In Vitro Studies Of Combination Of Down-regulation Of Surviving Gene Expression With Chemotherapy In Induction Of Apoptosis In Hep-2 Cells

Laryngeal cancer is one of the most common malignant neoplasms, severely impair human health. In recent years the development of functional surgery for laryngeal cancer enabled the patient to obtain higher five year survival rate and satisfactory quality of life. There are still about 30-40% patients with laryngeal cancer died of recurrence and metastasis of carcinoma. Under of the rapid development of molecular biological technique and genetic engineering gene therapy increasingly receives value and demonstrates the good application prospect.The solid tumor is vascular-dependent pathological change. Vascular endotheliar growth factor (VEGF) is a specific and potent angiogenic factor. Theoretically down-regulation VEGF expression suppresses tumor development.Survivin was separated in 1997. Survivin is a new member of the inhibitor of apoptosis protein (IAPs) family. Survivin is expressed and over-expressed in a variety of human malignant tumors, but lacks expression in normal tissues. This unique localization of survivin causes it possibly to become potential target of the tumor gene therapy. Anti-cancer therapy targeting surviving may block its anti-apoptosis pathway, only kills the tumor cell, and does not injure the normal cell. In this study we observed the effect of combination of treatment of chemotherapy with down-regulation of surviving gene expression the on tumor cells.we investigate the ability of induction of apoptosis and inhibition of VEGF expression by down-regulation the expression of anti-apoptosis gene survivin expression in Hep-2 cells using antisense surviving RNA. In the meantime This study opens up new ideas (or possibilities) for treatment of laryngeal carcinomaThis study is classified into the following sections:1. The role of antisense survivin RNA vector in Hep-2 apoptosis and proliferation in vitro:We observed that the effect of transfected anti-sense surviving RNA on tumor cell proliferation in vitro by the growth curve, MTT assay, flow cytometry and electronic microscope. The results suggested the growth and proliferation of Hep-2 cells transfected with the recombinant of antisense survivin RNA vector (HpEGFP/Survivin) were suppressed significantly than those not transfected cells with empty vector (HpEGFP-C1) (p<0.01).This showed that anti-sense surviving RNA inhibits tumor cell proliferation in vitro and the combination of cisplatin (CDDP) and 5-fluorouracil (5-FU) with down-regulation of surviving gene expression by anti-sense surviving RNA enhances inhibition of tumor cell proliferation.2. VEGF expression in laryngeal carcinoma:By immunohistochemistrial analysis high expression of VEGF was observed in 39 of 54 patients with laryngeal squamous cell carcinoma. The intensity of VEGF expression was significantly correlated with severity of laryngeal carcinoma. VEGF expression in lymph node metastasis group is higher than that non-lymph node metastasis. This demonstrated that VEGF expression was closely correlated with tumorgenesis and metastasis in the human laryngeal cancer.3. VEGF expression in Hep-2 cell.VEGF expression is less in HpEGF/Survivin then in Hep-2 and HpEGF-C1.Conclusions:1. The recombinant of antisense survivin RNA could induce apoptosis of Hep-2 cells by down-regulating expression of endogenous survivin in vitro.2. Combination of chemotherapy with down-regulation of surviving gene expression enhances induction of apoptosis in Hep-2 cells3. VEGF is high expression in laryngeal carcinoma.4. VEGF is lower expression in Hep-2 cell of the recombinanting antisense survivin RNA...