Expression Of Fat-1 Gene Inhibits Proliferation Of Colon Cancer Cells HT-29

Objective To investigate the effect of fat-1 gene encoding n-3 fatty acid desaturase onproliferation and apoptosis of colon cancer cells HT-29.To construct and identify transgenic mice with fat-1 gene.Methods Constructed eukaryotic expression vector (pEGFP-fat-1), transfected intoHT-29 cells by liposomal reagent.The expression of fat-1 gene was detected byfluorescent micrographs and RT-PCR, Gas chromatography, MTT, flow cytometry wereused to examine the change of n-6/n-3 PUFAs ratio, proliferation, cell cycle, apoptosis,respectively, iNOS and COX-2 expression were examined by RT-PCR. Constructedanimal expression vector pEF-neo and microinjected into arsenoblasts of mousezygote.And then sent into uteruses of female mouse to produce transgenic mice.Thepositive G0 generation of fat-1 transgenic mice was identified by PCR and Southern blot.Results After transfection of fat-1 gene, n-6/n-3 PUFAs ratio was decreased significantly.Apoptosis of HT-29 cells was induced and cell cycle was changed. Apoptosis mainlyappeared in synthesis phase.The expression of iNOS and COX-2 were down-regulatedconsequently. Four G₀ generation mice were abtained.Conclusion fat-1 gene encoding n-3 fatty acid desaturase can significantly decreasen-6/n-3 ratio. Consequently,apoptosis was triggered and cell cycle was changed. It issuggested that iNOS/COX-2 -dependent mechanism is one of the ways to cause thesechange, fat-1 gene is able to be integrated into mouse to obtain transgenic mice, whichprovide the animal model to study fat-1 gene.