AAV-mediated human PEDF inhibits tumor growth and metastasis in murine colorectal peritoneal carcinomatosis model
oleh: Wu Qin Jie, Gong Chang Yang, Luo Shun Tao, Zhang Dong Mei, Zhang Shuang, Shi Hua Shan, Lu Lian, Yan Heng Xiu, He Sha Sha, Li Dan Dan, Yang Li, Zhao Xia, Wei Yu Quan
| Format: | Article |
|---|---|
| Diterbitkan: | BMC 2012-03-01 |
Deskripsi
<p>Abstract</p> <p>Background</p> <p>Angiogenesis plays an important role in tumor growth and metastasis, therefore antiangiogenic therapy was widely investigated as a promising approach for cancer therapy. Recently, pigment epithelium-derived factor (PEDF) has been shown to be the most potent inhibitor of angiogenesis. Adeno-associated virus (AAV) vectors have been intensively studied due to their wide tropisms, nonpathogenicity, and long-term transgene expression <it>in vivo</it>. The objective of this work was to evaluate the ability of AAV-mediated human PEDF (hPEDF) as a potent tumor suppressor and a potential candidate for cancer gene therapy.</p> <p>Methods</p> <p>Recombinant AAV<sub>2 </sub>encoding hPEDF (rAAV<sub>2</sub>-hPEDF) was constructed and produced, and then was assigned for <it>in vitro </it>and <it>in vivo </it>experiments. Conditioned medium from cells infected with rAAV<sub>2</sub>-hPEDF was used for cell proliferation and tube formation tests of human umbilical vein endothelial cells (HUVECs). Subsequently, colorectal peritoneal carcinomatosis (CRPC) mouse model was established and treated with rAAV<sub>2</sub>-hPEDF. Therapeutic efficacy of rAAV<sub>2</sub>-hPEDF were investigated, including tumor growth and metastasis, survival time, microvessel density (MVD) and apoptosis index of tumor tissues, and hPEDF levels in serum and ascites.</p> <p>Results</p> <p>rAAV<sub>2</sub>-hPEDF was successfully constructed, and transmission electron microscope (TEM) showed that rAAV<sub>2</sub>-hPEDF particles were non-enveloped icosahedral shape with a diameter of approximately 20 nm. rAAV<sub>2</sub>-hPEDF-infected cells expressed hPEDF protein, and the conditioned medium from infected cells inhibited proliferation and tube-formation of HUVECs <it>in vitro</it>. Furthermore, in CRPC mouse model, rAAV<sub>2</sub>-hPEDF significantly suppressed tumor growth and metastasis, and prolonged survival time of treated mice. Immunofluorescence studies indicated that rAAV<sub>2</sub>-hPEDF could inhibit angiogenesis and induce apoptosis in tumor tissues. Besides, hPEDF levels in serum and ascites of rAAV<sub>2</sub>-hPEDF-treated mice were significant higher than those in rAAV<sub>2</sub>-null or normal saline (NS) groups.</p> <p>Conclusions</p> <p>Thus, our results suggest that rAAV<sub>2</sub>-hPEDF may be a potential candidate as an antiangiogenic therapy agent.</p>