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標題: | 缺乏PIAS3使胃癌和肝癌對PARP抑制劑敏感化的研究 PIAS3 deficiency sensitizes gastric and hepatic cancers to PARP (poly ADP-ribose polymerase) inhibition |
作者: | Tsu-Wei Lin 林祖薇 |
指導教授: | 吳青錫(Ching-Shyi Wu) |
關鍵字: | PIAS3,PARP抑制劑,胃癌,肝癌, PIAS3,PARP inhibitors,gastric cancer,hepatic cancer, |
出版年 : | 2019 |
學位: | 碩士 |
摘要: | 在所有DNA損傷之中,DNA的雙股斷裂是最具有傷害性的一種。同源重組 (homologous recombination, HR),一個需要ATR (ataxia telangiectasia and Rad3 related) 的過程,可以無誤的修復雙股斷裂。先前的研究中顯示PIAS3 (protein inhibitor of activated STAT 3) 不單單只是ATR-Chk1訊息傳遞路徑的調控者,更 可能參與在同源重組之中。而在最近的研究以及TCGA資料庫的分析中,顯示了PIAS3的表現量在胃癌和肝癌中特別低,因此我們提出缺乏PIAS3的胃癌和肝癌細胞可藉由抑制PARP而敏感化。Olaparib和Rucaparib,兩種用來治療BRCA缺損的卵巢癌的PARP抑制劑,在DNA損傷反應缺損的癌細胞中具有合成致死的效果,被用來測試這個假說。我們利用免疫墨點法確認了幾種胃癌和肝癌細胞的PIAS3表現低下,而細胞生存測試顯示低PIAS3表現的胃癌 (AGS, MKN45) 和肝癌細胞 (Huh-7, HepG2) 對於PARP抑制劑是敏感的。除此之外,合併使用低劑量拓撲異構酶1 (Topoisomerase I) 抑制劑在胃癌細胞上具有加成效果。免疫螢光染色法顯示Olaparib和Rucaparib在AGS和Huh-7細胞上可產生相當的DNA雙股斷裂,然而在Rucaparib處理後的細胞會從DNA雙股斷裂中回復較慢。除此之外,在異位表現PIAS3後的肝癌細胞株Huh-7可對PARP抑制劑具有抗性,可能是透過部分恢復ATR活化的功能。除了PARP抑制劑,細胞生存測試也顯示ATR抑制劑對低PIAS3表現的胃癌和肝癌細胞都是有效果的。我們的發現顯示PARP以及ATR抑制劑在PIAS3缺乏的癌症上可能具有醫療潛力。 DNA double-strand breaks (DSBs) are the most deleterious among all types of DNA damage. Homologous recombination (HR), a process requires ATR (ataxia telangiectasia and Rad3 related), repairs DSBs flawlessly. Previous studies have shown that PIAS3 is not only a modulator of ATR-Chk1 signaling pathway but also implicated in HR. Recent studies and analyses of TCGA (The Cancer Genome Atlas) databank suggest that expression of PIAS3 is low in a remarkable fractions of both gastric and hepatic cancers. We hypothesize that gastric and hepatic cancer cells with PIAS3 deficiency can be sensitized by PARP inhibition. Olaparib and Rucaparib, two PARP inhibitors indicated for BRCA mutated ovarian cancers, are employed to test this hypothesis. Western blotting confirms that several gastric and hepatic cancer cell lines are PIAS3 deficiency. Cell viability assays show that low-PIAS3 gastric (AGS, MKN45) and hepatic cancer (Huh-7, HepG2) cells are sensitive to PARPi. In addition, combination with topoisomerase I inhibitor can have a synergistic effect in gastric cancer cells. Immunofluorescence staining reveals that Olaparib and Rucaparib induced comparable level of DNA DSBs in AGS and Huh-7 cells, however the recovery from DNA DSBs is much slower in Rucaparib treated cells. Besides, ectopically expressed PIAS3 confers resistance to PARPi in hepatic cancer cell line, Huh-7, which may be partially through the activation of ATR. Besides PARPi, viability assay also shows that ATRi is effective to both low-PIAS3 gastric and hepatic cancer. Our findings suggest that PARPi and ATRi may be potential therapeutics for treating PIAS3-deficient cancers. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/72902 |
DOI: | 10.6342/NTU201901790 |
全文授權: | 有償授權 |
顯示於系所單位: | 藥理學科所 |
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