Elevated VEGFA mRNA levels in oral squamous cell carcinomas and tumor margins: a preliminary study.

BACKGROUND: New blood vessel formation events are essential for tumor clonal expansion and progression. Despite the importance of vascular endothelial growth factor A (VEGFA) for tumor angiogenesis, few studies have evaluated the expression profile of this gene in oral squamous cell carcinoma (OSCC) and tumor margins (TM). This study aimed to evaluate the expression of the VEGFA gene and its protein in OSCC and TM. METHODS: Gene expression was evaluated in cryopreserved samples of OSCCs (n = 44), TM (n = 7), and normal mucosa from healthy patients (n = 3; NM). Quantitative PCRs were performed using the TaqMan system for the VEGFA gene, and gene expression was determined using the 2(-∆∆CQ) method. For immunohistochemical evaluation, 27 OSCC samples were embedded in a tissue microarray (TMA) block and reactions were performed using the Advance system. RESULTS: VEGFA transcript levels were 1.7-fold higher in OSCC than in NM samples. VEGFA mRNA was overexpressed in TM samples compared to NM (3.4-fold) and OSCC (2.0-fold) samples. VEGFA transcript level was overexpressed in T3-T4 tumors, metastatic lymph nodes, and stage III-IV OSCCs. Immunoreactivity of the VEGFA protein was detected in the cytoplasm of parenchymal and stromal cells, mainly in endothelial cells and fibroblasts. CONCLUSION: Our results show that VEGFA was overexpressed in aggressive OSCCs and that VEGFA expression may be an important prognostic factor in this type of cancer. Finally, tumor margins may be involved in the production of angiogenic molecules.

Transcriptional profiles of SHH pathway genes in keratocystic odontogenic tumor and ameloblastoma.

BACKGROUND: Sonic hedgehog (SHH) pathway activation has been identified as a key factor in the development of many types of tumors, including odontogenic tumors. Our study examined the expression of genes in the SHH pathway to characterize their roles in the pathogenesis of keratocystic odontogenic tumors (KOT) and ameloblastomas (AB). METHODS: We quantified the expression of SHH, SMO, PTCH1, SUFU, GLI1, CCND1, and BCL2 genes by qPCR in a total of 23 KOT, 11 AB, and three non-neoplastic oral mucosa (NNM). We also measured the expression of proteins related to this pathway (CCND1 and BCL2) by immunohistochemistry. RESULTS: We observed overexpression of SMO, PTCH1, GLI1, and CCND1 genes in both KOT (23/23) and AB (11/11). However, we did not detect expression of the SHH gene in 21/23 KOT and 10/11 AB tumors. Low levels of the SUFU gene were expressed in KOT (P = 0.0199) and AB (P = 0.0127) relative to the NNM. Recurrent KOT exhibited high levels of SMO (P = 0.035), PTCH1 (P = 0.048), CCND1 (P = 0.048), and BCL2 (P = 0.045) transcripts. Using immunolabeling of CCND1, we observed no statistical difference between primary and recurrent KOT (P = 0.8815), sporadic and NBCCS-KOT (P = 0.7688), and unicystic and solid AB (P = 0.7521). CONCLUSIONS: Overexpression of upstream (PTCH1 and SMO) and downstream (GLI1, CCND1 and BCL2) genes in the SHH pathway leads to the constitutive activation of this pathway in KOT and AB and may suggest a mechanism for the development of these types of tumors.

Keratocystic odontogenic tumour: an experience in the Northeast of Brazil.

INTRODUCTION: Keratocystic odontogenic tumours raise particular interest, because of their high recurrence rate and association with nevoid basal cell carcinoma syndrome. OBJECTIVE: To analyze the clinical and histopathological features of all cases diagnosed as keratocystic odontogenic tumour in a Brazilian population. METHODS: A total of 64 keratocystic odontogenic tumours, arising in forty-six patients, were evaluated using the following parameters: association with nevoid basal cell carcinoma syndrome, gender, age at first diagnosis, race, anatomical location, symptoms, radiographic features, history of recurrence, association with teeth, and treatment. RESULTS: Keratocystic odontogenic tumours were more frequent among women than men (1:0.84). The mean patient age was 31.5 years (SD: +/- 16.6). Ten tumours (16.4%) involved the maxilla and 51 (83.6%) the mandible. Swelling (n = 12; 46.1%), followed by pain and swelling (n = 4; 15.3%), were most common clinical manifestations. A unilocular radiotransparency with well-defined margins was the main radiographic finding (n = 29; 87.8%). A significant association was observed between the multilocular radiographic pattern and recurrence (p < 0.05, Fisher's Test). Sixty-one (95.3%) tumours were treated by surgical enucleation followed by bone curettage, and the recurrence rate was 13% (n = 6). This study showed that the keratocystic odontogenic tumours relapsed within a mean period of 25-36 months. CONCLUSION: Despite the results of this study being similar to previous reports found in the literature, it provides an important insight about keratocystic odontogenic tumours in a Brazilian population.

Immunolocalisation of laminin-1 in keratocystic odontogenic tumors.

Keratocystic odontogenic tumors (KOTs) are distinct odontogenic lesions frequently affecting the jawbones. They may be associated with nevoid basal cell carcinoma syndrome (NBCCS), and may exhibit disorders involving the extracellular matrix. The aim of this study was to investigate the immunolocalisation of laminin-1 in 20 cases of KOTs in order to contribute to the characterization of this protein, which is little studied in odontogenic tumors. Our results showed laminin-1 in all 20 KOTs studied; its labelling intensity was weak in three cases (15%), moderate in five (25%) and strong in 12 cases (60%). Laminin-1 immunolocalisation was predominantly continuous in 18 (90%) KOTs, including areas of acanthosis, subepithelial split and epithelial buds. Weak immunolabelling was observed in regions exhibiting an inflammatory process, especially in the case of intense inflammation. These findings suggest that laminin-1 does not participate in biological processes such as cystic epithelium-cystic wall separation or the formation of epithelial islands in KOTs. Furthermore, the discontinuous and weak labelling of this protein in the basement membrane of these tumors is probably a consequence of the inflammatory process in the tumor stroma.

Altered expression of cytokeratins in primary, recurrent and syndrome keratocystic odontogenic tumors.

Keratocystic odontogenic tumor (KOT) is a benign cystic tumor that affects the jaw bones and may be associated with the nevoid basal cell carcinoma syndrome (NBCCS). Twenty-five cases diagnosed as KOT, including primary and recurrent tumors and those associated with NBCCS, were submitted to immunohistochemical study for analysis of cytokeratins (CKs) 7, 8, 10, 13, 14, 18 and 19. The results showed CK13 immunostained on the intermediate layers and upper cells. CK14 was expressed in all epithelial layers and in those areas where inflammation and subepithelial splits were present; this protein was preserved within the basal cells. CK 18 was expressed mainly in the basal layer, whereas CK19 was expressed mainly on the intermediate and superficial layers. The remaining CKs tested were not immuoreactive. The status of maturation of cytokeratin seems to be altered on KOTs, and this is not distinct when different tumors are compared.