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A study on the clinical utilities of liquid biopsy circulating tumor DNA in pancreatic cancer [an abstract of dissertation and a summary of dissertation review]
No full text配架番号：292
グアニン四重鎖構造のトポロジーがCpGオリゴ核酸の免疫活性化能に与える影響 [全文の要約]
No full textこの博士論文全文の閲覧方法については、以下のサイトをご参照ください。【担当：理学部図書室】https://www.lib.hokudai.ac.jp/dissertations/copy-guides
Study on the Role of DNA Ploidy Heterogeneity in Cancer Cell Populations in the Emergence of Radioresistant Cells after Radiotherapy
No full textIntratumor heterogeneity is a potential cause of treatment resistance. The existence of radioresistant cancer cells are risk factors for recurrence and they are occasionally detected in recurrent tumors after radiotherapy. Heterogeneity in DNA content has also been reported in human cancer; however, little is known about the role of intratumor DNA ploidy heterogeneity in the emergence of radioresistant cells after radiotherapy. In the present study, human colorectal cancer-derived SW480 cells, which are composed of two cell populations with different chromosome numbers, were used as a model for cancer cell populations with ploidy heterogeneity. The influence of culture environment on DNA ploidy heterogeneity and the mechanism on emergence of radioresistant cells after fractionated radiotherapy to the cell population with DNA ploidy heterogeneity were examined.
Predominant cell population in SW480 cells was reversed in the culture environment with high-glucose concentration, resulting in SW480.hu cells to be obtained. Radioresistant clone SW480RR cells were established after fractionated X-irradiation of SW480.hu cells. Compared with the parental SW480.hu cell population, which mostly comprised cells with higher ploidy, the radioresistant clones showed lower ploidy and less initial DNA damage. The lower ploidy cells in the parental cell population were identified as having radioresistance prior to fractionated irradiation; thus, SW480RR cells were considered intrinsically radioresistant cells which have survived fractionated X-irradiation. The most likely mechanism is the selection of an intrinsically radioresistant population, with a background in which lower ploidy cells exhibit lower initial DNA damage.
This study highlighted the potential importance of intratumor DNA ploidy heterogeneity in radioresistance by providing a practical example indicating the link between the emergence of radioresistant cells after fractionated irradiation and intratumor DNA ploidy heterogeneity
Development and Application of Quantitative MRI Indices for Advancing Brain Function Evaluation [an abstract of entire text]
No full textこの博士論文全文の閲覧方法については、以下のサイトをご参照ください。https://www.lib.hokudai.ac.jp/dissertations/copy-guides
