The present invention relates to a method of producing cancer stem cells that comprises culturing a living cell population containing cancer cells in the presence of a gel substance to obtain a living cell population containing cancer stem cells, wherein the gel substance is a material that induces expression of osteopontin in at least a portion of cells contained in the living cell population. Moreover, the present invention relates to an agent for inducing conversion of cancer cells to cancer stem cells that comprises a gel substance that induces expression of osteopontin in at least a portion of the cells contained in a living cell population. The gel substance is a synthetic polymer gel composed of, for example, double network gel, PNaSS gel, PCDME gel, PA gel, RAMPS gel, PDMA gel or PAAc gel. The present invention provides means and a method that enable the preparation of cancer stem cells in a relatively short period of time and at a relatively low culturing cost without requiring expensive equipment.

A three dimensional cell culture and bioreactor system is provided. The system comprises one or more cell culture chamber. Each cell culture chamber comprises an inlet port and an outlet port in fluid communication with the cell culture chamber. The cell culture chambers may be segregated or in fluid communication with one another. The systems may be used to conduct drug efficacy test, isolate certain cell types from a complex tissue sample of multiple cell types, allow for the ex vivo culturing of patient tissue samples to help guide the course of treatment, and conduct co-culture experiments.

The purpose of the present invention is to provide: a cancer stem cell mass from which cells incapable of forming cancer are substantially removed and which has a characteristic property of reproducing a layered structure of a cancer tissue; a process for producing the cancer stem cell mass; and use of the cancer stem cell mass. For achieving the purpose, the present inventors grew a human cancer tissue repeatedly in a NOG mouse, separated cancer cells from the grown cancer tissue, and made a comparison of various cancer cell culture processes with each other. As a result, a cancer stem cell composition which is homogeneous and is substantially free of the coexistence of cells capable of forming cancer and cells incapable of forming cancer in a mixed state can be produced successively by employing an attached culture process using a serum-free stem cell culture medium rather than a generally employed floating culture process, and consequently the present invention has been accomplished.

The invention relates to improved culture methods for expanding epithelial stem cells and obtaining organoids, to culture media involved in said methods, and to uses of said organoids.

The invention relates to a method for culturing a subpopulation of circulating epithelial tumour cells from a body fluid of a human or animal suffering from an epithelial tumour, wherein cells contained in the body fluid each containing at last one cell nucleus are separated from the body fluid and cultured over at least 24 hours in suspension, with formation of spheroids.

The present invention is in the field of oncology, and more particularly of cancer stem cells. It relates to a method for producing cancer stem cells based on overexpression of Δ133p53β isoform, Δ133p53γ isoform, or both Δ133p53β and Δ133p53γ isoforms; a method for predicting the risk that treatment with a chemotherapeutic anti-cancer agent induces cancer stem cells in a subject suffering from cancer from a cancer sample of said subject, based on detection of an increase in Δ133p53β isoform, Δ133p53γ isoform, or both Δ133p53β and Δ133p53γ isoforms following chemotherapeutic anti-cancer treatment; to therapeutic uses of a combination of chemotherapeutic anti-cancer agent and an agent reducing Δ133p53β isoform, Δ133p53γ isoform, or both Δ133p53β and Δ133p53γ isoforms expression; and also to screening methods for anti-cancer stem cells agents.

The invention relates to improved culture methods for expanding epithelial stem cells and obtaining organoids, to culture media involved in said methods, and to uses of said organoids.

A composition for inducing dedifferentiation from cancer cells to cancer stem cells comprising a ribosome-activating inhibitor as an active ingredient, a method of culturing a cancer organoid based thereon and an anticancer drug screening platform, and the increase of colorectal cancer stem cell group induced by the exposure of ribosome-inactivating stress was regulated by the ATF3 gene.

An isolated rat liver cancer stem cell line which is named as TW-1 is provided. A method for drug screening by using the isolated rat liver cancer stem cell line is also provided.

The invention relates to a method for culturing a subpopulation of circulating epithelial tumour cells from a body fluid of a human or animal suffering from an epithelial tumour, wherein cells contained in the body fluid each containing at least one cell nucleus are separated from the body fluid and cultured over at least 24 hours in suspension, with formation of spheroids.