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IR‐induced phosphorylation of rpS3 and TRAF2 regulates radioresistance in non‐small cell lung cancer cells (609.1)
Author(s) -
Kim EunGi,
Kwon TaeWoo,
Son Beomseok,
Lee Jongbong,
Youn BuHyun,
Lee Jung Sub
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.609.1
Subject(s) - radioresistance , cancer research , phosphorylation , a549 cell , traf2 , radiosensitivity , lung cancer , chemistry , biology , microbiology and biotechnology , oncology , medicine , cell culture , apoptosis , radiation therapy , biochemistry , genetics , tumor necrosis factor receptor
Radioresistance is a main impediment to effective radiotherapy. However, the exact molecular mechanism of radioresistance has not been understood yet. To elucidate the mechanism in lung cancer, we compared radiation responses in two types of non‐small cell lung cancer (NSCLC) cells with different radiosensitivity. In radioresistant NSCLC cells, ionizing radiation (IR) led to CK2α‐ and PKC‐mediated phosphorylation of rpS3 and TRAF2, respectively, which induced dissociation of rpS3‐TRAF2 complex and NF‐кB activation, resulting in up‐regulation of prosurvival genes. Also, dissociated phospho‐rpS3 translocated into nucleus and bound with NF‐кB complex, contributing to p65 DNA binding property and specificity. However, in radiosensitive NSCLC cells, IR‐mediated rpS3 phosphorylation was not detected due to the absence of CK2α overexpression. Taken together, our findings revealed a novel radioresistance mechanism through functional orchestration of rpS3, TRAF2, and NF‐кB in NSCLC cells. Moreover, we provided the first evidence for the function of rpS3 as a new TRAF2‐binding protein and demonstrated that phosphorylation of both rpS3 and TRAF2 is a key control point of radioresistance in NSCLC cells. Grant Funding Source : Supported by the Radiation Technology R&D Program (2013M2A2A7042502)