Mucoepidermoid Carcinoma Cell Research Articles

Mel-CAM Expression in Common Oral Carcinomas.

Statement of the Problem: Mel-CAM (CD146, MUC18) is a 113-kD heterophilic cell-cell adhesion glycoprotein found in normal and tumoral tissues. The biologic functions and role of the Mel-CAM can be employed as a diagnostic marker in pathology.Purpose: The aim of this study was assessing the expression of Mel-CAM in common oral carcinomas like salivary gland mucoepidermoid carcinoma (MEC) and oral squamous cell carcinoma (OSCC) to differentiate the OSCC from high-grade MEC.Materials and Method: This study was performed on 19 specimens of MEC and 17 specimens of OSCC, which were retrieved from the archive of Department of Pathology of Taleghani Hospital, Tehran, Iran. Immunohistochemical staining was performed by using antibody against CD146. The data were analyzed using SPSS software through Mann-Whitney, Spearman's correlation coefficient, and Kruskal-Wallis tests.Results: Mel-CAM was expressed in all MEC samples and 10 OSCC cases. The two groups were significantly different regarding the CD146 expression (p= 0.035). Furthermore, the CD146 expression was found to be significantly correlated with the invasion mode (p= 0.002), tumor size (p= 0.012), and histological grade (p= 0.024) in OSCC group. No significant correlation existed between the expression, intensity, and location with the histological grade of MEC (p> 0.05) nor was any significant correlation detected between the CD146 expression and lymph node metastasis in neither group.Conclusion: Regarding the significant correlation between the CD146 expression and the prognostic factors in OSCC, this marker may predict the prognosis in OSCC patients, but not the MEC lesions. It cannot be used for differentiating high-grade MEC and OSCC.

Claudin expression is maintained in mucoepidermoid carcinoma of the salivary gland

ObjectiveThe aim of the present study was to investigate the expression of claudin-1, -3, -4, -5 and -7 proteins in mucoepidermoid carcinoma of oral cavity and analyze whether EGF may interfere in the expression of the genes that encode claudins using in vitro models. Material and methodsUsing immunohistochemistry, the expression of claudins was searched in 36 histologically graded cases of mucoepidermoid carcinoma. The association of expression of claudins with clinical-pathological parameters was evaluated. An in vitro step investigated the influence of EGF on gene expression of claudins by real time RT-PCR technique. ResultsClaudin-1, -3, -4, -5, and -7 were highly expressed in most mucoepidermoid carcinomas. These expressions were compared with clinicopathological parameters. High expression of claudin-1 was associated with patients over 40 years-old (p = 0.05) and Caucasians (p = 0.024). In vitro experiments demonstrated a tendency for Claudin gene expression increase after EGF stimulus. ConclusionsThe expression of claudins is maintained in mucoepidermoid carcinoma cells and EGF could be related with this expression. Our results point out to a fundamental biological importance to CLDNs in normal and neoplastic tissue. The expression patterns of CLDNs does not yet allow a clinical application, but the biological knowledge will ground evidence to new studies towards possible target-therapies.

Comparative Analysis of P63, Maspin and Matrix Metalloproteinase 2 Expression in Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of Salivary Glands.

Statement of the Problem: The tumor suppressor role of myoepithelial cells and related mechanisms in breast tumors are well understood. However, the role of these cells in tumors of salivary glands is debatable.Purpose: The present study was designed to determine the expression of p63, mammary serine protease inhibitor (maspin) and matrix metalloproteinase 2 (MMP-2) in mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ADCC) of salivary glands due to various cellular differentiation and structure. The association between the expression of these markers and clinicopathologic features and myoepithelial differentiation were also evaluated.Materials and Method: P63, maspin, and MMP-2 expression were immunohistochemically studied in 67 cases including35 cases of MEC and 32 cases of ADCC. The smooth muscle actin (SMA) staining was also applied to confirm the presence of myoepithelial differentiation. Data was analyzed using Chi-square test, Mann-Whitney U test and t-test.Results: The expression of p63 (p= 0.009) and maspin (p= 0.012) significantly differed between the study groups. P63 positive cells in MEC were negative for SMA staining in contrast to ADCC. Furthermore, the expression of P63 (p= 0.045) and maspin (p= 0.019) significantly and inversely correlated with histologic grade in ADCC. Likewise, positive significant correlation was detected between histologic grade and expression of P63 (p= 0.018) and MMP-2 (p= 0.003) in MEC samples.Conclusion: Our findings showed that MEC is devoid of myoepithelial cells. The difference in expression of P63 and maspin in ADCC and MEC highlighted the role and presence of myoepithelial cells in ADCC. Indeed, the high expression of P63 and maspin in well-differentiated ADCCs suggests the tumor suppressor effect of myoepithelial cells. Considering the association between the evaluated markers and histological grade, p63 in both tumors, maspin in ADCC and MMP-2 in MEC may be efficient predictors of clinical behavior.

Prediction of Malignancy in Salivary Gland Tumors by a New Cytology Reporting System.

The aim of this study was to analyze the risk of malignancy in salivary gland tumors on the basis of the Milan System for Reporting Salivary Gland Cytopathology. A retrospective review was performed of the charts of patients with salivary gland tumors in whom the final diagnosis was confirmed by surgical excision. Preoperative fine needle aspiration results were categorized according to the Milan System for Reporting Salivary Gland Cytopathology: non-diagnostic (category I), nonneoplastic (category II), atypia of undetermined significance (category III), neoplasm (category IV), suspicious for malignancy (category V), and malignant (category VI). Fine needle aspiration and final diagnosis were compared, and the risk of malignancy and operative/oncological outcomes were analyzed. A total of 288 patients were enrolled in this study. Postoperative histopathologic salivary gland malignancies were found in 30 (10.4%) patients. Risk of malignancy was 7.1%, 0%, 48.0%, 4.8%, 88.7%, and 100% in categories I, II, III, IV, V, and VI, respectively. The most common malignant tumor in category III was salivary duct carcinoma (37.5%), followed by acinic cell carcinoma (25.0%), mucoepidermoid carcinoma (25.0%), and squamous cell carcinoma (12.5%). The 5-year survival rate of patients with malignant tumors showed no statistical difference between category III and category V/VI (P = .140). Risk of malignancy was 88.9% and 100% in category V and VI, respectively. A half of atypia of undetermined significance (category III) cases were malignant. Once diagnosed, the prognosis of malignant tumor in category III was similar with that in category V/VI.

Oridonin induces the apoptosis of mucoepidermoid carcinoma cell lines in a myeloid cell leukemia‑1‑dependent manner.

Oridonin, an active diterpenoid isolated from Rabdosia rubescens, has been reported to exhibit anticancer activities in several tumors. The aim of the present study was to investigate the anticancer effects and molecular mechanisms of oridonin in mucoepidermoid carcinoma (MEC). Treatment with oridonin induced the apoptosis of MC‑3 and YD‑15 cell and inhibited the expression of myeloid cell leukemia‑1 (MCL‑1) through the regulation of the protein level through post‑translational regulation in these cell lines. Oridonin significantly increased the expression level of truncated Bid (t‑Bid) as a downstream target of MCL‑1 and subsequently decreased the mitochondrial membrane potential. The ectopic expression of MCL‑1 protein was sufficient to reverse the induction of apoptosis and the increased t‑Bid expression induced by oridonin in both cell lines. Taken together, these results suggest that oridonin exerts an apoptotic effect through the modulation of MCL‑1 and t‑Bid in human MEC cell lines and may thus be a potential anticancer drug candidate for the treatment of human MEC.

Incidence and survival trends of parotid malignancies over 42 years.

There is a paucity of information regarding the incidence and survival of parotid malignancies over time. The Surveillance, Epidemiology, and End Results population-based cancer registry was queried for parotid malignancies from 1973 to 2015. The age-adjusted incidence of parotid malignancies has increased by 58.1% (7.87-12.44 per 1 000 000). Analysis of histologic type revealed an increased annual percent change (APC) of acinar cell carcinoma (1.38) and squamous cell carcinoma (1.58), but decreased APC of adenoid cystic carcinoma (-1.63) and adenocarcinoma NOS (-0.86) (P < .05). The disease-specific survival of mucoepidermoid carcinoma, adenocarcinoma NOS, and squamous cell carcinoma significantly improved (P < .05) over time. The incidence of parotid cancer is rising steadily since 1973, while the incidence of overall head and neck cancer has decreased. Further research is necessary to understand the etiology, risk factors, and pathophysiology of parotid cancer to curb its rising incidence. 4.

Aquaporin 1, 3, and 5 Patterns in Salivary Gland Mucoepidermoid Carcinoma: Expression in Surgical Specimens and an In Vitro Pilot Study.

Salivary gland aquaporins (AQPs) are essential for the control of saliva production and maintenance of glandular structure. However, little is known of their role in salivary gland neoplasia. Salivary gland tumors comprise a heterogeneous group of lesions, featuring variable histological characteristics and diverse clinical behaviors. Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. The aim of this study was to evaluate the expression of AQP1, AQP3, and AQP5 in 24 MEC samples by immunohistochemistry. AQP1 expression was observed in vascular endothelium throughout the tumor stroma. AQP3 was expressed in epidermoid and mucosal cells and AQP5 was expressed in mucosal cells of MEC. These proteins were expressed in the human MEC cell line UH-HMC-3A. Cellular ultrastructural aspects were analyzed by electron microscopy to certificate the tumor cell phenotype. In summary, our results show that, despite the fact that these molecules are important for salivary gland physiology, they may not play a distinct role in tumorigenesis in MEC. Additionally, the in vitro model may offer new possibilities to further investigate mechanisms of these molecules in tumor biology and their real significance in prognosis and possible target therapies.

Metallothionein Expression and its Influence on the In Vitro Biological Behavior of Mucoepidermoid Carcinoma.

Mucoepidermoid carcinoma (MEC) is the most common tumor in the salivary glands, often presenting with recurrence and metastasis due to its high invasive capacity. Metallothionein (MT), a zinc storage protein that supplies this element for protease activity, is probably related to mucoepidermoid carcinoma behavior. This prompted us to characterize a cell line derived from mucoepidermoid carcinoma and to correlate metallothionein expression with transforming growth factor-α (TGF-α), tumor necrosis factor-α (TNF-α) and matrix metalloproteinases (MMPs). Transcriptomic analysis and cytogenetic assays were performed to detect the expression of genes of interest and cellular chromosomal alterations, respectively. MEC cells with a depleted metallothionein 2A (MT2A) gene were subjected to Western blot to correlate metallothionein expression with growth factors and MMPs. Additionally, cells with depleted MT were subjected to migration and invasion assays. The transcriptomic study revealed reads mapped to cytokeratins 19 and AE1/AE3, α-smooth muscle actin, vimentin, and fibronectin. Cytogenetic evaluation demonstrated structural and numerical alterations, including the translocation t(11;19)(q21;p13), characteristic of MEC. Metallothionein depletion was correlated with the decreased expression of TGF-α and MMP-9, while TNF-α protein levels were augmented. Migration and invasion activity were diminished after metallothionein silencing. Our findings suggest an important role of MT in MEC invasion, through the regulation of proteins involved in this process.

Necrotizing sialometaplasia: a case report of a non-ulcerated histopathological presentation

A 27-year-old woman presented with the chief complaint of severe pain in the palate region, which had been present for two months. Upon examination, she was found to have a firm, non-ulcerated nodule measuring about 2.5cm at the palatal junction. Incisional biopsy was recommended because the clinical differential diagnosis was mucoepidermoid carcinoma or squamous cell carcinoma. Anatomopathological examination revealed squamous metaplasia of the salivary gland ducts with preservation of the lobular architecture. Immunohistochemistry showed metaplastic ducts with low reactivity for p53 and Ki67, as well as positivity for CK AE1/AE3, CK7, p63, S-100, and SMA. The final diagnosis was necrotizing sialometaplasia. No treatment is required for this disease. Thirty-nine days after biopsy, total remission was observed with no signs of relapse after two years.

Gefitinib Represses JAK-STAT Signaling Activated by CRTC1-MAML2 Fusion in Mucoepidermoid Carcinoma Cells.

Gefitinib is well-known as a tyrosine kinase inhibitor targeting non-smalllung- cancer (NSCLC) containing EGFR mutations. However, its effectiveness in treating mucoepidermoid carcinoma (MEC) without such EGFR mutations suggests additional targets. The CRTC1-MAML2 (C1-M2) fusion typical for MEC has been proposed to be a gefitinib target. To test this hypothesis, we developed a set of siRNAs to down-regulate C1-M2 expression. RNA-seq and Western blot techniques were applied to analyze the effects of gefitinib and siC1-M2 on the transcriptome of and the phosphorylation of tyrosine kinases in a MEC cell line H292. Deep-sequencing transcriptome analysis revealed that gefitinib extensively inhibited transcription of genes in JAK-STAT and MAPK/ERK pathways. Both siC1-M2 and gefitinib inhibited the phosphorylation of multiple signaling kinases in these signaling pathways, indicating that gefitinib inhibited JAK-STAT and MAPK/ERK pathways activated by C1-M2 fusion. Moreover, gefitinib inhibition of EGFR and MAPK/ERK was more effective than that of AKT, JAK2 and STATs, and their dependence on C1-M2 could be uncoupled. Taken together, our results suggest that gefitinib simultaneously represses phosphorylation of multiple key signaling proteins which are activated in MEC, in part by C1-M2 fusion. Gefitinib-repressed kinase phosphorylation explains the transcriptional repression of genes in JAK-STAT and MAPK/ERK pathways. These findings provide new insights into the efficacy of gefitinib in treating mucoepidermoid carcinoma, and suggest that a combination of gefitinib and other inhibitors specifically against C1-M2 fusion could be more effective.

Performance Evaluation of a Classification Model for Oral Tumor Diagnosis

This paper extracted features from region of interest of histopathology images, formulated a classification model for diagnosis, simulated the model and evaluated the performance of the model. This is with a view to developing a histopathology image classification model for oral tumor diagnosis. The input for the classification is the oral histopathology images obtained from Obafemi Awolowo University Dental Clinic histopathology archive. The model for oral tumor diagnosis was formulated using the multilayered perceptron type of artificial neural network. Image preprocessing on the images was done using Contrast Limited Adaptive Histogram Equalization (CLAHE), features were extracted using Gray Level Confusion Matrix (GLCM). The important features were identified using Sequential Forward Selection (SFS) algorithm. The model classified oral tumor diagnosis into tive classes: Ameloblastoma, Giant Cell Lesions, Pleomorphic Adenoma, Mucoepidermoid Carcinoma and Squamous Cell Carcinoma. The performance of the model was evaluated using specificity and sensitivity. The result obtained showed that the model yielded an average accuracy of 82.14%. The sensitivity and the specificity values of Ameloblastoma were 85.71% and 89.4%, of Giant Cell Lesions were 83.33% and 94.74%, of Pleomorphic Adenoma were 75% and 95.24%, of Mucoepidermoid Carcinoma were 100% and 100%, and of Squamous Cell Carcinoma were 71.43% and 94.74% respectively. The model is capable of assisting pathologists in making consistent and accurate diagnosis. It can be considered as a second opinion to augment a pathologist&amp;rsquo;s diagnostic decision.

MULTIPLE MYELOMA: PRIMARY PALATAL MANIFESTATION

Multiple myeloma (MM) is a neoplastic disorder originating from clonal proliferation of malignant plasma cells in the bone marrow microenvironment. MM is identified by the accumulation of differentiated B cells. The aim of this study is to report a case of a 65-year-old man presenting with a sessile swelling on the left palate measuring 8 cm in its largest diameter and covered by a necrotic membrane on the central surface area. Provisional clinical diagnosis included mucoepidermoid carcinoma and squamous cell carcinoma and an incisional biopsy was performed. Histologic analysis showed a diffuse proliferation of malignant cells with plasmablastic differentiation. Immunoreactions, bone marrow biopsy and systemic evaluation of the patient confirmed the diagnosis of MM. The patient was classified as stage 0 of the disease, underwent chemotherapy and use of thalidomide, and is under clinical control for 6 months. Multiple myeloma (MM) is a neoplastic disorder originating from clonal proliferation of malignant plasma cells in the bone marrow microenvironment. MM is identified by the accumulation of differentiated B cells. The aim of this study is to report a case of a 65-year-old man presenting with a sessile swelling on the left palate measuring 8 cm in its largest diameter and covered by a necrotic membrane on the central surface area. Provisional clinical diagnosis included mucoepidermoid carcinoma and squamous cell carcinoma and an incisional biopsy was performed. Histologic analysis showed a diffuse proliferation of malignant cells with plasmablastic differentiation. Immunoreactions, bone marrow biopsy and systemic evaluation of the patient confirmed the diagnosis of MM. The patient was classified as stage 0 of the disease, underwent chemotherapy and use of thalidomide, and is under clinical control for 6 months.

Are demographics associated with mucoepidermoid or acinic cell carcinoma parotid malignancies in children?

ObjectiveTo identify possible associations between patient demographics and parotid cancer histological type in pediatric patients.MethodsPediatric patients (ages: birth-18.0 years) in the Surveillance, Epidemiology, and End Results (SEER) database were included from 1973 to 2014 based on a diagnosis of mucoepidermoid carcinoma or acinic cell carcinoma of the parotid gland using the ICD O-3 codes of C07.9 and 8430 or 8550. Patients were classified into the following cohorts: <14 and 14–18 years of age based on the mean age at diagnosis.ResultsThree hundred and three pediatric patients were diagnosed with mucoepidermoid carcinoma or acinic cell carcinoma of the parotid gland within the SEER 18 registries. Female pediatric patients 14–18 years of age were 7.68 times more likely to have an acinic cell carcinoma (adjusted OR: 7.68 [95% CI: 2.01–29.44]). When stratified by histological type, 58.9% of female pediatric patients ≥14 years of age had an acinic cell carcinoma as compared to 37.3% of male pediatric patients ≥14 years of age, 36.5% of female pediatric patients <14 years of age, and 34.0% of male pediatric patients <14 years of age (P = 0.01).ConclusionsBased on this study, pediatric female patients between the ages of 14 and 18 years are the most likely cohort to have acinic cell carcinoma. The results of this study may assist providers during the work up of a pediatric patient with a suspected parotid malignancy.

Baicalin-induced Cytotoxicity and Apoptosis in Multidrug-resistant MC3/5FU Mucoepidermoid Carcinoma Cell Line

Background: Multidrug Resistance (MDR) is a serious hindrance to cancer chemotherapy and profoundly influences the clinical findings. Many Traditional Chinese Medicines (TCM) have been tested with the aim of developing effective resistance modulators or anticancer drugs to overcome the MDR of human cancers. Methods: The anticancer effect of baicalin on multidrug-resistant MC3/5FU (5-fluorouracil) cells was investigated by MTT test and xenografts in nude mice. Cell apoptosis was studied by transmission electron microscopy, Hoechst-33342 staining, DNA fragmentation detection, and flow cytometry. RT-PCR and Rhodamine 123 efflux assay was also used to detect its effect on ABC drug transporter proteins, ABCB1 (P-glycoprotein, P-gp) and ABCC1 (multidrug resistance protein 1, MRP1). Results: The results indicate that there was no significant effect of baicalin on ABC transporters expression or efflux function, although it induced potent growth inhibition in MC3/5FU cells. Flow cytometry, Hoechst 33342 staining and transmission electron microscope revealed that baicalin caused MC3/5FU cell death through the induction of apoptosis. It is demonstrated that baicalininduced apoptosis could be mediated by up-regulation of Bax and caspase-3 protein levels and downregulation of Bcl-2 protein levels. In addition, daily intraperitoneal injection of baicalin (100 and 200 mg/kg) for 2 weeks significantly inhibited the growth of MC3/5FU cells xenografts in nude mice. Conclusion: Our results suggest that baicalin possesses considerable cytotoxic activity in multidrug resistance MC3/5FU cells in vitro and in vivo.

Conflicting Diagnosis of a Palatal Lesion: A Case Report of Necrotizing Sialometaplasia

Necrotizing sialometaplasia (NS) is a rare condition which can be easily confused with malignancy. Its presentation initially parallels mucoepidermoid carcinoma or squamous cell carcinoma, however, NS is a benign, self-limiting inflammatory disease of the mucus-secreting minor salivary glands. NS is thought to be caused by trauma which induces vascular ischemia of these minor salivary glands. Diagnosing NS continues to be difficult, and clinical history remains one of the pillars of ruling out cancer. This report details a case of NS in a 37-year-old male who presented to the Womack Army Medical Center Oral and Maxillofacial Surgery Clinic with an exophytic mass in his right-hand palate. He had a history of recent trauma induced to the area via incision and drainage to address what was believed to be a palatal space infection. Later, an incisional biopsy was performed after the exophytic mass persisted. The initial local pathology report favored low-grade mucoepidermoid carcinoma, but after review by the Joint Pathology Center at Walter Reed Military Medical Center, the consensus diagnosis was established as NS. The patient returned to the clinic five weeks later with the exophytic mass no longer present and the biopsy site healing well.

Abstract 874: The CRTC1/MAML2 oncogene induces a PGC-1a splice variant that sensitizes mucoepidermoid carcinoma cells to PPARg inhibition

Abstract Mucoepidermoid carcinoma (MEC) is the most common type of malignant salivary gland tumor. MECs frequently exhibit a recurrent t(11;19)(q21;p13) chromosomal translocation that fuses the transcriptional coactivators CRTC1 (CREB-Regulated Transcription Coactivator 1; C1) and MAML2 (Mastermind-Like 2; M2). Though many C1/M2-positive tumors are easily resected, some do progress to advanced, metastatic disease accompanied by poor 5-year survival rates. Thus, it is critical to understand the mechanisms by which C1/M2 drives tumor growth and progression in order to identify therapeutic vulnerabilities. Our lab recently identified a correlation between C1/M2 expression and increased levels of the growth hormone IGF-1. This hormone plays critical roles in the development and homeostasis of normal salivary glands, and its dysregulation has been implicated in several cancers including colon and lung cancers. Interestingly, we demonstrate that IGF-1 is not directly upregulated by C1/M2. Rather, we have discovered a novel C1/M2-driven signaling circuit whereby constitutive CREB activation drives the increased production of a minor PGC-1α (PPARγ Coactivator 1α) splice variant, PGC-1α4, which is responsible for the high IGF-1 levels observed in C1/M2-positive MEC cells. Notably, the PGC-1α4 splice variant is minimally expressed in normal tissues and C1/M2-negative cell lines but is selectively upregulated in C1/M2-positive cell lines. We show that C1/M2 directly binds CREB at the PGC-1α4 promoter to induce expression of this variant, resulting in increased IGF-1 expression. IGF-1 promoter analysis revealed a significant enrichment of PPARγ binding motifs and functional studies confirm that this promoter is regulated by PPARγ. Consequently, we demonstrate that a novel PPARγ inverse agonist is capable of repressing IGF-1 promoter activity and reducing growth and clonogenic potential of C1/M2-positive cell lines that exhibit high PGC-1α4 expression. Collectively, our results reveal a novel therapeutic vulnerability in salivary MEC cells that may extend more broadly to other cancers that exhibit dysregulated CREB activity. Citation Format: Adele M. Musicant, Kshitij P. Sharma, Erin C. Henry, Jason Tasoulas, Ricardo Padilla, Monideepa Sengupta, Colin Flaveny, Antonio L. Amelio. The CRTC1/MAML2 oncogene induces a PGC-1a splice variant that sensitizes mucoepidermoid carcinoma cells to PPARg inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 874.

Abstract 712: Down-regulation and nuclear localization of survivin by sodium butyrate induces caspase-dependent apoptosis in human oral mucoepidermoid carcinoma

Abstract Sodium butyrate (NaBu) is a histone deacetylase inhibitor that possess an apoptotic ability. However, the molecular mechanism by which NaBu induces apoptosis in human oral mucoepidermoid carcinoma (MEC), a type of salivary gland tumor, remains unclear. The anticancer effects of NaBu and its related molecular mechanisms were determined by trypan blue exclusion assay, 4'-6-diamidino-2-phenylindole staining, live/dead assay, human apoptosis array, RT-PCR, western blotting, immunocytochemistry, preparation of nuclear fractions, and nude mice tumor xenograft. In this study, we found that NaBu inhibited growth and induced apoptosis in the human oral MEC cell lines MC3 and YD15 with the acetylation of histone proteins H2A and H3. NaBu apparently down-regulated survivin protein, as evidenced by the results of the human apoptosis antibody array, and modulated it at the post-translational process. Interestingly, NaBu caused nuclear translocation of survivin protein in both cell lines. NaBu also resulted in decreased expression levels of Bcl-xL mRNA and protein, leading to induction of caspase-dependent apoptosis in human oral MEC cell lines. In addition, NaBu administration inhibited tumor growth in vivo at a dosage of 500 mg/kg/day, but it did not cause any hepatic or renal toxicity. This study provides new insights into the molecular mechanism of apoptotic actions by NaBu in human oral MEC and the basis of its clinical application for the treatment of human oral MEC. Citation Format: Chi Hyun Ahn, Sung-Dae Cho. Down-regulation and nuclear localization of survivin by sodium butyrate induces caspase-dependent apoptosis in human oral mucoepidermoid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 712.

Norcantharidin Suppresses YD-15 Cell Invasion Through Inhibition of FAK/Paxillin and F-Actin Reorganization

Norcantharidin (NCTD), a demethylated derivative of cantharidin, has been reported to exhibit activity against various types of cancers. However, the anti-invasive effects of NCTD and its molecular mechanism in human mucoepidermoid carcinoma (MEC) remain incompletely elucidated. Clonogenic, wound healing, invasion, zymography, western blotting and immunocytochemistry assays were performed in YD-15 cells to investigate the anti-invasive effect of NCTD and its molecular mechanism of action. The inhibitory effects of NCTD on invasiveness were compared with those of a novel focal adhesion kinase (FAK) kinase inhibitor, PF-562271. NCTD markedly suppressed the colony formation, migration, and invasion of YD-15 cells as well as the activities of MMP-2 and MMP-9. It disrupted F-actin reorganization through suppressing the FAK/Paxillin axis. Moreover, NCTD exhibited a powerful anti-invasive effect compared with that of PF-562271 in YD-15 cells. Collectively, these results suggest that NCTD has a potential anti-invasive activity against YD-15 cells. This study may clarify the impact of NCTD on migration and invasion of human MEC cells.

Heme Oxygenase-1 is a Key Molecule Underlying Differential Response of TW-37-Induced Apoptosis in Human Mucoepidermoid Carcinoma Cells.

TW-37 is a small-molecule inhibitor of Bcl-2 family proteins, which can induce anti-cancer activities in various types of cancer. In the current study, we investigated the potential molecular mechanism underlying the differential response to TW-37-induced apoptosis in two human mucoepidermoid carcinoma (MEC) cell lines. The differential response and underlying molecular mechanism of human MEC cells to TW-37 was evaluated by trypan blue exclusion assay, western blotting, 4’, 6-diamidino-2-phenylindole staining, annexin V/propidium iodide double staining, analysis of the sub-G1 population, human apoptosis array, and measurements of intracellular reactive oxygen species (ROS). TW-37 decreased cell viability and induced apoptosis in YD-15 cells, but not in MC3 cells. Proteome profiling using a human apoptosis array revealed four candidate proteins and of these, heme oxygenase-1 (HO-1) was mainly related to the differential response to TW-37 of YD-15 and MC3 cells. TW-37 also led to a significant increase in intracellular levels of ROS in YD-15 cells, which is associated with apoptosis induction. The ectopic expression of HO-1 recovered YD-15 cells from TW-37-induced apoptosis by reducing intracellular levels of ROS. The expression of HO-1 was reduced through both transcriptional and post-translational modification during TW-37-mediated apoptosis. We conclude that HO-1 is a potential indicator to estimate response to TW37-induced apoptosis in human MEC.

Effect of Rutaecarpine on the Benzo(a)pyrene‐Induced DNA Damage In Vitro

Benzo[a]pyrene (BaP) is one of the most potent mutagens and carcinogens known. The metabolic pathway of BaP involves several steps initiated by cytochromeP450 (CYP) enzymes such as CYP1A1 to give the ultimate carcinogen benzo(a)pyrene‐7,8‐diol‐9,10‐epoxide (BPDE). BPDE is responsible for genotoxic effects by alkylating the DNA at the N2 position of guanine bases. Rutaecarpine, a pentacyclic indolopyridoquinazolinone alkaloid isolated from the unripe fruit of Evodia rutaecarpa, has been used in traditional medicine to treat various diseases. It has been reported as a CYP1 family inducer. Our objective is to determine if co‐administered BaP and rutaecarpine would increase the formation of BPDE, which will ultimately increase the DNA damage. We utilized ethoxyresorufin‐O‐deethylase (EROD) assay to measure CYP1A1 enzyme activity and Muse™Multi‐Color DNA Damage Kit to examine DNA damage levels. The results showed that BaP (5 μM) and rutaecarpine (1.25–10 μM) significantly induced CYP1A1 enzyme activity (p&lt;0.005) when administered separately in mucoepidermoid pulmonary carcinoma (H292) cells, with induction by rutaecarpine occurring in a concentration‐dependent manner. Interestingly, co‐administration of rutaecarpine, especially at a high concentration (10 μM), with BaP caused induction of CYP1A1 to a lesser extent as compared with either compound alone. Similar results were observed in hepatocellular carcinoma (Hep3B) cells. It was subsequently confirmed by the analysis of DNA damage in both H292 and Hep3B cells, in which the percent of DNA damage decreased by more than 2‐fold after combined concurrent administration of rutaecarpine and BaP, compared with BaP alone. In summary, our data supports the possibility of a protective effect of rutaecarpine against BaP‐induced DNA damage in vitro.Support or Funding InformationThis research was supported by a Scholarly and Artistic Activity Grant from University of the Pacific.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.