Controlled cocultures of HeLa cells and human umbilical vein endothelial cells on detachable substrates

Abstract

We investigated the interactions between HeLa cells and human umbilical vein endothelial cells (HUVECs) by monitoring their movements in a controllable coculture system. Two complementary, detachable, cell-substrates, one of polystyrene (PS) and the other of poly(dimethylsiloxane) (PDMS), were fabricated by replica molding. Coculturing was started by mechanically assembling two complementary substrates. One substrate was covered with a confluent layer of HeLa cells and its complement covered with confluent HUVECs. Using this coculture system as a tumor/endothelium model, we found that the HeLa cells migrated towards the HUVECs, while, simultaneously, the HUVECs retreated and that both types of cells migrated approximately twice as rapidly (two hundred microns per twenty-four hours) as they did alone. Additionally, when direct contact between the two cell types was prevented, the HUVECs initially migrated towards the HeLa cells and then retreated. The characteristics of the cell movements, i.e. direction and speed, probably are consequences of cell-cell signaling, with such signals possibly important during tumor cell intra- and extravasation.

Characterization of the interaction between fibroblasts and tumor cells on a microfluidic co‐culture device

“…Therefore, it is of great importance to investigate the heterotypic cell interactions between tumor cells and fibroblasts. At present, co-culture is often used to investigate the interactions between heterotypic cells by using Transwell assay [9,10], in which two types of cells are separated into upper and lower chambers by a semi-permeable membrane, or by bathing cells in conditioned medium [11][12][13][14]. However, these assays are limited by the tedious manual operations which require several procedures, and they are all typical end-point assays, which are difficult to realize real-time observation.…”

“…Recently, several work has been reported to perform co-culture on microfluidic platform, including capillary morphogenesis [14]; macrophage cells invasion [18], HeLa and HUVECs cells movements [13]. These work mainly focus on the investigation of single cellular process at a time which only provide limited information to characterize the biological events in cells.…”

A microfluidic co-culture system to monitor tumor-stromal interactions on a chip

“…These results suggested tumor-induced apoptosis of stromal cells, which could be caused by paracrine signaling of ROS released by tumor cells to control the homeostasis of local microenvironment. 34,47,51 On the other hand, the tumor cell migration appeared to be promoted in the co-culture (Figure 6(f)) compared to monoculture (Figure 6(d)). …”

“…45,46 It has also been reported that direct contact of tumor cells with endothelial cells results in generation of ROS that causes oxidation of cell membrane and DNA breakdown of endothelial cells. 34,47 ROS is a class of natural byproduct of normal metabolism of oxygen and generated during mitochondrial respiration, and they play important roles in cell signaling and homeostasis. Normally, ROS is quenched by intracellular anti-oxidants.…”

“…Prior reports have shown various designs, including valves, 30 laminar flow between immiscible liquids, 31,32 separate compartments for dynamic co-culture, 33 and detachable substrates, where the cells are individually cultured on different substrates. 34 Some researchers have also used scaffold materials such as collagen to create barriers between two cell types in a 3-dimensional co-culture system. 35 Many microfluidic co-culture systems are targeted to specific applications, such as macrophage-osteoblast interaction 36 or bacterial cancer targeting.…”