The effect of Squamous cell carcinoma antigen on radiation resistance

Research Project

Project/Area Number	12670878
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Radiation science
Research Institution	Kochi Medical School
Principal Investigator	UEMURA Yoshiki Kochi Medical School, Internal Medicine, Assistant Professor, 医学部附属病院, 講師 (90203489)
Project Period (FY)	2000 – 2003
Project Status	Completed (Fiscal Year 2003)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Keywords	SCCA / irradiation / SCCA / radiation / squamaous cell carcinoma / SCCA1 / SCCA2 / Squamous cell carcinoma / irradiation / アポトーシス
Research Abstract	Subcellular fractionation and subsequently western blot analysis of head and neck squamous cell carcinoma cell line SQ2OB and cervical cancer cell line SKGIIIB, which constitutively produce SCCA1 and SCCA2, showed that SCCA1 and SCCA2 exclusively exist in the cytosol. Then we studied the effects of irradiation on the expression of SCCA1 and SCCA2. As a result, the stable cell line transfected with SCCA1-GFP or SCCA2-GFP significantly resisted against the cytotoxic effect of irradiation. The extent of the resistant effect was not significantly different between the two stable cell lines. Nuclear stain showed that the apoptotic changes by irradiation were slight in the stable cell lines cells compared to the control cells. We examined whether SCCA1 and SCCA2, which exist in the cytosol under usual conditions, would move to the nucleus under irradiation. As a result, we could not find the changes of GFP locus by a range of irradiation(0-10Gy) in both cells transfected with SCCA1-GFP and SCCA2-GFP. We examined the effects of irradiation on the pnosphorylation of p38 MAPK, p44/42 MAPK and c-Jun in the transfected cells because it is known that these signaling pathways are closely associated with induction of apoptosis by irradiation. In this study, we demonstrated that irradiation increased the phosphorylation of p38 MAPK, p44/42 MAPK and c-Jun. The extent of the phosphorylation was smaller in the transfected cells than the control cells, suggesting that expression of SCCA1 and SCCA2 could protect cells from apoptotic damages through MAPK signaling pathways.