Inhibition of YAP Sensitizes the Selumetinib Treatment for Neurofibromatosis Type 1 Related Plexiform Neurofibroma.

Background: Targeted therapy of Neurofibromatosis type 1 (NF1) related plexiform neurofibroma (pNF) aiming at MEK molecule has not demonstrated a convincing result for complete disease inhibition, probably due to other signal pathways crosstalk. Our previous study revealed an increased nuclear translocation of YAP molecule in NF1 related pNF. Herein, we decided to further investigate the therapeutic relations of YAP interference during the MEK treatment against NF1 related pNF. Methods: By means of selumetinib (MEK-inhibitor), RNA-sequencing was firstly performed to identify the changes of signal pathways in pNF Schwann cells, which was probably related to YAP regulation. Nuclear-cytoplasmic fractionation and western blotting were performed to show the intracellular YAP changes under selumetinib treatment. Thirdly, a series of in vitro assays were performed including flow cytometry, CCK-8, and colony/sphere formation under dual treatment of selumetinib and verteporfin (YAP-inhibitor). In addition, Chou-Talalay method was adopted to evaluate the synergistic inhibiting effects of such drug combination. Xenograft study was also used to detect the combining effects in vivo. Results: RNA-sequencing revealed that selumetinib treatment might be associated with the undesirable activation of Hippo pathway in NF1 related pNF tumor cells, which might reduce its pharmaceutic effects. Next, nuclear-cytoplasmic fractionation and further studies demonstrated that selumetinib could promote the nuclear translocation and transcriptional activation of YAP in vitro, which might cause the aforementioned resistance to selumetinib treatment. Additionally, when combined treatments were performed based on verteporfin and selumetinib, synergistic effects were observed on cytotoxicity of NF1 related pNF tumor cells in vitro and in vivo xenograft models. Conclusion: YAP inhibition can effectively sensitize NF1 related pNF tumor cells to selumetinib. Dual targeting of YAP and MEK might be a promising therapeutic strategy for treating NF1 related pNF.

Increased nuclear translation of YAP might act as a potential therapeutic target for NF1-related plexiform neurofibroma.

Plexiform neurofibroma (pNF) in the head and neck is a characteristic feature in patients with neurofibromatosis type 1 (NF1) and is associated with significant disfigurement and psychological distress. Yes-associated protein (YAP), the key molecule involved in the Hippo pathway, is a vital transductor that regulates the proliferation and remyelinating of Schwann cells. The functional status of YAP and its feasibility as a potential target are still unknown in pNF. A total of 17 pNF tumor tissue specimens from the head and neck were collected at the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. Histologically, diagnosis of the Schwann cell region in pNF was achieved with hematoxylin-eosin staining, positive reactions for S100, SOX10, ERK and p-ERK, and low identification of Ki67 and SMA. Compared with normal nerve tissue, obviously increased nuclear YAP was detected in the Schwann cell region of pNF, with a mean nuclear staining rate of 67.11%. Based on the shNF1 Schwann cell model (the RSC96 cell line), with upregulated expression of RAS, ERK and p-ERK, p-YAP (Ser127) and p-YAP (Ser397) were significantly decreased and total YAP and nuclear YAP were increased. According to a confocal assay, the interference of shNF1 substantially promoted YAP nuclear translocation. Compared with control Schwann cells, the YAP inhibitor CA3 might have a more sensitive effect (IC50: NC=0.96±0.04, shNF1=0.71±0.02, P<0.05) on the shNF1 Schwann cell model than the classic MEK1/2 inhibitor selumetinib (IC50: NC=14.36±0.95, shNF1=24.83±0.98, P>0.05). For in vivo inhibition, the CA3 group and the selumetinib group displayed a similar inhibition effect with no significant difference. Increased nuclear translation and the functional state of YAP implies that the YAP-Hippo pathway might play an important role in the formation and remyelination of pNF. Compared with selumetinib, the YAP inhibitor can exhibit a similar but more sensitive effect on NF1-/- Schwann cells. These observations imply that YAP as a novel or adjuvant therapy target in the treatment of pNF.

Standardize routine angiography assessment of leg vasculatures before fibular flap harvest: lessons of congenital and acquired vascular anomalies undetected by color Doppler and physical examinations.

BACKGROUND: Fibular flaps have been widely used for mandibular and maxillary reconstructions. On occasion, anatomical variants of fibular arteries (FA) will be encountered. PURPOSE: Although anatomical variants of FA during fibular harvest have been reported, controversy exists regarding whether simple color Doppler ultrasonography (CDU) and physical examinations (PE) are sufficient for early preoperative detection. MATERIAL AND METHODS: A 10-year retrospective analysis in our department was performed to find the patients with various FA anomalies confirmed by computed tomography angiography (CTA) or intraoperative findings. RESULTS: A total number of 19 FA anomalies were found either pre- or intraoperatively in 16 patients, in whom three cases were with bilateral FA variants. Type IIIC variants, also called arteria peronea magna (great peroneal artery), were confirmed in two legs, while the majority (13 legs) had type IIIA hypoplastic/aplastic posterior tibialis arteries (PTA). Four legs had new type IIID (low FA and PTA bifurcations). Preoperative CDU and PE only suspected anomalies in two legs. Six cases proceeded with using the affected fibulas, within whom vascular grafts were used in half of them for lengthening the FA pedicle. Local ischemia, partial soleus muscle necrosis, and claudication were reported in one. CONCLUSIONS: Routine CTA before every fibular harvest, rather than simple PE and CDU, should be added for screening contraindications and ensuring safety for fibular flap harvest.

Salvage Surgery for Recurrent Tongue Cancer With Contralateral Neck Metastasis.

PURPOSE: Treatment recommendations have been widely reported for primary tongue squamous cell carcinoma (TSCC) with contralateral neck metastases (CNMs), but little is known concerning recurrent TSCCs with CNMs, especially in patients who have undergone ipsilateral neck dissection. The aim of this study was to estimate overall survival (OS) and to identify prognostic factors associated with OS in patients treated for recurrent TSCCs. PATIENTS AND METHODS: We performed a retrospective cohort study of patients who underwent salvage surgery (SS) for recurrent TSCC in our institution between January 2010 and December 2014. Before SS, all patients had been surgically treated for primary TSCC with ipsilateral neck dissection. The primary outcome variable was OS, and the patients were grouped by the primary predictor variable of CNM status for comparison. Other heterogeneous variables of interest included demographics, medical histories, clinicopathologic characteristics, surgical data, and adjuvant treatment modalities. In addition, the midline involvement and anatomic subsites of local recurrences were evaluated. Univariate log-rank and Cox regression tests were used for statistical analyses. RESULTS: The study sample included 177 subjects with a mean age of 55.4 years, and 44.6% were males. The median OS was 18 months. Within the entire cohort, the incidence of CNM was 23.7% (n = 42), with an inclination (n = 30) for contralateral level I or II. Factors associated with improved survival included CNM (hazard ratio [HR], 2.108; 95% confidence interval [95% CI], 1.341 to 3.315; P = .001), disease-free interval (HR, 0.601; 95% CI, 0.387 to 0.934; P = .023), and local recurrence subsite score (HR, 3.276; 95% CI, 0.924 to 11.623; P = .001). CONCLUSIONS: Patients with both recurrent TSCCs and CNMs had a dismal prognosis (OS rate, 16.2%) compared with those without CNMs (OS rate, 52.7%). SS for TSCC patients with collateral failures should be used cautiously because of the very unfavorable outcomes.

Regional metastasis to anatomies beyond traditional neck dissection boundaries: a multi-institutional analysis focused on unconventional metastases in oral cancer patients.

BACKGROUND: Regional metastasis sometimes occurs in anatomies that are not included in traditional neck dissections. The purpose of this study was to evaluate the treatment outcomes of squamous cell carcinoma of oral cavity (SCCOC) patients with unconventional metastatic lymph nodes (UMLNs) in sublingual, buccinator, and parotid anatomies. METHODS: This retrospective multi-institutional analysis of squamous cell carcinoma of oral cavity patients with unconventional metastatic lymph nodes was performed from January 2008 to December 2015. All the included patients received surgical treatment for unconventional metastatic lymph nodes. The end point of the study was to determine the factors influencing these patients' survival and the corresponding solutions to improve survival. Pathological grade, contralateral metastasis, extranodal extension, and other factors were collected and analyzed by logistic regression and the Cox model. RESULTS: A total of 89 patients were identified. Among these patients, 25 (28.1%) received primary treatment, 28 (31.5%) received staged (therapeutic) neck dissections, and 36 (40.4%) had recurrent or residual diseases. Altogether, 45 patients (51%) had buccinator node metastases, 31 (35%) had sublingual metastases, 12 (14%) had parotid metastases, and 1 had both buccinator and parotid metastases. Regarding regional metastases, 31 patients (34.8%) had isolated unconventional metastatic lymph nodes. Adjuvant therapies were administered to 72 (80.9%) patients, 25 (28.1%) of whom were treated with radio-chemotherapies. The overall survival rate was 38.2%. Multivariate analysis found that the subsites of unconventional metastatic lymph nodes (P = 0.029), extranodal extension in both unconventional metastatic lymph nodes (P = 0.025) and cervical lymph nodes (P = 0.015), sites of primary or recurrent squamous cell carcinoma of oral cavity (P = 0.035), and types of neck dissections (P = 0.025) were significantly associated with overall survival. CONCLUSIONS: Unconventional metastatic lymph nodes are uncommon, yet awareness of potential unconventional metastatic lymph nodes should be heightened. Early surgical interventions are warranted in patients with sublingual or buccinator metastases, while caution should be given to those with parotid metastases. Aggressive en bloc (in-continuity) resections may be mandatory in advanced oral cancer cases for close anatomic locations with possible buccal or sublingual metastases.

Retracted: Effects of Nano-Hydroxyapatite/Polyetheretherketone-Coated, Sandblasted, Large-Grit, and Acid-Etched Implants on Inflammatory Cytokines and Osseointegration in a Peri-Implantitis Model in Beagle Dogs.

The article is withdrawn by the authors request.

Effect of Choukroun Platelet-Rich Fibrin Combined With Autologous Micro-Morselized Bone on the Repair of Mandibular Defects in Rabbits.

PURPOSE: The aim of this study was to explore the effect of Choukroun platelet-rich fibrin (PRF) combined with autologous micro-morselized bone on the repair of mandibular defects in rabbits. MATERIALS AND METHODS: Thirty-six healthy New Zealand rabbits were selected for the present study. After models of mandibular defects were established, rabbits were randomly divided into Choukroun PRF, autologous micro-morselized bone (autologous), Choukroun PRF combined with autologous bone (combined) and model groups. After the rabbits were sacrificed at 2, 8, and 12 weeks postoperatively, their bone formation was assessed by x-ray and scanning electron microscopy, and the histologic changes of the mandibular defect area were detected by hematoxylin and eosin staining. Cone-beam computed tomography was used to observe the size of the change of the mandibular defect area. Bone mineral density (BMD) was analyzed by dual-energy x-ray absorptiometry. RESULTS: The bone defect in the combined group showed better repair, increased bone mineral content, and denser callus than the other groups, and the defect area was filled with mature trabecular bone. In the Choukroun PRF and autologous groups, the defect area was smaller and filled with osteoporotic trabecular bone. A clear mandibular defect area was still observed in the model group. Compared with the other groups, the combined group showed more bone regeneration, more fibrous tissue regeneration, and greater bone maturity at all time points. The combined group had the highest BMD, there was no relevant difference in BMD between the Choukroun PRF and autologous groups, and the model group had the lowest BMD. BMD in all 4 groups increased with time. CONCLUSION: These findings indicate that Choukroun PRF combined with autologous micro-morselized bone can substantially improve the repair of mandibular defects in rabbits, and the effect is superior to Choukroun PRF or autologous micro-morselized bone alone.

Effects of Nano-Hydroxyapatite/Polyetheretherketone-Coated, Sandblasted, Large-Grit, and Acid-Etched Implants on Inflammatory Cytokines and Osseointegration in a Peri-Implantitis Model in Beagle Dogs.

BACKGROUND This study explored the effects of nano-hydroxyapatite/polyetheretherketone (n-HA/PEEK)- coated sandblasted, large-grit, and acid-etched (SLA) implants on inflammatory cytokines and osseointegration in peri-implantitis model beagle dogs. MATERIAL AND METHODS Peri-implantitis models were established. Eight beagle dogs were randomly and evenly assigned into SLA tied, SLA + n-HA/PEEK tied, SLA untied, or SLA + n-HA/PEEK untied groups. A special periodontal probe was used to detect the plaque index (PLI), probing depth (PD), and modified Sulcus Bleeding Index (mSBI). Gingival crevicular fluid was collected and an ELISA kit was utilized to detect IL-1, IL-6, and IL-17 levels. The colony-forming units were counted and the maximum shear strength of implants was tested using the axial pullout test. HE staining was used to detect the inflammation of peri-implant bone tissues. Osseointegration was observed through toluidine blue staining. Bone-to-implant contact (BIC) was obtained through histological observation and the mineral apposition rate (MAR) was calculated after immune fluorescent double staining. RESULTS The SLA tied group demonstrated higher levels of PLI, PD, mSBI, IL-1, IL-6, and IL-17 and a higher degree of inflammation than the SLA + n-HA/PEEK tied group. The tied groups also displayed similar results over the untied groups at the same time point. The maximum shear strength, BIC, and MAR in the SLA tied group were significantly lower than in the SLA + n-HA/PEEK tied group. CONCLUSIONS Our findings demonstrate that SLA + n-HA/PEEK implants can promote osseointegration and relieve the inflammation response of peri-implantitis in beagle dogs.

Risk Factors for Pedicle Flap Complications in 251 Elderly Chinese Patients Who Underwent Oral and Maxillofacial Reconstruction.

PURPOSE: To determine risk factors for pedicle flap complications in elderly patients undergoing oral and maxillofacial reconstruction. PATIENTS AND METHODS: The authors designed and implemented a retrospective cohort study and enrolled a sample of patients at least 75 years old who underwent resection of oral and maxillofacial tumors and pedicle flap reconstruction from January 2004 through December 2013. The primary predictor variable was reconstructive technique grouped into 5 types of pedicle flap. The difference among groups was tested with the χ(2) test and t test. The primary outcome variable was the presence of flap complication, which was divided into minor and major groups. Other variables were grouped into the following sets: demographic, operative, and adjuvant treatments. Univariate, bivariate, and regression statistics were computed and statistical significance was set at a P value less than .05. RESULTS: The study sample was composed of 251 patients with a mean age of 78 years and 62.95% were men. Of these, 68.13% had various preoperative systemic diseases. With regard to flap type, 120 underwent reconstruction with a pectoralis major myocutaneous flap, 5 with a submental island flap, 4 with a submandibular gland flap, 13 with a platysma myocutaneous flap, and 109 with a sternocleidomastoid flap. TNM stage (negative correlation) and smoking (positive correlation) correlated with flap type. There were 48 complications, of which 32 were minor and 16 were major; flap failure was observed in only 1 patient. Risk factors associated with complications were types of pedicle flap, age, heart score, hypertension, diabetes, postoperative hypoproteinemia, and drug-induced liver injury. CONCLUSION: The pedicle flap is suitable and safe for the reconstruction of defects caused by the ablation of oral and maxillofacial tumors in elderly patients. Preoperative evaluation of positive risk factors, including type of surgery and systemic conditions, is very important for the selection of an appropriate flap for such patients.

Clinical application of the dorsalis pedis free flap for reconstruction of oral cancer defects.

PURPOSE: The purposes of this study were to evaluate the clinical application and efficacy of the dorsalis pedis fasciocutaneous flap in the reconstruction of oral cavity defects and to assess the associated donor-site morbidity. PATIENTS AND METHODS: From September 2009 to December 2012, 7 patients with associated oral cavity defects resulting from tumor resection underwent reconstruction with a dorsalis pedis fasciocutaneous flap. Surgical anatomy and harvesting procedure of the dorsalis pedis flap are described. Special consideration was given to the associated donor-site morbidity. RESULTS: All flaps survived without any complications. All 7 flaps were based on the dorsalis pedis artery and the greater saphenous vein for perfusion and drainage respectively. In all 7 cases, the donor site was closed with a full-thickness skin graft, with no associated healing complications or functional deficit of the foot. The resulting scar was well hidden in the lower extremity. CONCLUSIONS: The dorsalis pedis fasciocutaneous flap is a thin and pliable flap sharing many similarities with the radial forearm flap, thus making it ideal for intraoral reconstruction. Proper intraoperative and postoperative care of the donor site can result in minimal morbidity, as shown in this study. This flap may provide an ideal alternative to the radial forearm free flap, with the added advantages of a well-hidden scar and a high level of patient satisfaction.

Superficial Circumflex Iliac Artery Perforator Flap: A Promising Candidate for Large Soft Tissue Reconstruction of Retromolar and Lateral Buccal Defects After Oncologic Surgery.

PURPOSE: Surgical reconstruction of extensive retromolar and lateral buccal defects after oncologic resection remains a major challenge because early and aggressive invasion by retromolar malignancies generally entails wider resection of several local anatomic structures to attain tumor-free margins. The superficial circumflex iliac artery perforator (SCIP) flap, which is a promising candidate with multiple advantages, provides a better choice of quality and esthetics for such reconstruction. PATIENTS AND METHODS: Three patients (median age, 44.7 yr; age range, 23 to 63 yr) diagnosed with retromolar or lateral buccal squamous cell carcinoma (or mucoepidermoid carcinoma) underwent ablative surgery and simultaneous SCIP flap reconstruction. Preoperative computed tomographic angiographic (CTA) and color ultrasonographic images were used for confirmation and positioning of the SCIPs. Volumes of defects and corresponding SCIP flaps were recorded and analyzed. In addition, pre- and postoperative functions of speech, swallowing, and mouth opening and donor-site morbidity were compared. RESULTS: The SCIP flaps were raised according to information gathered from CTA and sonographic imaging. The median pedicle length reached 8.2 cm and the flap sizes ranged from 5 × 6 to 6.0 × 8.0 cm. All flaps survived uneventfully during the perioperative period and subsequent follow-up showed no recurrence. Compatible donor-recipient volume, easy harvesting, acceptable postoperative functions, and inconspicuous donor-site scars were regarded as the main advantages of the SCIP flaps. CONCLUSION: For defects after resection of retromolar and lateral buccal tumors, the SCIP flap might play an innovative and supplementary role to traditional soft tissue reconstruction approaches.

Microvascular reconstruction in elderly oral cancer patients: does diabetes status have a predictive role in free flap complications?

PURPOSE: Flap complications still present challenges in the field of microsurgical reconstruction. The aim of this study was to explore the role of diabetes mellitus in free flap prognosis in elderly patients (≥60 years) after oral tumor resection. PATIENTS AND METHODS: The data of aged oral cancer patients who had undergone reconstructions with free flaps in our institution were gathered in this retrospective cohort study. The samples were classified into diabetic and nondiabetic groups. The predictive roles of diabetes status and other factors in free flap prognosis were analyzed. The primary outcome variable was the presence of flap complications, which was subdivided into major (requiring re-exploration or local surgery) and minor (dressing or drug treatment) groups. Major complications were defined as the second outcome variable. Univariate and multivariable analyses were used for data statistics. RESULTS: A total of 309 patients (176 men [57%] and 133 women [43%]) aged 60 years or older were included in this study. There were 105 diabetic patients (34%) and 204 nondiabetic patients (66%). A total of 75 flap complications occurred during the perioperative period, with an overall incidence of 24.3% (44 diabetic patients [41.9%] and 31 nondiabetic patients [15.2%], P ≤ .001). The odds of susceptibility for flap complication development in elderly diabetic patients was 3.413 times that of nondiabetic patients (odds ratio, 3.413; P ≤ .001). Of 75 flap complications, 43 (13.9%) were deemed major complications (24 diabetic patients [22.9%] and 19 nondiabetic patients [9.3%], P ≤ .001). This statistical association was further confirmed by multivariate analysis (odds ratio, 2.885; P = .002). CONCLUSIONS: Diabetes mellitus increases the risk of the development of free flap complications in elderly patients when dealing with oral reconstruction after tumor removal.

Surgical management of osteoradionecrosis of the jaws.

OBJECTIVE: The objective of this study is to evaluate our 10-year clinical experience in surgical management of patients with osteoradionecrosis (ORN) unresolved with conservative nonoperative treatment. PATIENTS AND METHODS: The medical records of 120 patients who had been surgically treated for ORN during a 10-year period (January 2003 to January 2013) were retrospectively reviewed. RESULTS: The most predilection ORN site was mandible (82.5%), followed by the maxilla (11.7%). ORN developed within initial 12 months in 39.2% and within the first 3 years in 68.3%. The median radiation dose was 68.1 Gy (range, 35-148 Gy), but 51 patients (42.5%) experienced ORN even though radiation doses were controlled under 60 Gy. Surgical trauma, as we believed, was the most important factor leading to this result. Among all the patients, 12 (10.0%) patients were found ineligible for operative treatment due to comorbid systematic diseases whereas none healed or improved. In terms of surgical management of the rest of the 108 patients, 90 (75.0%) patients underwent radical resection (4 patients unhealed), and 18 (15.0%) patients underwent mild surgical procedures such as sequestrectomy or debridement (1 patient unhealed). Of the 90 radical resection patients, 58 patients underwent radical resections and immediate microvascular flap reconstruction (19 bone flaps and 39 soft flaps), and 32 patients only experience radical resection (5 patients received second-stage reconstruction). According to follow-up information, 55 patients were free of disease. CONCLUSION: Though priority should be given to surgical treatment for the patient whose ORN does not respond to conservative nonoperative treatment, we may as well take into account more individualized regimens based on ORN severity. A hard lesson learned from our article is that the oral maxillofacial surgeon should minimize the trauma for jaws as possible as he can, especially to patients who need to receive postoperative radiotherapy.

Giant cell angiofibroma misdiagnosed as a vascular malformation and treated with absolute alcohol for one year: a case report and review of the literature.

PURPOSE: To present the clinical, imaging, pathological and immunohistochemical features of giant cell angiofibroma (GCA). CASE PRESENTATION: In this paper we report an atypical case of a GCA extending from the parotid to the parapharyngeal space. The lesion was being treated as a vascular malformation for one year prior to surgical removal. We summarize the clinical manifestations, imaging, pathological and molecular features of this rare disease.After complete surgical removal of the tumor, immunohistochemical analysis revealed strong positivity for the mesenchymal markers vimentin, CD34, CD31 and CD99 in neoplastic cells. Tumor proliferation antigen marker Ki67 was partly positive (<5% of cells). Tumor cells were negative for muscle-specific actin, epithelial membrane antigen, smooth muscle actin, cytokeratin pan, S100, desmin, glial fibrillary acidic protein, myogenin, MyoD1 and F8. The morphological and immunohistochemical profile was consistent with the diagnosis of GCA. CONCLUSION: GCA is a rare soft tissue tumor that can easily be misdiagnosed in the clinical preoperative setting. In view of the clinical, pathological and molecular features of the tumor, complete surgical removal is the current optimal treatment option, providing accurate diagnosis and low to minimal recurrence rate.

Schwann cell derived pleiotrophin stimulates fibroblast for proliferation and excessive collagen deposition in plexiform neurofibroma.

Neurofibromatosis type 1 associated plexiform neurofibroma (pNF) is characterized by abundant fibroblasts and dense collagen, yet the intricate interactions between tumor-origin cells (Schwann cells) and neurofibroma-associated fibroblasts (NFAFs) remain elusive. Employing single-cell RNA sequencing on human pNF samples, we generated a comprehensive transcriptomics dataset and conducted cell-cell communication analysis to unravel the molecular dynamics between Schwann cells and NFAFs. Our focus centered on the pleiotrophin (PTN)/nucleolin (NCL) axis as a pivotal ligand-receptor pair orchestrating this interaction. Validation of PTN involvement was affirmed through coculture models and recombinant protein experiments. Functional and mechanistic investigations, employing assays such as CCK8, EdU, Western Blot, ELISA, Hydroxyproline Assay, and Human phospho-kinase array, provided critical insights. We employed siRNA or inhibitors to intercept the PTN/NCL/proline-rich Akt substrate of 40 kDa (PRAS40) axis, validating the associated molecular mechanism. Our analysis highlighted a subset of Schwann cells closely linked to collagen deposition, underscoring their significance in pNF development. The PTN/NCL axis emerged as a key mediator of the Schwann cell-NFAF interaction. Furthermore, our study demonstrated that elevated PTN levels enhanced NFAF proliferation and collagen synthesis, either independently or synergistically with TGF-ß1 in vitro. Activation of the downstream molecule PRAS40 was noted in NFAFs upon PTN treatment. Crucially, by targeting NCL and PRAS40, we successfully reversed collagen synthesis within NFAFs. In conclusion, our findings unveil the pivotal role of the PTN/NCL/PRAS40 axis in driving pNF development by promoting NFAFs proliferation and function. Targeting this pathway emerges as a potential therapeutic strategy for pNF. This study contributes novel insights into the molecular mechanisms governing pNF pathogenesis.

Identification of Exosome-Related Genes Associated with Prognosis and Immune Infiltration Features in Head-Neck Squamous Cell Carcinoma.

The highly immunosuppressive nature of head-neck squamous cell cancer (HNSCC) is not fully understood. Exosomes play crucial roles in the communication between cancer and non-cancer cells, but the clinical significance of the expression of exosome-related genes (ERGs) remains unclear in HNSCC. This study aimed to establish an HNSCC-ERGs model by using mass spectrometry (MS)-based label-free quantitative proteomics in combination with the TCGA primary HNSCC dataset. The study managed to classify the HNSCC patients into two subtypes based on the expression level of prognostic ERGs, which showed significant differences in prognosis and immune infiltration. LASSO regression algorithm was used to establish a risk prediction model based on seven risky genes (PYGL, ACTN2, TSPAN15, EXT2, PLAU, ITGA5), and the high-risk group was associated with poor survival prognosis and suppressive immune status. HPRT1 and PYGL were found to be independent prognostic factors through univariate and multivariate Cox regression analyses. Immune and ssGSEA analysis revealed that HPRT1 and PYGL were significantly related to immunosuppression, immune response, and critical signaling transduction pathways in HNSCC. Immunohistochemistry results further validated the expression level, clinical value, and immunosuppressive function of HPRT1 and PYGL in HNSCC patients. In conclusion, this study established molecular subtypes and a prediction risk model based on the ERGs. Furthermore, the findings suggested that HPRT1 and PYGL might play critical roles in reshaping the tumor microenvironment.

An integrated bioinformatics analysis of the S100 in head and neck squamous cell carcinoma.

Background: This study aims to evaluate the expression profile and clinical value of the S100 family in head and neck squamous cell carcinoma (HNSCC). Methods: The expression patterns, clinicopathological features, prognostic significance and underlying correlations of S100 family genes in HNSCC were determined by bioinformatics analysis with the application of several databases, including the The Cancer Genome Atlas (TCGA) and Oncomine for differential expression gene (DEG) analysis, and a series of analysis tools, including Database for Annotation, Visualization and Integrated Discovery (DAVID), cBioPortal, Kaplan-Meier Plotter, Tumor Immune Estimation Resource (TIMER) and R software packages. Results: The results from the study demonstrated that S100A4, S100A10, and S100A13 may act as prognostic markers through overall survival (OS), disease-free survival (DFS) and tumor infiltrating immune cell enrichment and a prognostic S100 family gene model comprising S100A1-A4, S100A8, S100A10, S100A12, and S100A13 was identified. The messenger RNA (mRNA) expression of S100A1, S100A9, S100A14, and S100A7A was significantly different in HNSCC patients, together with a high mutation rate of the S100 family was found. Evaluation of clinicopathological value demonstrated the heterogeneity of S100 family functions. S100A1, S100A7, S100A8, S100A9, S100A13, S100A14, and S100A16 were observed to significantly correlate with multiple biological processes (BPs) of HNSCC, including initiation, lymph node metastasis, and lymphovascular invasion. In addition, the S100 family were significantly associated with epithelial-mesenchymal transition (EMT)-related genes. Conclusions: This present study demonstrated that S100 family members are implicated in the initiation, progression, metastasis and survival of HNSCC.

Single-Cell Transcriptome Analysis Reveals Changes of Tumor Immune Microenvironment in Oral Squamous Cell Carcinoma After Chemotherapy.

Induction chemotherapy in oral squamous cell carcinoma is a controversial issue in clinical practice. To investigate the evolution of cancer cells and tumor microenvironment (TME) response to chemotherapy in oral squamous cell carcinoma, single-cell transcriptome analysis was performed in a post-chemotherapy squamous cell carcinoma located in oral cavity. The main cell types were identified based on gene expression patterns determined using dimensionality reduction and unsupervised cell clustering. Non-negative matrix factorization clustering of the gene expression of Cancer-associated fibroblasts (CAFs) and macrophages was performed. Kyoto Encyclopedia of Genes and Genomes pathway analyses and gene set enrichment analysis were performed to explore significant functional pathways. CellPhoneDB and NicheNet were used to detect the intercellular communication between cell types. CAFs were divided into "inflammatory CAFs," "antigen-presenting CAFs" and "myofibroblastic CAFs." Three classic subgroups of tumor-associated macrophages (TAMs) were detected, namely C1Q (+), FCN1 (+) and SPP1(+) TAMs. The inflammatory cytokine expression is elevated, and several molecular pathways, such as PI3K/Akt/mTORC1, TNF-α via NFκB, TGF-ß, IL-6/JAK2/STAT3 and CXCL12/CXCR4 axis associated with epithelial-mesenchymal transition were enriched in TME. Also, CD74-MIF/COPA/APP interactions were expressed in TME of oral squamous cell carcinoma after chemotherapy. The results revealed the characteristics of TME in post-chemotherapy oral squamous cell carcinoma at single-cell transcriptome level, providing new insights and clues for further investigation.

M1-like tumor-associated macrophages cascade a mesenchymal/stem-like phenotype of oral squamous cell carcinoma via the IL6/Stat3/THBS1 feedback loop.

BACKGROUND: Tumor-associated macrophages (TAMs) have a leading position in the tumor microenvironment. Previously, we have demonstrated that M1-like TAMs activated by exosome-transferred THBS1 promote malignant migration in oral squamous cell carcinoma (OSCC). However, the functional roles and associated molecular mechanisms of the activated M1-like TAMs need to be further clarified in OSCC. METHODS: Conditioned Media (CM) were harvested from the exosome activated M1-like TAMs. We measured the malignant behaviors of OSCC under the treatment of CM from M1-like TAMs by performing colony forming assays, invasion assays, wound-healing assays, spheroid forming assays and in vivo xenograft experiments. The underlying mechanisms were investigated by RNA-seq, cytokines analysis, intracellular signaling pathway analysis, ChIP assays, bioinformatics analysis and validation. RESULTS: M1-like TAMs significantly promoted the epithelial-mesenchymal transition (EMT) process, and induced the cancer-stem like cells (CSCs) by upregulating the expression of MME and MMP14 in OSCC cells. Cytokine analysis revealed a shark increase of IL6 secretion from M1-like TAMs. Blocking IL6 in the CM from M1-like TAMs could significantly weaken its effects on the colony forming, invasion, migration, microsphere forming and xenograft forming abilities of OSCC cells. Cellular signaling assays indicated the activation of Jak/Stat3 pathway in the OSCC cells treated by the CM from M1-like TAMs. Blocking the activation of the Jak/Stat3 pathway could significantly weaken the effects of M1-like TAMs on the colony forming, invasion, migration, microsphere forming and xenograft forming abilities of OSCC cells. Further RNA-seq analysis and bioinformatics analysis revealed an increased expression of THBS1 in the OSCC cells treated by M1-like TAMs. Bioinformatics prediction and ChIP assays revealed the activation of Stat3 by CM from M1-like TAMs could directly promote the transcription of THBS1 in OSCC cells. CONCLUSIONS: We proposed that M1-like TAMs could cascade a mesenchymal/stem-like phenotype of OSCC via the IL6/Stat3/THBS1 feedback loop. A better understanding on the functional roles and associated molecular mechanisms of M1-like TAMs might facilitate the development of novel therapies for supplementing the current treatment strategies for OSCC patients.

A bibliometric analysis on studies of nanomedicine applications in head and neck squamous cell carcinoma.

BACKGROUND: Bibliometric analysis highlights the pivotal studies and topics that have shaped the understanding and management of a disease in its designated field. Herein, original articles on the applications of nanotechnology in head and neck squamous cell carcinoma (HNSCC) were characterized and analyzed. METHODS: A comprehensive search was carried out using a bibliometric methodology, and eligible articles on nanomedicine research in HNSCC were retrieved from the Scopus database. RESULTS: A total of 309 eligible articles were retrieved, and the total citation count was 7,468. An ascending trend in citation count was observed since 2004, which increased substantially between 2014 and 2019. There were 144 (52.7%) original articles on oral cavity carcinomas. Chemotherapy (n=53, 19.4%), chemoprevention (n=35, 11.3%), and photodynamic therapy (n=23, 8.4%) were the three most published topics on the applications of nanotechnology in the therapy of HNSCC. Sentinel node detection (n=25, 9.2%) and noninvasive cancer diagnosis (n=22, 8.1%) were the two most published topics in the diagnostic area of HNSCC. A vast majority of these articles were preclinical studies, and only four articles (1.5%) were phase I/II clinical studies on chemotherapy and radiotherapy. CONCLUSIONS: To the best of our knowledge, this is the first study to analyze the bibliometric characteristics of original articles on nanomedicine in HNSCC. The results of this study not only provide a historical perspective on the scientific evolution in this field, but also revealed the trends and key topics within it that may help facilitate further research.