【Abstract】Objective To investigate whether SUMO-1 enhances the apoptosis induced by wild-type p53 plasmid transfection in HepG2 cells. Methods The HepG2 cells were transfected respectively or simultaneouly with the following expressional plasmids as pcDNA3-wtp53（pwtp53，including human wild-type p53 gene），pCMV-HDM1B（pMDM2，including HDM2 gene， homologous gene as murine double minute gene 2），pcDNA3-His6-SUMO-1（pSUMO-1 ，including small ubiquitin-like modifier1 gene）and plasmid pcDNA3.The proteins expressed in cells were detected by means of Western blotting and the apoptosis rates of cells were measured by flow cytometry. Results The protein bands of p53 and MDM2 could be seen in cells transfected with pwtp53 and pMDM2. Meanwhile，the relative larger molecular weight bands were also seen in cells transfected with pSUMO-1 which represented the p53 and MDM2 protein modification by SUMO-1. Merely the trace of p53 protein was detected in cells not transfected with any plasmid or only transfected with empty plasmid and pSUMO-1. In cells transfected with pwtp53 and pwtp53+pSUMO-1，the apoptosis rates were (16.79±1.62)%and (18.15±1.36)%. When transfected with pwtp53+pMDM2，the rate decreased to (5.17±1.23)%. The apoptosis rate would come up again to (14.06±1.84)% after transfected with pwtp53+pMDM2+pSUMO-1 and the difference of rates were significant compared to the cells transfected with pwtp53+pMDM2 (PH＜0.01）. The apoptosis rates in other cells were less than 2% and had no significant difference. Conclusion SUMO-1 could increase the apoptosis induced by wild-type p53 plasmid transfection in HepG2 cells through combining to p53 protein or its post-translational modification and inhibiting p53 degradation by MDM2.
【Abstract】Objective To investigate the change of vascular endothelial growth factor (VEGF) expression in HepG2 cells under hypoxia. Methods HepG2 cells were cultured under hypoxia（hypoxia group） and normal condition (control group). VEGF expression of HepG2 cells was examined by immunohistochemical staining. The growth of HepG2 cells was examined by MTT colorimetry and cell count. VEGF level in the culture medium was measured by ELISA.Results After 48 h and 72 h of culture, the growth rate of HepG2 cells in hypoxia group was lower than that in control group (P＜0.05). The cell count in hypoxia group (2.51×104/μl and 2.69×104/μl, respectively) was much lower than that in control group(3.01×104/μl and 3.52×104/μl) after 48h and 72h of culture (P＜0.05). In hypoxia group, VEGF level in the culture medium after 24 h and 48 h was higher than that in control group (P＜0.05, P＜0.01). Conclusion Hypoxia may enhance the VEGF expression in HepG2 cells and this could be the reason of high expression of VEGF after transcatheterized hepatic arterial chemoembolization.
【Abstract】ObjectiveTo construct a recombinant eukaryotic expression vector for human endostatin in order to study the inhibitory effect of liposome-mediated endostatin gene on the growth of human liver carcinoma in nude mice. MethodsHuman endostatin cDNA including IL-2 secreting peptide was cloned into eukaryotic expression plasmid pcDNA3.0 to construct recombinant plasmid pCD-sEndo. pCD-sEndo plasmid was transferred into hepatocarcinoma cell line SMMC-7721 mediated by liposome Dosper, the expression and secretion of endostatin gene was detected by RTPCR and Western blot analysis. The suspension of SMMC-7721 cells was injected subcutaneously at the back of 32 nude mice to establish the model of human liver carcinoma. The mice were divided into 4 groups randomly, and injected with Dosper+pCD-sEndo, Dosper+pcDNA3.0, Dosper and physiological brine separately. Tumor volume was measured by stages. The mice were executed after the drug had been given for 1 week, then the microvessel density (MVD) of the tumor tissue was detected with immunohistochemical method and apoptotic index of tumor cells was measured by TUNEL-stain. ResultsThe eukaryotic expression vector pCD-sEndo was successfully constructed and was confirmed by enzyme digestion and sequence analysis. Expression of endostatin gene was detected in transfected SMMS-7721 cells by RTPCR in vitro, and endostatin protein was also detected in the supernatant of transfected SMMS-7721 cells by Western blot. In vivo study, the growth of human liver carcinoma was inhibited in the group injected with endostatin gene: the average volume of tumor in this group was significantly smaller than that in other groups （P＜0.05）; the average MVD in this group was 6.2±2.5, significantly less than that in the group injected with physiological brine (32.8±6.4), Dosper （27.8±6.4）, or Dosper+pcDNA3.0 (25.5±5.5), P＜0.05. The average apoptotic index of tumor cells in treatment group, brine group, Dosper group and Desper+pcDNA3.0 group was 24.5±7.3, 7.6±2.5, 9.5±3.0 and 11.2±3.6 respectively, it was evidently higher in the treatment group than in the latter three groups. ConclusionHuman endostatin mediated by cation liposome could decrease the microvessel number of implanted human hepatocarcinoma in nude mice. It could also accelerate apoptosis of tumor cells and inhibit growth of tumor.
Objective To assess the applied significance of carbon nanoparticles in central compartment lymph node dissection in treatment of cN0 papillary thyroid carcinoma. Methods Sixty-eight patients with cN0 papillary thyroid carcinoma who were treated in Tongji Hospital of Tongji Medical College from May. to Oct. in 2012 were randomly allocated to the control group （n=32） and the carbon nanoparticles trace group （tracer group， n=36）， receiving non-carbon nanoparticles trace and carbon nanoparticles trace respectively. All patients were received total resection of thyroid plus the affected side and （or） contralateral side central compartment lymph node dissection. The lymph node-related indexes（including number of dissected lymph node at Ⅵarea and lymph node metastasis rate at Ⅵarea） and operative indexs （including operation time， blood loss， drainage time， complication， and hospital stay） were collected and compared between the 2 groups. Results There were 205 and 324 dissected lymph node at central compartment in control group and tracer group respectively. The results of postoperative pathology showed that the number of lymph node in central compartment of the tracer group was much more than those of control group （8.99±2.24 vs. 6.41±1.56， P＜0.001）. The metastasis rate of central compartment lymph node were 40.6% （13/32） in control group and 47.2% （17/36） in tracer group， but there was no significant difference between the 2 groups （P=0.762）. But in medial area of laryngeal recurrent nerve， the metastasis rate in the tracer group （38.9%， 14/36） was much higher than those of control group （12.5%， 4/32）， P=0.029. There were no significant differences in the operation time， blood loss， drainage time， hospital stay， and complication incidence such as bleeding， temporary hypocalcemia， and injury of superior laryngeal nerve between 2 groups （P＞0.05）. All the patients in 2 groups had followed-up for 6 months without death， recurrence， and metastasis.Conclusions The lymphatic tracer technique of carbon nanoparticles may improve the number of dissected lymph nodes in central region of cN0 papillary thyroid carcinoma， without increasing （or prolonging） operation time， intraoperative blood loss， and postoperative hospital stay， and can accurately represent the metastasis of lymph node， thus to make the staging of the tumor accurately and guide postoperative treatment.