Matrix Protein of Vesicular Stomatitis Virus Exhibits Extraordinary Antitumor Effect

Researchers at Sichuan University have discovered that the matrix protein of vesicular stomatitis virus (VSV) can induce remarkable apoptosis of cancer cells and initiate an immune response, leading to an extraordinary antitumor effect. This study provides promising results for the development of a novel cancer gene therapy agent. The researchers introduced the M protein plasmid into various tumor cell lines in vitro, including lung cancer cell LLC, A549, colon cancer cell CT26, and fibrosarcoma cell MethA. The results showed that the M protein induced apoptosis of cancer cells in vitro compared to controls.

Key Takeaways:

• The M protein of VSV can act as both an apoptosis inducer and immune response initiator, exhibiting an extraordinary antitumor effect.
• The researchers introduced the M protein plasmid into various tumor cell lines in vitro, including lung cancer cell LLC, A549, colon cancer cell CT26, and fibrosarcoma cell MethA.
• The results showed that the M protein induced apoptosis of cancer cells in vitro compared to controls, with a significant increase in apoptosis observed in M protein-treated tumor cells.
• Fifty micrograms of plasmid in a complex with 250 μg cationic liposome was injected intratumorally into mice bearing LLC or MethA tumor model every 3 days for 6 times, resulting in a significant delay in tumor growth.
• The researchers observed that the tumors treated with M protein plasmid were even completely regressed in MethA fibrosarcoma, with the mice acquiring longtime protection against the same tumor cell in rechallenge experiments.
• Activated cytotoxic T lymphocytes (CTLs) were further detected by means of 51Cr release assay in the spleen of the treated mice.

Statistics:

• 50 μg of plasmid was sufficient to induce apoptosis of cancer cells in vitro.
• 250 μg of cationic liposome was used to deliver the plasmid in vitro.
• Tumors treated with M protein plasmid grew much more slowly, with a significant increase in apoptosis observed compared to controls.
• The survival of mice bearing LLC or MethA tumor model was significantly prolonged when treated with M protein plasmid compared to controls.
• The M protein plasmid-treated tumor tissue showed widespread distribution of apoptotic cells and CD8+ T cells.

Sources:

• Zhao, J., Wen, Y., Li, Q., Wang, Y., Wu, H., Xu, J., Chen, X., Wu, Y., Fan, L., Yang, H., Liu, T., Ding, Z., Du, X., Diao, P., Li, J., Wu, H., Kan, B., Lei, S., Deng, H., Mao, Y., Zhao, X., Wei, Y. A promising cancer gene therapy agent based on the matrix protein of vesicular stomatitis virus. FASEB J. 22, 4272-4280 (2008).
• Federation American Society Experimental Biology. Faseb Journal.