Vesicular Stomatitis Virus Matrix Protein Gene Enhances The Antitumor Effects Of Radiation In Mice

Vesicular stomatitis virus (VSV) matrix (M) protein can directly induce apoptosis by inhibiting host gene expression when expressed in the absence of other viral components. We found that the M protein gene complexed to DOTAP- cholesterol liposome (Lip-MP) can suppress malignant tumor growth in vitro and in vivo. Radiotherapy is one of the most widely utilized and effective therapies for cancer.But little is known about the biological effect of Lip-MP combined with radiation. The present study was designed to determine whether Lip-MP enhances the antitumor activity of radiation in vitro and in vivo.Lewis lung carcinoma (LL2) cells treated with Lip-MP plus radiation, displayed the apparently increased apoptotic cells compared with treatment with Lip-MP or radiation alone. Mice bearing LL2 or Meth A fibrosarcoma (Meth A) were treated with intratumoral or intravenous injections of Lip-MP (50μg or 30μg/day, 0, 3, 6, 9 day) plus radiation (LL2: 5Gy/day and Meth A: 4Gy/day, 2～6days). Combined treatment with Lip-MP and radiation significantly reduced mean tumor volumes compared with either treatment alone in both tumor models and prolong survival time Meth A tumor models and intravenous injections group of LL2 tumor models. And antitumor effects...