Study Of Mechanism For Expression Of GRIM-19 On Inhibition Of Cervical Cancer Cell Xenograft Tumor

[Background] Cervical cancer in developing countries is still one of the most common morbidity and mortality diseases of in female genital tract malignant tumors. For cervical carcinoma, one important pathogenic factor is the human papilloma virus (human papillomavirus, HPV) infection, and HPV subtypes have been identified up to more than 120 kinds of high-risk HPV (high-risk HPV, HR-HPV) such as HPV16, 18 and so on, which are closely related with the incidence of CIN and cervical cancer. The therapies of treating cervical cancer include surgery, radiation therapy, and chemo- therapy. As the representative of the biological treatment, gene therapy has become the fourth treatment modality. Gene therapy is to deliver target genes into the target cells by gene transfer technology to obtain a specific treatment function, and then execute or mediate tumor killing to achieve the therapeutic purposes. Clinical efficacy has been made in certain drugs such as Trastuzumab. Interferon treatment for viral infection is now used commonly, but the effect of its anti-cervical cancer is not obvious. Gene associated with retinoid-interferon-induced mortality-19 (GRIM-19) is a novel apoptosis gene, which can induce cell apoptosis through a variety of mechanisms. The expression of GRIM-19 in normal cells can maintain a normal life cycle, so that cells from aging to apoptosis; while the low expression of GRIM-19 in certain cells do not normally enter the normal cell cycle, these cells then were transformed into tumors. Previous research has found that the expression of GRIM-19 in cervical tissues significantly reduced in vitro. After transfection of GRIM-19 into cervical cancer cell lines, we found a significant slow down in cell proliferation in vitro, and suppressed the tumor growth in vivo, but the specific mechanisms of GRIM-19 in inhibition of the growth of human cervical cancer were still unclear.[Objectives] To clarify the expression of GRIM-19 specific mechanisms of inhibiting tumor growth from four respects: cell invasion, cell proliferation, apoptosis and angiogenesis[Methods] The extraction tumor tissues were tested the following indicators:â‘ The expression of Ki-67, micro-vessel density was detected in tissue sections by immunohistochemical staining;â‘¡The protein expression of GRIM-19, STAT3, p-STAT3, survivin , MMP-2, MMP-9, VEGF was detected by Western Blot;â‘¢The expression of GRIM-19, STAT3, cyclin B1, Bcl-L2 was investigated by RT-PCR;â‘£cell apoptosis was examined by Tunel test.[Results] Compared with xenograft tumor of HeLa/Con cells, the transplanted tumors from HeLa/GRIM-19 cells have the following characteristics:â‘ immunohistochemistry results showed that the expression of Ki-67 significantly decreased, RT-PCR and Western Blot results suggested that STAT3 and its downstream gene expression are significantly reduced, indicating that GRIM-19 gene could inhibit cell proliferation;â‘¡The expression of MMP-2, MMP-9 was inhibited, indicating that GRIM-19 gene could inhibit malignant cell invasion;â‘¢A significant reduction of microvessel density was found in tumor slides; the expression of VEGF is inhibited, indicating that GRIM-19 gene has a role in inhibiting tumor angiogenesis;â‘£The results of Tunel showed a significant increase in apoptotic cells in tumor slides.[Conclusion] The expression of GRIM-19 inhibits the proliferation angiogenesis, cell invasion of cervical carcinoma, and promoted apoptosis of tumor cells. Improving the GRIM-19 expression in cells is expected to becoming the new way for cervical cancer therapy.