Objective: To study the clinicopathologic and genetic features of papillary cystic low-grade mucoepidermoid carcinoma (LG-MEC) and cystadenoma. Methods: A retrospective review was performed on salivary gland tumor patients with papillary cystic architecture who presented to department of oral pathology, Peking University School and Hospital of Stomatology between January 2010 and June 2022. Among this cohort, there were 17 males and 17 females with a range age of 23-82 years [(55.6±14.6) years]. Diagnosis was confirmed by histological, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) analysis. Finally, 15 papillary cystic LG-MEC and 19 cystadenoma patients were included in the present study. All patients were followed clinically and radiologically, and the duration of follow-up ranged from 1 to 141 months. Results: All neoplasms showed papillary proliferation with multilocular or giant cystic tumors. Papillary cystic LG-MEC was characterized by epidermoid cells, intermediate cell and mucous cells with multiple lining-layers. Papillary cystic LG-MEC had mild cellular atypia and a pushing infiltration. Cystadenoma was characterized by cuboidal, columnar and ciliated pseudostratified columnar lining epithelium. Squamous metaplasia, mucinous metaplasia and acidophilic degeneration could also be observed focally in cystadenoma. For IHC staining, papillary cystic LG-MEC showed diffusely and strongly positive for mucin 4 (MUC4) (15/15) and mucin 5 Subtype AC (MUC5AC) (4/15) in the epidermoid cells, intermediate cell and mucous cells. The epidermoid cells and intermediate cells were diffusely positive for p40 and p63. The Ki-67 index was about 10%-15% in LG-MEC. As a contrast, p40 (17/19) and p63 (14/15) were only detected in the basal cells of cystadenoma. Cystadenoma showed focal MUC5AC (4/19)expression and MUC4 (19/19)diffuse expression. In addition, the Ki-67 index was 5%-10% in cystadenoma. The MAML2 gene translocation was detected in 11 LG-MEC patients, but none in cystadenoma. Conclusions: The differential diagnosis points between papillary cystic LG-MEC and cystadenoma included the specific epidermoid cells, intermediate cells and mucus cells in LG-MEC, cell atypia, the pushing-infiltration pattern, diffuse expression of p40 and p63 in the lining epithelium, and a MAML2 gene rearrangement. The molecular test of MAML2 should be recommended to reduce missed LG-MEC diagnoses.
Male ; Female ; Humans ; Carcinoma, Mucoepidermoid/pathology* ; In Situ Hybridization, Fluorescence ; Ki-67 Antigen/genetics* ; Biomarkers, Tumor/analysis* ; Salivary Gland Neoplasms/diagnosis* ; Transcription Factors/metabolism* ; Cystadenoma ; Metaplasia

Adenocarcinoma ; pathology ; Adenocarcinoma, Clear Cell ; genetics ; metabolism ; Carcinoma ; pathology ; Carcinoma, Acinar Cell ; pathology ; Carcinoma, Adenoid Cystic ; genetics ; metabolism ; Carcinoma, Mucoepidermoid ; genetics ; pathology ; Humans ; Myoepithelioma ; pathology ; Neoplasm Grading ; Oncogene Fusion ; Oncogene Proteins, Fusion ; metabolism ; Salivary Gland Neoplasms ; genetics ; pathology ; Salivary Glands ; pathology ; Translocation, Genetic

OBJECTIVETo study the expressions of matrix metalloproteinase 2 (MMP2) and E-cadherin (E-CD) in salivary mucoepidermoid carcinoma, and their relationship with clinical stages, pathological grading, lymph node metastasis and prognosis.

METHODSSurgical specimens of salivary mucoepidermiod carcinoma and normal salivary gland tissue were collected. MMP-2 and E-CD were stained immunohistochemically with streptavidin peroxidase method.

RESULTSThe expression of MMP-2 was increased and the expression of E-CD was reduced or negative in salivary mucoepidemoid carcinoma compared with those of the normal salivary gland. Expression of MMP-2 and E-CD was closely correlated with lymph node metastasis of the mucoepidermoid carcinoma. MMP-2 was positively correlated with the prognosis of mucoepidermoid carcinoma, and E-CD was negatively correlated to the prognosis of mucoepidermoid carcinoma.

CONCLUSIONThe expression of MMP-2 and E-CD is closely correlated with the metastasis and prognosis of salivary mucoepidermoid carcinoma.

Cadherins ; biosynthesis ; genetics ; Carcinoma, Mucoepidermoid ; metabolism ; pathology ; Humans ; Matrix Metalloproteinase 2 ; biosynthesis ; genetics ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Prognosis ; Salivary Gland Neoplasms ; metabolism ; pathology

Since genetic abnormalities of human cancer are greatly geographically dependent, cultural and environmental backgrounds are thought to be closely related to the carcinogenic process. In the present study, eight human cell lines were established by culture from untreated carcinomas of the oral cancer, of which five were from primary oral squamous cell carcinomas (OSC), one from a mucoepidermoid carcinoma (MEC) and one each originating from metastatic OSC and MEC. All the studied tumor lines grew as monolayers, and showed: i) an epithelial origin by the presence of cytokeratin, and ii) tumorigenic potential in nude mice. Western blot analysis revealed i) over expression of EGFR in six of the cell lines ii) decreased expression of E- cadherin in six cell lines compared to normal human oral mucosa. A mutational analysis showed: point mutations of p53 at exon 7, with transversion, and at exon 8, with transition. These well-characterized human YD cell lines should serve as useful tools in the study of the molecular pathogenesis and biological characteristics of head and neck cancer cells, and in the future testing of new therapeutic reagents for oral cancer.
Adult ; Aged ; Animals ; Base Sequence ; Carcinoma, Mucoepidermoid/genetics/*metabolism/*pathology ; Carcinoma, Squamous Cell/genetics/*metabolism/*pathology ; *Cell Line, Tumor ; Epithelial Cells/metabolism ; Female ; Humans ; Male ; Mice ; Mice, Nude ; Middle Aged ; Mouth Neoplasms/genetics/*metabolism/*pathology ; Mutation/genetics ; Papillomavirus/physiology ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Research Support, Non-U.S. Gov't ; Tumor Markers, Biological ; Tumor Suppressor Protein p53/genetics/metabolism ; Xenograft Model Antitumor Assays

OBJECTIVETo investigate the effects of hexamethylene bisacetamide (HMBA) on related genes expression of apoptosis and cell proliferating in human mucoepidermoid carcinoma cell line MEC-1.

METHODSMEC-1 was induced 72 hours by 0.002 mol/L HMBA in vitro. The morphologic observation and the expression of PCNA, bcl-2, bax protein and bcl-2 mRNA were determined by microscope, immunohistochemistry, in situ hybridization and image analysis.

RESULTSThe expression of bax, bcl-2 protein and bcl-2 mRNA were higher than control group (P < 0.01). The related genes of cell proliferating PCNA were decreased in control group.

CONCLUSIONSHMBA could inhibit the MEC-1 cell proliferation by down-regulation of PCNA expression, it could also induce apoptosis effectively that might be through the way of up-regulation of bax and bcl-2 gene expression.

Acetamides ; pharmacology ; Antineoplastic Agents ; pharmacology ; Apoptosis ; genetics ; Carcinoma, Mucoepidermoid ; drug therapy ; metabolism ; pathology ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Gene Expression ; drug effects ; Genes, bcl-2 ; Humans ; Proliferating Cell Nuclear Antigen ; analysis ; RNA, Messenger ; analysis ; Tumor Cells, Cultured