Expression of cdk6 in head and neck squamous cell carcinoma.

Objective: Cdk6 is a key regulator during the G1/S cell cycle transition. Aberrant expression of cdk6 protein has been observed in many cancer types. However, little is known about the expression of cdk6 in head and neck squamous cell carcinoma (HNSCC) and its clinical significance.

Aberrant expression of p-Smad3 in oral carcinogenesis.

Objective: Smads are the keys of transforming growth factor β (TGFβ) signaling cascade and play a crucial role in many cancers. Once TGFβ receptors are activated, Smad2 and Smad3 are phosphorylated and form complexes with Smad4. These complexes translocate from the cytoplasm to the nucleus where they regulate the target genes.

Overexpression of survivin and caspase 3 in oral carcinogenesis.

Survivin is an inhibitor of apoptosis protein that inhibits caspase 3 function. While cytoplasmic survivin suppresses apoptosis, nuclear survivin regulates cell division. Little is known about the subcellular localization of survivin in oral carcinogenesis.

Co-expression of hepatocyte growth factor and c-met in epithelial odontogenic tumors.

Hepatocyte growth factor (HGF) and its receptor, c-met, have been shown to regulate cell proliferation, motility and morphology in a variety of cell types. A significant role of the HGF/c-met pathway has been demonstrated in various tumors, however, little is known about the role of HGF/c-met pathway in odontogenic tumors. The aim of this study was to characterize the expression of HGF and c-met in 30 ameloblastomas, 7 unicystic ameloblastomas (luminal type), 10 calcifying cystic odontogenic tumors, 10 adenomatoid odontogenic tumors (AOTs), 30 keratocytic odontogenic tumors (KCOTs) and 6 ameloblastic carcinomas using an immunohistochemical method.

Overexpression of cdk4 and p16 in oral lichen planus supports the concept of premalignancy.

Background: Cell cycle arrest and increased cell proliferation have been demonstrated in oral lichen planus (OLP). This study evaluated the expression of cdk4, cdk6 and p16, important proteins in the G1 phase, in OLP and compared the expression of these proteins of OLP with those of normal mucosa.

Methods: Expression of cdk4, cdk6 and p16 were investigated in 23 OLP and 10 normal mucosae using immunohistochemistry technique.

Alteration in the expression of cdk4 and cdk6 proteins in oral cancer and premalignant lesions.

Background:   Cdk4 and cdk6, key players in G1 phase, have been shown to play an important role in the development of oral squamous cell carcinoma (OSCC). This study investigated the expression of these two proteins in OSCC and premalignant lesions including oral leukoplakia (OL) with and without dysplasia and determined if alterations in the expression of these two proteins could be used as markers of malignant transformation.

Methods: Expressions of cdk4 and cdk6 were evaluated in 61 samples including OSCC, OL with and without dysplasia and normal oral mucosa using immunohistochemistry method.

Immuno-histochemical expression of p53 protein and iNOS in odontogenic cysts.

Objective: The present study investigated the expression of p53 protein and iNOS in odontogenic keratocysts (OKCs), dentigerous cysts (DCs) and radicular cysts (RCs) and determined the correlation of these 2 proteins within each cyst type.

Material And Method: p53 and iNOS in epithelial lining cells were analyzed in 20 OKCs, 20 DCs and 20 RCs using immuno-histochemistry. The percentage of positive cells was assessed and presented as mean +/-SD.

Expression of p16 in oral cancer and premalignant lesions.

Background: Expression of p16 has been proposed as a marker for malignant transformation. This study aimed to evaluate p16 expression in oral squamous cell carcinoma (OSCC) and premalignant lesions including oral leukoplakia (OL) with and without dysplasia.

Methods: Expression of p16 was investigated in 56 samples including OSCC, OL with and without dysplasia, and normal oral mucosa.

A clinicopathologic study of oral leukoplakia and erythroplakia in a Thai population.

Objectives: To determine the prevalence of oral leukoplakia and erythroplakia in a group of Thai patients and to study the clinical and pathologic features of these 2 lesions.

Method And Materials: Cases having provisional diagnoses of leukoplakia and erythroplakia between 1973 and 2004 were retrieved from the files of the Department of Oral Pathology, Faculty of Dentistry, Mahidol University. Clinical and pathologic features were reviewed and analyzed.

Calcifying epithelial odontogenic tumor: an immunohistochemical case study.

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic tumor. A case of CEOT in a 25-year-old female is presented here. Histologically, the case showed sheets of polyhedral epithelial cells with deep eosinophilic cytoplasm and prominent nuclei.

Expression of basement membrane components in odontogenic tumors.

Objective: The objective was to characterize the expression of BMCs (laminins 1 and 5, collagen type IV, and fibronectin) in ameloblastomas, calcifying cystic odontogenic tumors (CCOTs), and adenomatoid odontogenic tumors (AOTs).

Study Design: BMCs were analyzed in 14 ameloblastomas, 7 CCOTs, and 7 AOTs using immunohistochemistry.

Results: In normal oral mucosa, linear deposits of these proteins were found at the epithelial-mesenchymal junction, but not in epithelial cytoplasm.

A retrospective study of 60 cases of salivary gland tumors in a Thai population.

Sixty cases of salivary gland tumors were diagnosed in the Oral Pathology Department, Faculty of Dentistry, Mahidol University, Bangkok, Thailand, from 1973 to 2002. Fifty-two cases (86.7%) involved the intraoral minor salivary glands, six cases (10%) were found in the major glands, and two cases (3.