Expression Of Stat3 Gene In Laryngeal Squamous Cell And Their Clinical Significance

Among the respiratory carcinoma, the incidence of laryngeal carcinoma is only inferior to pulmonary carcinoma, it is the most common malignant disease occurring in head and neck, and accounts for 5.7%-7.6% of all malignant tumors. The incidence of laryngeal cancer is rising year by year, because of various factors contributing to the oncogenesis of laryngeal cancer, such as smoking, alcohol, air pollution, viral infection, genetic background, sex hormone and so on.Although the operation technique has been improved greatly and other treatments such as radiotherapy, chemotherapy and photon therapy have taken effect, the survival rate of laryngeal cancer is still very low. Especially their curative effects are not optimistic to advanced stage and relapse and metastasis of laryngeal carcinoma, the results make many patients losing remedial opportunity. With unceasing advancement of the gene therapy technology, it has become a research focus to malignant tumors. A lot of scholars still explore gene to treat malignant tumors, and wish for gene therapy blocking development of malignant tumor at the molecular level. Consequently it offers a new opportunity for tumor treatment. The study has elucidated that physiological function of oncogene and anti-oncogene could accommodate cell proliferation and differentiation, the abnormality of their construction and expression is the important molecular basement for cells'cancerization. Their functional disorder is a principal mechanism of tumorigenesis. According to the studies in vitro, to block or inhibit the expression of anti-oncogene might inhibit proliferation of tumour cells. In the JAK-STAT path, STAT3(signal transducers and activators of transcription 3) is one important substrate for JAKs and it has been the key point in the path which persistent activation can result in the cells'abnormal proliferation and cancerization. And it has been confirmed that STAT3's over activation and expression has significant correlation with many malignant tumors, such as leukemia, multiple myeloma, SCCHN(squamous cell carcinoma of the head and neck), multiple melanoma, breast carcinoma, prostatic carcinoma, pulmonary carcinoma, gastric carcinoma, esophageal carcinoma, carcinoma of gallbladder and cutaneous carcinoma et al, which suggests that STAT3's over activation and expression is important for tumor cells'over proliferation. So that the blockade of STAT3 signal conduction path of tumor cell surely take effect in the treatment for tumors which has been confirmed by lately studies. In late years although internal and overseas scholars make in-depth studies to STAT3, and has proved that over activation and expression of STAT3 is intimately correlative with malignant tumorigenesis, there are few studies of STAT3 in laryngeal carcinoma. So our study aims at testing expression of STAT3 in human laryngeal squamousecarcinoma cell by immunochemistry, to explore its relationship with the develop- ment of laryngeal carcinoma. Accordingly it offers a theory reference for laryngeal carcinoma treatment.Immunohistochemical technique was used to examine expression of STAT3 in 38 cases of laryngeal cancer and 12 cases of control group, the results showed positive stainings of MT protein were localized in cell plasm. The positive rates of STAT3 in laryngeal cancer were significantly higher than those in normal tissues (P<0.01). The result indicates expression of STAT3 is relative to laryngeal tumorigenesis. STAT3 had a close relationship with histological grades(P<0.05). Overexpression of STAT3 protein was tested in the cancers with lymph nodes metastasis (P<0.05). It is indicated that more poorly differentiated laryngeal carcinoma, more high STAT3 expression. With the expression of STAT3 increas- ing, the rate of lymph-node- metabasis increased and the differentiation degree of laryngeal carcinomas increased, which suggests that the intensity of STAT3's expression might have intimated correlation with development of laryngeal carcinomas. There was no significant difference between the expression of STAT3 and tumor stage (P>0.05), the same results were observed also in the age term and the sex term (P>0.05). It implies that the expression of STAT3 is not correlated with disease region and extent of laryngeal carcinomas.The positive rates of STAT3 in laryngeal cancer were significantly higher than those in control group, and it have a significantly correlation with histological grades and cervical lymphnode metastasis. With the expression of STAT3 increasing, both of the rate of lymph node metastasis and the differentiation degree of laryngeal carcinomas increased. These results suggest that the high expression of STAT3 might have a correlation with some ill clinical pathology parameter and development of laryngeal carcinomas. So testing expression of STAT3 could conduce to auxiliary diagnosis and prognose of laryngeal carcinomas, for development and prognose of laryngeal carcinomas offering a new index. The blockade of STAT3 signal conduction path might inhibit proliferation of laryngeal carcinomas cell. It offers a new theory for gene treatment of laryngeal carcinomas.