The Preliminary Study Of Correlation Between TGFβ1and DNA-PKcs Protein Expression In Cervical Cancer Tissues And Cell Lines Before And After Radiotherapy And The Short Term Effect

Objective:To detect the correlation between the expression of transforming growthfactorβ1(TGFβ1) and DNA dependent protein kinase catalytic subunit (DNA-PKcs)protein in cervical carcinoma tissues、cervical adenocarcinoma Hela cell line andsquamous carcinoma Siha cell line before and after the X-ray and short term effect.Methods:1)The cervical cancer tissue samples from the patients before radiotherapyand those received cumulative radiation dose to10Gy were respectively collected,then immunohistochemical staining and photodensitometry was performed to comparethe changes of expression of TGFβ1and DNA-Pkcs proteins before and afterradiotherapy in cervical carcinoma. The regression of tumor in patients duringradiotherapy was also observed and the correlation between the expression of twoproteins and short term effect was analyzed.2) The cervical adenocarcinoma Hela cellline and squamous carcinoma Siha cell line were received gradually increasing doses(2Gy、4Gy、6Gy、8Gy、10Gy) X-ray irradiation, thereafter immunohistochemicalstaining of cell lines and photodensitometry were carried on to compare theexpression of TGFβ1and DNA-Pkcs proteins, and the curve of cell growth was drawnwith the tumor potential doubling time (Tpot) and the proliferation inhibition rateswere detected by clone formation assay. The correlation between the two proteinexpression and the proliferation of the cell lines was analyzed.Results:1)The expression of TGFβ1protein was increased in12cases of cervical carcinoma tissues after radiotherapy (P<0.05), however, the expression of DNA-PKcsprotein decreased slightly without statistical significance (P>0.05). The correlation ofthe two proteins expression was not significant before and after radiotherapy(r=-0.156，P>0.05; r=-0.287，P>0.05, respectively). No significant correlation wasfound between the two proteins expression and half-elimination time of the tumor orcomplete tumor regression time.2)The expression of TGFβ1and DNA-PKcs proteinin Hela and Siha cell lines was increased with increasing doses of X-ray, the highestexpression of two proteins was found at6Gy, then decreased gradually. The expressionof DNA-PKcs protein in Hela and Siha cell lines formed a negative correlation withTpo（tr=-0.817, P<0.05; r=-0.850, P<0.05, respectively）, but the expression of TGFβ1protein in Hela and Siha cell lines formed no significant correlation with Tpot（r=-0.729, P>0.05; r=-0-440, P>0.05, respectively）. There was no significantcorrelation between the expression of two proteins in Hela and Siha cell lines(r=0.794，P>0.05；r=0.766，P>0.05, respectively). Wilcoxon signed rank test showedno significant difference of the expression of TGFβ1and DNA-PKcs proteins in Helaand Siha cell lines（P>0.10）. Clone formation assay showed that the proliferationinhibition rates of the two cell lines were gradually increased with ascending doses ofX-ray irradiation.Conclusion:1) In cervical cancer, the expression of TGFβ1protein increased afterthe X-ray irradiation, but there was no significant change of DNA-PKcs protein.Neither the correlation between the two protein nor the correlation between them andthe short term effect were significant.2)In Hela and Siha cell lines, the expression ofTGFβ1and DNA-PKcs proteins increased with rising radiation doses. There was nosignificant correlation between the expression of two proteins in Hela and Siha celllines. The expression of DNA-PKcs proteins expressed a negative correlation withTpot, which indicated that the overexpression of DNA-PKcs proteins may be relatedto the acceleration of cell proliferation in radiotherapy; but the expression of TGFβ1proteins expressed no significant correlation with Tpot, which indicated that theexpression of DNA-PKcs proteins may be not related to the acceleration of cell proliferation in radiotherapy.