Reconstruction of large composite buccal defects using single soft tissue flap--analysis of functional outcome.

Resection of advanced gingivo-buccal tumors results in a posterolateral mandibular and large soft tissue defect. Because of large soft tissue requirement, these defects are difficult to reconstruct using a single osteocutaneous flap. A double free flap reconstruction of such defects is recommended. However, double flap may not be feasible in certain situations. In this study, we objectively evaluated functional and cosmetic outcomes following single soft-tissue flap reconstruction in a group of patients where double flap reconstruction was not feasible. Patient and defect characteristics were obtained from charts. The speech and swallowing functions of patients were prospectively assessed by a dedicated therapist. The cosmetic outcome of reconstruction was evaluated by an independent observer. Fifty-six patients with large soft tissue and segmental posterolateral mandible defect, reconstructed with anterolateral thigh or pectoralis major flap from May 2009 till December 2010 were included. In this series, none of the flaps were lost; two patients with pectoralis major flap developed partial skin paddle loss. Most of the patients developed mandibular drift; however, majority of these patients had no postoperative trismus. All patients resumed regular or soft solid oral diet. The mean speech intelligibility was more than 70%. Majority of patients had satisfactory cosmetic outcome. The defects were classified into regions resected to develop a reconstruction algorithm for optimal reconstruction using a free or pedicle flap. In conclusion, patients with large oro-mandibular defect undergoing single soft tissue flap reconstruction have satisfactory functional and cosmetic outcome.

Inhibition of Jun NH2-terminal kinases suppresses the growth of experimental head and neck squamous cell carcinoma.

PURPOSE: This study was carried out to investigate whether c-Jun NH2-terminal kinases (JNK) are potential targets for treating head and neck squamous cell carcinoma (HNSCC). EXPERIMENTAL DESIGN: JNK activity was first evaluated in 20 paired samples of human HNSCC. The antitumor activity of SP600125, a reversible nonselective ATP-competitive inhibitor of JNKs, was then investigated both in an HNSCC xenograft model and in vitro using immunohistochemistry, immunoblotting, enzyme immunoassay, flow cytometry, and a Matrigel assay of capillary tube formation. Complementary studies were carried out using small interfering RNA to JNK1/2. RESULTS: JNK activity was increased in human HNSCC compared with normal-appearing epithelium. Treatment of mice bearing HNSCC xenografts with SP600125 resulted in >60% inhibition of tumor growth relative to vehicle-treated animals. Inhibition of tumor growth was associated with significant reductions in both cell proliferation and microvessel density. SP600125 inhibited tumor cell proliferation by causing delays in both the S and G2-M phases of the cell cycle. Inhibition of angiogenesis seemed to reflect effects on both tumor and endothelial cells. The JNK inhibitor suppressed the production of vascular endothelial growth factor and interleukin-8 by tumor cells and also inhibited endothelial cell proliferation and capillary tube formation. Reduced amounts and phosphorylation of epidermal growth factor receptor were found in tumor cells after treatment with SP600125. Small interfering RNA-mediated suppression of JNK1/2 led to reduced tumor cell proliferation and decreased levels of epidermal growth factor receptor, vascular endothelial growth factor, and interleukin-8. CONCLUSIONS: JNK activity is commonly increased in HNSCC. Our preclinical results provide a rationale for evaluating JNK inhibition as an approach to treating HNSCC.

Elevated Levels of Urinary PGE-M Are Found in Tobacco Users and Indicate a Poor Prognosis for Oral Squamous Cell Carcinoma Patients.

Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) plays a role in the development and progression of epithelial malignancies. Measurements of urinary PGE-M, a stable metabolite of PGE2, reflect systemic PGE2 levels. Here, we investigated whether urinary PGE-M levels were elevated in healthy tobacco users and in patients with oral squamous cell carcinoma (OSCC). Median urinary PGE-M levels were increased in healthy tobacco quid chewers [21.3 ng/mg creatinine (Cr); n = 33; P = 0.03] and smokers (32.1 ng/mg Cr; n = 31; P < 0.001) compared with never tobacco quid chewers-never smokers (18.8 ng/mg Cr; n = 30). Urinary PGE-M levels were also compared in OSCC patients versus healthy tobacco users. An approximately 1-fold increase in median urinary PGE-M level was found in OSCC patients (48.7 ng/mg Cr, n = 78) versus healthy controls (24.5 ng/mg Cr, n = 64; P < 0.001). We further determined whether baseline urinary PGE-M levels were prognostic in OSCC patients who underwent treatment with curative intent. A nearly 1-fold increase in baseline urinary PGE-M levels (64.7 vs. 33.8 ng/mg Cr, P < 0.001) was found in the group of OSCC patients who progressed (n = 37) compared with the group that remained progression free (n = 41). Patients with high baseline levels of urinary PGE-M had both worse disease-specific survival [HR, 1.01 per unit increase; 95% confidence interval (CI), 1.01-1.02; P < 0.001] and overall survival (HR, 1.01 per unit increase; 95% CI, 1.00-1.02; P = 0.03). Taken together, our findings raise the possibility that NSAIDs, prototypic inhibitors of PGE2 synthesis, may be beneficial for reducing the risk of tobacco-related aerodigestive malignancies or treating OSCC patients with high urinary PGE-M levels. Cancer Prev Res; 9(6); 428-36. ©2016 AACR.

A Minimal DNA Methylation Signature in Oral Tongue Squamous Cell Carcinoma Links Altered Methylation with Tumor Attributes.

UNLABELLED: Oral tongue squamous cell carcinomas (OTSCC) are a homogenous group of aggressive tumors in the head and neck region that spread early to lymph nodes and have a higher incidence of regional failure. In addition, there is a rising incidence of oral tongue cancer in younger populations. Studies on functional DNA methylation changes linked with altered gene expression are critical for understanding the mechanisms underlying tumor development and metastasis. Such studies also provide important insight into biomarkers linked with viral infection, tumor metastasis, and patient survival in OTSCC. Therefore, we performed genome-wide methylation analysis of tumors (N = 52) and correlated altered methylation with differential gene expression. The minimal tumor-specific DNA 5-methylcytosine signature identified genes near 16 different differentially methylated regions, which were validated using genomic data from The Cancer Genome Atlas cohort. In our cohort, hypermethylation of MIR10B was significantly associated with the differential expression of its target genes NR4A3 and BCL2L11 (P = 0.0125 and P = 0.014, respectively), which was inversely correlated with disease-free survival (P = 9E-15 and P = 2E-15, respectively) in patients. Finally, differential methylation in FUT3, TRIM5, TSPAN7, MAP3K8, RPS6KA2, SLC9A9, and NPAS3 genes was found to be predictive of certain clinical and epidemiologic parameters. IMPLICATIONS: This study reveals a functional minimal methylation profile in oral tongue tumors with associated risk habits, clinical, and epidemiologic outcomes. In addition, NR4A3 downregulation and correlation with patient survival suggests a potential target for therapeutic intervention in oral tongue tumors. Data from the current study are deposited in the NCBI Geo database (accession number GSE75540). Mol Cancer Res; 14(9); 805-19. ©2016 AACR.

Neoadjuvant chemotherapy in oral cancers: Selecting the right patients.

The standard of care treatment for oral squamous cell carcinoma (OSCC) at present, consist of surgical resection followed by adjuvant radiotherapy and chemotherapy as indicated. Despite recent advances the overall prognosis remains guarded. Role of neoadjuvant chemotherapy is being explored with premise of reducing extent of surgical resection, improving loco-regional control and decreasing distant metastasis, thereby improving treatment outcomes by decreasing mortality and morbidity. However, indications of neoadjuvant chemotherapy in oral cancers are not clearly defined. Majority of studies have failed to demonstrate a significant benefit of neoadjuvant chemotherapy in terms of loco regional control and overall survival in resectable OSCC. In a select subset of patients with locally very advanced and unresectable OSCC, neoadjuvant chemotherapy has been shown to cause tumor shrinkage and improve resectability. These hypothesis generating findings of reduction in distant metastasis, improved resectability and functional outcome, however need further validation. In summary, the role of neoadjuvant chemotherapy for OSCC remains investigational and has a limited role outside clinical trial.

Gene and miRNA expression changes in squamous cell carcinoma of larynx and hypopharynx.

Laryngo-pharyngeal squamous cell carcinomas are one of the most common head and neck cancers. Despite the presence of a large body of information, molecular biomarkers are not currently used in the diagnosis, treatment and management of patients for this group of cancer. Here, we have profiled expression of genes and microRNAs of larynx and hypopharynx tumors using high-throughput sequencing experiments. We found that matrix metalloproteinases along with SCEL, CRNN, KRT4, SPINK5, and TGM3 among others have significantly altered expression in these tumors. Alongside gene expression, the microRNAs hsa-miR-139, hsa-miR-203 and the hsa-miR-424/503 cluster have aberrant expression in these cancers. Using target genes for these microRNAs, we found the involvement of pathways linked to cell cycle, p53 signaling, and viral carcinogenesis significant (P-values 10(-13), 10(-9) and 10(-7) respectively). Finally, using an ensemble machine-learning tool, we discovered a unique 8-gene signature for this group of cancers that differentiates the group from the other tumor subsites of head and neck region. We investigated the role of promoter methylation in one of these genes, WIF1, and found no correlation between DNA methylation and down-regulation of WIF1. We validated our findings of gene expression, 8-gene signature and promoter methylation using q-PCR, data from TCGA and q-MSP respectively. Data presented in this manuscript has been submitted to the NCBI Geo database with the accession number GSE67994.

Factors predicting outcome after salvage treatment for stage IV oral squamous cell carcinoma: Evidence of the potential importance of the cyclooxygenase-2-prostaglandin E2 pathway.

BACKGROUND: We determined the clinicopathological factors that predicted outcome after salvage treatment for stage IV oral squamous cell carcinoma (OSCC). Additionally, the prognostic significance of the cyclooxygenase-2 (COX-2)/microsomal prostaglandin-E synthase-1 (mPGES-1) pathway was evaluated. METHODS: Thirty-one patients who underwent salvage surgery were included. COX-2 and mPGES-1 levels were quantified by real time polymerase chain reaction (PCR). RESULTS: The 2-year disease-free and overall survival rates were 46% and 53%, respectively. Adequacy of initial treatment, tobacco smoking, and the presence of pathological risk factors were predictive of mortality. In patients who had not received chemotherapy before salvage surgery, high levels of intratumoral COX-2 and mPGES-1 were associated with poor prognosis. By contrast, high intratumoral COX-2 and mPGES-1 after chemotherapy were associated with improved outcomes. CONCLUSION: Clinicopathological factors may inform treatment decisions in patients with stage IV OSCC. Expression patterns of COX-2 and mPGES-1 correlated with outcome and warrant further investigation. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1142-1149, 2015.

Versatility of adipofascial anterolateral thigh flap for reconstruction of maxillary defects with infratemporal fossa extension.

Tumors arising from the posterior hard palate or posterolateral maxilla may extend to involve the infratemporal fossa (ITF). Resection of these tumors results in infrastructural maxillectomy with ITF defects. In this study, we describe the use of an adipofascial anterolateral thigh flap (ALT) specifically for such defects. This case series includes four patients who underwent an infrastructure maxillectomy with ITF clearance and the resultant defects were reconstructed using adipofascial anterolateral thigh flaps. The complications as well as the functional outcomes were assessed. This study included patients with lesions involving the hard palate, posterolateral part of maxilla with extension into the ITF. The mean flap dimension was 150 cm(2) (range, 120-180 cm(2)). All flaps were harvested based on a single perforator. The flap was used to obliterate the ITF defect and also to achieve oroantral separation. All flaps mucosalized well within 6 weeks. All patients were on oral diet and had adequate mouth opening. There were no donor-site complications. Adipofascial ALT is an excellent choice for infrastructural maxillectomy defects with ITF extension. The intraoral part got mucosalized well and provided a smooth and taut surface. A large adipofascial tissue flap helps obliterate the ITF, thus minimizing complications.

Inhibition of rapamycin-induced AKT activation elicits differential antitumor response in head and neck cancers.

The PI3K/AKT/mTOR pathway is an important signaling axis that is perturbed in majority of cancers. Biomarkers such as pS6RP, GLUT1, and tumor FDG uptake are being evaluated in patient stratification for mTOR pathway inhibitors. In the absence of a clear understanding of the underlying mechanisms in tumor signaling, the biomarker strategy for patient stratification is of limited use. Here, we show that no discernible correlation exists between FDG uptake and the corresponding Ki67, GLUT1, pS6RP expression in tumor biopsies from patients with head and neck cancer. Correlation between GLUT1 and pS6RP levels in tumors was observed but elevated pS6RP was noticed even in the absence of concomitant AKT activation, suggesting that other downstream molecules of PI3K/AKT and/or other pathways upstream of mTOR are active in these tumors. Using an ex vivo platform, we identified putative responders to rapamycin, an mTOR inhibitor in these tumors. However, rapamycin did not induce antitumor effect in the majority of tumors with activated mTOR, potentially attributable to the observation that rapamycin induces feedback activation of AKT. Accordingly, treatment of these tumors with an AKT inhibitor and rapamycin uniformly resulted in abrogation of mTOR inhibition-induced AKT activation in all tumors but failed to induce antitumor response in a subset. Phosphoproteomic profiling of tumors resistant to dual AKT/mTOR inhibitors revealed differential activation of multiple pathways involved in proliferation and survival. Collectively, our results suggest that, in addition to biomarker-based segregation, functional assessment of a patient's tumor before treatment with mTOR/AKT inhibitors may be useful for patient stratification.

Morbidity profile and functional outcome of modified facial translocation approaches for skull base tumors.

The primary objective of this study was to evaluate morbidity associated with facial translocation approaches for skull base and results of various technical modifications. Forty consecutive patients who underwent facial translocation approaches for accessing skull base tumors from July 2005 to June 2010 were included in this study. There were 25 patients who underwent standard facial translocation, 4 patients medial mini, and 11 patients underwent extended facial translocation. Thirteen patients had benign disease and 27 patients had malignant disease. Resection was R0 in 36 and R1 in 4 patients. Most patients had acceptable cosmetic results. None of the patients had problems related to occlusion or speech and swallowing. The commonest complication observed was nasal crusting in 16 patients. Grade 2 trismus and exposure of mini plate was seen in three patients. Two patients developed necrosis of translocated bone. Three patients developed palatal fistula before modification of palatal incision. Facial translocation provides a satisfactory access for adequate clearance of skull base tumors with satisfactory aesthetic and functional results. With modifications of the surgical technique and implementation of new surgical tools, the morbidity of facial translocation approaches will continue to decrease.

Single perforator based anterolateral thigh flap for reconstruction of large composite defects of oral cavity.

Composite defects of oral cavity are a reconstructive challenge. Anterolateral thigh flap provides large and pliable tissue for reconstruction of these defects. However, wide variations in the vascular anatomy, variable perforator number and location are reported. The aim of this study was to evaluate the reliability of single perforator based large anterolateral thigh for reconstruction of complex oral cavity defects following ablative surgery. We report a series of 25 consecutive patients who underwent reconstruction of oral cavity defects with anterolateral thigh flap based on single perforator between August 2009 and August 2010. The mean flap dimension was 261cm(2) (range 80-540cm(2)). In 21 patients the flap was bi-paddled and used for inner and outer lining for cheek. None of the flaps developed perforator insufficiency. Two flaps were lost due to delayed neck wound sepsis after 7th post operative day. This study establishes safety and reliability of using a large and/or bi-paddled anterolateral thigh flap based on single perforator for reconstruction of complex oral cavity defects.

UV radiation inhibits 15-hydroxyprostaglandin dehydrogenase levels in human skin: evidence of transcriptional suppression.

Elevated levels of prostaglandins (PG) have been detected in the skin following UV radiation (UVR). PGs play an important role in mediating both the acute and the chronic consequences of UVR exposure. UVR-mediated induction of cyclooxygenase-2 (COX-2) contributes to increased PG synthesis. In theory, reduced catabolism might also contribute to increased PG levels. 15-Hydroxyprostaglandin deyhdrogenase (15-PGDH), a tumor suppressor gene, plays a major role in PG catabolism. In this study, we investigated whether UVR exposure suppressed 15-PGDH while inducing COX-2 in keratinocytes and in human skin. UVR exposure caused dose-dependent induction of COX-2, suppression of 15-PGDH, and increased prostaglandin E(2) (PGE(2)) production in HaCaT cells. Exposure to UVR suppressed the transcription of 15-PGDH, resulting in reduced 15-PGDH mRNA, protein, and enzyme activities. UVR exposure induced Slug, a repressive transcription factor that bound to the 15-PGDH promoter. Silencing Slug blocked UVR-mediated downregulation of 15-PGDH. The effects of UVR were also evaluated in the EpiDerm skin model, a three-dimensional model of human epidermis. Here too, COX-2 levels were induced and 15-PGDH levels suppressed following UVR exposure. Next, the effects of UVR were evaluated in human subjects. UVR treatment induced COX-2 while suppressing 15-PGDH mRNA in the skin of 9 of 10 subjects. Collectively, these data suggest that reduced expression of 15-PGDH contributes to the elevated levels of PGs found in the skin following UVR exposure. Possibly, agents that prevent UVR-mediated downregulation of 15-PGDH will affect the acute or the long-term consequences of UVR exposure, including nonmelanoma skin cancer.

HDAC6 modulates Hsp90 chaperone activity and regulates activation of aryl hydrocarbon receptor signaling.

The aryl hydrocarbon receptor (AhR), a ligand-activated member of the basic helix-loop-helix family of transcription factors, binds with high affinity to polycyclic aromatic hydrocarbons (PAH) and the environmental toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin). Most of the biochemical, biological, and toxicological responses caused by exposure to PAHs and polychlorinated dioxins are mediated, at least in part, by the AhR. The AhR is a client protein of Hsp90, a molecular chaperone that can be reversibly acetylated with functional consequences. The main objective of this study was to determine whether modulating Hsp90 acetylation would affect ligand-mediated activation of AhR signaling. Trichostatin A and suberoylanilide hydroxamic acid, two broad spectrum HDAC inhibitors, blocked PAH and dioxin-mediated induction of CYP1A1 and CYP1B1 in cell lines derived from the human aerodigestive tract. Silencing HDAC6 or treatment with tubacin, a pharmacological inhibitor of HDAC6, also suppressed the induction of CYP1A1 and CYP1B1. Inhibiting HDAC6 led to hyperacetylation of Hsp90 and loss of complex formation with AhR, cochaperone p23, and XAP-2. Inactivation or silencing of HDAC6 also led to reduced binding of ligand to the AhR and decreased translocation of the AhR from cytosol to nucleus in response to ligand. Ligand-induced recruitment of the AhR to the CYP1A1 and CYP1B1 promoters was inhibited when HDAC6 was inactivated. Mutation analysis of Hsp90 Lys(294) shows that its acetylation status is a strong determinant of interactions with AhR and p23 in addition to ligand-mediated activation of AhR signaling. Collectively, these results show that HDAC6 activity regulates the acetylation of Hsp90, the ability of Hsp90 to chaperone the AhR, and the expression of AhR-dependent genes. Given the established link between activation of AhR signaling and xenobiotic metabolism, inhibitors of HDAC6 may alter drug or carcinogen metabolism.

UVR exposure sensitizes keratinocytes to DNA adduct formation.

UV radiation (UVR) and exposure to tobacco smoke, a source of polycyclic aromatic hydrocarbons (PAH), have been linked to skin carcinogenesis. UVR-mediated activation of the aryl hydrocarbon receptor (AhR) stimulates the transcription of CYP1A1 and CYP1B1, which encode proteins that convert PAH to genotoxic metabolites. We determined whether UVR exposure sensitized human keratinocytes to PAH-induced DNA adduct formation. UVR exposure induced CYP1A1 and CYP1B1 in HaCaT cells, an effect that was mimicked by photooxidized tryptophan (aTRP) and FICZ, a component of aTRP. UVR exposure or pretreatment with aTRP or FICZ also sensitized cells to benzo(a)pyrene (B[a]P)-induced DNA adduct formation. alphaNF, an AhR antagonist, suppressed UVR-, aTRP-, and FICZ-mediated induction of CYP1A1 and CYP1B1 and inhibited B[a]P-induced DNA adduct formation. Treatment with 17-AAG, an Hsp90 inhibitor, caused a marked decrease in levels of AhR; inhibited UVR-, aTRP-, and FICZ-mediated induction of CYP1A1 and CYP1B1; and blocked the sensitization of HaCaT cells to B[a]P-induced DNA adduct formation. FICZ has been suggested to be a physiologic ligand of the AhR that may have systemic effects. Hence, studies of FICZ were also carried out in MSK-Leuk1 cells, a model of oral leukoplakia. Pretreatment with alpha-naphthoflavone or 17-AAG blocked FICZ-mediated induction of CYP1A1 and CYP1B1, and suppressed the increased B[a]P-induced DNA adduct formation. Collectively, these results suggest that sunlight may activate AhR signaling and thereby sensitize cells to PAH-mediated DNA adduct formation. Antagonists of AhR signaling may have a role in the chemoprevention of photocarcinogenesis.

Elevated levels of urinary prostaglandin e metabolite indicate a poor prognosis in ever smoker head and neck squamous cell carcinoma patients.

Cyclooxygenase (COX)-derived prostaglandin E(2) (PGE(2)) plays a role in the development and progression of several tumor types including head and neck squamous cell carcinoma (HNSCC). Measurements of urinary PGE metabolite (PGE-M) can be used as an index of systemic PGE(2) production. In ever smokers, increased levels of urinary PGE-M reflect increased COX-2 activity. In this study, we determined whether baseline levels of urinary PGE-M were prognostic for ever smoker HNSCC patients. A retrospective chart review of ever smoker HNSCC patients treated with curative intent was done. Fifteen of 31 evaluable patients developed progressive disease (recurrence or a second primary tumor) after a median follow-up of 38 months. There were no statistically significant differences between patients with (n = 15) or without disease progression (n = 16) with regard to stage, site, treatment received, smoking status, and aspirin use during follow-up. Median urinary PGE-M levels were significantly higher in HNSCC patients with disease progression (21.7 ng/mg creatinine) compared with patients without (13.35 ng/mg creatinine; P = 0.03). Importantly, patients with high baseline levels of urinary PGE-M had a significantly greater risk of disease progression (hazard ratio, 4.76, 95% CI, 1.31-17.30; P < 0.01) and death (hazard ratio, 9.54; 95% CI, 1.17-77.7; P = 0.01) than patients with low baseline levels of urinary PGE-M. These differences were most evident among patients with early-stage disease. Taken together, our findings suggest that high baseline levels of urinary PGE-M indicate a poor prognosis in HNSCC patients. Possibly, HNSCC patients with high COX-2 activity manifested by elevated urinary PGE-M will benefit from treatment with a COX-2 inhibitor.