RESUMEN
Myoepithelial tumors of soft tissue are rare mesenchymal neoplasms that overlap with their salivary gland and skin counterparts at both the histopathologic and molecular levels. EWSR1 gene rearrangements with various fusion partners represent a common genetic event in myoepithelial tumors of soft tissue, whether benign or malignant, and may prove useful as a diagnostic tool in difficult cases. However, the number of diagnostic entities with EWSR1 gene rearrangements has grown considerably in recent years, and there is significant morphologic and immunophenotypic overlap amongst this group, underscoring the importance of fusion testing to detect fusion partners that are characteristic of discrete diagnostic entities. Herein, we report a malignant myoepithelial tumor of soft tissue/myoepithelial carcinoma with an undifferentiated round cell morphology arising in a pediatric patient with a EWSR1-ATF1 gene fusion.
Asunto(s)
Carcinoma de Células Pequeñas/genética , Mioepitelioma/genética , Proteínas de Fusión Oncogénica/genética , Neoplasias de los Tejidos Blandos/genética , Adolescente , Biomarcadores de Tumor/genética , Carcinoma de Células Pequeñas/diagnóstico , Carcinoma de Células Pequeñas/patología , Diagnóstico Diferencial , Humanos , Masculino , Mioepitelioma/diagnóstico , Mioepitelioma/patología , Sarcoma/diagnóstico , Neoplasias de los Tejidos Blandos/diagnóstico , Neoplasias de los Tejidos Blandos/patologíaRESUMEN
We hypothesized that there is a relationship between the preexisting pleomorphic adenoma [PA]), histologic grade of epithelial-myoepithelial carcinomas (EMCAs), and genetic alterations. EMCAs (n=39) were analyzed for morphologic and molecular evidence of preexisting PA (PLAG1, HMGA2 status by fluorescence in situ hybridization, FISH, and FGFR1-PLAG1 fusion by next-generation sequencing, NGS). Twenty-three EMCAs were further analyzed by NGS for mutations and copy number variation in 50 cancer-related genes. On the basis of combined morphologic and molecular evidence of PA, the following subsets of EMCA emerged: (a) EMCAs with morphologic evidence of preexisting PA, but intact PLAG1 and HMGA2 (12/39, 31%), (b) Carcinomas with PLAG1 alterations (9/39, 23%), or (c) HMGA2 alterations (10/39, 26%), and (d) de novo carcinomas, without morphologic or molecular evidence of PA (8/39, 21%). Twelve high-grade EMCAs (12/39, 31%) occurred across all subsets. The median disease-free survival was 80 months (95% confidence interval, 77-84 mo). Disease-free survival and other clinicopathologic parameters did not differ by the above defined subsets. HRAS mutations were more common in EMCAs with intact PLAG1 and HMGA2 (7/9 vs. 1/14, P<0.001). Other genetic abnormalities (TP53 [n=2], FBXW7 [n=1], SMARCB1 deletion [n=1]) were seen only in high-grade EMCAs with intact PLAG1 and HMGA2. We conclude that most EMCAs arose ex PA (31/39, 80%) and the genetic profile of EMCA varies with the absence or presence of preexisting PA and its cytogenetic signature. Progression to higher grade EMCA with intact PLAG1 and HMGA2 correlates with the presence of TP53, FBXW7 mutations, or SMARCB1 deletion.
Asunto(s)
Adenoma Pleomórfico/patología , Biomarcadores de Tumor/genética , Mutación , Mioepitelioma/patología , Neoplasias Glandulares y Epiteliales/patología , Neoplasias de las Glándulas Salivales/patología , Adenoma Pleomórfico/diagnóstico , Adenoma Pleomórfico/genética , Adenoma Pleomórfico/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Proteínas de Unión al ADN/genética , Supervivencia sin Enfermedad , Proteína 7 que Contiene Repeticiones F-Box-WD/genética , Femenino , Estudios de Seguimiento , Proteína HMGA2/genética , Humanos , Hibridación Fluorescente in Situ , Masculino , Persona de Mediana Edad , Mioepitelioma/diagnóstico , Mioepitelioma/genética , Mioepitelioma/cirugía , Clasificación del Tumor , Neoplasias Glandulares y Epiteliales/diagnóstico , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Glandulares y Epiteliales/cirugía , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteína SMARCB1/genética , Neoplasias de las Glándulas Salivales/diagnóstico , Neoplasias de las Glándulas Salivales/genética , Neoplasias de las Glándulas Salivales/cirugía , Análisis de Secuencia de ADN , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Glial fibrillary acidic protein (GFAP) is a member of the intermediary filament protein family. It is an important component of astrocytes and a known diagnostic marker of glial differentiation. GFAP is expressed in other neural tumors and pleomorphic adenoma and, less frequently, in cartilage tumors, chordomas, and soft tissue myoepitheliomas. The aim of this study was to evaluate the role of GFAP and its reliability in nonglial tumors as an immunohistochemical marker. We evaluated GFAP gene and protein expression using Q-PCR and immunohistochemistry, respectively, in 81 and 387 cases of soft tissue, bone tumors, and salivary pleomorphic adenomas. Immunohistochemistry staining for GFAP was observed in all osteosarcomas (8 cases), all pleomorphic adenomas (7 cases), in 5 of 6 soft tissue myoepitheliomas, and in 21 of 76 chondrosarcomas. By Q-PCR, GFAP was highly expressed in pleomorphic adenomas and, to a lesser extent, chondrosarcomas, soft tissue myoepitheliomas, and chondroblastic osteosarcomas. The results that we obtained by immunohistochemistry and Q-PCR were well correlated. GFAP is a potential marker for tumors with cartilaginous differentiation, supported by evidence that GFAP is expressed in certain cases of myoepithelial tumors by immunohistochemistry, including soft tissue myoepitheliomas, which are related to cartilaginous differentiation. These findings contribute significantly to the diagnosis of soft tissue myoepitheliomas with cartilaginous differentiation and chondroblastic osteosarcoma in mesenchymal tumors.
Asunto(s)
Adenoma Pleomórfico/química , Biomarcadores de Tumor/análisis , Neoplasias Óseas/química , Cartílago/química , Proteína Ácida Fibrilar de la Glía/análisis , Mioepitelioma/química , Neoplasias de las Glándulas Salivales/química , Neoplasias de los Tejidos Blandos/química , Adenoma Pleomórfico/genética , Adenoma Pleomórfico/patología , Biomarcadores de Tumor/genética , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Cartílago/patología , Diferenciación Celular , Regulación Neoplásica de la Expresión Génica , Proteína Ácida Fibrilar de la Glía/genética , Humanos , Inmunohistoquímica , Mioepitelioma/genética , Mioepitelioma/patología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias de las Glándulas Salivales/genética , Neoplasias de las Glándulas Salivales/patología , Neoplasias de los Tejidos Blandos/genética , Neoplasias de los Tejidos Blandos/patologíaRESUMEN
We studied the induction of protease activity by the laminin alpha1-derived peptide AG73 in cells from adenoid cystic carcinoma (CAC2) and myoepithelioma (M1), respectively a malignant and a benign salivary gland tumors. Laminin alpha1 chain and MMP9 were immunolocalized in adenoid cystic carcinoma and myoepithelioma in vivo and in vitro. Cells grown inside AG73-enriched laminin-111 exhibited large spaces in the extracellular matrix, suggestive of remodeling. The broad spectrum MMP inhibitor GM6001 decreased spaces induced by AG73 in CAC2 and M1 cells. This result strongly suggests that AG73-mediated matrix remodeling involves matrix metalloproteinases. CAC2 and M1 cells cultured on AG73 showed a dose-dependent increase of MMP9 secretion, as detected by zymography. Furthermore, siRNA silencing of MMP9 decreased remodeling in 3D cultures. We searched for AG73 receptors regulating MMP9 activity in our cell lines. CAC2 and M1 cells grown on AG73 exhibited colocalization of syndecan-1 and beta1 integrin. siRNA knockdown of syndecan-1 expression in these cells resulted in decreased adhesion to AG73 and reduced protease and remodeling activity. We investigated syndecan-1 co-receptors in both cell lines. Silencing beta1 integrin inhibited adhesion to AG73, matrix remodeling and protease activity. Double-knockdown experiments were carried out to further explore syndecan-1 and beta1 integrin cooperation. CAC2 cells transfected with both syndecan-1 and beta1 integrin siRNA oligos showed significant decrease in adhesion to AG73. Simultaneous silencing of receptors also induced a decrease in protease activity. Our results suggest that syndecan-1 and beta1 integrin signaling downstream of AG73 regulate adhesion and MMP production by CAC2 and M1 cells.
Asunto(s)
Integrina beta1/metabolismo , Laminina/farmacología , Metaloproteinasas de la Matriz/metabolismo , Fragmentos de Péptidos/farmacología , Neoplasias de las Glándulas Salivales/patología , Sindecano-1/metabolismo , Western Blotting , Calcio/metabolismo , Carcinoma Adenoide Quístico/genética , Carcinoma Adenoide Quístico/metabolismo , Carcinoma Adenoide Quístico/patología , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Quelantes/farmacología , Dipéptidos/farmacología , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Heparina/farmacología , Humanos , Inmunohistoquímica , Integrina beta1/genética , Laminina/metabolismo , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz , Metaloproteinasas de la Matriz/genética , Mioepitelioma/genética , Mioepitelioma/metabolismo , Mioepitelioma/patología , ARN Interferente Pequeño/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias de las Glándulas Salivales/genética , Neoplasias de las Glándulas Salivales/metabolismo , Transducción de Señal/fisiología , Sindecano-1/genéticaRESUMEN
BACKGROUND: The normal duct and lobular system of the mammary gland is lined with luminal and myoepithelial cell types. Although evidence suggests that myoepithelial cells might suppress tumor growth, invasion and angiogenesis, their role remains a major enigma in breast cancer biology and few models are currently available for exploring their influence. Several years ago a spontaneous transplantable mammary adenocarcinoma (M38) arose in our BALB/c colony; it contains a malignant myoepithelial cell component and is able to metastasize to draining lymph nodes and lung. METHODS: To characterize this tumor further, primary M38 cultures were established. The low-passage LM38-LP subline contained two main cell components up to the 30th subculture, whereas the higher passage LM38-HP subline was mainly composed of small spindle-shaped cells. In addition, a large spindle cell clone (LM38-D2) was established by dilutional cloning of the low-passage MM38-LP cells. These cell lines were studied by immunocytochemistry, electron microscopy and ploidy, and syngeneic mice were inoculated subcutaneously and intravenously with the different cell lines, either singly or combined to establish their tumorigenic and metastatic capacity. RESULTS: The two subpopulations of LM38-LP cultures were characterized as luminal and myoepithelium-like cells, whereas LM38-HP was mainly composed of small, spindle-shaped epithelial cells and LM38-D2 contained only large myoepithelial cells. All of them were tumorigenic when inoculated into syngeneic mice, but only LM38-LP cultures containing both conserved luminal and myoepithelial malignant cells developed aggressive papillary adenocarcinomas that spread to lung and regional lymph nodes. CONCLUSION: The differentiated histopathology and metastatic ability of the spontaneous transplantable M38 murine mammary tumor is associated with the presence and/or interaction of both luminal and myoepithelial tumor cell types.