Luciferase Reporter Stable Cell Line-MCF-7

A large body of clinical evidence supports the use of the cell cycle as a target for cancer therapy. The researchers developed genetically engineered bioluminescent reporter genes by fusing full-length cyclin E with C-terminal luciferase (named CycE-Luc and CycE-Luc2). Next, they transfected these reporter genes into the HeLa cell line or the ER-positive breast cancer cell line MCF-7. In cellular experiments, the bioluminescent signals of CycE-Luc and CycE-Luc2 accumulated in the G1 phase and decreased after exiting the G1 phase. Expression of the CycE-Luc and CycE-Luc2 fusion proteins was regulated in a cell-cycle-dependent manner mediated through ubiquitination and degradation by the proteasome. Researchers demonstrated in in vitro and in vivo experiments that these reporter genes can quantitatively and dynamically monitor cell cycle arrest induced by anticancer drugs (palbociclib or 5-FU) through real-time and non-invasive bioluminescence imaging. Thus, the ability of these optical reporter genes to reflect changes in the G1 phase of the cell cycle is expected to be a future translational clinical approach for predicting and monitoring the response to palbociclib in ER-positive breast cancer patients.

Figure 1. Researchers used the ER-positive breast cancer cell line MCF-7 to test whether the CycE-Luc2 reporter gene could monitor cell cycle changes. By treating CycE-Luc2 overexpressing MCF-7 cells with nocodazole or bis-thymidine blockade, it was found that luciferase activity was lowest under nocodazole treatment and highest 12 hours after release, whereas luciferase activity under bis-thymidine treatment was higher at 0 hours of release and lowest after 6 h, and then gradually increased. These results confirm the sensitivity of CycE-Luc2 in monitoring G1 phase in breast cancer cells. (Guo C, et al., 2021)