Abstract:

[Abstract] Objective To investigate the effects of p53 on expression and activity of protein kinase R (PKR) as well as biological characters of HeLa cells from cervical carcinoma patients. Methods Recombinant plasmid vector pEGFPC1/p53 was constructed to over-express p53 then it was transfected into HeLa cells. Transcription levels of p53 and PKR mRNA were detected by reverse transcriptase polymerase chain reaction (RT-PCR) among pEGFP-C1/p53 transfection group, pEGFP-C1 transfection group and blank control group（only transfection reagent was added）； Protein expression lev? els of p53, PKR, phosphated PKR（p-PKR） and phosphated α subunit of eukaryotic initiation factor 2（p-eIF2α） which is the downstream substrate of PKR were detected by Western Blot among three groups； Proliferation of HeLa cell were deter? mined by methyl thiazolyl tetrazolium（MTT） assay； Invasion of HeLa cell were determined by Transwell cell assay. Results Recombinant plasmid vector pEGFP-C1/p53 was successfully constructed to overexpress p53； Transcription level of p53 and PKR mRNA in pEGFP-C1/p53 transfection group were higher than those in pEGFP-C1 transfection group and in blank control group (P＜ 0.05)， and there were no significant difference between their levels in pEGFP-C1 transfection group and in blank control group； Protein expression levels of p53, PKR, p-PKR andp-eIF2α in pEGFP-C1/p53 transfection group were higher than those in pEGFP-C1 transfection group and in blank control group (P＜ 0.05)， and there were no sig? nificant difference between those expression levels in pEGFP-C1 transfection group and in blank control group； MTT and Transwell cell results showed that proliferation and invasion of HeLa cells in pEGFP-C1/p53 transfection group were weaker than those in pEGFP-C1 transfection group and in blank control group (P＜ 0.05)， and there were no significant difference between proliferation and invasion of HeLa cells in pEGFP-C1 transfection group and in blank control group. Conclusion p53 can up-regulate the expression and activity of PKR, promote activation of PKR/eIF2α signal transduction pas? sage and restrain cell proliferation and invasion of HeLa cells.

Key words: genes, P53, cell proliferation, protein kinases, neoplasm invasiveness, &alpha, subunit of eukaryotic initiation factor 2