A Novel Invasion Model Based On A Microfludic Device In3D Matrix

The movement of cancer cells into tissue surrounding the tumour and thevasculature is the first step in the spread of metastatic cancers, the stimulation process oftumor cell invasion rely on a better understanding of cell migration mechanisms withthe three dimensional culture,and should the useful for screening anti-cancertherapeutics. Multicelluar tumor spheroid can monitor the efficacy of anti-cancer drug，and testify the ability of the cancer cell invasion with the dimension culture. Traditionalmethods such as boyden chamber， spinner flask culture and the transwell chambermodel could not mimic the extracellular matrix for cancer cell invasion and also couldnot monitor the live process of cancer cell invasion,and spinner flask culture for MTScneed a rather strong shear force. With development of microfluidic technologies, we cancreate a microfluidic platform in vitro. In contrast to the traditional methods, thisplatform could be better to simulate extracellular matrix for cancer cell migration, totrack the process of cancer cell migration and to observe the tumor cell-extracellularmatrix interaction.Objective：For obtaining more authentic consequences of cancer cell invasion andthe process of MTSc with the three dimensional culture，we created a novel model invitro. In contrast to the traditional methods, this model could be better to simulateextracellular matrix for cancer cell invasion, to track the process of cancer cell invasionand MTCs，to observe the tumor cell-extracellular matrix interaction.Method：To evaluate the potential of this microfluidic device for the mechanism ofcancer cell invasion and MTCs，FITC-Dextran was used to visualize the gradient ofbiochemical factors to demonstrate of concentration gradient across the gel channel. theviability of HUVECs was assessed by labeling live and necrotic cells with2μM CalceinAM and10μg/mL propidium iodie respectively and viewed immediately by an invertedfluorescence microscope to testify Cell viability in the3D matrix，we mimickedextracellular matrix of MDA-MB-231cell and monitored the process of MDA-MB-231cell invasion with stable concentration gradient of tumor necrosis factor-α (TNF-α) in3D extracellular matrix，and to track the process of MCTSs formed by TNF-α or serumand to observe the tumor cell-extracellular matrix interaction.Result：The fluorescence intensity in the gel channel slowly increased and shaped agradient across the gel with time，and the gradient of biochemical factors was maintained for about10h. MDA-MB-23l exhibited high viability (up to95%) aftercultured in the device for72h, which suggested this microfluidic device was suitablefor cell culture. cancer cells responded to TNF-α stimulation with forming cellularprotrusions and migrating towards high TNF-α concentration. It was found that thatMDA-MB-231cells connected each other like a line in3D extracellular matrix.MDA-MB-231were so easy to aggregate and form MCSs in3D extracellularmatrix,there was a blending tendency with MCSs. TNF-α afects the aggregationproperties of MDA-MB-231cells into MCTSs,and the MCSs was smaller than100μL indiameter.Conclusion: The results suggest this microfluidic device can provide a suitableplatform for elucidating the mechanism of cancer invasion and screening anti-cancerdrugs for cancer therapy.