本研究ではリプログラミング遺伝子Oct4が多発性骨髄腫細胞に過剰発現することを見出し、その強制発現細胞を樹立して下流シグナルの変化を検索した。Oct4強制発現細胞では間葉系遺伝子発現が増強しEMT様現象を誘導すること、MRP1トランスポーターが過剰発現し薬剤耐性化に関わることがわかった。
新規フタルイミド体TC11の最適化体PEG-TC11を開発し、in vivoにおける薬物動態と抗骨髄腫作用を確認した。PEG-TCは、サリドマイド類の標的分子cereblonには結合せず、α-tubulin、nucleophosmin -1に結合しp53非依存的にG2/M arrestを引き起こした。
In this project, we found overexpression of Oct4 gene in multiple myeloma (MM) cells and also established Oct4-overexpresed MM cell lines. In the overexpressed cells, expression of mesenchymal genes such as Snail was increased, and the EMT-like morphological change was observed. Expression of MRP1 transporter proteins was also increased, and Oct-4-overexpressed cells obtained the resistance to various anti-MM drugs. 
We have also developed a novel phthalimide, TC11, and its optimized form, PEG-TC11. PEG-TC11 revealed strong growth inhibitory effects to MM cells in mice xenograft model. Even though TC11 and PEG-TC11 have structural similarity to thalidomide, they did not associated with the thalidomide-binding protein, cereblon, but with α-tubulin and nucleophosmin-1. By binding to α-tubulin and nucleophosmin-1, PEG-TC11 induced G2/M arrest without involvement of p53 and caused apoptosis of high-risk MM cells with p53 deletion.

研究種目 : 基盤研究 (C) (一般)
研究期間 : 2017～2019
課題番号 : 17K09940
研究分野 : 血液内科学