Modeling Ovarian Cancer Cell Colonization of Omentum: An Ex Vivo Method to Establish Milky Spot Colonization of Fluorescently Labeled Ovarian Cancer Cells in Murine Omentum Explants

The omentum, an adipose-rich tissue within the peritoneal cavity, consists of fat depots that provide a suitable microenvironment for metastatic cancer cells to colonize and form secondary tumors. To study this colonization ex vivo, begin by positioning a permeable membranous cell culture insert inside a culture plate.

Apply a tissue adhesive over the inner region of the insert membrane. Place a mouse omental explant on the adhesive to immobilize the tissue. Gently seed a suspension of fluorescently-labeled ovarian cancer cells on top of the omentum.

Next, fill the sides of the well with a suitable medium to supplement cell growth and incubate for the desired time. The omental tissue contains specialized structures called milky spots, which are clusters of immune cells packed around networks of blood vessels. These immune cells secrete certain chemical factors that attract cancer cells and promote their implantation. The colonized cancer cells proliferate, simulating metastatic conditions.

Finally, discard the spent media. Observe the culture using a fluorescent microscope to assess fluorescent cancer cell colonies within the omental tissue.