Abstract

With nanofabricated microfluidic systems, we studied the migration behaviors of two cell lines in vitro. Cells were allowed to migrate through areas of 15 mm in height, containing a microfluidic channel of 15 mm (height) by 15 mm (width) and 45 mm to 1cm in length. We observed that cells left their monolayer origin as individual cells to enter the entrance of the channel. After migration through the channel, the daughter cells resulting from the first division migrated away from each other to form two colonies. When each of the two colonies expanded into 32-cell colonies, the colonies disassociated into multiple small colonies. Our results indicate that cells can actively break off from the monolayer, and the dissociation of cells from each other is highly regulated. Future gene expression profiling study on cells prior and post disassociation should reveal genes that regulate the disassociation of cells from the monolayer. These genes are potential candidate genes which regulate cancer cells to leave the original tumor and become the metastasis. We demonstrated here that a microfluidic system can be a powerful means to study cell disassociation, which is a first step of cancer metastasis. Our system can be easily converted to an inexpensive high throughput device to screen drugs for inhibiting metastasis in the pharmaceutical industry.

Keywords: polydimethylsiloxane (PDMS), Microfluidic systems, blood circulation, monolayer, nanofabrication