ESCC cell line KYSE180-GFP (GFP lentivirus transfected into KYSE180) were subcutaneously injected to nude mice. GFP fluorescence is properly detected under in vivo imaging system 7 days after the injection. However, after 20 days, GFP fluorescence couldnot been detected. Then I do flow cytometry of the tumor cells, there was no GFP positive cells either. Why did this happen?
There may be several reasons
1. The cells may not have stable integration of GFP in the genome.
2. Death of GFP +ve cell population, where a non-GFP clone has advantages if a heterogeneous population exists. GFP levels will be variable in the larger, expanded cell population.
3. Immunogenicity of GFP
4. Cytotoxicity of GFP (ROS-mediated) can clear the cells in long term
5. Certain metabolites/compounds (Salicylic acid) can reduce GFP fluorescence
6. Epigenetic Modulation on Reporter gene expression
A careful analysis is needed to understand what's happening in your case.
There may be several reasons
1. The cells may not have stable integration of GFP in the genome.
2. Death of GFP +ve cell population, where a non-GFP clone has advantages if a heterogeneous population exists. GFP levels will be variable in the larger, expanded cell population.
3. Immunogenicity of GFP
4. Cytotoxicity of GFP (ROS-mediated) can clear the cells in long term
5. Certain metabolites/compounds (Salicylic acid) can reduce GFP fluorescence
6. Epigenetic Modulation on Reporter gene expression
A careful analysis is needed to understand what's happening in your case.
Hi Jiao Huang,
I'm agree with Manash K Paul's answer. Have some more information regarding it by checking the following link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3190146/
Regards
Article Comparison of the EF-1α and the CMV promoter for engineering...
Gaurav Sharma Manash K Paul Hi Thanks a lot. I also found an article says different promoters affect the stability .
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