Study Of Three-dimensional(3D) Models On Tumor Cells Resistance And Radiosensitivity

ObjectiveConstruction of three-dimensional cell model, observed morphological changes, study drug resistance and radiosensitivity of tumor cells between three-dimensional culture techniques and classical monolayer culturing techniques as well as its application prospects.Method:1.Construction three-dimensional cell model in vitro of human U87 glioma cells,human HDF fibroblasts and cells co-cultured with the same concentration, fluorescence microscope is used to observe and record the morphological changes.2.Were given different doses of radiation and different concentrations of drugs to deal with two cultured cells,fluorescence microscope used to observe the 3D and 2D cell morphological changes and migration proliferation,and then do MTT expriment to measure cell viability.Results:1.In 2D culture, for HDF, they spread on culture surface and display a flat morphology.But for U87, they tend to aggregate together to form the “foci”. Compared with its mono-culture, U87 follows a different growth pattern which is very close to that of HDF.2.In 2D culture, with increasing concentration of the drug, cell lost its normal morphology and detach from the culture plate. In 3D culture, even in 60 u M group, we cannot find any significant reduction in cell numbers. Surprisingly, after the exactly same treatment used in 2D culture, some cells still maintain a complex 3D structure. MTT Assay showed cells in 3D culture display lower sensitivity to silver nitrate than the cells in 2D culture. If the concentration of silver nitrate is larger than 40 u M, almost all of the cells diedin 2D. However, under the exactly same conditions, most cells still survived in 3D culture.3.Cultured for 6 days, microscopic morphology was observed: cells in monolayer culture in 2Gy group almost keep the normal cell morphology, but some cell number decrease. In 4Gy group, U87 displays cell shrinkage and some part of cells die. And for mono- and co-culture U87 cells, in 12 Gy group, apparently a large number of cells die.Cells in 3D culture in 2Gy, 4Gy and 12 Gy group and the control group had no significant difference form,but in 12 Gy group cell proliferation decreased. MTT results showed that in addition to HDF cells 2GY group(P = 0.05) the rest of the group 3D survival was significantly higher than 2D(P<0.05). Further extension of time in cell culture showed U87 in the control group,2Gy, 4Gy, 8Gy groups could form a three-dimensional structure, with increasing doses of the cells to migrate to the end of the glass tube need more time, a small fraction of cells in the group 12 Gy half the distance that can be migrated. In 2D cell culture with time showed no change, 4Gy group significantly decreased proliferation,in 12 Gy group, apparently a large number of cells die.Conclusion:The results, obtained in both 2D and 3D model systems, 3D cell culture have drug resistance and radiation insensitivity, more obvious differences in tumor cells. Show three-dimensional structure of tumor cell cultures closer to human tissue, with better growth and metastasis, closer to the possible mechanism of human solid tumor recurrence and metastasis. To radiosensitizer and chemotherapy drug resistance studies provide new ideas. In vitro 3D models used in cancer research, particularly their contribution to molecular studies of the early stages of metastasis, angiogenesis, the tumor microenvironment,and cancer stem cells,they will apply to mechanistic modeling of cancer stages or processes.