Yonara Maria Freire Soares Marques

MDM2, P53, P21WAF1 and pAKT protein levels in genesis and behaviour of adenoid cystic carcinoma ☆

BACKGROUND MDM2, P53, P21(WAF1) and pAKT are proteins associated with the balance between cell death and survival. There are many hypotheses regarding the role of these proteins in salivary gland tumours. However, many molecular events that activate or inactivate regulatory genes remain unknown. The aim of this study was to evaluate and to correlate MDM2, P53, P21(WAF1) and pAKT protein expressions in adenoid cystic carcinomas (ACC). METHODS Twenty-two cases of ACC were evaluated by immunohistochemistry and one cell line derived from ACC was analyzed by Western Blotting and immunofluorescence techniques. RESULTS Strong MDM2 and pAKT, variable P53 and null P21 expressions were found in the cases analyzed, but no statistical correlation was established when comparing MDM2 and pAKT expressions in the 3 different ACC subtypes. The ACC cell line showed intense nuclear and cytoplasmatic MDM2 and pAKT expressions and null P53 and P21 expressions. CONCLUSIONS Results indicate that MDM2 and pAKT are related to the tumorigenesis of ACC, but they might not be directly connected to tumour progression. We also demonstrate that the pAKT pathway is active in ACC and it seems to be activating the MDM2 shuttle from the cytoplasm to the nucleus, where it phosphorylates P53 and carries it to the cytoplasm for degradation.

Mdm2, p53, p21 and pAKT protein pathways in benign neoplasms of the salivary gland

The p53 protein can be altered virtually in all human cancers. In the absence of p53 mutations, p53 inactivation is possible via complex formation with other proteins, such as Mdm2. Previous studies have shown an overexpression of Mdm2 and lack of p53 expression in pleomorphic adenomas. The pAkt protein is closely related to Mdm2, and has not been previously reported in salivary gland tumors. The aim of this study was to analyze the expression of Mdm2, p53, p21 and pAkt proteins in pleomorphic adenomas and myoepitheliomas by immunohistochemistry, Western blotting and immunofluorescence techniques. Overexpression of Mdm2 and pAkt was present in all the cell lines and tumors studied, whereas the expression of p53 and p21 proteins was considered absent. In conclusion, the signaling pathway in benign salivary gland neoplasm showed an important participation of Mdm2 overexpression protein in tumor formation, progression through inactivation of p53 action, or both, and of pAkt overexpression through increased translocation of Mdm2 protein to cellular nuclei.

Oestrogen receptor β in adenoid cystic carcinoma of salivary glands.

Marques Y M F S, Giudice F S, Freitas V M, Abreu e Lima M d C C, Hunter K D, Speight P M & Machado de Sousa S C O 
(2012) Histopathology 60, 609–616
Oestrogen receptor β in adenoid cystic carcinoma of salivary glands

Papillary squamous cell carcinoma of the tongue

Papillary squamous cell carcinoma (PSCC) is a rare variant of squamous cell carcinoma (SSC) that can occur in situ or as an invasive tumor. It mainly affects the larynx, oropharynx, or nasopharynx. There have been only a few cases of PSCC reported in the oral cavity, and the most important differential diagnosis in this region is with verrucous carcinoma (VC). This report describes an unusual case of PSCC on the lateral border of the tongue. An 80-year-old woman was referred to the dental clinic with the chief complaint of a growing mass on the lateral border of the tongue, which she thought was related to her lower, complete, removable denture. The mass had been there for nearly 12 months after two unsuccessful attempts to remove the lesion followed by inconclusive pathological diagnosis. She had no symptoms of sore throat, cough, or otalgia. An extraoral examination revealed no abnormality. Intraoral examination (Fig 1A) revealed two exophytic nodules, 2.5 cm in diameter, with a papillary aspect and white patches on the surface. A low-magnification microscopic examination revealed an exophytic proliferation of squamous cells that appeared to be malignant and that covered the papillae with a fibrovascular core. Nests of atypical keratinocytes invaded the fibrovascular core and extended close to the underlying muscle of the tongue (Fig 1B). A higher magnification showed cell polarity loss, nuclear pleomorphism, nuclear hyperchromatism, prominent nucleoli, and several mitotic figures. The histopathological diagnosis was PSSC. Immunohistochemical assessment of cellular proliferative activity showed a significantly high percentage of Ki-67 expression (Fig 1B). Following the histologic diagnosis, the patient was referred to the A. C. Camargo Hospital for surgical treatment. The tumor was classified into T2N0M0 stage. The operation consisted of ample exeresis of the lesion with 1-cm margin and suprahyoid neck dissection. Her postoperative course

Oral Verruciform Xanthoma: A Case Report and Literature Review

Oral verruciform xanthoma represents an uncommon entity, which affects mainly oral mucosa. This paper presents the major clinical and histological features of oral verruciform xanthoma and reports a case on the tongue. The differential diagnosis and a literature review are also provided in light of recent information.

Spindle Cell Lipoma Occurring in the Buccal Mucosa: An Unusual Location of This Benign Lipomatous Neoplasm

Spindle cell lipoma is a benign lipomatous neoplasm, which rarely occurs in the oral cavity. The aims of this paper are to report a case of spindle cell lipoma located in buccal mucosa and discuss the main clinical, histological, and immunohistochemical findings of this entity. Thus, we report a 4-year history of an asymptomatic smooth surface nodule in an elderly Caucasian man with clinical hypothesis of fibroma. The histopathological examination showed spindle cells, mature adipose tissue, and many mast cells in a stroma of connective tissue presenting ropey collagen fibers bundles. After immunohistochemical analysis, the final diagnosis was spindle cell lipoma.