PML Regulates IL-6Expression And IL-6Mediated Bystander Effect In Irradiated Human Lung Carcinoma A549Cells

Objective: Study whether promyelocytic leukemia protein (PML) contributes toregulate radiation-induced inflammatory factors expression in human lung carcinomaA549cells, and discover the role of PML irreadiation-induced bystander effects,including IR-CM induced cell proliferation inhibition and NSE decrease. Methods:QRT-PCR, ELISA, Western-blot, CCK-8, and the antibody-neutralization test were usedto study whether PML regulated the expression of irradiation-induced pro-inflammatorycytokines (including IL-6and IL-8); and the function of PML in bystander cells’proliferation and NSE expression. Results: After10Gy irradiation, the number ofPML-NBs increased quickly in A549cells, while PML mRNA and protein expressionwere significantly increased at72hours. Several inflammatory cytokines (IL-1, IL-4,IL-5, IL-6, IL-8, IL-12, IL-13, TGF-β and TNF-γ) were induced by irradiation in A549cells, and upregulation of IL-1, IL-6, IL-8and TNF-γ mRNA were inhibited by PMLknocking-down. Furthermore, irradiation activated the expression of IL-6and IL-8indoses and time dependent manner. qRT-PCR and ELISA assay found that, IL-6and IL-8production were significantly reduced in PML knockdown A549cells. Finally, PMLmediate IR-CM induced un-irradiated bystander cells’ proliferation inhibition.Knocking-down PML protein resulted in abnormal NSE expression in surroundingun-irradiated A549cells because of IL-6de-regulation. Conclusion: PML contributes toregulate ionizing radiation (IR)-induced cytokines expression alterations in A549cells,and participates in the the signaling pathways of irradiation-induced bystander effect,via modulating expressions of these cytokines, such as IL-6. These studies providednew signaling pathway of PML in inter cellular signal transduction and tumor microenvironment control after IR. Objective: Investigate the expression and sub-cellular localization of RNA-bindingprotein Ro60in neoplasms before and after γ-ray irradiation, and the function of Ro60in tumor cell proliferation and radio-sensitivity. Analyze the relationship between Ro60and p53in gastric cancer. Methods: The cellular localization of Ro60was examinedbefore and after irradiation. Cell proliferation and radio-sensitivity were detected byCCK-8and trypan blue assay. qRT-PCR was used to detect the expression of Ro60andp53mRNA in clinical gastric cancer samples. Results: Irradiation increased Ro60expression and induced significantly nuclear aggregation of Ro60. The cell proliferationbefore and after irradiation was drastically reduced while cell death increased in Ro60over-expressed tumor cells. In thirty-nine gastric cases, the expression between Ro60and p53have positive correlation. Conclusion: γ-ray irradiation altered Ro60expression and localization, and Ro60played important role in tumor cell proliferationand radio-sensitivity. In gastric cancer tissue samples, p53and Ro60mRNA havestatistical dependence.