Study On Characterizing A Novel Culture System Of Liver Or Colon Cancer Stem Cells And The Establishment Of Cancer Stem Cell Lines

Stem cells are defined as initial cells that have the ability to self-renewal and the potential to proliferate, differentiate, which can generate one or many end cells with certain function of a particular tissue through differentiation. That is also the main biological character of adult stem cell, and the adult stem cell will form new mature tissue, which is similar to the growth, propagation, metabasis, extension and recrudescence after radiotherapy and/or chemotherapy of malignant. In the base of this biological character of stem cell and clinical phenotype of malignant, recently some scientists propose that there are a group cells with the same stem's biologic activity in the tumor, which are called cancer stem cell or tumor initiating cell, T- Ic. Recently, more and more datas indicate that cancer stem cell exist in most cancer cell population, and the cancer stem cells play a critical role in tumorigenesis, development, metabasis, recrudescence, through it we have profound recognition of tumor and improve cancer tatargeting therapy. People further research the biological character and the special maker gene of cancer stem cell. This project used different stem cell culture mediums to sort and culture the cancer stem cell like cells from different cancer cell lines and detected the level of the cancer stem cell marker gene expression in those cells.The paper using different stem cell culture mediums gradually screen a novel culture system, which can enrich cancer stem cells. We named the different stem cell culture mediums A1, A2, B1, B2, C1, C2, and C3. The experimental results indicate that B1 is the suitable novel culture system for human colon cancer stem-like cells and B1,C1,C3 are the suitable novel culture systems for human hepatoma cancer stem-like cells.The cancer cells which were cultured with stem cell culture medium A1 could not form suspending cell sphere, but stem cell culture medium A2 made cells loosely aggregate together or form suspending cell sphere without passage. In stem cell culture medium B1 and B2, human hepatoma cell line Hep3B and human colon cancer cell line SW620 both had suspending cell sphere only using stem cell culture medium B2. Those cells are similar to the cancer stem cells reported in morphology, and the cancer stem cell maker gene expressed highly. Because of the serial passage of suspending cell sphere for 2 months from human colon cancer cell line SW620, we established the cell line.The suspending cell sphere from human hepatoma cell line Hep3B could serially passage for one month.Thus we used stem cell culture medium C1, C2 and C3 to culture human hepatoma cell line Hep3B and Huh7. We discovered that those cells were suspending, could grow into sphere. Although many cells would be died, those cells could form sphere again after passage. We detected the cancer stem cell maker gene highly expressing and established the cell lines.The experimental results indicate that we established three novel culture system for cancer stem-like cells and sorted and cultured the cancer stem-like cells from cancer cell lines using stem cell culture medium. Both morphology and the level of maker gene expressing in those cells are similar to the records. We could establish cancer stem-like cell line successfully, settling the foundation for subsequent experiment.