each. The post-tracheotomy tracheal stenosis was evaluated by tracheal computed tomography (CT) coupled with advantage workstation 4.0 software for reconstruction. Both groups had the following similar characteristics: age, gender, tracheotomy days, or interval between decannulation and CT scan evaluation. However, the incision time was statistically less in the H group (16.4s) compared with the W group (43.4s). Tracheal stenosis was found in five patients (25%) in the H group and four patients (20%) in the W group, with no significant differences. Nevertheless, neither dyspnea or stridor after decannulation, difficulty in tube exchange, nor accidental extrusion was reported in either groups. The horizontal incision for elective tracheotomy is simpler and faster than the window-type tracheal excision. The complication rate is not significantly different in both groups. We therefore, recommend using horizontal incision for elective tracheotomy in patients with oral cavity cancer.

Biomechanical modeling and design optimization of cartilage myringoplasty using finite element analysis.

The purpose of this study was to determine the acoustic transfer characteristics of cartilage for optimal cartilage myringoplasty. In order to do so, we developed a cartilage plate/tympanic membrane-coupled model using finite element analysis. Cartilage specimens of the tragus were obtained from fresh human cadavers, and the parameters of the tragus were determined by curve fitting and cross-calibration. A cartilage plate was used to repair an eardrum perforation, and the new coupled tympanic membrane-cartilage complex was loaded into our 3-dimensional biomechanical model of the middle ear for analysis. Our results show that first the beta-damping value of the cartilage plate depends on frequency. The value of beta damping was close to 3 x 10(-4) s at lower frequencies and 5 x 10(-6) s at higher frequencies. Secondly, reducing cartilage thickness leads to an improvement of its acoustic transfer qualities. From an acoustics point of view, the 0.1- to 0.2-mm cartilage plate seems to be most preferable with regard to tympanic membrane vibration. Furthermore, thicknesses of 0.2 mm at lower frequencies and 0.1 mm at higher frequencies were regarded as good compromises between sufficient mechanical stability and low acoustic transfer loss.

Secondary free-tissue reconstruction for metachronous tumors of the head and neck: techniques, results, and outcomes.

Malignancies of the head and neck are not uncommon in the Far East due to the habit of betel-nut chewing. The development of a second primary neoplasm is a constant fear for those who have had successful treatment of a primary cancer. A total of 82 patients, treated with microvascular reconstruction after surgical resection of head and neck cancer, were studied retrospectively. Twenty-one patients who had repeated reconstructive microsurgery for a second primary head and neck malignancy were enrolled as the study group. Sixty-one patients treated for the first-diagnosed malignancy were considered as the control group. There were no statistical differences between the two groups, either in terms of operation time, hospital stay, successful rate, or complication rate. The results show that, if required, one should not hesitate to repeat the free-tissue transfer after ablating a second primary neoplasm.

Radiation-induced oscillopsia in nasopharyngeal carcinoma patients.

PURPOSE: To apply a battery of audiovestibular function tests and magnetic resonance imaging (MRI) to investigate the causes of oscillopsia in nasopharyngeal carcinoma (NPC) patients after irradiation (RT). METHODS AND MATERIALS: Of 300 NPC patients, 12 (4%) developed oscillopsia after RT. The mean accumulated radiation dose to the nasopharynx was 112 +/- 30 Gy. Each patient underwent a battery of audiovestibular function tests, including audiometry and the dynamic illegible E, caloric, and rotational tests. RESULTS: Excluding 3 patients with neck fibrosis who could not perform the head turning movement, the remaining 9 patients displayed 100% abnormal dynamic illegible E test results and 100% abnormal refixation saccades. All 12 patients presented with bilateral hearing loss, caloric reductions, and reduced gains of the vestibular ocular reflex (VOR) on the rotational test, indicating bilateral VOR loss. After excluding tumor relapse and radiation necrosis of the brain by MRI, the oscillopsia in these 12 irradiated NPC patients was attributed to bilateral VOR loss. CONCLUSION: Radiation-induced oscillopsia in our NPC patients was attributed to bilateral VOR loss, possibly as a result of higher radiation doses. Hence, the therapeutic benefits of a second course of RT are associated with the potential risk of oscillopsia after RT.

Is dextran infusion as an antithrombotic agent necessary in microvascular reconstruction of the upper aerodigestive tract?

Patent microvascular anastomoses are mandatory for a successful free tissue transfer. Dextran 40 is widely used by reconstructive microsurgeons in conjunction with free tissue transfer, to prevent flap loss. Unfortunately, dextran-induced adverse reactions, such as anaphylactoid reactions, adult respiratory distress syndrome, cardiac overload, hemorrhage, and renal damage, remain the major risks in routine use of dextran 40. The authors retrospectively analyzed the patency rates of 55 microvascular tissue transfers of a single microsurgeon after tumor ablation of malignancies of the upper aerodigestive tract between August, 1997 and March, 2001. The patency rates of free flap reconstructions were 96 percent for the dextran-infusion group and 100 percent for the dextran-free group. There was no statistically significant difference between the patency rates of these two groups. The results showed that the routine use of dextran as an antithrombotic agent is not necessary in microvascular reconstruction. The disadvantages of dextran infusion can be effectively prevented.

The "Sun window" - a simple and effective alternative to the use of background contrast material during microvascular anastomosis.

A new and simple alternative method, the "Sun window," is introduced for creating a comfortable environment while doing microvascular anastomoses. A prospective randomized study, analyzing the anastomosis time for 34 free radial forearm flaps, was conducted to validate the effectiveness of this method. The time required for doing anastomoses with and without a "Sun window" are 8.74 +/- 1.46 and 10.36 +/- 1.20, respectively, p < 0.01. The results demonstrated that the "Sun window" is an effective method for promoting the patency rate and accuracy of microvascular anastomosis.