Patent ID: 11965180
Assignee: CHUGAI SEIYAKU KABUSHIKI KAISHA
Field: Measurement (Instruments)
Classification: CPC C  A  G | IPC C  G

Claim 0:
1. A method of identifying a drug candidate, comprising:
(i) transplanting a sample comprising human colon cancer tissue into NOD/SCID/gammacnull or NOD-scid/IL-2Rgnull (NOG) mice to produce a human colon cancer cell mass;
(ii) isolating the human colon cancer cell mass from the NOD/SCID/gammacnull or NOD-scid/IL-2Rgnull (NOG) mice;
(iii) preparing cells from the human colon cancer cell mass;
(iv) culturing the cells prepared from the human colon cancer cell mass in an in vitro adherent culture system using a serum-free stem cell medium, wherein culturing the cells comprises removing floating cells, and wherein adherent cells from the human colon cancer cell mass produce a population of human colon cancer stem cells from which cells with no cancer-forming ability have been substantially removed,
wherein the population of human colon cancer stem cells are positive for LGR5;
(v) culturing the population of human colon cancer stem cells from which cells with no cancer-forming ability have been substantially removed, wherein the population is characterized by reproducing a hierarchical structure of a cancer tissue, and the population is cultured as a spheroid culture under in vitro conditions to reproduce a characteristic structure of a cancer development process originating from human colon cancer stem cells or a biological property of human colon cancer stem cells;
(vi) treating the cultured human colon cancer stem cells of (v) with a test substance;
(vii) observing a change in the hierarchical structure formed from the human colon cancer stem cells, a cancer development process originating from the human colon cancer stem cells, or a biological property of the human colon cancer stem cells; and
(viii) identifying a test substance that inhibits formation of the hierarchical structure formed from the human colon cancer stem cells, a cancer development process originating from the human colon cancer stem cells, or a biological property of the human colon cancer stem cells, as the drug candidate.