Research On Isolation, Determination And Gene Correction Of Bladder Cancer Stem Cells

ObjectiveCancer stem cell hypothesis indicates that the primal reason for tumorigenesis and development of tumors is the existence of cancer stem cell.The concept of cancer stem cell (CSC) conduces to the discovery of target cell in gene targeted therapy. Several kinds of human tumor stem cell have been isolated and identified successfully, but including no cancer stem cell of bladder cancer. Based on the former achievement and the viewpoint of "two kinds of tumors" posed by Prof.Chang Jiwu, we will authenticate the capability of subpopulation group of bladder cancer stem cell in initiating and maintaining cancer. We will also research on the gene reparation of Bmi-1 which is a very important related gene of cancer stem cell.We hope our experiment will make a foundation for the isolation, identity and gene targeted therapy of bladder cancer stem cell.MethodsBy the use of immunomagnetic beads sorting, we sort EMA-CD44v6+subset cells to carry out the sub-group of cells in tumor-bearing nude mice experiment. Through the passage of the tumor cell culture and experimental pathology of tumor specimens, we analyze the sub-group of cells in the capacity of starting and maintaining the tumor.By the use of biomedical technology, we analyzed Bmi-1(bladder cancer stem cell-related gene) genetic information and found that Bmi-1 gene mutation makes sense. By the use of RDO gene repair tool,we repaired the Bmi-1 gene mutation in situ. Carrying out the gene repaired EMA-CD44v6+ subset cells in tumor-bearing nude mice experiments, we got a preliminary assessment of the effects of gene repair.ResultThe smallest dose of EMA-CD44v6+subset causing tumor is decreased to 5.0×103 and the pathological results support the sub-group of cells have cancer stem cell characteristics. The G-A point mutation on the sixth exon of Bmi-1 gene is a significant genetic mutation. The smallest dose of restored EMA-CD44v6+ subset causing tumor is 1.0×104 and the pathological experiments confirm that DNA repair makes the ability of causing tumor of the sub-group weakened.ConclusionThe EMA-CD44v6+ subset cells of bladder cancer have the ability to start and maintain the tumor with tumor stem cell properties. Bladder cancer stem cells-related Bmi-1 gene has a structural abnormality and genetic repair can reduce the ability of EMA-CD44v6+ subset cells in tumorigenic.