Related Experiment Video
Updated: Aug 18, 2026
Handling of the Cotton Rat in Studies for the Pre-clinical Evaluation of Oncolytic Viruses
Published on: November 24, 2014
Inefficient killing of quiescent human epithelial cells by replicating adenoviruses: potential implications for their
Mei Ting Vaillancourt1, Isabella Atencio, Erlinda Quijano
1Canji Inc., San Diego, California, USA. mei.vaillancourt@canji.com
Abstract:
Cultured primary human cells have been widely used to assess the selectivity of oncolytic viruses as potential anticancer agents. As culture conditions can potentially have a significant impact on virus replication and ultimately cell killing, we evaluated the effects of dl309, a wild-type adenovirus, and dl01 / 07, a conditionally replicating adenovirus mutant, on quiescent and proliferating primary mammary epithelial cells. When primary cells were induced into quiescence, both viruses exhibited similar attenuated cell killing. However, cell killing by dl309 was superior to dl01 / 07 in proliferating primary cells. Analysis of viral effects at the level of entry, E2F activation, DNA replication, and late gene expression indicated that attenuation of dl309 in quiescent cells correlated with decreased expression of viral late genes such as hexon. In contrast, attenuation of dl01 / 07 in quiescent cells correlated with inefficient induction of E2F activity and inability to undergo efficient DNA replication. In proliferating cells, dl309 replicated efficiently, whereas dl01 / 07 still showed attenuated replication. In summary, our results indicate the intrinsic preference of wild-type adenoviruses for killing proliferating cells, which is an attractive feature for using adenoviruses as oncolytic agents. These results also highlight the need for the use of appropriate growth conditions for primary cells in vitro to distinguish subtle differences in cell killing among various oncolytic viruses.
Insights
Wild-type adenovirus (dl309) effectively kills proliferating cancer cells, while a mutant virus (dl01/07) shows reduced efficacy. Cell growth conditions significantly impact oncolytic virus effectiveness.
Area of Science:
- Oncology
- Virology
- Cell Biology
Background:
- Primary human cells are crucial for evaluating oncolytic viruses as cancer therapies.
- Culture conditions can influence virus replication and cancer cell killing efficacy.
- Understanding these effects is vital for developing effective oncolytic virotherapy.
Purpose of the Study:
- To compare the efficacy of a wild-type adenovirus (dl309) and a mutant adenovirus (dl01/07) against quiescent and proliferating primary human mammary epithelial cells.
- To investigate the impact of cell proliferation status on adenovirus-mediated cell killing.
- To elucidate the mechanisms underlying differential viral replication and cell killing based on cell growth conditions.
Main Methods:
- Primary human mammary epithelial cells were cultured under quiescent and proliferating conditions.
- Cells were infected with wild-type adenovirus (dl309) and mutant adenovirus (dl01/07).
- Viral effects were analyzed by assessing cell killing, viral entry, E2F activation, DNA replication, and late gene expression.
Main Results:
- Both viruses showed attenuated cell killing in quiescent cells.
- Wild-type dl309 demonstrated superior cell killing compared to dl01/07 in proliferating cells.
- Differential viral replication correlated with cell proliferation status, with dl309 replicating efficiently in proliferating cells while dl01/07 remained attenuated.
Conclusions:
- Wild-type adenoviruses intrinsically prefer proliferating cells, making them promising oncolytic agents.
- Cellular quiescence attenuates the efficacy of both wild-type and mutant adenoviruses.
- Appropriate in vitro culture conditions are essential for accurately assessing oncolytic virus performance and distinguishing subtle differences in cell killing.
Related Concept Videos
01:30Inhibitors of Viral Protein Synthesis
01:22Antiviral Nucleoside Inhibitors
01:51Mechanisms of Retrovirus-induced Cancers