AEG-1 promotes angiogenesis and may be a novel treatment target for tongue squamous cell carcinoma.

BACKGROUND: The study explored the potential function of astrocyte elevated gene-1 (AEG-1) on angiogenesis in tongue squamous cell carcinoma (TSCC) in TSCC cell lines. METHODS: The different degrees of angiogenesis were detected in TSCC cell lines expressing different levels of AEG-1 by chick chorioallantoic membrane (CAM) experimental model. Next, we established xenografts of different TSCC cell lines with different expression levels of AEG-1 in nude mice and conducted immunohistochemistry to evaluate the expression of the angiogenesis-associated factor, that is, vascular endothelial growth receptor factor 2 (VEGFR-2) and microvessel density (MVD). Vascular endothelial growth factor (VEGF) was detected by ELISA. RESULTS: CAM assay showed that the number of vessels was significantly reduced in AEG-1-down um1 cell line (p < .05), whereas the number was significantly increased in AEG-1-over um2 cell line (p < .05). Moreover, up-regulated AEG-1 expression level was associated with higher tumor angiogenesis, which was reflected by augmented expression levels of VEGF (p < .01), VEGFR-2 (p < .05), and MVD counting (p < .01). CONCLUSIONS: This study demonstrated that AEG-1 can promote tumor angiogenesis in TSCC and inhibition of tumor angiogenesis by repressing the expression of AEG-1 may be a novel potential treatment approach for TSCC.

Knockdown of Cdc6 inhibits proliferation of tongue squamous cell carcinoma Tca8113 cells.

The present study aimed at evaluating the effects of Cdc6 downregulation on the proliferation of Tca8113 cells. Two lentiviral vectors (KD1 and KD2) expression cdc6 siRNA were constructed and then infected into Tca8113 cells. Real-time PCR and Western blot analysis were performed to detect the mRNA and protein expression of Cdc6. MTT assays were employed to delineate the growth curves, and flow cytometry was performed to assess cell-cycle progression and apoptosis in Tca8113 cells. Following infection with the lentiviral vectors, real-time PCR and Western blot analysis revealed that Cdc6 expression was markedly suppressed in Tca8113 cells. When compared with the negative control group, the mRNA expression of Cdc6 was reduced by 50% and 65% and the protein expression by 65.87% and 79.38% in cells harboring KD1 or KD2, respectively. Cell growth was slowed, and the growth inhibition rate was 25.84% and 30.34% in Tca8113 cells following infection with KD1 or KD2, respectively. In addition, cell-cycle progression was altered. In KD- infected Tca8113 cells, the proportion of cells in the S phase was markedly reduced, but the proportion in the G1 phase was significantly increased; this was accompanied by an increase in cell apoptosis. Downregulation of Cdc6 effectively inhibited the proliferation of Tca8113 cells.

Pulmonary metastases from an Ameloblastoma: case report and review of the literature.

Ameloblastomas have a high recurrence rate, and because of their biological tendency towards local invasion are considered borderline tumours. Despite this, reports of metastasis of these tumours are rare. This report presents a patient with mandibular ameloblastoma that recurred 29 years after surgery and metastasized to both lungs. Because of the large range of the area of metastasis, complete surgical resection of the tumours was impossible. After confirming the diagnosis by biopsy of the pulmonary lesions the pulmonary metastases were not treated actively. Observation over 4 years showed no obvious change in the lung metastasis. Recent cases are summarized and analyzed in this paper, with respect to its occurrence, pathological types, methods of treatment and other related aspects.

Spatio-temporal localization of HIF-1alpha and COX-2 during irradiation-induced oral mucositis in a rat model system.

PURPOSE: Oral mucositis is a common side effect of radiotherapy for head and neck cancer. The purpose of this study was to examine the significance of and the relationship between hypoxia inducible factor-1alpha (HIF-1alpha) and cyclooxygenase-2 (COX-2) gene expression and the corresponding protein levels in irradiated rat mucosa. MATERIAL AND METHODS: A Sprague-Dawley rat model of irradiation-induced oral mucositis was generated. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the HIF-1alpha and COX-2 mRNA level in rat buccal mucosa exposed to a fractionated irradiation regime. The Streptavidin-Biotin-Complex method was applied to delineate the in situ localization, intensity, and distribution of both proteins. The right buccal mucosa was not irradiated and used as control tissue. RESULTS: The RT-PCR analyses demonstrated that, upon irradiation, HIF-1alpha and COX-2 expression was significantly induced in the left buccal mucosa in contrast to control buccal mucosa. Based on immunohistochemical analyses, the HIF-1alpha and COX-2 level, in situ localization, and the type of cells exhibiting the highest HIF-1alpha and COX-2 amounts appear to correlate. CONCLUSIONS: The expression and protein levels of HIF-1alpha and COX-2 are substantially enhanced in irradiated rat mucosa and correlate with each other and with the severity of irradiation-induced oral mucositis.

Expression of Mcm7 and Cdc6 in oral squamous cell carcinoma and precancerous lesions.

BACKGROUND: The present study aimed at evaluating the clinical importance of Mcm7 and Cdc6 expression in oral squamous cell carcinoma (OSCC) and precancerous lesions. MATERIALS AND METHODS: RT-PCR and immunohistochemistry analysis were performed on 47 frozen samples and 98 paraffin-embedded samples to evaluate the mRNA and protein expressions of Mcm7 and Cdc6. RESULTS: RT-PCR and immunohistochemistry indicated positive expressions of Mcm7 mRNA and protein in normal oral mucosa, precancerous lesions and OSCC. Significant differences were found between all the groups. Cdc6 mRNA and protein had low expressions in normal oral mucosa but were highly expressed in precancerous lesions and OSCC. Mcm7 and Cdc6 expressions in the lymph node metastasis cases were significantly higher than those of the nonmetastatic carcinomas. CONCLUSION: High expressions of Mcm7 and Cdc6 are correlated with the development and metastasis of OSCC and may become a molecular marker for the early diagnosis and prognosis prediction for OSCC.

mRNA expression of the DNA replication-initiation proteins in epithelial dysplasia and squamous cell carcinoma of the tongue.

BACKGROUND: The tongue squamous cell carcinomas (SCCs) are characterized by high mitotic activity, and early detection is desirable. Overexpression of the DNA replication-initiation proteins has been associated with dysplasia and malignancy. Our aim was to determine whether these proteins are useful biomarkers for assessing the development of tongue SCC. METHODS: We analyzed the mRNA expression of CDC6, CDT1, MCM2 and CDC45 in formalin-fixed, paraffin-embedded benign and malignant tongue tissues using quantitative real-time PCR followed by statistical analysis. RESULTS: We found that the expression levels are significantly higher in malignant SCC than mild precancerous epithelial dysplasia, and the expression levels in general increase with increasing grade of precancerous lesions from mild, moderate to severe epithelial dysplasia. CDC6 and CDC45 expression is dependent of the dysplasia grade and lymph node status. CDT1 expression is higher in severe dysplasia than in mild and moderate dysplasia. MCM2 expression is dependent of the dysplasia grade, lymph node status and clinical stage. The expression of the four genes is independent of tumor size or histological grade. A simple linear regression analysis revealed a linear increase in the mRNA levels of the four genes from the mild to severe dysplasia and SCC. A strong association was established between CDC6 and CDT1, and between MCM2 and CDC45 expression. The nonparametric receiver operating characteristic analysis suggested that MCM2 and CDC45 had a higher accuracy than CDC6 and CDT1 for distinguishing dysplasia from tongue SCC. CONCLUSION: These proteins can be used as biomarkers to distinguish precancerous dysplasia from SCC and are useful for early detection and diagnosis of SCC as an adjunct to clinicopathological parameters.

[Potential of cdc25A-Fas chimeric expression vector in inducing apoptosis of Tca8113 cells in vitro].

BACKGROUND & OBJECTIVE: Previous studies have revealed the close relationship between Fas/FasL pathway and carcinogenesis of oral squamous cell carcinoma (OSCC). This study was designed to explore the potential of cdc25A-Fas chimeric expression vector in inducing apoptosis of human OSCC cell line Tca8113. METHODS: The 2 chimeric expression vector pAdTrack-CMV-cdc25A-Fas (pCCF), and pAdTrack-cdc25A-Fas (pCF) were constructed by gene engineering, pCCF, pCF, and the control plasmid pAdTrack-CMV were transfected into Tca8113 cells by liposome, respectively. The transfection efficiency was presented by the expression of the report gene, green fluorescence protein (GFP). The mRNA and protein levels of Fas were determined by Northern blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and immunohistochemistry methods. The apoptosis of transfected Tca8113 cells was analyzed by techniques of DNA agarose gel electrophoresis, TUNEL, Annexin V label, and flow cytometry (FCM). RESULTS: (1) The chimeric expression vectors pCCF, and pCF were successfully transfected into Tca8113 cells and the maximum transfection (15%) was observed at the 5th-7th day after transfection. (2) Up-regulation of Fas expression was detected at the 3rd day after transfection in pCCF, and pCF transfection groups. At 3rd, 5th, and 7th day after transfection, Fas protein was found to express on membrane and in plasma of transfected Tca8113 cells with distinct morphology of partial apoptosis. (3) From 2.5 days after transfection, early apoptosis had been observed in pCCF, and pCF transfection groups. At 3rd day, the increased apoptosis index (AI,=25%) of pCCF, and pCF transfection groups was significant higher than that of control group (P< 0.05), whereas there was no significant difference in AI between pCCF transfection group and pCF transfection group (P >0.05). (4) FCM analysis showed that the peak of GFP-expression cells was identical to that of the apoptotic cells. CONCLUSION: The cdc25A-Fas chimeric expression vector was able to initiate the apoptosis of Tca8113 cells by up-regulating Fas expression. This result indicated that the 27 bp cdc25A fragment can be designed as a cis-regulatory element to modulate the effects of C-Myc/Max in cellular proliferation and apoptosis.