Altered expression of podoplanin in keratocystic odontogenic tumours following decompression.

Marsupialisation or decompression is frequently performed as a conservative therapy for keratocystic odontogenic tumours (KCOTs). Positive podoplanin (PDPN) expression in the epithelium of KCOT has been previously reported and may be associated with neoplastic invasion. In the present study, changes in PDPN expression were observed in the epithelium of KCOTs following decompression. In total, 16 pairs of paraffin-embedded tissue specimens obtained at the time of decompression and at two-stage curettage or enucleation were collected and immunohistochemically examined using an antibody against PDPN. The intensity of PDPN staining was evaluated with a semi-quantitative detection method and statistically analysed. The immunohistochemical reactivity of PDPN was consistently markedly positive in 93.8% of KCOT samples prior to decompression. The positive staining was immunolocalised to the cell membrane and cytoplasm of cells in the basal layer and extended into the suprabasal layer for two to three cell layers. At the time of curettage, 2 of the 16 (12.5%) cases were completely negative, 11 of the 16 (68.8%) cases were locally positive and 3 of the 16 (18.7%) cases showed a 'linear staining' pattern, as the PDPN-positive cells were restricted to within the single basal layer. The expression level of PDPN was significantly decreased (P<0.05) and a significant loss or reduction of PDPN expression was observed in KCOTs following decompression. Larger sample groups are required to further verify this result.

Cyclooxygenase-2 expression in keratocystic odontogenic tumour decreased following decompression.

Marsupialisation or decompression is frequently performed as a conservative therapy for keratocystic odontogenic tumours (KCOTs). Positive cyclooxygenase-2 (COX-2) expression in the epithelium of KCOTs was recently reported and may be associated with neoplastic invasion and progression. The aim of the present study was to investigate the change in COX-2 expression in the KCOT epithelium following decompression. In this study, 16 pairs of KCOT biopsy specimens obtained during decompression or enucleation were collected and analysed. Formalin-fixed, paraffin-embedded blocks were sectioned and immunohistochemically investigated using anti-COX-2 antibody. The molecular expression was semi-quantitatively evaluated as follows: 0, negative; 1, weakly to moderately positive; and 2, strongly positive. In the samples obtained prior to decompression, the positive staining for COX-2 was immunolocalised to the cell membrane and the cytoplasm, it involved the full thickness of the epithelium and 15 of the 16 specimens (93.8%) exhibited mild to strong positivity. As regards the samples obtained following decompression, only 3 of the 16 specimens (18.8%) exhibited a mild positivity. The expression levels of COX-2 were significantly decreased following decompression (P<0.05). It may be concluded that loss or a significant reduction of COX-2 expression is associated with decompression in KCOTs. However, large-scale studies are required to verify these results and improve our knowledge of the possible involvement of COX-2 in the pathogenic mechanism underlying the development of KCOTs.

Focal adhesion kinase serves as a marker of cervical lymph node metastasis and is a potential therapeutic target in tongue cancer.

PURPOSE: The aims of the present study were to examine whether focal adhesion kinase (FAK) expression is correlated with cervical lymph node metastasis of tongue cancer and to investigate the roles of FAK in the process of cancer cell migration, invasion and anoikis resistance using the human tongue cancer cell line, Tca8113. METHODS: FAK expression was evaluated in 5 normal oral mucosa, 10 premalignant lesions, 80 primary tongue cancers and 41 lymph node metastases using anti-FAK immunohistochemistry. The migration, invasion and anoikis resistance of tongue cancer cells were evaluated using wound healing assays, invasion assays and anoikis induction. The effect of FAK inhibition was evaluated using RNA interference (RNAi). RESULTS: In total, 55 of 80 primary tongue cancers (69%) showed high expression of FAK, and 25 of 80 tumors (31%) and all normal oral mucosa or premalignant lesions showed low expression of FAK. There was a significant correlation between FAK expression and the cervical lymph node metastasis of tongue cancer. Moreover, RNAi-mediated FAK reduction decreased tongue cancer cell migration, invasion and anoikis resistance. CONCLUSIONS: These results suggest that FAK may serve as a marker of cervical lymph node metastasis of tongue cancer and that RNAi targeting FAK could serve as a potential therapeutic for the treatment of tongue cancer.

[Application of the free vascularized lateral upper arm flap in intraoral reconstruction following ablative tumour surgery].

OBJECTIVE: To evaluate the application of the lateral arm free flap (LAFF) in the reconstruction for intraoral defects. METHODS: Intraoral reconstruction was performed using the LAFF for 10 patients with oral squamous cell carcinoma of the tongue (n = 3), cheek (n = 4), gingiva (n = 1) and oropharynx (n = 2). There were 8 men and 2 women (mean age, 52 years). RESULTS: Nine LAFF healed uneventfully. One flap was lost on the second postoperative day due to venous insufficiency. The donor defect was closed primarily In all patients. There were no significant complications at the donor site. CONCLUSIONS: Because of the thin and pliable nature, the lateral upper arm flap can be recommended as a choice for repair of moderate-sized defects of the oral maxillofacial area.

[Scanning electron microscopic study of titanium-hydroxyapatite, the functionally graded-material implanted in rabbits].

OBJECTIVE: The purpose of this study was to observe the tissue tolerance of Ti-HA functionally graded-material (FGM) and the form of the material-bone interface. METHODS: The sintered Ti -HA FGM, pure HA and pure Ti were respectively implanted into the parietal bone of rabbits. The specimens were observed by SEM at 2, 4, 8 postoperative weeks. RESULTS: In the early stage, the new bone surrounding the Ti -HA FGM formed earlier with larger amount and better maturity than the pure Ti. The condition was similar to the pure HA. Two months after the operation, direct bonding of material-bone interface was formed between the Ti -HA FGM and the new bone as an integral body. However, there was a little space left between the new bone and the pure Ti. CONCLUSIONS: The Ti -HA FGM has good tissue tolerance. Its early integration with bone is similar to pure HA and better than pure Ti.