The Study On Expression Of Survivin,Bcl-2 As Well As Their Relationship With Proliferation Activity And Apoptosis In Oromaxillofacial Sarcoma

Oromaxillofacial sarcoma(OMFS) is a malignant tumor originated from mesenchymal tissue of oral and maxillofacial region which not only has obvious difference of histology, many kinds and lower incidence rate but also is characterized by high malignant degree, early distant metastasis, insignificant effect for combined therapy and poor prognosis. So it is very difficult in treating the malignant tumor clinically. Molecular biology of tumors revealed that the imbalanced cell proliferation and cell apoptosis is an important mechanism of the tumorigenesis and progression. In recent years, the research of inhibitor apoptosis genes has been a hot topic in molecular oncology. Survivin is a new member of the IAPs(Inhibitor apoptosis of proteins) family. It regularly expresses in G2/M phase and suppresses the activity of caspase-3 and caspase-7 to inhibit cell apoptosis. It is also involved in regulation of proliferation. Bcl-2 protein is the most common antiapoptotic protein, which can inhibit cell apoptosis, decrease the need of growth factor for cell, prolong cell life. But Bcl-2 protein cannot contribute to cell proliferation. At present, little is known about study on the expression of Survivin , Bcl-2 as well as their relationship with proliferation activity and apoptosis in OMFS.Objective This study aimed at investigating the expression of Survivin , Bcl-2 aswell as their relationship with proliferation activity and apoptosis in OMFS in order to evaluate their roles in tumorigenesis and progression of OMFS,and understand the biological character of OMFS, so as to provide a potential new way for early diagnosis, prognosis assessment and indicating theraputics of OMFS.Materials and methods1. 37 OMFS samples, 14 benign mesenchymal tumor samples and 5 normal mesenchymal tissue samples were collected. The tissues were fixed in 10% formalin and embedded in paraffin. No patients had received preoperative chemotherapy, radiation therapy or other biological therapy.2. Immunohistochemical streptavidin peroxidase method was used to detect the expression of Survivin , Bcl-2 , PCNA in all samples. Cell apoptosis was examined by TUNEL method.3. The results were analyzed by SPSS 10.0 software wrap, using Chi-square, Fisher's exact test, analysis of variance (ANOVA) and t-test. Statistically significant level was considered as "alpha equals 0.05".Results1. The Survivin positive rate in oromaxillofacial sarcomas was 81.08% and none in benign tumors. The result showed a significant difference between the two groups(P<0.05). In highly, moderately and poorly differentiation OMFS groups, the positive rates of Survivin expression were 58.33%, 80.00% and 100.00% respectively, and a statistical significance was only observed for Survivin between the highly and poorly differentiation OMFS groups(P<0.05). The results showed no significant difference between the sarcomas with and without lymph node metastasis or sarcomas with local recurrence(P>0.05). The expression level of Survivin was higher in sarcomas with distant metastasis than those without distant metastasis, but there was no significant difference between the two groups(P>0.05).2. The Bcl-2 positive rate was 67.57% in OMFS group and 28.57% in benign tumor group respectively. The difference between them was significant(P<0.05). In highly, moderately and poorly differentiation OMFS groups, the positive rates of Bcl-2 expressionwere 41.67%, 70.00%, 86.67% respectively. And a statistical significance was only observed for Bcl-2 expression between the highly and poorly differentiation OMFS groups. No correlation was observed between expression of Bcl-2 protein and the biological behaviors of OMFS(P>0.05).3. Compared to benign mesenchymal tumors, PCNA proliferation index(PCNA-LI) was significantly higher in OMFS(P<0.05). The expression level of PCNA-LI tended to increase with the decrease of the degree of the histological differentiation. In highly, moderately and poorly differentiation OMFS groups, there were significant diffe...