Mucoepidermoid Carcinoma Cell Research Articles

Salivary Gland Tumors: A 20 Year Review From a Single Community Practice.

Objective: Salivary gland tumors are a heterogenous group of lesions with variable pathology and clinical outcomes. Most published data are derived from studies conducted at tertiary care centers. Our study analyzed the experience from a community setting to determine significant differences, if any, in pathological distribution and clinical outcomes compared to the existing literature. Methods: We performed a retrospective analysis of all major salivary gland tumors that presented to a large community practice over a 20 year period. Retrospective chart analysis was performed for demographics, clinical presentation, imaging, cytology, histopathology, and clinical outcome data. Results: Of 806 patients, the parotid gland was the most common site in 683 patients (84.7%), followed by submandibular in 78 (9.7%) and sublingual in 45 (5.6%). A total of 203 patients were managed conservatively with observation without definitive diagnosis or lost to follow-up. A total of 495 patients underwent surgical intervention within the community practice. Twenty-six patients underwent surgical excision at an outside hospital. Eighty-two patients were determined to have a benign diagnosis based on ultrasound-guided fine needle aspiration or excisional biopsy alone. Final histopathology was benign in 505 cases (83.7%), while 98 tumors (16.3%) received a diagnosis of primary or secondary malignancy. For the parotid gland, pleomorphic adenoma (155) and Warthin's tumor (155) were the most common benign diagnoses, while mucoepidermoid carcinoma (13), adenocarcinoma (8), and acinic cell carcinoma (8) were the most common primary malignancies. Conclusions: We found a higher rate of benign tumor pathology compared to the existing literature. While the outcome data on surgical treatment of benign tumors are comparable to the existing literature, the same conclusion cannot be drawn for malignant tumors, given relatively small numbers in our series and likely disparity in the complexity of the surgical cases in tertiary care centers.

Inhibition of anti-tumour reactivity of immune cells in the salivary gland cancer: A proteomic approach

BackgroundAdenoid cystic carcinoma (ACC), mucoepidermoid carcinoma (MEC), and oral squamous cell carcinoma (OSCC) respond differently to immunotherapy. Pembrolizumab, an immune checkpoint inhibitor, has been approved by the Food and Drug Administration for the treatment of squamous cell carcinomas of the head and neck region. While MEC has shown some response to pembrolizumab; however, ACC is the least responsive. At the molecular level, head and neck cancers produce immunosuppressive molecules, resulting in immune evasion. Therefore, we hypothesised that salivary gland cancer cells produce a higher number of immunosuppressive proteins that cause suppression of the immune system's anti-tumour reactivity. MethodTo determine differential protein expressions in OSCC, MEC, and ACC, we constructed cancer–immune cell co-culture models using different oral and salivary gland cancer cells. We performed SWATH, proteome profilers, gene ontology biological function, functional annotation clustering and protein interaction network analysis of all cancer samples in the co-culture models. ResultsAnalysis of the acquired data showed that the overexpressed proteins in the OSCC cells and participated more in metabolic process, while in the salivary gland cancer cells, overexpressed proteins participated more in immune processes, immune checkpoint pathway. Upon protein function analysis of salivary gland cells, the overexpressed proteins found negatively affecting immune process and checkpoint pathway proteins. ConclusionOverall, we conclude that salivary gland cancer is less responsive to immunotherapy, possibly because of the high presence of immunosuppressive proteins. However, further analysis is needed to verify the biological functions and interactive partners of each differentially expressed protein in ACC cells.

Development and Validation of Nomograms to Predict Risk and Prognosis in Salivary Gland Carcinoma Patient with Distant Metastases.

Background: Salivary gland carcinoma (SGC) patients with distant metastasis (DM) are rare, and understanding this disease is insufficient. Nomograms can predict the prognostic probability of patients, while few studies have examined diagnostic and prognostic factors in SGC patients with DM. The purpose of this study was to establish and validate the risk and prognostic nomograms of SGC patients with DM. Methods: Based on the SEER database, we analyzed the data of SGC patients between 2004 and 2015. Logistic regression analyses and Cox proportional hazards regression analyses were used to identify risk and prognostic factors for DM in SGC patients. Based on the Akaike information criterion (AIC) value and likelihood ratio test, the best-fitting model was selected to build risk and prognostic nomograms, and the results were evaluated by receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and Kaplan-Meier (K-M) survival curves. ROC curves were also used to compare the nomograms with the American Joint Committee on Cancer (AJCC) staging system. Results: 7418 SGC patients were included in the study, and 307 (4.14%) of them were diagnosed with DM. This study identified that there are variables (age ≥ 80, no-parotid gland primary site, histologic type of mucoepidermoid carcinoma and squamous cell carcinoma, T stage ≥ T2, N staged ≥ N1, histologic grade ≥ III, and tumor size ≥ 41 mm) associated with the occurrence of DM in SGC patients. Therefore, we constructed diagnostic and prognostic nomograms after incorporating these variables. ROC curves illustrated the better predictive efficacy of 2 nomograms over the AJCC staging system. DCA curves, calibration curves, and K-M survival curves showed that 2 nomograms can accurately predict the occurrence and prognosis of DM among SGC patients in training and validation sets. Conclusion: It was shown that the nomograms were highly discriminative in predicting the diagnosis and prognosis of SGC patients with DM, and could identify high-risk patients, thereby providing SGC patients with individualized treatment plans.

Effects of bisphenol A on murine salivary glands and human tumor cell lines

Bisphenol A (BPA) is an endocrine-disrupting chemical with a potential role in endocrine cancers. However, the effects of BPA on the salivary glands have been barely explored. We investigated the impact of in vivo sub-chronic exposure to BPA and its in vitro effects on human salivary gland mucoepidermoid carcinoma cell lines. Male and female mice were exposed to BPA (30 mg/kg/day). Sublingual and submandibular salivary glands from an estrogen-deficiency model were also analyzed. BPA concentration in salivary glands was evaluated by gas chromatography coupled to ion trap mass spectrometry. Immunohistochemical analysis using anti-p63 and anti-α-SMA antibodies was performed on mouse salivary gland tissues. Gene expression of estrogen receptors alpha and beta, P63 and α-SMA was quantified in mouse salivary gland and/or mucoepidermoid (UM-HMC-1 and UM-HMC-3A) cell lines. Cell viability, p63 and Ki-67 immunostaining were evaluated in vitro. BPA disrupted the tissue architecture of the submandibular and sublingual glands, particularly in female mice, and increased the expression of estrogen receptors and p63, effects that were accompanied by significant BPA accumulation in these tissues. Conversely, ovariectomy slightly impacted BPA-induced morphological changes. In vitro, BPA did not affect the proliferation of neoplastic cells, but augmented the expression of p63 and estrogen receptors. The present data highlight a potential harmful effect of BPA on salivary gland tissues, particularly in female mice, and salivary gland tumor cells. Our findings suggest that estrogen-dependent pathways may orchestrate the effects of BPA in salivary glands.

Exploring the Epidemiology and Survival Trends in Pediatric Major Salivary Gland Malignancies: Insights from the National Cancer Database.

To investigate the clinicopathological, therapeutic, and survival data on pediatric major salivary gland cancers. National Cancer Database (NCDB) query from 2004 to 2018. In total, 967 cases of individuals under the age of 21 were identified. Most cancers affected the parotid gland (86%). Mucoepidermoid carcinoma (41.3%) and acinic cell adenocarcinoma (33.6%) were the most common. Tumors occurred more often from age 11 to 21, and females were more affected. Histology varied by age, gender, and race. In the 0-5 age group, mucoepidermoid carcinoma and myoepithelial carcinoma/sarcoma/rhabdomyosarcoma were the most common pathologies. In patients over 5 years old, mucoepidermoid carcinoma was the most frequent tumor in boys, while acinic cell adenocarcinoma was more common in girls. African American patients had a higher incidence of mucoepidermoid carcinoma, while White patients in the 0-5 age group had a higher incidence of myoepithelial carcinoma/sarcoma/rhabdomyosarcoma tumors. Low-grade tumors were commonly diagnosed at stage I, but the 0-5 age group had a high frequency of stage IV tumors. The overall 5-year survival rate was 94.9%, with 90% for the 0-5 years age group and 96% for the 11-15 years age group. Negative margins were associated with higher 5-year survival rates in high-stage tumors (93%) compared to positive margins (80%). Submandibular malignancies had worse 5-year survival rates across all age groups. Major salivary gland malignancies in pediatric patients exhibit variations in histopathologic characteristics by age, gender, and race. Negative margins impact 5-year survival rates, especially in high-stage tumors.

DEPLETION OF MUCOEPIDERMOID CARCINOMA CANCER STEM CELLS BY HISTONE DEACETYLASE AND NFkB INHIBITORS

Background Platinum-based systemic therapy is used in metastatic or disseminated mucoepidermoid carcinoma (MEC), yet it presented low response rates. Further, drug resistance remains a major obstacle to MEC treatment leading to tumor recurrence, disease progression, and metastasis, which could be associated with cancer stem cells (CSCs). Objective Investigate the effects of SAHA (Histone deacetylase inhibitor) and Emetine (NFkB inhibitor) on CSCs derived from three MEC cell lines. Study Design UM-HMC-1, UM-HMC-2, and UM-HMC-3A MEC cell lines were used to investigate the effects of SAHA and Emetine on CSCs. The concentration of the drugs was obtained by a previous proliferation assay. CSCs were assayed by in vitro tumorspheres formation in two moments. Results First, we demonstrated that a single administration of SAHA and Emetine was able to inhibit the tumorsphere formation in all MEC cell lines. Next, we evaluated whether the therapy was able to reduce the number of formed tumorspheres, and we showed a complete reduction in UM-HMC2 (** p<0.01) by Emetine, and a significant reduction in UM-HMC3a (* p<0.05) by SAHA. Conclusion Our findings suggest that HDAC and NFKB inhibitors might be an alternative approach to treating MEC, although they disrupt CSC. Funding Fapesp 2016/05710-4 Platinum-based systemic therapy is used in metastatic or disseminated mucoepidermoid carcinoma (MEC), yet it presented low response rates. Further, drug resistance remains a major obstacle to MEC treatment leading to tumor recurrence, disease progression, and metastasis, which could be associated with cancer stem cells (CSCs). Investigate the effects of SAHA (Histone deacetylase inhibitor) and Emetine (NFkB inhibitor) on CSCs derived from three MEC cell lines. UM-HMC-1, UM-HMC-2, and UM-HMC-3A MEC cell lines were used to investigate the effects of SAHA and Emetine on CSCs. The concentration of the drugs was obtained by a previous proliferation assay. CSCs were assayed by in vitro tumorspheres formation in two moments. First, we demonstrated that a single administration of SAHA and Emetine was able to inhibit the tumorsphere formation in all MEC cell lines. Next, we evaluated whether the therapy was able to reduce the number of formed tumorspheres, and we showed a complete reduction in UM-HMC2 (** p<0.01) by Emetine, and a significant reduction in UM-HMC3a (* p<0.05) by SAHA. Our findings suggest that HDAC and NFKB inhibitors might be an alternative approach to treating MEC, although they disrupt CSC.

Head and neck carcinoma in children: A clinicopathological study of 42 cases

Background/purposeCancer is an important part of the global burden of childhood diseases. Head and neck carcinoma in children is rare and related research is limited. This study aimed to investigate the clinicopathological features of childhood head and neck carcinoma. Materials and methodsForty-two cases of childhood head and neck carcinoma treated in our institution were reviewed and analyzed. ResultsMedian age overall was 11 years. Twenty-three patients (54.8%) were male and 19 (45.2%) were female. Parotid gland location was most common (54.8%). Mucoepidermoid carcinoma and squamous cell carcinoma were the most common histological types (57.1% and 11.9%, respectively). Two patients had a history of bone marrow transplantation and two had a history of odontogenic keratocyst. The recurrence rate after treatment was 8.6%. ConclusionEarly diagnosis and treatment and close follow-up of childhood head and neck carcinoma are warranted to prevent recurrence and improve clinical outcome.

Increased Chymase-Positive Mast Cells in High-Grade Mucoepidermoid Carcinoma of the Parotid Gland

It has long been known that high-grade mucoepidermoid carcinoma (MEC) has a poor prognosis, but the detailed molecular and biological mechanisms underlying this are not fully understood. In the present study, the pattern of chymase-positive mast cells, as well as chymase gene expression, in high-grade MEC was compared to that of low-grade and intermediate-grade MEC by using 44 resected tumor samples of MEC of the parotid gland. Chymase expression, as well as chymase-positive mast cells, was found to be markedly increased in high-grade MEC. Significant increases in PCNA-positive cells and VEGF gene expression, as well as lymphangiogenesis, were also confirmed in high-grade MEC. Chymase substrates, such as the latent transforming growth factor-beta (TGF-β) 1 and pro-matrix metalloproteinase (MMP)-9, were also detected immunohistologically in high-grade MEC. These findings suggested that the increased chymase activity may increase proliferative activity, as well as metastasis in the malignant condition, and the inhibition of chymase may be a strategy to improve the poor prognosis of high-grade MEC of the parotid gland.

Systematic Review of Management and Survival Outcome of Parotid Cancers with Lateral Skull Base Invasion.

Lateral skull base involvement from parotid cancers is a rare condition and is considered a poor prognostic indicator. The aim of this study was to systematically review the literature of parotid tumors with temporal bone invasion to analyze the survival outcome. A systematic literature review was performed in August 2022, without time limits, and 289 patients affected by parotid gland cancers and lateral skull base involvement were included. The most common symptoms in parotid tumors at the onset were indolent mass, facial weakness, pain, and hearing loss; the chi-square value is 23.1063, with a statistically significance (p = < 0.000121). The five most common histologies were adenoid cystic carcinoma, acinic cell carcinoma, mucoepidermoid carcinoma, adenocarcinoma, and squamous cell carcinoma. The facial nerve function after surgery showed statistically significance (functional vs. non-functional; chi-square was 91.7698, p = < 0.00001). Mean follow-up was 36.2 months (range 0.3-192). At the last follow-up, more patients died of disease (DOD; 60/289, 21%) than other causes (DOOC; 5/289, 2%). There is a statistically significant correlation between patients died for tumor (DOD) and patients died for other causes (DOOC) (p = < 0.0001), suggesting that the lateral skull base invasion negatively impacts on survival. Basing on the results of our systematic review, lateral skull base involvement from parotid recurrent/advance tumors should be considered a poor prognostic factor, as the majority of patients die due to this condition. It also would be necessary to have "clear"works, with full data (demographic, clinical, surgical data), and with a longer follow up, in order to assess the best treatment modality of these patients.

Expression and localisation of MUC1 modified with sialylated core-2 O-glycans in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is the most frequent of the rare salivary gland malignancies. We previously reported high expression of Mucin 1 (MUC1) modified with sialylated core-2 O-glycans in MEC by using tissue homogenates. In this study, we characterised glycan structures of MEC and identified the localisation of cells expressing these distinctive glycans on MUC1. Mucins were extracted from the frozen tissues of three patients with MEC, and normal salivary glands (NSGs) extracted from seven patients, separated by supported molecular matrix electrophoresis (SMME) and the membranes stained with various lectins. In addition, formalin-fixed, paraffin-embedded sections from three patients with MEC were subjected to immunohistochemistry (IHC) with various monoclonal antibodies and analysed for C2GnT-1 expression by in situ hybridisation (ISH). Lectin blotting of the SMME membranes revealed that glycans on MUC1 from MEC samples contained α2,3-linked sialic acid. In IHC, MUC1 was diffusely detected at MEC-affected regions but was specifically detected at apical membranes in NSGs. ISH showed that C2GnT-1 was expressed at the MUC1-positive in MEC-affected regions but not in the NSG. MEC cells produced MUC1 modified with α2,3-linked sialic acid-containing core-2 O-glycans. MUC1 containing these glycans deserves further study as a new potential diagnostic marker of MEC.

Diagnosis and Management of Parotid Gland Cancer with Focus on the Role of Preoperative Fine-Needle Aspiration Cytology: A 10-Year-Long Retrospective Study with 5-Year Follow-Up.

Salivary gland cancers represent a rare heterogeneous group of neoplasms with complex clinicopathological characteristics and distinct biological behaviour. The appropriate diagnosis and management of parotid gland cancer are challenging and should be based on the clinical, imaging, cytological, and histological features. The present study analysed the use of preoperative fine-needle aspiration cytology (FNAC) and intraoperative frozen section (FS) to guide the appropriate surgical and postoperative treatment of parotid gland cancers. We selected 48 patients with primary malignancy of the parotid gland surgically treated between 1 January 2008 and 30 June 2017 at the Maxillo-Facial Surgery Division, University Hospital of Parma, Italy. The patients had postoperative histological diagnosis of malignant parotid cancer and were followed up for longer than 5years. The 48 patients included in this study had a mean age of 56.7years. The most frequent type of parotid gland cancer was carcinoma ex pleomorphic adenoma (22.9%), followed by mucoepidermoid carcinoma (16.7%) and acinic cell carcinoma (14.6%). All 48 patients underwent preoperative FNAC: 29 (60.4%) and 19 (39.6%) were suggestive of malignant and benign lesions, respectively. In 31 patients, intraoperative FS was performed. Compared to previous studies, the present study showed significantly lower diagnostic sensitivity of FNAC for parotid gland cancers. The preoperative diagnostic accuracy for suspected malignant cases may be improved by repeat analysis of the cytological specimen by experts, preoperative core needle biopsy, and/or intraoperative FS analysis of the suspected mass.

Establishment of Mucoepidermoid Carcinoma Cell Lines from Surgical and Recurrence Biopsy Specimens.

Patients with advanced/recurrent mucoepidermoid carcinoma (MEC) have a poor prognosis. This study aimed to establish and characterize human mucoepidermoid carcinoma cell lines from the initial surgical specimen and biopsy specimen upon recurrence from the same patient to provide a resource for MEC research. MEC specimens from the initial surgical procedure and biopsy upon recurrence were used to establish cell lines. The established cell lines were cytogenetically characterized using multi-color fluorescence in situ hybridization and detection, and the sequence of the CRTC1-MAML2 chimeric gene was determined. Furthermore, the susceptibility of head and neck mucoepidermoid carcinoma to standard treatment drugs such as cisplatin, 5-fluorouracil, and cetuximab was investigated. We successfully established unique MEC cell lines, AMU-MEC1, from an initial surgical specimen and AMU-MEC1-R1 and AMU-MEC1-R2 from the recurrent biopsy specimen in the same patient. These cell lines exhibited epithelial morphology and developed in vitro-like cobblestones. They shared eight chromosomal abnormalities, including der(19)ins(19;11)(p13;?), which resulted in a chimeric CRTC1-MAML2 gene, indicating the same origin of the cell lines. The susceptibility of all cell lines to cisplatin and 5-fluorouracil was low. Interestingly, EGFR dependency for cell growth decreased in AMU-MEC-R1 and AMU-MEC-R2 but was retained in AMU-MEC1. These cytogenetic and biochemical findings suggest that the established cell lines can be used to investigate the disease progression mechanisms and develop novel therapeutics for MEC.

In Vitro Carbon Ion Beam and Gemcitabine Chemoradiation in a Mucoepidermoid Carcinoma Cell Line.

To determine the interaction of gemcitabine in chemoradiotherapy with heavy carbon ions in vitro in a mucoepidermoid carcinoma (MEC) cell line. The human lymphatic MEC metastasis cell line NCI-H292 was used. The cells were treated with photons, carbon ions, and gemcitabine. Survival fractions (SF), apoptosis, and cell cycle progression were analyzed. A paired two-sided t-test was used. Significance was defined as p<0.05. Cell proliferation assays showed a significant reduction in SF for combined photon chemoradiation versus photons only. The linear-quadratic fits of combined therapy with carbon ion dose of 0 to 2.5 Gy led to reductions of mean 15% in SF. The LD50 (lethal radiation dose required to reduce cell survival by 50%) for carbon ions only was 0.7 Gy and for carbon ions with gemcitabine 0.6 Gy. The LD50 for photons (with gemcitabine) was 2.8 Gy (2.0 Gy) and for carbon ions (with gemcitabine) 0.7 Gy (0.6 Gy), resulting in a relative biological effectiveness at 10% cell survival (RBE10) of 3.0 (2.7). Carbon ions and photons reduced S phase and increased G2/M phase cell distribution. Isolated treatment with gemcitabine as well as combination with photons led to prolonged S phase transit, whereas combined treatment with carbon ions led to early accumulation in G2/M phase. A significant increase in the sub-G1 population as a hint of relevant number of apoptotic cells was not observed. Gemcitabine showed radiosensitizing effects in combination with photons. The combination of gemcitabine and carbon ions had independent additive effects. Carbon ions only had a RBE10 of 3.0, compared to photons only. The combination of gemcitabine, photon, and carbon ions in patients with MEC seems promising and warrants further investigation.

Chrysin Induces Apoptosis via the MAPK Pathway and Regulates ERK/mTOR-Mediated Autophagy in MC-3 Cells.

Chrysin is a flavonoid found abundantly in substances, such as honey and phytochemicals, and is known to exhibit anticancer effects against various cancer cells. Nevertheless, the anticancer effect of chrysin against oral cancer has not yet been verified. Furthermore, the mechanism underlying autophagy is yet to be clearly elucidated. Thus, this study investigated chrysin-mediated apoptosis and autophagy in human mucoepidermoid carcinoma (MC-3) cells. The change in MC-3 cell viability was examined using a 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide cell viability assay, as well as 40,6-diamidino-2-phenylindole, annexin V, and propidium iodide staining. Western blotting was used to analyze the proteins related to apoptosis and the mitogen-activated protein kinase (MAPK) pathway. In addition, the presence or absence of autophagy and changes in the expression of related proteins were investigated using acridine orange staining and Western blot. The results suggested that chrysin induced apoptosis and autophagy in MC-3 oral cancer cells via the MAPK/extracellular signal-regulated kinase pathway. Moreover, the induced autophagy exerted a cytoprotective effect against apoptosis. Thus, the further reduced cell viability due to autophagy as well as apoptosis induction highlight therapeutic potential of chrysin for oral cancer.

Simultaneous Expression of PD-1 and PD-L1 in Peripheral and Central Immune Cells and Tumor Cells in the Benign and Malignant Salivary Gland Tumors Microenvironment.

To investigate the differential expression of PD-1 and PD-L1 in salivary gland tumors (SGTs, malignant and benign subtypes) and determine their association with the clinicopathological characterization of the patients. The immunohistochemistry was used to examine PD-1 and PD-L1 expression in specimens from 83 patients with primary SGTs including salivary ductal carcinoma (SDC), adenoid cystic carcinoma (AdCC), acinic cell carcinoma (ACC), mucoepidermoid carcinoma (MEC), warthin's tumors (WT), poleomorphic adenoma (PA) and other subtypes. The expression of PD-1 in peripheral and central immune cells (ICs) of MEC, and peripheral ICs of ACC was significantly higher than those with AdCC (P = 0.02, P = 0.02, P = 0.03, respectively). Interestingly, the expression of PD-1 was also observed in peripheral and central malignant tumor cells (TCs), particularly in SDC and ACC. Despite no significant difference in PD-L1 expression of TCs among malignant subtypes, the peripheral and central ICs of ACC and MEC were revealed to express PDL-1 significantly more than those with AdCC (P < 0.05). WTs were rich in PD-1/PD-L1 expressing ICs. However, the tumor microenvironment of PA generally had low levels of PD-1/PD-L1 expression. In general, the expression of PD-1 in peripheral and central TCs was found to be significantly higher in malignant tumors than in benign ones (P = 0.002 and P = 0.003, respectively). The simultaneous presentation of PD-1 and PD-L1 in TCs and ICs of SGTs, their significant association with disease severity as well as the positive correlation between these immune checkpoints may suggest the therapeutic potential of anti-PD-1 and anti-PDL-1 combinational immunotherapy for SGTs.

Epidemiological and clinical characteristics of 407 salivary glands neoplasms in surgically treated patients in 2010-2020

INTRODUCTION Tumors of the salivary glands account for approximately 3 to 4% of all head and neck neoplasms. It is estimated that 10-15% of them are malignant. The most common benign tumor is pleomorphic adenoma, while the most common malignant tumors are adenoid cystic carcinoma and mucoepidermoid carcinoma. Neoplasms of the salivary glands are extremely histologically diverse, which results from the complex embryogenesis of the salivary glands. The identified risk factors for tumors of the salivary glands are: ultraviolet radiation, ionizing radiation, viral infections, nicotine and alcohol. MATERIAL AND METHOD The aim of the study was an epidemiological analysis of patients with salivary gland neoplasms, the distribution and histopathological characteristics of individual neoplasms treated at the Department of Otorhinolaryngology of the Medical University of Warsaw in 2010-2020. The diagnoses were analyzed according to the latest WHO 2017 histological classification of salivary gland tumors. In addition, the material was supplemented with data on the 5-year survival rates of patients with malignant neoplasms obtained from the Registry of Marital Status. RESULTS AND DISCUSSION The material contained 407 neoplasms of the salivary glands over a 11-year period, of which malignant neoplasms accounted for 17.4%. The malignant tumors were dominated by: adenoid cystic carcinoma (28,2%), mucoepidermoid carcinoma (12,7%), and acinic cell carcinoma (9,9%). Lymphomas (15,5%) were also a large group. The benign neoplasms were dominated by pleomorphic adenoma (54.1%) and Warthin&apos;s tumor (36%). Tumors of the salivary gland the most often affected the parotid gland (92%). CONCLUSIONS The obtained data are consistent with the general epidemiological data described in the current literature.

P53 Inhibits Bmi-1-driven Self-Renewal and Defines Salivary Gland Cancer Stemness.

Mucoepidermoid carcinoma (MEC) is a poorly understood salivary gland malignancy with limited therapeutic options. Cancer stem cells (CSC) are considered drivers of cancer progression by mediating tumor recurrence and metastasis. We have shown that clinically relevant small molecule inhibitors of MDM2-p53 interaction activate p53 signaling and reduce the fraction of CSC in MEC. Here we examined the functional role of p53 in the plasticity and self-renewal of MEC CSC. Using gene silencing and therapeutic activation of p53, we analyzed the cell-cycle profiles and apoptosis levels of CSCs in MEC cell lines (UM-HMC-1, -3A, -3B) via flow cytometry and looked at the effects on survival/self-renewal of the CSCs through sphere assays. We evaluated the effect of p53 on tumor development (N = 51) and disease recurrence (N = 17) using in vivo subcutaneous and orthotopic murine models of MEC. Recurrence was followed for 250 days after tumor resection. Although p53 activation does not induce MEC CSC apoptosis, it reduces stemness properties such as self-renewal by regulating Bmi-1 expression and driving CSC towards differentiation. In contrast, downregulation of p53 causes expansion of the CSC population while promoting tumor growth. Remarkably, therapeutic activation of p53 prevented CSC-mediated tumor recurrence in preclinical trials. Collectively, these results demonstrate that p53 defines the stemness of MEC and suggest that therapeutic activation of p53 might have clinical utility in patients with salivary gland MEC.

A combined microinvasive trans-submandibular and nasendoscopy surgical approach to dissect recurrent or radiotherapy-insensitive nasopharyngeal carcinoma.

ObjectiveTo investigate a novel combined microinvasive trans-submandibular and nasendoscopy surgical approach for nasopharyngeal carcinoma involving the parapharyngeal space.MethodsSeven patients diagnosed with nasopharyngeal carcinoma involving the parapharyngeal space between May 2018 and April 2021, two males and five females, aged 37–63 years.Six of the 7 patients underwent submental flap preparation and dissection of the lymph nodes in the upper neck and parapharyngeal space on the lesion side. The nasopharynx lesions and tumor margins were dissected under nasal endoscopy. The medial boundary of internal carotid artery separated by open cervical approach was used as the lateral boundary of the tumor to realize en bloc resection of the tumor.ResultsThe patients were preoperatively diagnosed with T2~3N0M0 nasopharyngeal carcinoma, including mucoepidermoid carcinoma (n=2), papillary adenocarcinoma (n=1), and nonkeratinizing squamous cell carcinoma (n=4). The tumors were removed completely, and patients achieved primary healing of the incision. No recurrence and no serious complications were recorded during the 13–48 month follow-up.ConclusionComplete resection of the tumor was obtained in the 7 patients without recurrence and serious complications during the follow-up. The findings of this cohort study suggest that, patients with recurrent nasopharyngeal carcinoma after radiotherapy and radiotherapy-insensitive types of nasopharyngeal carcinoma, the combined microinvasive trans-submandibular and nasendoscopy surgical approach may be considered as an surgical options. The results of this study provide an additional option for surgical treatment of NPC in the clinic.

HDAC AND NFKB INHIBITORS REDUCE CANCER STEM CELLS AND SENSITIZE MUCOEPIDERMOID CARCINOMA CELL LINES TO CISPLATIN

Objectives To evaluate the potential of histone deacetylase (HDAC) suberoylanilide hydroxamic acid (SAHA) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) (emetine) inhibitors, isolated and associated with cisplatin (CDDP) in salivary gland mucoepidermoid carcinoma (MEC) cell lines, specifically through cancer stem cell (CSC) modulation. Study Design Cell viability was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Immunofluorescence staining was performed to identify the acetylation of lysine 9 from histone H3 protein (H3k9ac) and phosphorylated protein p65 (NFkB pathway). CSC was evaluated by quantifying the enzymatic activity of aldehyde dehydrogenases (ALDH) using flow cytometry and by in vitro tumorsphere formation. Results A single administration of SAHA (1 μM) induced histone acetylation, whereas 0.05 μM of emetine resulted in inhibition of the NF-kB pathway. We showed a disruption of CSC, illustrated by a reduction of enzymatic activity of ALDH and inhibition of tumorsphere formation. Furthermore, we observed that MEC tumor cells were sensitized to CDDP after the administration of a combination of SAHA and emetine. Conclusions Our findings suggest that HDAC and NF-kB inhibitors might be an alternative approach to treat MEC through disruption of CSC and sensitizing cells to conventional therapy. To evaluate the potential of histone deacetylase (HDAC) suberoylanilide hydroxamic acid (SAHA) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) (emetine) inhibitors, isolated and associated with cisplatin (CDDP) in salivary gland mucoepidermoid carcinoma (MEC) cell lines, specifically through cancer stem cell (CSC) modulation. Cell viability was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Immunofluorescence staining was performed to identify the acetylation of lysine 9 from histone H3 protein (H3k9ac) and phosphorylated protein p65 (NFkB pathway). CSC was evaluated by quantifying the enzymatic activity of aldehyde dehydrogenases (ALDH) using flow cytometry and by in vitro tumorsphere formation. A single administration of SAHA (1 μM) induced histone acetylation, whereas 0.05 μM of emetine resulted in inhibition of the NF-kB pathway. We showed a disruption of CSC, illustrated by a reduction of enzymatic activity of ALDH and inhibition of tumorsphere formation. Furthermore, we observed that MEC tumor cells were sensitized to CDDP after the administration of a combination of SAHA and emetine. Our findings suggest that HDAC and NF-kB inhibitors might be an alternative approach to treat MEC through disruption of CSC and sensitizing cells to conventional therapy.

CROSS-TALK OF PROTEINS RELATED TO INVADOPODIA AND THE INVASION PROCESS IN SALIVARY GLAND MUCOEPIDERMOID CARCINOMA

<h3>Objectives</h3> To evaluate the immunoexpression of Tks4, Tks5, cortactin, and MT1-MMP proteins in salivary gland mucoepidermoid carcinoma (MEC). <h3>Study Design</h3> Immunohistochemistry was performed to compare the expression of the 4 proteins in samples of MEC (<i>n</i> = 19) and healthy salivary glands (SG) (<i>n</i> = 10). The immunostaining assessment was performed by measuring the area (in µm) and the fraction (in %) of immunostaining of antibodies using the software ImageJ. The data were statistically analyzed using the Kruskal-Wallis test with Dunn's post hoc test for different proteins. Spearman correlation test was also performed. <h3>Results</h3> All MEC samples expressed Tks4, Tks5, cortactin, and MT1-MMP. There was a high immunoexpression of the 4 proteins in the MEC samples compared with the SG samples (*<i>P</i> < .05). In neoplastic MEC cells, expression of Tks4 and Tks5 proteins was correlated (*<i>P</i> < .05). <h3>Conclusions</h3> From the data obtained and in view of the important role of these proteins in the formation of invadopodia and in the cell invasion process, the expression of these proteins together in the MEC, as well as the correlation of Tks4 and Tks5, may suggest a possible relationship between these proteins and the invasive behavior of this neoplasm.