Effect of ionization on the expression of hypoxia-inducible factor-1alpha and VEGF in hepatocellular carcinoma HepG2 cells under anoxic condition / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of ionization on the expression of hypoxia-inducible factor-1alpha and vascular endothelial growth factor (VEGF) in human hepatocellular carcinoma HepG2 cells under anoxic condition, and search for an effective method for improving the radiosensitivity of the tumor cells.</p><p><b>METHODS</b>HepG2 cells were divided into 4 groups, namely the control group, hypoxia group, ionization radiation group, and hypoxia and radiation group, with corresponding treatments. The cell apoptosis was detected by fluorescence microscope, and the cell viability analyzed by MTT assay. The expressions of HIF-1alpha and VEGF mRNAs were detected by RT-PCR.</p><p><b>RESULTS</b>A few apoptotic cells were found in hypoxia group, but significant apoptosis occurred in the radiation group; fewer apoptotic cells were observed in the hypoxia and radiation group than in the hypoxia group. The viable cell fraction increased in the order of the control group>hypoxia group> hypoxia plus radiation group> radiation group (P<0.05), and the expression of HIF-1alpha mRNA increased in the order of hypoxia plus radiation group>hypoxia group>radiation group (P<0.05), and no significant difference was found in the radiation group and control group. The expression of VEGF mRNA increased in the order of hypoxia plus radiation group> hypoxia group>radiation group>control group (P<0.05).</p><p><b>CONCLUSION</b>The expression of HIF-1alpha may protect the hepatocellular carcinoma cells from damages by radiation in hypoxic condition, and HIF-1alpha decreases the radiosensitivity of the cells possibly by inducing VEGF expression.</p>

Comparison of concurrent chemo-radiotherapy and sequential chemo-radiotherapy for locally advanced non-small cell lung cancer / 中华放射肿瘤学杂志

Objective Prospective comparison was done on concurrent chemo-radiotherapy and se- quential chemo-radiotherapy for unresectable stageⅢnon-small cell lung cancer(NSCLC) and to evaluate three different regimens of concurrent chemo-radiotherapy.Methods Ninety-six such patients were ran- domized into four groups:1.sequential chemo-radiotherapy group received two cycles of induction chemother- apy with 40 mg/m~2 of cisplatin on D 1-3,29-31 and 100 mg/m~2 of etoposide on D 1-3,29-31 before conven- tional radiotherapy,2.concurrent chemo-radiotherapy group 1 received 100 mg/m~2 etoposide on D 1-3 and DDP 40 mg/m~2 on D 1-3,D 29-31,iv.drip,3.concurrent chemo-radiotherapy group 2 received concurrent chemotherapy with 40 mg/m~2 of paclitaxel every Monday during conventional radiotherapy,4.concurrent chemo-radiotherapy group 3 received concurrent chemotherapy with 40 mg/m~2 of paclitaxel every Monday during three-dimensional conformal radiotherapy.All patients were irradiated with 2.0 Gy/fraction,5 frac- tions/week,to a total dose of 60-64 Gy.They all received two cycles of consolidation themotherapy with 40 mg/m~2 of cisplatin on D 1-3 and 100 mg/m~2 of etoposide on D 1-3.Results The overa/1 response rate was 67%,71%,71% and 79% for sequential ehemo-radiotherapy group,concurrent chemo-radiotherapy group 1,2 and 3,respectively.There was a significant difference between the concurrent chemo-radiotherapy and sequential chemo-radiotherapy(P＜0.05).The 1-,3-and 5-year overall survival rate(OS) was 54%,8% and 4%;71%,17% and 8%;79%,17% and 8%;83%,46% and 13%,respectively for the four groups. The difference among all these groups(P=0.017) was significant.It was also significant between the con- current chemo-radiotherapy group 1 and 3 (P=0.046).The difference of distant metastasis rate among all the groups was statistically insignificant (P＞0.05) also was the difference of toxicity (P＞0.05),but the severe toxicity of concurrent chemo-radiotherapy groups 1 and 2 were higher than the sequential chemo-radio- therapy group and concurrent chemo-radiotherapy group 3.Conclusions Better locoregional progression- free survival and overall survival of unresectable stageⅢnon-small cell lung cancer could be achieved by concurrent chemo-radiotherapy as compared with sequential chemo-radiotherapy though at the expense of in- crease in toxicity.With the combination of concurrent chemo-radiotherapy and conforrnal radiotherapy,the o- verall survival rate could be much improved with miider toxicity.