Study Of Clinical Function In Thyroid Gland Of Apoptosis's Related Gene Bcl-2, Bax And NF-KB

Thyroid carcinoma is the most common malignant tumor in otolaryngology-head and neck surgery. It is well known that cell apoptosis is significantly related to carcinogenesis. Imbalance of cells in proliferation and apoptosis play impotent roles in the development and progression of cancer. Apoptosis is regulated by serial of genes and their productions. The genes related to apoptosis are usually classified into two groups according to their roles, one for enhancing cell apoptosis, such as Bcl-2 and another for inhibiting cell apoptosis, such as Bax. Over-expression of Bcl-2 protein was associated with low apoptosis in neoplasm tissues. And over-expression of Bcl-2 had been observed in most of malignant tumors, such as non-small cell lung cancer, nasopharyngeal carcinoma, womb carcinoma, gastric carcinoma and breast cancer. Therefore, Bcl-2 plays important roles in the regulation of apoptosis and development of human cancer. Bax gene is located in a lot of organs such as brain, stomach and thymus gland. Abnormalities of balance in two genes develop a various carcinomas in some organs. NF-kB is a potential transcription factor that regulates apoptosis, immunologic reaction and inflammatory.NF-kB has functions in enhancing survival rate of cancer cells through regulating the activation of several genes and promoting the expression of anti-apoptosis proteins. A number of studies have shown that cancer cells were all death under the roles of radiation and TNF when mutant IKB was transfected into cancer cells in vitro. Effects of suppression of mutant IKB on cancer cells are involving in inhibitingfunction of NF-KB when NF-KB connects with IkB. The genes regulated by NF-kB play important roles in tumor invasion and metastasis. A number of studies have shown that migration and invasion of cancer cell are a preconditional for the tumor diffusion and metastasis. Analysis of the NF-kB has found that there is a recognition site of NF-kB in cell adhesion molecules gene and NF-kB shows functional significance in cell adhesiveness and metastasis due to high expressions of adhesive protein stimulated by NF-kB. NF-kB also promotes the tumor metastasis by up-regulating the expression of MHC-I gene and decreasing immunologic reaction because NF-kB recognizes the site of MHC-I gene. NF-kB has functions in a positive regulation of the expression of protein hydrolytic enzyme in extracellular matrix. Degradation of extracellular matrix and basement membrane cause the cancer invasion. Recently, a lot of studies have been demonstrated that high expression of NF-kB was detected in the most of human cancers such as osteosarcoma, ovary cancer, breast cancer, hepatocarcinoma, glioma and carcinoma of bladder. Over-expression of NF-kB is associated with the tissue types, WHO types and prognosis of osteosarcoma. Therefore, it is a good way to inhibit the activation of NF-kB for enhancement of apoptosis. It is reported that NF-kB was associated with Bcl-2.The development of thyroid carcinoma is significantly associated with the genes related to apoptosis Studies of Bcl-2 gene family have been revealed that abnormalities of Bcl-2 expression were found in thyroid carcinoma, and little is known about the relation of NF-kB to thyroid carcinomaand the correlation between NF-kB and Bcl-2 in thyroid carcinoma. The aims of this study are to analyses the relationship between the expressions of Bcl-2, Bax and NF-kB and clinicopathological factors, as well as to better explore the correlation between Bcl-2 and NF-kB in the development of thyroid carcinoma. By using the method of immunohistochemistry. we detected the expressions of Bcl-2, Bax and NF-kB in 34 cases of thyroid carcinoma, 9 cases of thyroid tumor and 10 cases of nodular goiter.Our results are as follows:1. The expression of Bcl-2 was positive in 25 of 34 cases with thyroid cancer (75.76%), and negative in both 9 cases with thyroid tumor and 10 cases with nodular goiter.2. Bcl-2 expression of thyroid cancer was not associated with age, sex, histological type, clinical stage and...