A Study On Bioactive Hydrogel Used In The Selection And Treatment Of Cancer Stem Cells

Cancer is one of the major diseases which threatens human health, but traditionaltreatment methods fail to completely eradicate cancer. Because of the complexity of thepathogenesis of cancer, it has not been known clearly. Proposing the theory of cancerstem cells for tumor occurrence and development of recurrence provides a new researchidea, also brings a new dawn for the treatment of cancer. However, cancer stem cells areextremely rare in tumors, thus it is very difficult to isolate cancer stem cells. At present,commonly used methods for the isolation of cancer stem cell are serum-free culture andflow sorting. It is urgent to establish a new effective separation method because both ofmethods have certain shortcomings.Cancer stem cells and normal stem cells have many similar signaling pathways, sowe can mimic stem cells microenvironment to select lower differentiation tumor stemcells. Hydrogel is widely used in three-dimensional cell culture due to its uniqueproperties. We used hydrogels to simulate the stem cell microenvironment in order toseclect and enrich cancer stem cells. We explored the screening efficiency ofimmobilized cytokine, elastic modulus and hyaluronan concentration. Optimal systemwas thus sucessfully established by evaluating the colony numbers and dimaters.We further used molecular biology techniques and mouse model for determiningwhether the colony was cancer stem cells. We exploited immunofluorescence toexamine the expression of cancer stem cell markers CD24, CD44and MDR1. Resultsshowed that CD44and multi-drug resistance protein1are up-regulated. We usedquantitative real-time PCR to detect the expression of stem cell markers CD44, Sca-1,Nestin, Tert, Nanog and Sox2. The results revealed that the expression of4T1cancerstem cells biomarkers CD44and Sca-1are up-regulated as well as stem cellsbiomarkers Nestin, Tert, Nanog and Sox2are up-regulated. Moreover, rencent studydemonstrated that Dclk1as a unique cancer stem cell biomarker can be effectively usedfor distinguishing stem cell and cancer stem cell. Our immunofluorescence resultsshowed that the expression of Dclk1are up-regulated, and it indicated that Dclk1waspromising to be a biomarker of breast cancer cell line4T1. In the mouse model,2000cancer stem cells can quickly form a tumor subcutaneously in homologous Balb/c mice.Even1000cells can also form a tumor effectivly. The results demonstrated that thebioactive hydrogel we build can effectively select and enrich cancer stem cells.Our previous study demonstrated that anti-Cripto-1blocking antibody can be usedin the treatment of cancer in vivo and in vitro. We speculated that anti-Cripto-1blockingantibody can also reverse cancer stem cell. Therefore, we studied anti-Cripto-1blockingantibody used for the treatment of cancer stem cells. The results showed that the anti-Cripto-1monoclonal antibody can effectively reduce the survival of cancer stemcells, and decreased tumorigenicity, thence the anti-Cripto-1monoclonal antibody is apromising drug for the theatment of cancer stem cells.