| BackgroundAdenoid cystic carcinoma (ACC) is a kind of malignant tumor originated from glandular organ. In the maxillofacial region, the salivary glands are particularly affected by ACC and, less frequently, the lacrimal glands. ACC of the lacrimal gland, the incidence rate of which ranked the second place (only after pleomorphic tumor) in lacrimal gland epithelial tumor, is the most common and malignant tumor in lacrimal gland epithelial tumor. The invasive biological behaviour is the main reason for the poor prognosis of this disease. At present, operation is the main conventional therapy for this disease, and radiotherapy plays an important role in the prevention of postoperative recurrence. Molecular biology believes that tumor is a kind of complex genetic disease with uncontrolled cell growth, lack of cell differentiation and cell dysplasia which were resulted from abnormal expression of genes caused by DNA damage in some chromosomes.Modern medcine thinks that the expression of tumor-related feature genes in different tissues (such as cancer, tumor and normal tissues) has difference in the process of the generation and development of tumors. The exploration and discovery of these feature genes with expression difference is critical for the further understanding of tumor pathogenesis, the improvement of targeted therapy and the early prevention and prognosis work. Survivn and Livin gene are two newly found anti-apoptosis proteins with expression specificity in IAPs family. They can directly or indirectly inhibit the activity of related factors in the process of Caspase-3apoptotic signal transduction, which is a focus of study. In addition, traditional Chinese medicine occupies an important position in modern anti-tumor drugs. Having obvious anti-tumor activity and function of adjuvant chemotherapy, extract of ginkgo biloba can inhibit the proliferation of tumor cell and accelerate the apoptosis of cell through regulating the expression of apoptotic gene; Moreover, it has less adverse effect on the cell in normal tissue. Extract of ginkgo biloba has been more and more widely applied in clinic.There have not been reports about the expression of Survivin, Livin and Caspase-3gene in ACC of the lacrimal gland and the effect of Ginkgo biloba extrac on the development and progression of LGCC till now.ObjectiveThis study devoted to find the expression differences of Survivin, Livin and Caspase-3in the ACC, pleomorphic adenoma and the normal tissue of the lacrimal gland and investigate the role that these three genes play in the tumorigenesis and development of ACC of the lacrimal gland, as well as the relationship between the clinical prognosis of this disease and these genes.We also devoted to determine the influence of EGB on the proliferation, apoptosis of ACC-2cell and the expression of Caspase-3,Livin and Survivin, which can provide certain theoretical basis for clarifying the pathogenesis of adenoid cystic carcinoma and exploring new direction of treatment.Methods1. RT-PCR, immunoblotting and immunohistochemistry were used to detect the expression of Survivin, Livin and Caspase-3in the ACC, pleomorphic adenoma and the normal tissue of the lacrimal gland.Then, mathematic algorithm was utilized to establish models about the expression correlation between genes2. The ACC-2cells of adenoid cystic carcinoma of the lacrimal gland were incubated in vitro. Cell proliferation was tested by MTT method. Annexin V/PI double-staining flow cytometer was used to detect cell apoptosis and cell cycle. Protein expression was measured by immunoblotting method in order to analyze the influence of EGB on the proliferation and apoptosis of ACC-2cells and the protein expression of Caspase-3, Livin and Survivin.Results1. Livin and Survivin were low or not expressed in the normal lacrimal gland tissue and highly expressed in pleomorphic adenoma and ACC of the lacrimal gland, and the expression amount increased with the increase of the malignant degree. Caspase-3was highly expressed in the normal lacrimal gland tissue, and the expression amount of which decreased with the increase of the malignant degree of pleomorphic adenoma and ACC of the lacrimal gland.2. The expressions of Livin and Survivin in the ACC of the lacrimal gland were negatively correlated with Caspase-3, but there was no correlation between the former two. The expressions of Caspase-3and Livin were closely related to the clinical stage, pathological type and metastasis of the ACC of the lacrimal gland, while Survivin was only related to tumor size and metastasis.3. EGB in different concentration had certain inhibitory effect on the in vitro proliferation of ACC-2cells, and the inhibitory effect increased with the increase of the EGB concentration. The dose-effect relationship was significant (P<0.01). EGB can gradually increase ACC-2cells in G0-G1stage and decrease it in G2-M and S stage. With the increase of dose, the apoptosis rate of ACC-2cell obviously increased. EGB in different concentration had certain inhibitory effect on the Livin and Survivin gene of ACC-2cells, and the inhibitory effect increased with the increase of the EGB concentration. On the contrary, the relative amount of Caspase-3gene gradually increased with the increase of the administration dosage of EGB.Conclusion1. The incidence of the ACC of the lacrimal gland may be related to the abnormal up-regulation of Livin and Survivin gene and the down-regulation of Caspase-3gene. The expressions of Caspase-3and Livin were closely related to the clinical stage, pathological type and metastasis of the ACC of the lacrimal gland, and Survivin was related to the tumor size and metastasis.2. The expressions of Livin and Survivin in the ACC of the lacrimal gland were negatively correlated with Caspase-3, but there was no correlation between the former two.3. EGB can inhibit the in vitro multiplication of ACC-2cells and promote the apoptosis. It has certain promotion effect on Caspase-3gene expression while some inhibtory effect on the expression of Livin and Survivin gene, and the promotion or inhibtory effect increases with the increase of dose. |
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