Disease relevance of Adenoma, Pleomorphic

• Thirteen of 17 pleomorphic adenomas with a normal karyotype and 5 of 10 with 12q13-15 abnormalities overexpressed PLAG1, which demonstrates that PLAG1 activation is a frequent event in adenomas irrespective of karyotype [1].
• Although most of the tumor cells in both malignant melanoma and pleomorphic adenoma were labeled with the anti-sense RNA probe, unlabeled tumor cells were also present in their vicinity, suggesting there was a heterogeneity among the cells in both tumor types with respect to S100 protein mRNA expression [2].
• At an echo time of 136 msec, Cho/Cr ratios were obtained in 26 (47%) of 55 spectra, with a mean value (+/- standard deviation) of 1.73 +/- 0.47, 5.49 +/- 1.86, 3.46 +/- 0.84, and 2.45 for malignant tumors, Warthin tumors, pleomorphic adenomas, and oncocytoma, respectively [3].
• Chondroitin 6-sulphate PG was detected in the ECM of pleomorphic adenomas and clear cell carcinomas and in pseudocystic spaces of adenoid cystic carcinomas, but only in vessel walls in non-neoplastic tissues [4].
• Normal rat and human parotid glands as well as pleomorphic adenomas and squamous cell carcinomas of this gland were examined by the indirect immunoperoxidase technique using antibodies to the keratin polypeptide of 67,000 dalton, and 55,000 dalton and anti-actin auto-antibodies [5].

High impact information on Adenoma, Pleomorphic

• Pleomorphic adenoma gene 1 (PLAG1) proto-oncogene overexpression is implicated in various human neoplasias, including salivary gland pleomorphic adenomas [6].
• Pleomorphic adenoma gene (PLAG) 1, the main translocation target in pleomorphic adenomas of the salivary glands, is a member of a new subfamily of zinc finger proteins comprising the tumor suppressor candidate PLAG-like1 (also called ZAC1 or lost on transformation 1) and PLAGL2 [7].
• PLAG1, the main translocation target in pleomorphic adenoma of the salivary glands, is a positive regulator of IGF-II [8].
• Here, we report that in a primary pleomorphic adenoma of the parotid gland, the FHIT gene, which spans the chromosome 3p14.2 fragile site FRA3B, and is frequently disrupted in tumors, acts as a fusion partner of HMGIC [9].
• Translocation, deletion/amplification, and expression of HMGIC and MDM2 in a carcinoma ex pleomorphic adenoma [10].

Chemical compound and disease context of Adenoma, Pleomorphic

• Moreover, the high expression of guanylin in pleomorphic adenoma and Warthin tumors (cystadenolymphoma), the most common neoplasms of salivary glands, predicts guanylin as a significant marker in tumor pathology [11].
• At an echo time of 272 msec, Cho/Cr ratios were obtained in 16 (30%) of 53 spectra, with a mean value of 2.27 +/- 0.69, 6.92 +/- 1.47, and 3.67 +/- 1.23 for malignant tumors, Warthin tumors, and pleomorphic adenomas, respectively [3].
• Pleomorphic adenoma of the salivary glands: correlation between gallium-67 uptake and histopathological components [12].
• Our data provide the first molecular evidence that the luminal and nonluminal cells in pleomorphic adenomas arise from the same clone in most cases, and the morphologically diverse nonluminal cells are monoclonal [13].
• The trichloroacetic acid-soluble proteins isolated from gland homogenates were also reduced in two of the carcinoma samples but increased in the pleomorphic adenomas [14].

Biological context of Adenoma, Pleomorphic

• The recurrent translocation t(5;8)(p13;q12) in pleomorphic adenomas results in upregulation of PLAG1 gene expression under control of the LIFR promoter [15].
• After microdissecting the different histological components, 42 pleomorphic adenomas of the parotid gland were analysed for INK4a-ARF inactivation by DNA sequence analysis, methylation-specific PCR (MSP), restriction enzyme-related polymerase chain reaction (RE-PCR), mRNA expression, microsatellite analysis, and immunohistochemistry [16].
• In primary pleomorphic adenomas, cells strongly immunoreactive for PLAG1 were detected in the outer layer of tubulo-ductal structures, which are thought to be the origin of cells with bi-directional, epithelial, and mesenchymal phenotypes [17].
• Pleomorphic adenoma gene 1 (PLAG1), shown to be consistently rearranged in pleomorphic adenomas, is activated by chromosomal translocations involving 8q12, the chromosome region that is most frequently affected in these tumors [18].
• Histologic localization of PLAG1 (pleomorphic adenoma gene 1) in pleomorphic adenoma of the salivary gland: cytogenetic evidence of common origin of phenotypically diverse cells [17].

Anatomical context of Adenoma, Pleomorphic

• Although CD34 is a marker of endothelial cells, CD34 was expressed in the endothelial cells in only a few areas around the epithelial elements and in the fibrous element of pleomorphic adenomas [19].
• Two of 11 frozen pleomorphic adenomas contained the muscle-specific intermediate filament desmin, which is not found in the normal glands [20].
• Hepatocellular carcinoma with solitary metastasis in pleomorphic adenoma of the submandibular gland [21].
• Cell membrane expression of MIB-1 in salivary gland pleomorphic adenoma [22].
• The presence of iNOS in normal salivary ducts and pleomorphic adenoma is most likely due to expression by myoepithelial cells [23].

Gene context of Adenoma, Pleomorphic

• In conclusion, our results reveal the recurrent involvement of the NFIB gene as translocation partner gene of HMGIC in pleomorphic adenomas [24].
• The presence of GFAP-like immunoreactivity in normal myoepithelial cells strongly supports the extensive involvement of this cell in pleomorphic adenomas [25].
• Chondroid syringoma containing neoplastic myoepithelial cells stained strongly for both S100A2 and S100B [26].
• METHODS: We studied clinicopathologically the frequency and variation of cellular atypia among tumor cells and examined the expression status of p53 gene products as well as proliferating cell nuclear antigen (PCNA) in 101 surgical materials of pleomorphic adenomas [27].
• Marked chondroid formation or expression of type II collagen was frequently observed in pleomorphic adenomas that overexpressed BMP-2 mRNA [28].

Analytical, diagnostic and therapeutic context of Adenoma, Pleomorphic

• Heterogeneity in expression of S100 beta mRNA in human melanoma and pleomorphic adenoma demonstrated by in situ hybridization [2].
• Using Southern blot analysis we report here that the c-mos gene and its flanking sequences are structurally altered in pleomorphic adenomas with chromosomal rearrangements of 8q12 [29].
• An immunodiffusion test suggests that the GFAP-related antigen of the pleomorphic adenoma showing a minor heterogeneity of antigenic determinants is almost identical with GFAP [30].
• Corroborating the previous morphologic studies, immunohistochemistry demonstrated abundant extracellular elastin within the matrix of pleomorphic adenomas [31].
• Immunofluorescence signals for VEGF and others were confirmed in pleomorphic adenoma cells in culture [32].

References