ABSTRACT
Objective To inhibit the gene expression of signal transducer and activator of transcription factor 1 (STAT1) in human esophageal squamous cell carcinoma cell line Eca109 by RNA interference and investigate its effect on the radiosensitivity and cell cycle of Eca109 cells.Methods Interference vector pSTAT1-shRNA for STAT1 gene was designed and constructed.After being mixed with lentiviral packaging plasmids,the interference vectors were used to transfected 293T cells.Virus solution was collected to infect ECA109 cells.Real-time PCR and Western blot were used to measure the mRNA and protein expression levels of STAT1 in Eca109 cells.Colony formation assay and flow cytometry were used to evaluate the radiosensitivity and cell cycle distribution of Eca109 cells.Results All Eca109 cells were divided into blank control group,transfection-positive group,and transfection-negative group.The transfection-positive group showed significantly lower mRNA and protein expression levels of STAT1 than the other two groups.The values of D0,SF2,and Dq of transfection-positive group were 2.03 Gy,0.83,and 1.20 Gy,respectively,lower than those of blank control group (2.98 Gy,0.88,and 1.39 Gy) and those of transfection-negative cells (3.02 Gy,0.88,and 1.57 Gy).At 12 h,24 h,and 48 h after 4 Gy-irradiation,the transfection-positive group showed significantly higher percentage of G0 + G1 than the blank control group and transfection-negative group (34.13％ vs 22.03％ vs 22.27％,F =7.56,P =0.023 ; 43.80％ vs 28.40％ vs28.63％,F=10.01,P=0.012;53.20％ vs42.2％ vs41.83％,F＝10.73,P=0.010) and significantly lower percentage of G2 + M than the blank control group and transfection-negative group (14.33％ vs 32.23％ vs 32.23％,F=16.86,P=0.003;27.73％ vs 43.53％ vs 44.00％,F=26.62,P=0.001;14.23％ vs27.97％ vs27.93％,F=40.34,P=0.000).Conclusions RNAinterference of STAT1 in Eca109 cells does not affect the proliferation ability of Eca109 cells,and it can increase the radiosensitivity of Eca109 cells probably by regulating cell cycle after irradiation.
ABSTRACT
Objective To explore the prognosis and its related factors of three-dimensional conformal radiotherapy (3D-CRT) for elderly patients with esophageal carcinoma. Methods From January 2001 to August 2007, 89 elderly patients aged 65 years or more with esophageal carcinoma were treated with 3D-CRT. And the local control rates, survival rates and its related prognostic factors were evaluated retrospectively, using SSPS11.5 software. Results The 1-, 2-, 3-and 4-year local recurrence-free survival rates were 65.2%, 43.0%, 27.3% and 22.3%, respectively. The 1-,2-, 3-and 4-year overall survival rates were 68.5%, 48.8%, 36.8% and 25.2%, respectively. And the median survival time was 21.5 months. With univariate analysis, the significant prognostic factors included the different diet before radiotherapy (χ~2=6.26, P=0. 012), T stage (χ~2=8. 80, P=0. 003), N stage (χ~2=4.33, P=0. 038), clinical stage (χ~2=7.88, P=0. 005), the largest diameter of tumor in CT scanning image (χ~2=10.88, P=0.004), recent efficacy (χ~2=5.28, P=0. 022) and chemotherapy (χ~2=5.49, P=0.019). And the factors which were not related with prognosis included gender (χ~2=0.74, P=0. 390), age (χ~2=1.89, P=0. 170), lesion length showed by esophageal angiography (χ~2=2. 38, P=0.123), lesion length showed by CT (χ~2=2.69, P=0.101),primary tumor site (χ~2=2.12, P=0. 146), coexistent disease (χ~2=0. 03, P=0. 874), exposure mode (χ~2=0.04, P=0.847) and radiation dose (χ~2=0. 24, P=0. 627). Multivariate analysis revealed that the different diet before treatment (P=0. 002), the clinical stage (P=0. 007) and chemotherapy (P=0. 011) were independent prognostic factors. Radiation induced esophagitis was observed in 20 cases in grade 0, 30 cases in grade 1, 32 cases in grade 2, 7 cases in grade 3. And acute radiation pneumonitis was observed in 89 patients, with 57 in grade 0, 20 in grade 1, 8 in grade 2, 2 in grade 3 and 2 in grade 5. Until the end date of follow-up, 60 patients had died: 29 cases died of local recurrence or uncontrolled disease, 11 cases died of metastasis, 5 cases died of local recurrence with metastasis, and 15 cases died of other reasons. Conclusions 3D-CRT can be considered as an effective and feasible approach for elderly patients with esophageal cancer. The 3D-CRT provides them with less obstruction of diet, early clinical stage and longer survival time. 3D-CRT combined with chemotherapy may improve survival rate.