YWHAZ gene contributes to the radioresistance of oral squamous cell carcinoma cells

Objective:To investigate the contribution of YWHAZ gene on the radioresistance and metastasis ability of oral squamous cell carcinoma(OSCC)cells.Mathods:The relationship between the expression level of YWHAZ gene and the survival of head and neck squamous cell carcinoma(HNSC)patients was analyzed using Gene Expression Profiling Interactive Analysis(GEPIA)database.A radioresistance cell line(CAL-27R)was constructed by irradiating CAL-27 cells with frac-tional doses.Cell survival was measured by colony formation assay.Cell migration and invasion were detected by transwell assay.The formation of yH2AX foci was detected by immunofluorescence assay,The protein expressions were detected by Westemn blot assay.In some experiments,CAL-27R cells were effectively transferred with siRNA YWHAZ(siYWHAZ).Results:GEPIA database showed that the expression level of YWHAZ in HNSC tumors was higher than that in adjacent normal tissues,and the HNSC patients with higher level of YWHAZ had a shorter survival.In vitro experiments demonstrated that the expression of YWHAZ protein in CAL-27 cells was lower than HSC-3 cells(t=18.89,P<0.01)and radioresistant CAL-27R cells(t=25.70,P<0.01).Knockdown of YWHAZ gene significantly increased radiation-induced cell killing effect,apoptosis induction,and yH2AX foci formation inCAL-27R and HSC-3 cells.Moreover,siRNA YWHAZ transfection also reduced the invasion and migration abilities of the irradiated CAL 27R[t=21.09,P<0.01(migration);t=6.16,P<0.05(invasion)]and HSC-3 cells[t=34.53,P<0.001(migration);t=4.92,P<0.05(invasion)]and attenuated radiation-induced expressions of metastasis-related proteins,Conclusion:YWHAZ contributes to the radioresistance of oral squamous cells and thus it may applicable to be a potential target for OSOC radiotherapy.

Research progress of radiation induced bystander and abscopal effects in normal tissue

Radiation-induced bystander effect(RIBE)and abscopal effect(RIAE)are non-target cellular responses outside the radiation field.It has been recognized that these effects are of great significance to both radiation protection of environmental low-dose radiation and clinical radiotherapy in which the anti-tumor abscopal effect is even beneficial to patients.However,the mechanisms of them are still obscure.This review briefly introduced the inflammatory signaling factors and immune regulation in RIBE in vitro and RIAE on normal tissues and organisms,and emphasized the genetic consequences of RIAE.Based on a large number of investigation results,we suggest that it’s time to incorporate RIBE and RIAE into the concept of“classic”radiation biology.