The Up-Regulation Of KCC1 Gene Expression In Cervical Cancer Cells By IGF-â…¡ Through The Erk1/2MAPK And PI3K/AKT Pathways And Its Significance

ObjectivesCervical cancer is the second most frequently occurred tumor in female reproductive system worldwide,and its incidence rate is rapidly increasing each year. The onset age is also getting younger as well,and now,it has become a major threat to female health.In many basic researches concerning cervical cancer,the infection of human papillomavirus(HPV)as a cause has been identified and proved.However,in females with HPV infected,only few have developed into cervical cancer,which suggests that there are many other factors involved even though on the basis of HPV infection.Currently,the reseaches in the etiology of the cervical cancer are mostly focused on the directions of genetics,physiology and pathematology such as oncogenes, anti-oncogene,cell signal transduction pathways,apoptosis,cell life cycle and so on.However,in the process of cancerization from normal cervix to uterine cervix cancer, ions' transduction systems which play an important role in the cell homeostasis regulation and related the intra-cellular and ecto-cellular regulation are not known very well,and the researches are seldomly publiched.KC1 co-transport(KCC)is a kind of cell surface membrane protein,divided into 4 sub-types,where KCC1,KCC3,and KCC4 can also induce K~+ and Cl~- ions' movement in pairs at the level of cell membrane.Their activation plays an important role in the cell volume regulation,epithelium transportation,and ionic balance.We have detected significant updegrade in genetic expression of KCC1 in cervical cancer tissues compared with that in normal tissues and cervical lesion precancerous tissues via immunohistochemistry and immunofluorescent analysis of surgical specimens in an early stage of our study.To investigate the intra-cellular and ecto-cellular regulation of genetic expression of KCC1 in cervical cancer and the related activation of signal transduction pathways,we the alternation effect of insulin-like growth factors-2(IGF-Ⅱ) on the expression of KC1 co-transport-1(KCC1)in the SiHa cells of cervical cancer, and to explore the activation of Erk1/2MAPK and PI3K/AKT signal transduction pathways during the expression process.MethodsTo apply semi-quantitative RT-PCR and Western-blot analysis to measure the change in mRNA and protein expression of KCC1 after exposure to different concentrations of IGF-Ⅱfor different time durations in the SiHa cells of cervical cancer. The change in protein expression of the Erk1/2 and AKT pathways is also measured. Furthermore,the protein expression variation in Erk1/2,AKT,and KCC1 is observed after the addition of specific pathway blocker for the Erk1/2MAPK and PI3K/AKT pathways.The Image PC alpha 9,image analysis system,is applied for the blotting results of RT-PCR and Western-blot,where the accumulative absorption rate is calculated for each band.And we adopt statistical method of one-factor analysis of variance.A probability value＜0.05 was considered statistically significant.ResultsAfter being treated with IGF-Ⅱ,the expression of KCC1mRNA and protein in SiHa cell increased obviously,showing a time-dose dependent relationship,and the activity and phosphorylation of Erk1/2 and AKT channel protein increased;after adding specific channel blocker,the two channel protein manifested no obvious phosphorylation after treated with IGF-Ⅱ,and the change of expression of KCC1 protein was not significant. ConclusionIGF-Ⅱcan enhance expression of KCC1 gene expression in cervical cancer cells, and this is achieved via Erk1/2MAPK and PI3K/AKT signal translantion ways. Apecific inhibition on signal transduction can in some degrees stop the up-regulation effect of IGF-Ⅱon the KCC1 expression in cervical cancer cells.