Interferon-γ (IFN-γ), a key effector molecule in anti-tumor immune response, has been well documented to correlate with the intratumoral infiltration of immune cells. Of interest, however, a high level of IFN-γ has been reported in salivary adenoid cystic carcinoma (SACC), which is actually a type of immunologically cold cancer with few infiltrated immune cells. Investigating the functional significance of IFN-γ in SACC would help to explain such a paradoxical phenomenon. In the present study, we revealed that, compared to oral squamous cell carcinoma cells (a type of immunologically hot cancer), SACC cells were less sensitive to the growth-inhibition effect of IFN-γ. Moreover, the migration and invasion abilities of SACC cells were obviously enhanced upon IFN-γ treatment. In addition, our results revealed that exposure to IFN-γ significantly up-regulated the level of programmed death ligand 1 (PD-L1) on SACC cell-derived small extracellular vesicles (sEVs), which subsequently induced the apoptosis of CD8⁺ T cells through antagonizing PD-1. Importantly, it was also found that SACC patients with higher levels of plasma IFN-γ also had higher levels of circulating sEVs that carried PD-L1 on their surface. Our study unveils a mechanism that IFN-γ induces immunosuppression in SACC via sEV PD-L1, which would account for the scarce immune cell infiltration and insensitivity to immunotherapy.
B7-H1 Antigen/metabolism* ; CD8-Positive T-Lymphocytes/pathology* ; Carcinoma, Adenoid Cystic/pathology* ; Carcinoma, Squamous Cell/pathology* ; Cell Line, Tumor ; Humans ; Immunosuppression Therapy ; Interferon-gamma/pharmacology* ; Mouth Neoplasms/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; Salivary Gland Neoplasms/pathology*

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

PURPOSE: To investigate the difference of expression of autophagy and reactive oxygen species (ROS) related proteins in adenoid cystic carcinoma (ACC) of lacrimal gland in comparison with ACC of salivary gland. MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded tissue samples from patients pathologically diagnosed as lacrimal gland ACC (n=11) and salivary gland ACC (n=64) were used. Immunochemistry was used to measure expression of autophagy related proteins [beclin-1, light chain (LC) 3A, LC3B, p62, and BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3)] and ROS related proteins [catalase, thioredoxinreductase, glutathione S-transferasepi (GSTpi), thioredoxin interacting protein, and manganese superoxide dismutase (MnSOD)]. The prognostic factors related to disease-free and overall survival (OS) in lacrimal gland ACC by log-rank tests, were determined. RESULTS: GSTpi in stromal cells was more highly expressed in lacrimal gland ACC (p=0.006), however, MnSOD in epithelial cells was expressed more in salivary gland ACC (p=0.046). LC3B positivity and BNIP3 positivity in epithelial component were associated with shorter disease-free survival (both p=0.002), and LC3A positivity in stromal component was the factor related to shorter OS (p=0.005). CONCLUSION: This is the first study to demonstrate the expression of autophagy and ROS related proteins in lacrimal gland ACC in comparison with the salivary gland ACC, which would provide a basis for further study of autophagy and ROS mechanism as novel therapeutic targets in lacrimal gland ACC.
Adult ; Aged ; *Autophagy ; Beclin-1 ; Biomarkers, Tumor/metabolism ; Carcinoma, Adenoid Cystic/*metabolism/pathology ; Carrier Proteins ; Disease-Free Survival ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lacrimal Apparatus/metabolism/pathology ; Lacrimal Apparatus Diseases/*metabolism/pathology ; Male ; Membrane Proteins ; Middle Aged ; Proto-Oncogene Proteins ; Reactive Oxygen Species/*metabolism ; Salivary Gland Neoplasms/metabolism/*pathology ; Salivary Glands/pathology

OBJECTIVEThis study aimed to investigate the expression of midkine (MK) and microvessel density (MVD) in patients with salivary adenoid cystic carcinoma (SACC) and its clinical significance, as well as detect the correlation between the expression of MK and MVD in SACC.

METHODSImmunohistochemistry analysis (SP method) for MK and MVD were performed on 60 cases of SACC and 26 cases of normal salivary gland tissue. The expression of MK and MVD, as well as the correlation between the expression of MK and MVD in SACC were detected.

RESULTSIn SACC, the MK expression rate was 70.0% (42/60), and MK was not expressed in normal tissue. Statistical significance was found between SACC and normal tissue (P<0.05). The MVD values in SACC and normal salivary gland tissues were 38.73 +/- 8.96 and 11.15 +/- 3.33, respectively. These values were statistically significant (P<0.05). The expression levels of MK and MVD were unrelated to age, gender, and type in SACC (P>0.05), but correlated with tumor size, lymph node metastasis, and tumor-node-metastasis in SACC (P<0.05). The expression of MK and MVD was positively correlated with SACC (r=0.560, P<0.05).

CONCLUSIONSACC is correlated with the expression of MK protein and the increase in MVD, which may be some of the early diagnostic markers in SACC.

Carcinoma, Adenoid Cystic ; enzymology ; pathology ; Cytokines ; genetics ; metabolism ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Microvessels ; Nerve Growth Factors ; Salivary Gland Neoplasms ; enzymology ; pathology ; Salivary Glands ; enzymology

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 role of Slit-Robo signaling in the proliferation of human mucoepidermoid carcinoma Mc3 cells.

METHODSWe measured the expressions of Slit2 and Robo1 proteins in human mucoepidermoid carcinoma Mc3 cells using immunohistochemistry and flow cytometry. To test the role of Slit-Robo signaling in the proliferation of the cells, we treated the cells with the monoclonal antibody R5 against Robo1 receptor extracellular domain and observed the changes in the cell proliferation by cell counting and colonogenic assay; the expression of proliferating cell nuclear antigen (PCNA) in the cells following the treatment was measured with flow cytometry.

RESULTSTreatment of Mc3 cells with the monoclonal antibody R5 caused significantly suppressed cell growth and proliferation and obviously lowered the expression of PCNA.

CONCLUSIONSlit-Robo signaling can suppress the proliferation of Mc3 cells possibly by up-regulating the expression of PCNA.

Carcinoma, Mucoepidermoid ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Nerve Tissue Proteins ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism ; Receptors, Immunologic ; metabolism ; Salivary Gland Neoplasms ; pathology ; Signal Transduction

OBJECTIVETo investigate the expression of ErbB-3 binding protein-1 (EBP-1), matrix metalloproteinase 9 (MMP-9) and E-cadherin (E-cad) in adenoid cystic carcinoma and their correlation.

METHODSImmunohistochemistry(PV6000 method) was used to detect EBP-1, MMP-9 and E-cad expression in 66 cases of adenoid cystic carcinoma tissues and matched para-cancerous normal tissues. In this study all cases were successfully followed up.

RESULTSThe positive expression rate of EBP-1 in adenoid cystic carcinoma tissues was 85%. EBP-1 expression was significantly correlated to pathological pattern and clinical stage (P < 0.05), but not to gender and age. In addition, there was a negative correlation between EBP-1 and E-cad expression, and positive correlation between EBP-1 and MMP-9.

CONCLUSIONSEBP-1 and its correlation with MMP-9 and E-cad may be used as useful indicators for clinical assessment of tumor biological behavior and prognosis in patients with adenoid cystic carcinoma.

Adaptor Proteins, Signal Transducing ; metabolism ; Biomarkers, Tumor ; metabolism ; Cadherins ; metabolism ; Carcinoma, Adenoid Cystic ; metabolism ; pathology ; secondary ; Female ; Follow-Up Studies ; Humans ; Lung Neoplasms ; secondary ; Lymphatic Metastasis ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Staging ; RNA-Binding Proteins ; metabolism ; Salivary Gland Neoplasms ; metabolism ; pathology

OBJECTIVETo assess the epidermal growth factor receptor (EGFR) status in salivary adenoid cystic carcinoma and explore its role in cancer invasion.

METHODSFifty-four patients with pathologically confirmed salivary adenoid cystic carcinoma (SACC) were divided into invasion group and non-invasion group. The EGFR expression was determined by immunohistochemstry (SP staining). The relations between the EGFR expression and the SACC clinical pathological characteristics were analyzed.

RESULTSEGFR were mainly expressed in the cell membrane and cytoplasm in the tissue of SACC. The positive rate of EGFR expression in the tumor tissue was 75.9% (41/54), and EGFR was over-expressed in the cytoplasm. The positive rate of EGFR expression in invasion group was higher than that in the non-invasion group (10.0%, P < 0.05). EGFR expression were related with the SACC T stages, histological types, distant metastasis, lymph node metastasis, and nerve invasion (P < 0.05).

CONCLUSIONSA higher expression of EGFR gene in the cytoplasm may have important effect on the progression of invasive carcinoma. Further investigations are required to develop new strategy in the treatment of salivary adenoid cystic carcinoma.

Carcinoma, Adenoid Cystic ; metabolism ; pathology ; Cell Membrane ; metabolism ; Cytoplasm ; metabolism ; Female ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasm Staging ; Receptor, Epidermal Growth Factor ; metabolism ; Salivary Gland Neoplasms ; metabolism ; pathology

OBJECTIVETo investigate the expression of p38 mitogen-activated protein kinase (p38MAPK) in salivary adenoid cystic carcinoma (SACC) tissues and their clinicopathologic significance.

METHODSThe protein and mRNA expressions of p38MAPK were examined by immunohistochemistry and in situ hybridization, respectively, in 52 cases of SACC and in 11 normal salivary gland tissues adjacent to the tumors on a tissue microarray platform.

RESULTSThe positive rate of p38MAPK protein expression in the paracancerous normal salivary gland tissues and that in SACC were 36.4% and 96.2%, respectively, showing a significant statistical difference (P < 0.01). The protein expression of p38MAPK was positively correlated with the lymph node metastasis and nerve involvement (P < 0.05). The positive rates of p38MAPK mRNA in the paracancerous tissues and in the SACC tissues were 45.5% and 94.2%, respectively, with a significant statistical difference (P < 0.01). The mRNA expression of p38MAPK was positively correlated with the lymph node metastasis and nerve involvement (P < 0.05). In the SACC, there was a notable positive correlation between the p38MAPK protein and mRNA expressions (r = 0.409, P < 0.01).

CONCLUSIONSThe expression of p38MAPK is up-regulated in salivary adenoid cystic carcinoma. p38MARK may be involved in the tumorigenesis, development and metastasis of this cancer.

Adult ; Aged ; Carcinoma, Adenoid Cystic ; enzymology ; pathology ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; RNA, Messenger ; metabolism ; Salivary Gland Neoplasms ; enzymology ; pathology ; Salivary Glands ; enzymology ; Up-Regulation ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

Adenocarcinoma ; pathology ; Adenoma ; pathology ; Carcinoma, Adenoid Cystic ; epidemiology ; genetics ; metabolism ; pathology ; Carcinoma, Basosquamous ; pathology ; DNA, Mitochondrial ; genetics ; Diagnosis, Differential ; Humans ; Immunohistochemistry ; Incidence ; Proto-Oncogene Proteins c-kit ; metabolism ; Salivary Gland Neoplasms ; epidemiology ; genetics ; metabolism ; pathology ; Salivary Glands, Minor ; pathology ; beta-Defensins ; genetics