Chugai Seiyaku Kabushiki Kaisha, Ciea International Inc. and Pharmalogicals Research Pte. Ltd. | Date: 2011-07-21
An objective of the present invention is to facilitate the acquisition of antibody-producing cells that are infiltrating virus-infected cells, cancer cells, abnormal cells forming a benign hyperplasia, and the like, and to improve the efficiency of the production of antibodies as well as nucleic acids encoding them from the antibody-producing cells. The present inventors discovered that, when cancer tissues comprising infiltrating lymphocytes are transplanted into highly immunodeficient animals that do not have T cells, B cells, and NK cells and further exhibit a low IFN production ability, the differentiation and proliferation of infiltrating lymphocytes are unexpectedly promoted, and the number of plasma cells that produce antibodies recognizing cancer tissues increases dramatically, plasma cells can be separated easily, and antibodies or nucleic acids encoding them can be easily prepared from the plasma cells.
Pharmalogicals Research Pte. Ltd. and Chugai Seiyaku Kabushiki Kaisha | Date: 2012-09-07
An objective of the present invention is to provide: a cancer stem cell isolated using a cell marker; a substantively homogeneous cancer stem cell population including said cancer stem cell; and a method of preparing said cancer stem cell population. Another objective of the present invention is to provide: a method for separating cancer stem cells with a high proliferative potential and those with a low proliferative potential; a method for inducing cancer stem cells to have a different proliferative potential; and cancer stem cells separated or induced by these separation or induction methods. A further objective of the present invention is to provide: a method of screening for pharmaceuticals using said cancer stem cell or cancer stem cell population; a method for detecting the presence of said cancer stem cell or cancer stem cell population and for identifying or quantifying the same. The present inventors discovered that highly pure colon cancer stem cells (CSC) can be obtained in a large quantity, and identified two types of states of colon CSCs distinguishable through Lgr5 expression.
Chugai Seiyaku Kabushiki Kaisha and Pharmalogicals Research Pte. Ltd. | Date: 2011-10-06
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.
Kobayashi S.,PharmaLogicals Research Pte. Ltd. |
Kobayashi S.,Chugai Pharmaceutical Co. |
Yamada-Okabe H.,Chugai Pharmaceutical Co. |
Suzuki M.,Chugai Pharmaceutical Co. |
And 22 more authors.
Stem Cells | Year: 2012
The cancer stem cell (CSC) concept has been proposed as an attractive theory to explain cancer development, and CSCs themselves have been considered as targets for the development of diagnostics and therapeutics. However, many unanswered questions concerning the existence of slow cycling/quiescent, drug-resistant CSCs remain. Here we report the establishment of colon cancer CSC lines, interconversion of the CSCs between a proliferating and a drug-resistant state, and reconstitution of tumor hierarchy from the CSCs. Stable cell lines having CSC properties were established from human colon cancer after serial passages in NOD/Shi-scid, IL-2Rγnull (NOG) mice and subsequent adherent cell culture of these tumors. By generating specific antibodies against LGR5, we demonstrated that these cells expressed LGR5 and underwent self-renewal using symmetrical divisions. Upon exposure to irinotecan, the LGR5+ cells transitioned into an LGR5- drug-resistant state. The LGR5- cells converted to an LGR5+ state in the absence of the drug. DNA microarray analysis and immunohistochemistry demonstrated that HLA-DMA was specifically expressed in drug-resistant LGR5 - cells, and epiregulin was expressed in both LGR5+ and drug-resistant LGR5- cells. Both cells sustained tumor initiating activity in NOG mice, giving rise to a tumor tissue hierarchy. In addition, anti-epiregulin antibody was found to be efficacious in a metastatic model. Both LGR5+ and LGR5- cells were detected in the tumor tissues of colon cancer patients. The results provide new biological insights into drug resistance of CSCs and new therapeutic options for cancer treatment. © AlphaMed Press. Source