OBJECTIVE: To study the relationship between the radiotherapy resistance and autophagy. To provide a theoretiacal basis for drugs that regulate autophagy to improve radiotherapy sensitivity. METHOD: Flow cytometry (FCM) was performed to analyze the distribution of the cell cycle of CNE2 and CNE2/DDP cells under the action of X radiation. The expression of autopagy-specific gene Beclin1 and microtubule-associated protein light chain 3β (MAPLC3β) in CNE2 and CNE2/DDP cells was determined by real time PCR and Immumofluorescence staining. RESULT: CNE2/DDP and their parental CNE2 cells produced the G2-M phase arrest under the action of X radiation. With the radiation dose increasing,The cells which in the G2-M phase were more and more (P<0. 05). The G2-M phase arrest in CNE2/DDP cells was more obvious than in CNE2 cells (P<0. 05). The expression of Beclin1 and MAPLC3β in CNE2 and CNE2/DDP cells increased under the action of X radiation. What's more, the raise was more and more obvious with the increase of the irradiation dose(P<0. 05). The expression levels of Beclin1 and MAPLC3β in CNE2/DDP was lower than that in CNE2 cells (P<0. 05). CONCLUSION Autophagic cell death may be the one manner of death in nasopharyngeal carcinoma CNE2 and CNE2/DDP cells under the action of X radiation. The radiation resistance of CNE2/DDP cells may be related to the low expression of autophagy-related genes.
Apoptosis Regulatory Proteins ; genetics ; Autophagy ; Beclin-1 ; Carcinoma ; Cell Cycle ; Cell Line, Tumor ; radiation effects ; Dose-Response Relationship, Radiation ; Humans ; Membrane Proteins ; genetics ; Microtubule-Associated Proteins ; genetics ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; genetics ; Radiation Tolerance ; X-Rays

OBJECTIVETo explore the role of eukaryotic translation elongation factor 1A1 (eEF1A1) in regulating the invasion and metastasis of hepatocellular carcinoma (HCC) cells and the possible mechanism.

METHODSqRT-PCR and Western blotting were used to detect the mRNA and protein expression of eEF1A1 and NOB1 in different HCC cell lines and normal liver cells. The invasion and migration abilities of HCC cells with eEF1A1 knockdown or overexpression were examined using Transwell chamber assay and RTCA assay, and the changes in NOB1 mRNA and protein expressions in the cells were detected. The effects of increasing NOB1 expression in HCCLM3-sheEF1A1 cells and decreasing NOB1 expression in eEF1A1-overexpressing MHCC97h cells on eEF1A1 expression and cell invasion and migration abilities were analyzed using Western blotting, Transwell chamber assay and RTCA assay.

RESULTSThe expressions of eEF1A1 and NOB1 were significantly increased in positive correlation in HCC cells as compared with normal hepatocytes. Knockdown of eEF1A1 significantly decreased the invasion and migration of HCC cells and reduced the mRNA and protein expression of NOB1 ( < 0.01). Overexpression of eEF1A1 significantly enhanced invasion and migration of HCC cells and increased NOB1 mRNA and protein expressions ( < 0.01). Increasing NOB1 expression in HCCLM3-sheEF1A1 cells led to the restoration of NOB1 expression and cell invasion and migration abilities ( < 0.01), whereas decreasing NOB1 in MHCC97h-eEF1A1 cells resulted in inhibition of NOB1 expression and cell invasion and migration ( < 0.01).

CONCLUSIONSeEF1A1 positively regulates the expression of NOB1 to promote the invasion and migration of HCC cells .