p16 Protein and gigaxonin are associated with the ubiquitination of NFκB in cisplatin-induced senescence of cancer cells.

The molecular mechanism of p16-mediated senescence in cisplatin-treated cancer cells is not fully understood. Here we show that cisplatin treatment of head and neck cancer cells results in nuclear transport of p16 leading to a molecular modification of NFκB. Chromatin immunoprecipitation assays show that this modification is associated with the inhibition of NFκB interacting with its DNA binding sequences, leading to decreased expression of NFκB-transcribed proteins. LCMS proteomic analysis of LAP-TAP-purified proteins from HeLa cells containing a tetracycline-inducible GFP-S peptide-NFκB expression system identified gigaxonin, an ubiquitin E3 ligase adaptor, as an NFκB-interacting protein. Immunoblotting and siRNA studies confirmed the NFκB-gigaxonin interaction and the dependence of this binding on p16-NFκB binding. Using gel shift assays, we have confirmed p16-NFκB and gigaxonin-NFκB interactions. Furthermore, we have observed increased NFκB ubiquitination with cisplatin treatment that is abolished in the absence of p16 and gigaxonin expression. Analysis of 103 primary tumors has shown that increased nuclear p16 expression correlates with enhanced survival of head and neck cancer patients (p < 0.0000542), indicating the importance of nuclear p16 expression in prognosis. Finally, p16 expression is associated with reduced cytokine expression and the presence of human papilloma virus in chemoradiation-sensitive basaloid tumors. However, the absence of p16 expression is associated with enhanced cytokine expression and the absence of human papilloma virus in aggressive tumors. These results clearly demonstrate that nuclear p16 and gigaxonin play an important role in chemosensitivity of head and neck cancers through ubiquitination of NFκB.

Oncologic validity of recipient vessel preservation in microvascular free-flap reconstruction.

OBJECTIVES: The use of free-flap reconstruction requires a more limited neck dissection to allow for microvascular anastomosis. This study seeks to determine the oncologic validity of cervical vessel preservation. MATERIALS AND METHODS: The current study is a prospective review of cervical vessel biopsies from patients undergoing resection of squamous cell carcinoma (SCCA) tumors of the head and neck with free tissue reconstruction. RESULTS: From June 2010 to March 2012, 227 recipient vessel biopsies were performed on 100 patients. Three of these patients had grossly abnormal vessels, with malignancy confirmed by frozen section analysis. One patient had a vessel positive for malignancy that was grossly normal but found to have SCCA on the final pathology. CONCLUSIONS: When the recipient vessel appears grossly suspicious, a frozen section biopsy and re-resection should be considered. Recipient vessel trimmings should routinely be sent for permanent pathology since in rare cases, they can be involved by tumor, affecting the margin status, prognosis, and indications for adjuvant therapy.

Airway management and endoscopic treatment of subglottic and tracheal stenosis: the laryngeal mask airway technique.

OBJECTIVES: The objective is to present clinical outcomes of subglottic and tracheal stenosis treated by flexible bronchoscopic delivery of carbon dioxide (CO2) laser via laryngeal mask airway (LMA). METHODS: All consecutive, nontracheotomy dependent cases of subglottic and tracheal stenosis treated endoscopically over a 4-year period were retrospectively reviewed. The surgical approach consisted of radial incisions using a flexible fiber-based CO2 laser, balloon dilation, and topical application of mitomycin C. Ventilation during the procedure occurred through the LMA, and the CO2 laser fiber was delivered through the working channel of a flexible bronchoscope passed through the LMA. Number of dilations, period between dilations, and operative times were reviewed. RESULTS: Eleven patients who underwent airway intervention during the study period were identified. Average follow-up was 28 months. Etiologies of airway stenosis included intubation injury (6), idiopathic (4), or autoimmune disease (1), requiring an average of 1.3, 1.5, and 3 dilations, respectively. Average operative time was 67 minutes. Autoimmune etiology correlated with more frequent dilations. CONCLUSION: LMA is an effective way to manage ventilation while simultaneously allowing unencumbered flexible bronchoscopic access for laser surgery, balloon dilation, and mitomycin C application for airway stenosis. Long-term success in treating stenosis is achievable using this technique.

Schneiderian papillomas: comparative review of exophytic, oncocytic, and inverted types.

BACKGROUND: Sinonasal papillomas are benign epithelial neoplasms arising from Schneiderian mucosa. The three subtypes, exophytic, oncocytic, and inverted (inverted papilloma [IP]), should be distinguished from one another histopathologically. This study (1) highlights the histopathological and clinical differences between the Schneiderian papilloma subtypes and (2) identifies clinical features that potentially predict papilloma subtypes. METHODS: A retrospective review was performed of patients with Schneiderian papillomas over an 11-year period. RESULTS: Seventy patients with sinonasal papillomas who underwent sinus surgery were identified. There were 50 (71%) male and 20 (29%) female subjects diagnosed at an average age of 53 years (range, 13-80 years). Exophytic (n = 25), oncocytic (n = 9), and IP (n = 37) were identified. IP was associated with transformation into squamous cell carcinoma in three (8%) cases and dysplasia in three (8%) cases. Neither oncocytic nor exophytic subtypes were associated with dysplasia or malignancy. On multivariate analysis of potential predictors of papilloma subtype, history of chronic rhinosinusitis (CRS) and location of papilloma were significantly associated with papilloma subtype. Using classification and regression tree model, papilloma subtypes can be predicted based on presence or absence of CRS and papilloma location with nominal 82.4% accuracy. CONCLUSION: The inverted and exophytic type are the most common sinonasal papillomas, with the inverted type having an 8% rate of malignant transformation in this study. In contrast, the oncocytic type was not associated with dysplasia or malignancy in our series despite reports in the literature indicating malignant potential. History of CRS and papilloma location can provide clues to the histological subtype, which is important for surgical planning and patient counseling.

Radiologic assessment of the paranasal sinuses after endoscopic skull base surgery.

Objectives To identify sinuses demonstrating postoperative radiographic mucosal thickening after endoscopic exposure of the cranial base through the transsphenoidal corridor. Design Retrospective review. Setting University-based medical center. Participants Patients undergoing endoscopic transnasal transsphenoidal approaches to the skull base who had both preoperative and postoperative imaging. Main Outcome Measures Change in preoperative and postoperative imaging scores for each sinus and side at 3 and 6 months. The left-sided undissected sinuses served as internal controls for comparison. Results Fifty-one patients were identified with the aforementioned inclusion and exclusion criteria. The mean difference in preoperative and postoperative imaging scores for the right anterior ethmoid sinus was significantly different from the left-sided equivalents (p = 0.0020). The difference in the frontal sinuses approached significance (p = 0.0625). Conclusions Resection of the lower half of the middle turbinate and maxillary antrostomy and harvest of a nasoseptal flap are associated with an increased radiographic incidence of mucosal thickening of the ipsilateral anterior ethmoids compared with the undissected contralateral side. When accessing the transnasal transsphenoidal corridor for skull base surgery, preservation of native anatomy is associated with a lower incidence of mucosal thickening on postoperative imaging.

Parotidectomy and neck dissection in the management of conjunctival melanoma: are they necessary?

OBJECTIVES/HYPOTHESIS: The objectives of this study were to review traditional techniques for the management of conjunctival melanoma and assess the need for parotidectomy and neck dissection in the management of conjunctival melanoma. STUDY DESIGN: Retrospective review. METHODS: This study was a retrospective review conducted in a tertiary academic medical center of patients diagnosed with conjunctival melanoma over a 20-year period RESULTS: There were 39 patients diagnosed with conjunctival melanoma identified from January 1990 to December 2010. Follow-up varied from 2 to 201 months (median, 25 months). Of the patients, 16 (41%) had local recurrences at the primary site, two (13%) of whom later presented with parotid disease. One patient with parotid recurrence had a subsequent neck dissection for confirmed metastatic spread. No patient in this series had metastatic cervical disease without initial spread to the parotid. The probability of disease-free survival at 1, 2, and 5 years was 77%, 68%, and 50%, respectively. The probability of parotid free progression at 1, 2, and 5 years was 100%, 96%, and 90%, respectively. CONCLUSIONS: Conjunctival melanoma is a rare malignancy traditionally managed with aggressive treatment to optimize local control. The role for staging parotidectomy with or without neck dissection has been heavily debated. Based on our review, parotidectomy only needs to be undertaken when high suspicion for metastatic spread is present, such as a palpable or radiographically evident mass. In addition, without documented parotid disease, neck dissection is not required.

Cancer stem cells, microRNAs, and therapeutic strategies including natural products.

Embryonic stem cells divide continuously and differentiate into organs through the expression of specific transcription factors at specific time periods. Differentiated adult stem cells on the other hand remain in quiescent state and divide by receiving cues from the environment (extracellular matrix or niche), as in the case of wound healing from tissue injury or inflammation. Similarly, it is believed that cancer stem cells (CSCs), forming a smaller fraction of the tumor bulk, also remain in a quiescent state. These cells are capable of initiating and propagating neoplastic growth upon receiving environmental cues, such as overexpression of growth factors, cytokines, and chemokines. Candidate CSCs express distinct biomarkers that can be utilized for their identification and isolation. This review focuses on the known and candidate cancer stem cell markers identified in various solid tumors and the promising future of disease management and therapy targeted at these markers. The review also provides details on the differential expression of microRNAs (miRNAs), and the miRNA- and natural product-based therapies that could be applied for the treatment of cancer stem cells.

Respiratory epithelial adenomatoid hamartomas.

OBJECTIVES/HYPOTHESIS: The aim of this study was to understand the definition of respiratory epithelial adenomatoid hamartoma (REAH) and the association between REAH and chronic sinusitis and nasal polyposis, and to describe the histology and management of REAH. STUDY DESIGN: Retrospective review. METHODS: This retrospective review in a tertiary academic medical center studied patients with findings of REAH after endoscopic sinus surgery over a 10-year period. Age, sex, location, associated findings, radiographic features, and recurrences were reviewed. RESULTS: There were 54 patients with REAH identified who underwent endoscopic sinus surgery between January 2000 and May 2011. The ratio of disease between males and females was equal, and the average age at diagnosis was 52 years. Although the majority of cases had findings of REAH within the sinuses, eight (15%) were present as isolated masses within the nasal cavity. Available preoperative computed tomography scans were reviewed (n = 35), revealing no distinguishing features confirming REAH. Twenty-four cases (44%) were associated with an allergic type of chronic sinusitis and nine (17%) were associated with nasal polyposis. There were two (3.7%) recurrences, with no recurrences following repeat surgery. The average follow-up was 3.8 years. CONCLUSIONS: REAH is a benign entity characterized by abnormal glandular proliferation of the surface ciliated respiratory epithelium, admixed with goblet cells with no atypia or metaplastic change, rimmed by a thick basement membrane. It can present as an isolated mass within the nasal cavity or as an incidental finding in patients with chronic sinusitis. Nasal polyposis and allergic sinusitis can also be associated with REAH. Recurrences are rare with complete excision being essentially curative.

Neck mass due to pedicle ossification after oromandibular reconstruction.

OBJECTIVES/HYPOTHESIS: To determine the radiographic incidence of heterotopic ossification and the clinical incidence of neck masses secondary to heterotopic ossification in a series of patients who underwent fibula free flap oromandibular reconstruction. STUDY DESIGN: Retrospective review at a university medical center. METHODS: Patient database of 520 consecutive fibula free flaps from 1995 to 2010 was reviewed to identify patients who had postoperative computed tomography (CT) scans of the neck to further investigate the radiologic presence of heterotopic ossification. Patient chart review was also performed to identify patients who had clinical evidence of neck masses consistent with heterotopic ossification. RESULTS: Of the 66 patients who had postoperative CT scans available for radiologic assessment, 43 (65%) showed heterotopic ossification of the fibula periosteum. Clinically, 14 of 520 patients (2.6%) presented with firm, level I or II neck masses that proved to be secondary to heterotopic ossification. CONCLUSIONS: Development of a firm neck mass after treatment of head and neck cancer often indicates recurrent tumor. Heterotopic ossification has not been previously reported as a potential etiology of neck masses after fibula free flap oromandibular reconstruction in the head and neck surgery literature. The radiographic incidence of this phenomenon is high, and the clinical incidence of neck masses secondary to heterotopic ossification is low. Heterotopic ossification can be distinguished from recurrent tumor on the basis of physical examination, radiographic assessment, and/or fine-needle aspiration biopsy. Awareness of heterotopic ossification should be included in the differential diagnosis of patients with a neck mass who have undergone fibula free flap reconstructions.

Improved outcomes using a systematic and evidence-based approach to the laparoscopic Roux-en-Y gastric bypass in a single academic institution.

No standardized approach exists for laparoscopic Roux-en-Y gastric bypass (LRYGB). At a newly instituted bariatric surgery program, four experienced laparoscopic surgeons used the systematic and evidence-based approach consisting of multidisciplinary preoperative evaluation, screening, and education; standardized operative technique; inpatient clinical pathway; and close postoperative follow-up. The outcomes were subsequently analyzed to determine if this approach improved the morbidity and mortality. From January 2003 to June 2006, 835 consecutive LRYGBs were performed. The patient population was 85 per cent women with a mean body mass index (BMI) of 50.4 kg/m2 (range 33-96 kg/m2). The mean age was 44 (range 15-67). Sixty-two per cent of the patients had previous abdominal or pelvic operations. The conversion rate to open surgery was 0.2 per cent. The average length of hospital stay was 2.6 days (range 2-13 days). There were no anastomotic leaks or deaths. The 30-day readmission and re-operation rates were 3.2 per cent and 1.8 per cent, respectively. The incidence of anastomotic stricture, marginal ulcer, bleeding, pulmonary embolism, and internal hernia was 0.8 per cent, 3.5 per cent, 4.2 per cent, 0.1 per cent, and 0.4 per cent, respectively. A systematic and evidence-based approach to the LRYGB by experienced laparoscopic surgeons resulted in a lower incidence of complications when compared with the published results from other comparable institutions.

Adenoviral-encoded antigens are presented efficiently by a subset of dendritic cells expressing high levels of alpha(v)beta3 integrins.

Dendritic cells (DC) play a central role in antigen presentation and are often targeted by adenoviral (Ad)-based gene therapy. However, DC lack the coxsackie-Ad receptor, and little is known about the process by which they acquire and present Ad-encoded antigens. We examined the expression of alpha(v)beta3 integrins (CD51/CD61) on mouse bone marrow-derived DC (BM-DC) and their susceptibility to transduction by Ad vectors. Less than 10% of BM-DC precursors expressed CD51, but expression increased over time in culture with granulocyte macrophage-colony stimulating factor (GM-CSF)/interleukin (IL)-4. After 7 days, 28 +/- 1.7% of CD11c+ DC expressed high levels of CD51 (CD51(hi)), and the remaining DC expressed low levels of CD51 (CD51(lo)). CD51(hi) CD express higher major histocompatibility complex type 1 (MHC I); however, both of the DC subsets expressed similar levels of MHC II and costimulatory molecules. When exposed to a first-generation Ad vector, transgene expression was restricted to the CD51(hi) DC subset and blocked by soluble peptides expressing an arginine, glycine, aspartic acid (RGD) sequence, confirming the role of integrins in viral entry. Consistent with this, a modified Ad expressing an RGD-binding sequence in its fiber knob (Ad-RGD) transduced the CD51(hi) DC subset with significantly higher efficiency. When BM-DC were transduced with an Ad-expressing ovalbumin (Ad-OVA), the CD51(hi) subset proved superior in activating OT-I (T cell receptor-OVA) T cells. Similar to in vitro effects, systemic administration of GM-CSF/IL-4 increased the expression of CD51 on splenic DC and rendered these cells susceptible to Ad transduction. These results suggest that a limited subset of DC expressing high levels of alpha(v)beta3 integrins is preferentially transduced by Ad vectors and activates CD8+ T cell responses against Ad-encoded antigens.

Centrifugation enhances integrin-mediated transduction of dendritic cells by conventional and RGD-modified adenoviral vectors.

The level of antigen loading can impact on the capacity for dendritic cells (DC) to activate T cell responses. Several different approaches to adenoviral (Ad)-based transduction were therefore assessed for their effect on both transgene expression and T cell activation. While a conventional E1(-)/E3Delta Ad vector (Ad/GFP) produced a concentration-dependent expression of GFP, a modified vector expressing Arginine-Glycine-Aspartic Acid (RGD) sequence on its fiber knob (Ad-RGD/GFP) enhanced transgene expression by 9-20-fold at each MOI. The addition of centrifugal force (2000xg) during DC transduction with Ad/GFP also increased expression up to 20-fold. However, combining centrifugation with the Ad-RGD/GFP vector produced no effect on transduction rate and only a 1.5- to 2-fold increase in GFP expression, suggesting overlapping mechanisms of action. Consistent with this, exogenous RGD peptide blocked transduction regardless of the vector used, or the addition of centrifugal force, and transduction was primarily limited to DC expressing the CD51 integrin receptor. Ad vectors expressing ovalbumin (OVA) were used to assess transduced DC for their capacity to activate OVA-specific T cells. We observed a significant relationship between transgene expression and the capacity for T cell activation regardless of whether transgene expression was increased by using a higher MOI, an RGD-modified vector, or by employing centrifugal force. Furthermore, combining these approaches produced synergistic effects on T cell activation. We conclude that RGD-modified vectors and centrifugation both enhance DC transduction by increasing entry via integrin receptors and that the capacity for T cell activation can be optimized by combining approaches to achieve the highest possible level of transgene expression.