PROBLEM TO BE SOLVED: To provide a method for efficiently selecting micro RNA having proliferation-inhibiting ability to a cancer stem cell, and a proliferation inhibitor to a cancer stem cell which has particular micro RNA as an active ingredient, and a medicine for cancer treatment containing the inhibitor.SOLUTION: A method for screening micro RNA having proliferation-inhibiting ability to a cancer stem cell includes: a process of preparing an exosome fraction and a cytoplasm fraction from each of a cancer stem cell and a tissue stem cell in a tissue where a malignant tumor including the cancer stem cell is generated a process of comprehensively measuring an expression level of micro RNA in each of the fractions a process of specifying micro RNA which is expressed in both the exosome fraction and the cytoplasm fraction of the tissue stem cell, and in which an expression level in the exosome fraction and the cytoplasm fraction of the cancer stem cell is lower than an expression level of corresponding fractions of the tissue stem cell and a process of testing proliferation-inhibiting ability of the specified micro RNA to the cancer stem cell.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】がん幹細胞の増殖抑制能を有するマイクロRNAを効率的に選択する方法、並びに特定のマイクロRNAを有効成分とするがん幹細胞の増殖抑制剤、当該剤を含むがんの治療のための医薬の提供。【解決手段】がん幹細胞及び前記がん幹細胞を含む悪性腫瘍が発生する組織における組織幹細胞それぞれからエクソソーム画分及び細胞質画分を調製する工程、前記各画分におけるマイクロRNAの発現レベルを網羅的に測定する工程、前記組織幹細胞のエクソソーム画分及び細胞質画分の両方で発現しており、かつ前記がん幹細胞のエクソソーム画分及び細胞質画分における発現レベルが組織幹細胞の対応する画分における発現レベルより低いマイクロRNAを特定する工程、及び前記特定されたマイクロRNAの前記がん幹細胞に対する増殖抑制能を試験する工程を含む、がん幹細胞に対する増殖抑制能を有するマイクロRNAをスクリーニングする方法。【選択図】図1
