Influence of analytical procedures on miRNA expression analyses in saliva samples.

Aim of this study was to demonstrate the influence of different analytical procedures and techniques on the resulting miRNA expression profile in healthy control subjects and tumor patients using the oral squamous cell carcinoma (OSCC) model and to demonstrate the technical and biological reproducibility. Body fluids such as saliva are suitable for non-invasive miRNA analysis because ubiquitously circulating miRNA can be found in them. It was technically possible to distinguish between healthy and diseased samples based on the miRNA expression profile found. Regardless of the methodology used, good technical reproducibility of the results seems to be achievable. On the other hand, biological reproducibility was inadequate, which is why prompt sampling and sequencing is recommended. The data indicate that malignant lesions can be detected using miRNA signatures extracted from saliva. This could stimulate further research to establish standardized protocols and kits for sample collection, miRNA extraction, sequencing and interpretation of results.

Biological and Mechanical Performance of Dual-Setting Brushite-Silica Gel Cements.

Bone defects resulting from trauma, diseases, or surgical procedures pose significant challenges in the field of oral and maxillofacial surgery. The development of effective bone substitute materials that promote bone healing and regeneration is crucial for successful clinical outcomes. Calcium phosphate cements (CPCs) have emerged as promising candidates for bone replacement due to their biocompatibility, bioactivity, and ability to integrate with host tissues. However, there is a continuous demand for further improvements in the mechanical properties, biodegradability, and bioactivity of these materials. Dual setting of cements is one way to improve the performance of CPCs. Therefore, silicate matrices can be incorporated in these cements. Silicate-based materials have shown great potential in various biomedical applications, including tissue engineering and drug delivery systems. In the context of bone regeneration, silicate matrices offer unique advantages such as improved mechanical stability, controlled release of bioactive ions, and enhanced cellular responses. Comprehensive assessments of both the material properties and biological responses of our samples were conducted. Cytocompatibility was assessed through in vitro testing using osteoblastic (MG-63) and osteoclastic (RAW 264.7) cell lines. Cell activity on the surfaces was quantified, and scanning electron microscopy (SEM) was employed to capture images of the RAW cells. In our study, incorporation of tetraethyl orthosilicate (TEOS) in dual-curing cements significantly enhanced physical properties, attributed to increased crosslinking density and reduced pore size. Higher alkoxysilyl group concentration improved biocompatibility by facilitating greater crosslinking. Additionally, our findings suggest citrate's potential as an alternative retarder due to its positive interaction with the silicate matrix, offering insights for future dental material research. This paper aims to provide an overview of the importance of silicate matrices as modifiers for calcium phosphate cements, focusing on their impact on the mechanical properties, setting behaviour, and biocompatibility of the resulting composites.

Evaluation of Five-year Overall Survival Rates Among 18,331 Head and Neck Cancer Patients Exposed to Different Targeted Therapies Through Real-world Data in a Case-controlled Study.

BACKGROUND/AIM: Targeted therapy is an important and fast developing aspect of modern tumor therapy including therapy of head and neck cancer (HNC). Surgically treated patients often experience significant limitations to their ability to swallow, speak, or mimic expressions. In cases of recurrent tumors or palliative situations, targeted therapies such as immune checkpoint inhibitors (ICI) are frequently employed. This study compared different targeted therapies focusing on survival probability. PATIENTS AND METHODS: Data from patients with head and neck cancer treated with different therapy regimens from the TriNetX network were analyzed. Two groups were formed: Cohort I received one targeted therapy, whereas patients in cohort II received a different targeted therapy. Cohorts I and II were matched 1:1 with respect to certain confounders. After defining the primary outcome as "death", a Kaplan-Meier analysis was performed, and the risk ratio (RR), odds ratio (OR), and hazard ratio (HR) were calculated. RESULTS: A total of 18,331 patients with HNC treated with targeted therapy were analyzed. Patients treated with VEGF inhibitors had a significantly longer overall survival than patients treated with c-MET or EGFR inhibitors. Patients treated with PI3K inhibitors showed a significantly reduced survival probability compared to those treated with c-MET, mTOR, and RET inhibitors. CONCLUSION: EGFR inhibitors are one of the most frequently used targeted therapies in HNC. However, in the present analysis, a survival advantage of patients treated with c-MET inhibitors or VEGF inhibitors was observed compared to those treated with EGFR inhibitors.

Ibuprofen Reduces 5-Year Overall Survival of Head and Neck Cancer Patients With Immunotherapy - A Retrospective Case-controlled Real-World Data Analysis of 10,000 Patients.

BACKGROUND/AIM: Resistance to immunotherapy can be explained by an abnormal microbiome of the gut. In Europe in particular, the use of ibuprofen, with or without proton-pump inhibitors to protect the gastric mucosa, is widespread. This study aimed to investigate the impact of ibuprofen use on the effectiveness of immunotherapy in patients with head and neck carcinoma. PATIENTS AND METHODS: Data from patients with head and neck carcinoma (ICD-10-Codes: C00-C14) receiving pembrolizumab, from the TriNetX network, were analyzed. Two groups were formed for the analyses: Cohort I received ibuprofen at least once within 6 months before and after immunotherapy, whereas patients in cohort II received ibuprofen with proton-pump inhibitors or no ibuprofen at all. Cohorts I and II were matched 1:1 with respect to age, sex, lymph node metastases, nicotine dependence, alcohol dependence, and body mass index (BMI). The primary outcome was death and a Kaplan-Meier analysis was performed, and the risk ratio (RR), odds ratio (OR), and hazard ratio (HR) were calculated. RESULTS: The analysis showed that 823 patients with ibuprofen and 724 patients without ibuprofen died within 5 years, showing a significant risk difference of 5.3% (p=0.001). The RR was 1.137 [95% confidence interval (CI)=1.053-1.227], OR was 1.245 (95% CI=1.093-1.418), and HR was 1.202 (95%CI=1.088-1.329). CONCLUSION: Ibuprofen significantly decreases the drug effectiveness of immunotherapy and may be related to changes in the human microbiome. However, further prospective, randomized, and double-blind studies are needed to validate our data and to adequately address confounders.

Sex-specific Real-World 5-year Overall Survival Rates for (Radio)chemotherapy, Targeted Therapy, and Combinations in Patients With Head and Neck Cancer.

BACKGROUND/AIM: Sex-specific medicine, an emerging field in healthcare, has gained significant recognition and importance in recent years. To the best of our knowledge, there are currently no valid data on the influence of sex on 5-year overall survival of patients with head and neck cancer undergoing (radio)chemotherapy, targeted therapy, and combination treatments, using Real-World Data. We hypothesize that sex has a significant impact on 5-year overall survival across different therapy regimens for head and neck cancer. PATIENTS AND METHODS: Data from head and neck cancer patients treated with different regimens from the TriNetX network were analyzed. Two groups were formed: Cohort I (female) and cohort II (male), which were matched 1:1 with respect to certain confounders. After defining the primary outcome as "death", a Kaplan-Meier analysis was performed, and the risk ratio (RR), odds ratio (OR) and hazard ratio (HR) were calculated. RESULTS: A total of 16,529 patients with OSCC were analyzed. This retrospective case-matched analysis found a tendency for female patients to have a greater 5-year overall survival probability than male patients with respect to the various therapeutic regimens for OSCC. CONCLUSION: There is an urgent need for more personalized medicine in patients with head and neck cancer due to the limited data available. It is still questionable whether therapies are equally effective in men and women, although, according to the guidelines, the treatments are mostly the same for both sexes.

Accuracy Analysis of Computer-Assisted and Guided Dental Implantology by Comparing 3D Planning Data and Actual Implant Placement in a Mandibular Training Model: A Monocentric Comparison between Dental Students and Trained Implantologists.

The aim of this study was to investigate how precisely implantation can be realized by participants on a phantom head according to preliminary planning. Of particular interest here was the influence of participants' previous knowledge and surgical experience on the precision of the implant placement. The placed implants were scanned using an intraoral scanner, saved as STL files, and superimposed with the 3D-planned implant placement. Deviations from the planning were indicated in millimeters and degrees. We were able to show that on average, the deviations from computer-assisted 3D planning were less than 1 mm for implantologists, and the students also did not deviate more than 1.78 mm on average from 3D planning. This study shows that guided implantology provides predictable and reproducible results in dental implantology. Incorrect positioning, injuries to anatomical structures, and implant positions that cannot be prosthetically restored can thus be avoided.

Factors Influencing Recurrence after Surgical Treatment of Odontogenic Maxillary Sinusitis: An Analysis from the Oral and Maxillofacial Surgery Point of View.

The aim of the study was to determine the factors influencing the development of recurrence after the surgical treatment of odontogenic maxillary sinusitis in an oral and maxillofacial surgery clinic over a 7-year period. Demographic and anamnesis data, clinical and radiological findings, treatment and outcome were analyzed. A multivariable analysis was performed to find associations between patient age, causative focus, surgical access for sinus revision, multilayer closure with a buccal fat pad, inferior meatal antrostomy (IMA) for temporary sinus drainage and sinusitis recurrence. A total of 164 patients with a mean age of 51.7 years were included. Sinusitis recurrence was observed in nine patients (5.48%) within 6 months after primary surgery. No significant correlation was detected between patient age, causative focus, surgical access for sinus revision, multilayer closure with a buccal fat pad, IMA for sinus drainage and the development of recurrence (p > 0.05). Patients with a history of antiresorptive-related osteonecrosis of the jaw showed a significant tendency toward disease recurrence (p = 0.0375). In conclusion, except for antiresorptive administration, none of the investigated variables were related to a higher risk of sinusitis recurrence. We encourage a combined approach of intraoral removal of the infective focus and sinus drainage via FESS, as well as an individual treatment decision in a multidisciplinary setting with collaboration between dentistry, maxillofacial surgery and otorhinolaryngology to avoid sinusitis recurrence.

Justification of Indication for Cranial CT Imaging after Mild Traumatic Brain Injury According to the Current National Guidelines.

The primary aim was to evaluate the compliance of cranial CT indication with the national guideline-based decision rules in patients after mTBI. The secondary aim was to determine the incidence of CT pathologies among justified and unjustified CT scans and to investigate the diagnostic value of these decision rules. This is a retrospective, single-center study on 1837 patients (mean age = 70.7 years) referred to a clinic of oral and maxillofacial surgery following mTBI over a five-year period. The current national clinical decision rules and recommendations for mTBI were retrospectively applied to calculate the incidence of unjustified CT imaging. The intracranial pathologies among the justified and unjustified CT scans were presented using descriptive statistical analysis. The performance of the decision rules was ascertained by calculating the sensitivity, specificity, and predictive values. A total of 123 intracerebral lesions were radiologically detected in 102 (5.5%) of the study patients. Most (62.1%) of the CT scans strictly complied with the guideline recommendations, and 37.8% were not justified and likely avoidable. A significantly higher incidence of intracranial pathology was observed in patients with justified CT scans compared with patients with unjustified CT scans (7.9% vs. 2.5%, p < 0.0001). Patients with loss of consciousness, amnesia, seizures, cephalgia, somnolence, dizziness, nausea, and clinical signs of cranial fractures presented pathologic CT findings more frequently (p < 0.05). The decision rules identified CT pathologies with 92.28% sensitivity and 39.08% specificity. To conclude, compliance with the national decision rules for mTBI was low, and more than a third of the CT scans performed were identified as "likely avoidable". A higher incidence of pathologic CT findings was detected in patients with justified cranial CT imaging. The investigated decision rules showed a high sensitivity but low specificity for predicting CT pathologies.

Airway Management of Orofacial Infections Originating in the Mandible.

The primary aim of this study was to assess the incidence of a difficult airway and emergency tracheostomy in patients with orofacial infections originating in the mandible, and a secondary aim was to determine the potential predictors of difficult intubation. This retrospective single-center study included all patients who were referred between 2015 and 2022 with an orofacial infection originating in the mandible and who were surgically drained under intubation anesthesia. The incidence of a difficult airway regarding ventilation, laryngoscopy, and intubation was analyzed descriptively. Associations between potential influencing factors and difficult intubation were examined via multivariable analysis. A total of 361 patients (mean age: 47.7 years) were included in the analysis. A difficult airway was present in 121/361 (33.5%) patients. Difficult intubation was most common in patients with infections of the massetericomandibular space (42.6%), followed by infections of the mouth floor (40%) and pterygomandibular space (23.5%). Dyspnea and stridor were not associated with the localization of infection (p = 0.6486/p = 0.4418). Multivariable analysis revealed increased age, restricted mouth opening, higher Mallampati scores, and higher Cormack-Lehane classification grades as significant predictors of difficult intubation. Higher BMI, dysphagia, dyspnea, stridor and a non-palpable mandibular rim did not influence the airway management. Patients with a difficult airway were more likely to be admitted to the ICU after surgery than patients with regular airway were (p = 0.0001). To conclude, the incidence of a difficult airway was high in patients with orofacial infections originating in the mandible. Older age, limited mouth opening, a higher Mallampati score, and a higher Cormack-Lehane grade were reliable predictors of difficult intubation.

Comparison of Anatomical Preformed Titanium Implants and Patient-Specific CAD/CAM Implants in the Primary Reconstruction of Isolated Orbital Fractures-A Retrospective Study.

BACKGROUND/AIM: Reconstruction of the fractured orbit remains a challenge. The aim of this study was to compare anatomical preformed titanium orbital implants with patient-specific CAD/CAM implants for precision and intraoperative applicability. MATERIAL AND METHODS: A total of 75 orbital reconstructions from 2012 to 2022 were retrospectively assessed for their precision of implant position and intra- and postoperative revision rates. For this purpose, the implant position after digital orbital reconstruction was checked for deviations by mirroring the healthy orbit at 5 defined points, and the medical records of the patients were checked for revisions. RESULTS: The evaluation of the 45 anatomical preformed orbital implant cases showed significantly higher deviations and an implant inaccuracy of 66.6% than the 30 CAD/CAM cases with only 10% inaccuracy. In particular, the CAD/CAM implants were significantly more precise in medial and posterior positioning. In addition, the intraoperative revision rates of 26.6% vs. 11% after 3D intraoperative imaging and the postoperative revision rates of 13% vs. 0 for the anatomical preformed implants were significantly higher than for patient-specific implants. CONCLUSION: We conclude that patient-specific CAD/CAM orbital implants are highly suitable for primary orbital reconstruction. These seem to be preferable to anatomical preformed implants in terms of precision and revision rates.

Management of older adults after mild head trauma in an oral and maxillofacial surgery clinic.

PURPOSE: The primary aim was to determine the incidence of intracranial hemorrhage (ICH) after mild traumatic brain injury (mTBI) in patients aged ≥ 65 years. The secondary aim was to identify risk factors for intracranial lesions and evaluate the need for in-hospital observation in this age group. METHODS: This observational retrospective single-center study included all patients aged ≥ 65 years who were referred to our clinic for oral and plastic maxillofacial surgery following mTBI over a five-year period. Demographic and anamnesis data, clinical and radiological findings, and treatment were analyzed. Acute and delayed ICH and patient outcomes during hospitalization were evaluated using descriptive statistical analysis. A multivariable analysis was performed to find associations between CT findings and clinical data. RESULTS: A total of 1,062 patients (55.7% male, 44.2% female) with a mean age of 86.3 years were included in the analysis. Ground-level fall was the most frequent cause of trauma (52.3%). Fifty-nine patients (5.5%) developed an acute traumatic ICH, and 73 intracerebral lesions were radiologically observed. No association was detected between ICH rate and antithrombotic medication (p = 0.4353). The delayed ICH rate was 0.09% and the mortality rate was 0.09%. Significant risk factors for increased ICH were a Glasgow Coma Scale score of < 15, loss of consciousness, amnesia, cephalgia, somnolence, dizziness, and nausea according to multivariable analysis. CONCLUSION: Our study showed a low prevalence of acute and delayed ICH in older adults with mTBI. The ICH risk factors identified here should be considered when revising guidelines and developing a valid screening tool. Repeat CT imaging is recommended in patients with secondary neurological deterioration. In-hospital observation should be based on an assessment of frailty and comorbidities and not on CT findings alone.

Comparison of Laser-Sintered and Milled Patient-Specific Reconstruction Plates for Complications and Outcomes in Mandibular Defects-Comparative Analysis of a Single-Center Cohort.

CAD/CAM-manufactured implants are increasingly becoming the standard in current therapy. The question of whether the manufacturing-related rougher surface of selective laser fusion plates compared to milled, smoother reconstruction plates leads to increased postoperative complications such as infections, plate exposure, and fistulas has not yet been determined. A retrospective analysis of 98 patients who underwent surgical treatment with either a selective laser fusion plate or a milled reconstruction plate at our hospital was performed. The only significant predictors of the revision risk were the operation time and use of antiresorptive medication. In the KLS Martin® group, the risk of revision decreased by approximately 20% for each additional hour by which the operation time was increased (OR = 0.81). In the Depuy Synthes® group, the risk of revision increased by approximately 11% with each additional hour of operative time (OR = 0.81 × 1.37 = 1.11). Both groups showed no significant differences in the number of necessary revision surgeries as well as inpatient complications. In summary, we can say that the assumption that additively manufactured reconstruction plates have a rougher surface due to selective laser melting and thus make plaque accumulation and revisions more likely has not been confirmed. Overall, it seems imperative to select further studies regarding the clinical outcome depending on the selected plate system.

BRAF inhibitors in BRAF V600E-mutated ameloblastoma: systematic review of rare cases in the literature.

BACKGROUND: Ameloblastoma in 66% of the cases harbor a somatic mutation of the "mitogen-activated protein kinase" signaling pathway (BRAF V600E). In V600E mutations, BRAF is in the permanent "on" state and relays the growth-promoting signals independently of the EGFR pathway. Therefore, mutant BRAF represents a target for handful of new drugs. METHODS: We conducted a literature search, with the search terms "Vemurafenib, Dabrafenib, Ameloblastoma, and BRAF." These included seven case reports with nine patients who underwent monotherapy with Dabrafenib or Vemurafenib or combination therapy with Dabrafenib and Trametinib. RESULTS: The patients age ranges from 10 years up to 86 years. The distribution of women and men is 4:5. Patients with an initial diagnosis of ameloblastoma, as well as recurrences or metastasized ameloblastoma were treated. Indications cover neoadjuvant therapy up to the use in metastasized patients in an irresectable state. Results ranging from "only" tumor size reduction to restitutio ad integrum. CONCLUSION: We see the use of BRAF Inhibitors to reduce tumor size with consecutive surgical treatment as a reasonable option for therapy. However, we are aware that at present the data are based only on case reports with the longest follow-up of just 38 months. We encourage further clinical trials in the use of BRAF Inhibitors for selecting ameloblastoma patients in a multi-center setting.

MRONJ of the Mandible-From Decortication to a Complex Jaw Reconstruction Using a CAD/CAM-Guided Bilateral Scapula Flap.

Medication-related osteonecrosis of the jaw (MRONJ) has been an integral part of the maxillofacial patient population for some time. The therapeutic concept ranges from conservative approaches over less extended decortications to major jaw resections, which can result in a considerable loss of quality of life. Based on three case reports, this paper presents the long-term history of patients with MRONJ of the mandible, whose disease ultimately resulted in partial or total mandibular resection and subsequent multisegmental reconstruction using a microvascular anastomosed bone flap. Furthermore, a suitable alternative for complex mandibular reconstruction is demonstrated when using a free fibula flap is not possible. The options are limited, particularly when multisegmental restoration of mandibular continuity is required. One case presents a mandible reconstruction using a CAD/CAM-guided bilateral scapular free flap (CAD/CAM = Computer-Aided Design and Manufacturing), which has not been described for this purpose before. Due to the complexity, computer-assisted surgery and patient-specific implants seem reasonable, which is why a special focus was applied to this topic.

First-Hand Experience and Result with New Robot-Assisted Laser LeFort-I Osteotomy in Orthognathic Surgery: A Case Report.

BACKGROUND: We report the world's first developer-independent experience with robot-assisted laser Le Fort I osteotomy (LLFO) and drill-hole marking in orthognathic surgery. To overcome the geometric limitations of conventional rotating and piezosurgical instruments for performing osteotomies, we used the stand-alone robot-assisted laser system developed by Advanced Osteotomy Tools. The aim here was to evaluate the precision of this novel procedure in comparison to the standard procedure used in our clinic using a computer-aided design/computer-aided manufacturing (CAD/CAM) cutting guide and patient-specific implant. METHODS: A linear Le-Fort-I osteotomy was digitally planned and transferred to the robot. The linear portion of the Le-Fort I osteotomy was performed autonomously by the robot under direct visual control. Accuracy was analyzed by superimposing preoperative and postoperative computed tomography images, and verified intraoperatively using prefabricated patient-specific implant. RESULTS: The robot performed the linear osteotomy without any technical or safety issues. There was a maximum difference of 1.5 mm on average between the planned and the performed osteotomy. In the robot-assisted intraoperative drillhole marking of the maxilla, which was performed for the first time worldwide, were no measurable deviations between planning and actual positioning. CONCLUSION: Robotic-assisted orthognathic surgery could be a useful adjunct to conventional drills, burrs, and piezosurgical instruments for performing osteotomies. However, the time required for the actual osteotomy as well as isolated minor design aspects of the Dynamic Reference Frame (DRF), among other things, still need to be improved. Still further studies for final evaluation of safety and accuracy are also needed.

Sensitization of head and neck squamous cell carcinoma to apoptosis by combinational SMAC mimetic and Fas ligand-Fc treatment in vitro.

This study aimed to investigate the in vitro efficacy of three different SMAC mimetics for pro-apoptotic sensitization of HNSCC cells. We evaluated BV-6 in comparison to Birinapant and LCL161, for which pro-apoptotic sensitization effects have been demonstrated. Concentration-dependent response was measured for BV-6 in each cell line with an average IC50 value 8-fold lower than of aforementioned SMAC mimetics. Combination treatment of FasL (log2) and BV-6 (IC10) showed highly significant cell count reductions even in the lowest applied concentration in five cell lines (PCI-1: p = 0.0002, PCI-13: p = 0.0002, Detroit 562: p: p < 0.0001, FaDu: p < 0.0001, SCC-25: p = 0.0047). Synergistic effects (y < 1) were evident in eight out of 10 cell lines (PCI-1, PCI-9, PCI-13, PCI-68, Detroit 562, FaDu, SCC-25 and HaCaT). Annexin V assays revealed in nine cell lines very highly significant (p < 0.001) pro-apoptotic effects of BV-6. Western blots showed a heterogeneous IAP expression following SMAC mimetic treatment. Except for two cell lines, at least the cellular inhibitor of apoptosis protein 1 (cIAP1) was degraded in response to BV-6. For prospective targeted HNSCC therapy, this study identifies SMAC mimetics, particularly BV-6 as the compound with the highest pro-apoptotic potency, as promising antitumor agents.

Targeting inhibitors of apoptosis in oral squamous cell carcinoma in vitro.

Head and neck cancer, which predominantly arises from the oral mucosa, represents the sixth most common malignancy worldwide. These cancer cells can be resistant to programmed cell death triggered by extrinsic stimuli due to innate overexpression of inhibitor of apoptosis proteins (IAPs). The cellular protein second mitochondria-derived activator of caspases (SMAC) can antagonize IAP-induced caspase inhibition and thus trigger apoptosis. Here, we investigate the cell death-sensitizing effects of the SMAC mimetic LCL161 alone and in combination with Fas ligand (FasL) using a panel of six cell lines. Fas receptor (FasR) expression was analyzed by flow cytometry. Cells were treated with FasL and LCL161 alone or in combination, and cytotoxicity was measured using crystal violet assays. Annexin V and cell viability assays using zVAD-fmk and Necrostatin-1 (Nec-1) were carried out to assess the type of programmed cell death induced by LCL161. To demonstrate the sensitizing effects of LCL161, we employed the t-test to compare the effects of FasL alone and in combination with LCL161. Linear regression analysis was performed to determine initial and half maximal inhibitory concentrations (IC10 and IC50, respectively). Distinct FasR expression was detected in each cell line. Four of six cell lines were significantly sensitized to FasL by LCL161 (p < 0.05), and synergistic effects were observed (y < 1). Moreover, the initially resistant cell line SCC-25 was effectively sensitized to FasL by LCL161. Annexin V FACS analysis demonstrated apoptosis-sensitizing and apoptosis-inducing effects of LCL161 across all cell lines. Using specific cell death inhibitors (zVAD-fmk and Nec-1), we demonstrated that LCL161-initiated apoptosis could not be prevented, highlighting the proapoptotic potential of this mimetic in these cells. Our findings show the effectiveness of apoptotic sensitization of OSCC cells by LCL161 in combination with FasL, thus confirming the importance of an IAP-targeting therapeutic approach for oral squamous cell carcinoma.

The Selection of NFκB Inhibitors to Block Inflammation and Induce Sensitisation to FasL-Induced Apoptosis in HNSCC Cell Lines Is Critical for Their Use as a Prospective Cancer Therapy.

Inflammation is a central aspect of tumour biology and can contribute significantly to both the origination and progression of tumours. The NFκB pathway is one of the most important signal transduction pathways in inflammation and is, therefore, an excellent target for cancer therapy. In this work, we examined the influence of four NFκB inhibitors-Cortisol, MLN4924, QNZ and TPCA1-on proliferation, inflammation and sensitisation to apoptosis mediated by the death ligand FasL in the HNSCC cell lines PCI1, PCI9, PCI13, PCI52 and SCC25 and in the human dermal keratinocyte cell line HaCaT. We found that the selection of the inhibitor is critical to ensure that cells do not respond by inducing counteracting activities in the context of cancer therapy, e.g., the extreme IL-8 induction mediated by MLN4924 or FasL resistance mediated by Cortisol. However, TPCA1 was qualified by this in vitro study as an excellent therapeutic mediator in HNSCC by four positive qualities: (1) proliferation was inhibited at low µM-range concentrations; (2) TNFα-induced IL-8 secretion was blocked; (3) HNSCC cells were sensitized to TNFα-induced cell death; and (4) FasL-mediated apoptosis was not disrupted.

Apoptosis-sensitizing activity of birinapant in head and neck squamous cell carcinoma cell lines.

Inhibitor of apoptosis proteins, which are overexpressed in head and neck squamous cell carcinoma (HNSCC), may cause therapeutic resistance. Using SMAC mimetic compounds, including birinapant, to degrade and/or inhibit these proteins and sensitize apoptosis may enhance therapies in HNSCC. Fas expression was analyzed in nine HNSCC cell lines and one keratinocyte cell line via flow cytometry. These cell lines were treated with Fas ligand-Fc (FasL) and birinapant, a bivalent SMAC mimetic, in mono and combination therapies. Cytotoxicity was measured using a crystal violet assay. Annexin V assay was performed for detection of apoptosis. The treatment efficacy of mono and combination therapies was statistically analyzed. Nonlinear regression analysis was performed to determine the inhibitory concentration (IC10) of birinapant. Fas expression was detected in each cell line tested. Mono treatment with FasL revealed minor to no apoptotic effects in the majority of the cell lines. Crystal violet and Annexin V staining revealed increased apoptosis rates for all cell lines following incubation with birinapant in mono treatment. Combination treatment with FasL and birinapant (IC10) revealed additional and synergistic effects in eight out of the ten cell lines. To the best of our knowledge, the present study provided the first evidence of the apoptosis-sensitizing activity of combination treatment with FasL and birinapant in HNSCC cell lines.