Susceptibility of colorectal cancer cells to sindbis virus infection
Chao Li, Youling Gu, Dario Andrade and Yuechueng Liu
Sindbis virus (SIN), a member of the Togaviridae family, infects a broad range of cells and has been shown to be an effective anti-tumor agent. The infection efficiency of the virus, however, varies greatly among target cells. In this report, we compared the ability of SIN to infect colorectal cancer cells and cells of other cancer origin. While tumor cells from breast, leukemia, and prostate cancers were largely resistant to SIN infection, nine of the ten colorectal cancer cell lines tested were sensitive to SIN infection. Moreover, SIN susceptibility correlated with the metastatic potential of the colorectal cancer cells. Two highly aggressive and invasive cell lines, SW620 and COLO-320DM were the most sensitive to SIN infection. Similarly, SIN preferentially targeted metastatic tumor cells in a mouse xenograft model for colon cancer progression. The higher infection rate was not due to increased expression of the 67 kD laminin receptor, a specific receptor for SIN infection, although viral attachment and entry were markedly enhanced in SW620 cells. These results suggest that SIN may employ a novel cell attachment/entry mechanism during infection, allowing selective targeting of colorectal cancer cells.
Keywords: Colorectal cancer, oncolytic virus, Sindbis virus, laminin receptor