Aldehyde dehydrogenase 1: Its key role in cell physiology and oral carcinogenesis.

Aldehyde dehydrogenase (ALDH), an aldehyde-metabolizing enzyme, is a cytosolic antioxidant. It performs many important physiological catalytic and non-catalytic functions in mammalian cells. Apart from physiological functions, like the biosynthesis of vital molecules, this NAD(P)+ substrate-dependent enzyme superfamily is primarily involved in catalyzing the oxidation of highly reactive exogenous and endogenous aldehydes to their respective carboxylic acids. Among ALDH isoenzymes, ALDH1 has gained much attention as a prominent stem cell marker, as it is associated with the maintenance of stemness and the differentiation of normal stem cells, in addition to involvement in oncogenic functions, like cell proliferation, anti-apoptosis and the reduction of oxidative stress in cancer stem cells (CSCs). In this context, the authors review the physiological functions of ALDH1 in normal cells, normal stem cells and CSCs, along with the discussion of the putative role of ALDH1 in oral carcinogenesis by commenting on its expression in normal oral mucosa cells, oral potentially malignant disorders (OPMDs), like leukoplakia and dysplastic lesions, and oral squamous cell carcinoma (OSCC).

Altered immunoexpression of SOX2, OCT4 and Nanog in the normal-appearing oral mucosa of tobacco users.

BACKGROUND: Tobacco use is causatively associated with various human cancers, including oral carcinoma. A number of pathways have been delineated to describe its etiopathological link with oral carcinogenesis, including alterations in the expression of stem cell markers. Embryonic stem cell markers, such as sex-determining region Y-box 2 (SOX2), octamer-binding protein 4 (OCT4) and homeobox protein Nanog, which are mainly involved in the maintenance of stemness and pluripotency, have been positively associated with the pathogenesis of oral potentially malignant disorders and oral cancers. In this context, we attempted to explore the subcellular impact of tobacco through examining the expression of these stem cell markers in normal and normal-appearing oral mucosa in non-tobacco users and tobacco users. OBJECTIVES: The aim of the study was to analyze the immunoexpression of SOX2, OCT4 and Nanog in the normal-appearing oral mucosa (NAOM) of tobacco users as compared to the normal oral mucosa (NOM) of non-tobacco users. MATERIAL AND METHODS: The tissue samples of tobacco users and non-tobacco users (n = 50 per group) were immunohistochemically stained to assess the expression of SOX2, OCT4 and Nanog. RESULTS: In the oral mucosa of non-tobacco users, a peculiar parabasal expression pattern of SOX2 and OCT4 was observed, whereas Nanog was non-reactive. The grade of inflammation was found to be a predictive variable influencing the expression of the 2 markers. In tobacco users, variables such as male gender, mixed habit and basilar hyperplasia significantly controlled the basilar and suprabasilar expression of SOX2, OCT4 and Nanog. The expression of SOX2 and OCT4 was higher in tobacco users; in particular, OCT4 positivity was significantly increased (p < 0.001) in comparison with non-tobacco users. CONCLUSIONS: The altered expression of the examined stem cell markers could be an indication of early molecular changes in NAOM under the influence of tobacco.

Carotid Body Paraganglioma.

Carotid body paraganglioma (CBP) is a type neuroendocrine tumour arising from paraganglial chief cells of carotid body. Situated at the bifurcation of the common carotid artery, it constitutes 0.5% of all body tumours. Though CBP's is most common paraganglioma of head and neck it is a rare neoplasm and requires a thorough examination for a proper diagnosis and therapeutic management. Here, we present a case of 36 year old female patient with CBP in left side of the neck.

Benign cementoblastoma involving left deciduous first molar: A case report and review of literature.

Cementoblastoma, a benign mesenchymal odontogenic neoplasm is derived from ectomesenchymal cells of the periodontium. Cementoblastomas associated with primary teeth are extremely rare as permanent mandibular first molars are mostly affected. Only 17 cases of those associated with deciduous dentition have been reported so far. The present case report describes a true cementoblastoma of an 8-year-old male child in relation to the left first primary mandibular molar along with emphasis on differential diagnosis.

Reconnoitre ameloblastic carcinoma: A prognostic update.

AIM: Malignant odontogenic tumor, ameloblastic carcinoma (AC) is challenging to study owing to its rarity, complexity and limited availability of literature. This further makes it difficult to establish its clinical characteristics and prognosis. Our study aimed to evaluate AC's clinico-demographic factors and their relation with prognosis and survival. MATERIALS AND METHODS: Literature was systematically reviewed for cases pertaining to AC, starting from January 2000 to December 2016. All the required data was obtained, arranged and analysed using Cox regression ratio and Kaplan Meir survival analysis. From the database, 153 cases were retrieved as per the inclusion/exclusion criteria. RESULTS: The results demonstrated that age of patient, mode of treatment and metastasis affects overall survival. The categorisation of AC as primary or secondary type does not have any role in determining prognosis. CONCLUSION: Overall survival of AC patient depends upon age, site, treatment and metastasis. For a better prognosis early surgical management of the tumor appears to be the most favourable mode of treatment.

Pagetoid polyostotic fibrous dysplasia.

Fibrous dysplasia (FD) is a benign skeletal lesion occurring due to mutation of Gs α gene and involves one or multiple bones. We present a case of a 30-year-old female patient, with a 1-year history of swelling under her right eye that had gradually increased in size. Extraoral examination revealed a diffuse swelling extending anteroposteriorly from preauricular region to nasolabial fold, frontonasal region and superoinferiorly from zygoma to body of mandible, causing ipsilateral proptosis and contralateral deviation of nose. Intraoral examination showed obliteration of right upper and lower buccal vestibule. CT disclosed expansile lytic lesions involving multiple skull bones, jaws, sternum, rib and thoracic vertebrae. Histopathology displayed broad and interconnected trabeculae connected to the host bone exhibiting reversal lines resembling the mosaic pattern of Paget's disease. These features suggested pagetoid polyostotic FD. The patient underwent cosmetic recontouring and is under regular follow-up postoperatively.