Study On Interleukin-7 Gene Therapy For Ovarian Carcinoma

Ovarian carcinoma is one of the tumors which are most difficult to cure. Although much improves have taken place in surgery, chemio- and radiation therapy for recent years, the five -survival rate of advanced ovarian carcinoma remains low. It is therefore obvious that other therapies must be developped to prolong survival of patients with advanced disease. Recently.Along with the development of cell and gene engineering techniques, cytokine gene therapy have progressed and become the hot spot in antitumor therapy. Ovarian carcinoma is thought to be an appropriate model of cytokine gene therapy because of its difficulty to treat and recurrence. Interleukin-7(IL-7) is a relatively new cytokine. It has originally been described as a growth factor for B cell progenitors. Further studies show that IL-7 and IL-2 share many of the immune modulatory effects. In particular, IL-7 promotes maturation of CD4+ and CDg+ T cells, stimulates resting T cells to proliferate and induces cytotoxic T cells and LAKs to activate. Indeed, IL-7 has a potential significance in antitumor function because of its biologic activity. Adoptive immune therapy and gene therapy are two hot spot of IL-7 antitumor study. Recent experimental and clinical studies suggested that after IL-7 transfection, melanoma, colon carcinoma, renal carcinoma and fibrosarcoma cells had IL-7 high expression with an increasing of tumor immunity and cytotoxic sensitivity to LAKs and a decreasing of tumorigenicity. However, no report has been found on IL-7 gene therapy for ovarian carcinoma till now. In the present study, IL-7cDNA were transfected into ovarian epithelial carcinoma cell line SKOV3, and changes of cell morphology,proliferation activity, immunity, cytokine secretion andcytotoxic sensitivity to LAKs were observed. Thereby, the potential value of IL-7 gene therapy for ovarian carcinoma was discussed.Part I Molecular Cloning of Human IL-7 and Construction of IL-7 Eukaryotic ExpressionVectorObjective: to construct IL-7 eukaryotic expression vector using molecular cloning techniques. Methods: hIL-7 cDNA was cloned from spleen tissue by RT-PCR and inserted into PMD18-T plasmid,and identified by DNA sequencing. The recombinant plasmids refered to pBK-CMV-hIL-7 were constructed by inserting the cloned hIL-7 cDNA into dual (prokaryotic and eukaryotic) expression vector pBK-CMV and transformed into E.coli DH5