Making sense of giant cell lesions of the jaws (GCLJ): lessons learned from next-generation sequencing.

Next-generation sequencing has revealed mutations in several bone-related lesions and was recently used to uncover the genetic basis of giant cell lesions of the jaws (GCLJ). Consistent with their benign nature, GCLJ show a low tumor mutation burden. They also harbor somatic, heterozygous, mutually exclusive mutations in TRPV4, KRAS, or FGFR1. These signature mutations occur only in a subset of lesional cells, suggesting the existence of a 'landscaping effect', with mutant cells inducing abnormal accumulation of non-mutant cells that form the tumor mass. Osteoclast-rich lesions with histological similarities to GCLJ can occur in the jaws sporadically or in association with genetically inherited syndromes. Based on recent results, the pathogenesis of a subgroup of sporadic GCLJ seems closely related to non-ossifying fibroma of long bones, with both lesions sharing MAPK pathway-activating mutations. In this review, we extrapolate from these recent findings to contextualize GCLJ genetics and we highlight the therapeutic implications of this new information. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Defects of the Carney complex gene (PRKAR1A) in odontogenic tumors.

The surgical treatment of some odontogenic tumors often leads to tooth and maxillary bone loss as well as to facial deformity. Therefore, the identification of genes involved in the pathogenesis of odontogenic tumors may result in alternative molecular therapies. The PRKAR1A gene displays a loss of protein expression as well as somatic mutations in odontogenic myxomas, an odontogenic ectomesenchymal neoplasm. We used a combination of quantitative RT-PCR (qRT-PCR), immunohistochemistry, loss of heterozygosity (LOH) analysis, and direct sequencing of all PRKAR1A exons to assess if this gene is altered in mixed odontogenic tumors. Thirteen tumors were included in the study: six ameloblastic fibromas, four ameloblastic fibro-odontomas, one ameloblastic fibrodentinoma, and two ameloblastic fibrosarcomas. The epithelial components of the tumors were separated from the mesenchymal by laser microdissection in most of the cases. We also searched for odontogenic pathology in Prkar1a(+) (/) (-) mice. PRKAR1A mRNA/protein expression was decreased in the benign mixed odontogenic tumors in association with LOH at markers around the PRKAR1A gene. We also detected a missense and two synonymous mutations along with two 5'-UTR and four intronic mutations in mixed odontogenic tumors. Prkar1a(+) (/) (-) mice did not show evidence of odontogenic tumor formation, which indicates that additional genes may be involved in the pathogenesis of such tumors, at least in rodents. We conclude that the PRKAR1A gene and its locus are altered in mixed odontogenic tumors. PRKAR1A expression is decreased in a subset of tumors but not in all, and Prkar1a(+) (/) (-) mice do not show abnormalities, which indicates that additional genes play a role in this tumor's pathogenesis.

The impact of burning mouth syndrome on health-related quality of life.

BACKGROUND: Burning mouth syndrome is a chronic disorder that is characterized by a burning sensation and a normal clinical appearance of the oral mucosa. This condition often affects the health-related quality of life in patients. As such, the aim of this study was to compare the health-related quality of life of patients with BMS and healthy controls, using the validated Portuguese versions of the SF-36 and OHIP-49 questionnaires. METHODS: A calculated sample of Brazilian patients with BMS (n = 26) was compared with a control group (n = 27), paired for gender and age. Sociodemographic information and clinical characteristics were obtained, and interviews were conducted using the SF-36 and OHIP-49. To evaluate the normality of the variables, we used the Kolmogorov-Smirnov test. The chi-square test, Fisher exact test and Mann-Whitney U-Test were used to compare sociodemographic and clinical characteristics of individuals with BMS and controls Mann-Whitney U-test were carried out to compare SF-36 and OHIP-49 between BMS patients and controls. The significance level was set at 0.05. To compare the dimensions of the SF-36 and OHIP-49 between BMS patients and controls, we considered Bonferroni correction. So for comparison of the dimensions, the significance level was set at 0.00625 for SF-36 and at 0.00714 for OHIP-49. RESULTS: The clinical and demographic data were similar in both groups (P > 0.05). SF-36 scores were significantly lower in all domains for patients with BMS (P < 0.00625). OHIP-49 scores were higher for individuals with BMS (P < 0.00714). CONCLUSIONS: BMS has a negative impact on the health-related quality of life of individuals, as can be shown by instruments such as the SF-36 and OHIP-49. So, the evaluation of quality of life might be useful for more information about the nature and severity of BMS, to evaluate the effects of treatment protocols, in order to improve their outcomes by means a humanized clinical practice.

Clinical significance of EGFR, Her-2 and EGF in oral squamous cell carcinoma: a case control study.

BACKGROUND: The erbB receptors and their ligands are involved in the pathogenesis and progression of oral squamous cell carcinoma (OSCC). Although EGFR and Her-2 are frequently overexpressed in OSCC, few studies evaluated these proteins in saliva and their association with the tumor, which may represent potential usefulness in a clinical setting. METHODS: The levels of EGFR, Her-2, and EGF were evaluated in saliva of 46 patients with OSCC before and after the surgical removal of the lesion, as well as in matched healthy controls. The relationship of salivary levels and EGFR and Her-2 immunoexpression in tumor samples with clinicopathological features was analyzed. RESULTS: EGFR and Her-2 salivary levels did not show difference between to pre-surgery and control groups, however, both demonstrated an increase after surgical removal of the tumor. No association was detectable among receptor salivary levels, tissue expression and clinicopathological features. EGF levels in pre-surgery group were significantly lower when compared to the control group. CONCLUSIONS: EGFR and Her-2 were not considered to be valuable salivary tumor markers in OSCC, however, lower levels of EGF in saliva may suggest a higher susceptibility for OSCC development.