Interactions between cancer cells and stromal cells
We used microfluidic cell culture devices to investigate the communications via membrane tunneling nanotubes (TNTs) between cancer cells and myofibroblasts.
The whole device was made of PDMS by using standard soft-lithography microfabrication. More details can be found in Biomicrofluidics 8, 024107 (2014).
We can see mitochondria transferred through the TNT.
Controlling cell movements with blue light
We used a quartic intensity gradient of blue light (wavelength 473 nm) to induce directional migration of a lung cancer cell.
This optically induced directional migration can be suppressed by a scavenger of reactive oxygen species (ROS), Trolox.
Therefore this optically induced directional migration is related to the intracellular production of ROS. More details can be found in Biomedical Optics Express 6, 2624 (2015). We suggest using blue light to confine the migration of cancer cells in endoscopic surgery.
Cell membrane roughness and external stimulations
We used non-interferometric wide-field optical profilometry (NIWOP) to measure the membrane roughness on live neuroblastoma cell N2a.
We found that amyloid-beta 42 (a peptide related to Alzheimer’s disease) reduces the membrane roughness of N2a cells, and the effect of the oligomer conformation is stronger than that of the fibril conformation. Interestingly, this effect could be balanced by a direct-current electric field. More details can be found in Journal of Biomedical Optics 19, 011009 (2014).
Recently we are using other treatments, such as Taxol (an anti-cancer drug with neuron toxicity), to test the effects on membrane roughness.
SPIM observation on cellular spheroids
In order to reduce the phototoxicity of the illumination light during 3D observation on cellular spheroids, we employed selective plane illumination microscopy (SPIM) to observe the coculture of HepG2 (red) and HUVEC (green) cells in a microfluidic device.
With the treatment of VEGF and FGF, we could see the formation of circular-cross sectional lumen structure of some HUVECs in the cellular spheroids. For more details, please see Biomicrofluidics 8, 052109 (2014).
Currently we are using this system to study the interaction between cancer-associated fibroblasts (CAFs) and cancer cells under various treatments.