ABSTRACT
Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular, and cellular interactions. Ameloblastin (AMBN, also named "amelin" or "sheathlin") is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta (AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders. We recruited one kindred with autosomal-dominant amelogenesis imperfecta (ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Amelogenesis Imperfecta , Genetics , Cells, Cultured , China , Codon , Dentin , Congenital Abnormalities , Microsatellite Repeats , Microscopy, Electron, Scanning , Mutation, Missense , Pedigree , RNA , Transfection , Exome SequencingABSTRACT
<p><b>OBJECTIVE</b>To observe the effect of exosomes released by adenoid cystic carcinoma (ACC) cell line SACC-83 on the proliferation of ACC cells.</p><p><b>METHODS</b>Exosomes were isolated from SACC-83 cell culture supernatants using total exosome isolation reagents. The whole-mount exosomes were characterized using transmission electron microscope and Western blotting. The exosomes were labeled with green fluorescent dye PKH67 and co-cultured with SACC-83 cells for 48 h, followed by staining with Alexa Fluor 594 phalloidin and DAPI to observe exosome uptake by the cells using laser scanning confocal microscopy (LSCM). The cell proliferation was assessed using MTT assay and wound healing assay, and the expressions of ERK and P-ERK in the co-cultured SACC-83 cells were detected using Western blotting.</p><p><b>RESULTS</b>The exosomes isolated from SACC-83 cells showed a size range of 30-100 nm and expressed the exosomal markers CD9, CD63 and TSG101. LSCM showed exosome uptake by SACC-83 cells, which exhibited accelerated proliferation and significantly enhanced P-ERK expression ( < 0.05) without significant changes in ERK expression.</p><p><b>CONCLUSIONS</b>SACC-83 cells produce exosomes that promote the tumor cell proliferation and enhances the cellular expression of P-ERK, suggesting a potential role of MAPK/ERK pathway activation in exosome-mediated acceleration of ACC cell proliferation.</p>
ABSTRACT
OBJECTIVE@#Lymphoepithelial carcinoma (LEC) of salivary glands is a rare malignant neoplasm. The purpose of this research was to investigate the clinicalpathologic features and treatment methods of this rare disease.@*METHOD@#The clinical data and treatment outcomes of 17 patients from 2006 to 2012 were reviewed retrospectively.@*RESULT@#Ten males and seven females with a ratio of 1. 43:1 were involved. The II, III, IV stage cases were 7 (41.2%), 4 (23.5%), 6 (35.3%), respectively. The average follow-up duration was 2.56 years, and 12 patients had no evidence of recurrence. Five patients had local recurrence and (or) distant metastases within three years after surgery, including 4 deaths.@*CONCLUSION@#LEC in salivary gland is a high grade malignant tumor in oral and maxillofacial region, occurring predominately in parotid gland and submandibular gland. To prevent distant metastasis, radical surgery combined with chemoradiotherapy should be adopted.