ABSTRACT
AIM:To discover the effect of MCPH1 on the DNA damage induced by ionizing radiation in esoph-ageal cancer cells.METHODS:ECA109 cancer cells were radiated at dose of 8 Gy.The nuclear foci of relevant factors were detected 1 h after irradiation in the ECA109 cells after silence of MDC1 gene.A cell line was established that was sta-ble low expression of MCPH1.The nuclear foci induced by ionizing radiation after silence of MCPH1 were determined.RE-SULTS:The MCPH1 gene silenced ECA109 cell line was successfully constructed.A strong relationship between MDC1, MCPH1 andγ-H2AX was observed 1 h after 8 Gy irradiation.Silence of MDC1 did not affect the nuclear foci formation ofγ-H2AX and MCPH1.The nuclear foci of MDC1 but notγ-H2AX significantly reduced after silencing of MCPH1.CON-CLUSION:MCPH1 is located in the downstream of H2AX and upstream formation of MDC1, and regulates the nuclear fo-ci formation of MDC1 during DNA damage response.
ABSTRACT
Objective To discover the role of MCPH1 in DNA double-strand damage induced by ionizing radiation and its relationship with H2AX in esophageal cancer cell ECA109. Methods ECA109 cancer cells accepted 8 Gy 1 h after irradiation were collected for protein extraction and immunofluorescence then MCPH1 and H2AX protein expression and nuclear foci changes were observed. A stable low expression of H2AX cell lines was established and MCPH1 and H2AX protein expression and nuclear foci changes induced by ionizing radiation after silence H2AX were detected. Results (1)A stable low expression of H2AX cell lines in ECA109 cells was successfully constructed. (2)Ionizing radiation could cause the increase of r-H2AX and MCPH1 protein expression, as the same as nuclear focus increase of r-H2AX and MCPH1. (3)The protein level and nucleus focus of r-H2AX and MCPH1 were significantly reduced in ECA109 after silence H2AX. Conclusion MCPH1 is the part of DNA damage response triggered by ionizing radiation and is located in damage response downstream and can be regulated by H2AX.