Gastric cancer multicellular spheroid analysis by two-photon microscopy.

Gastric cancer (GC) is highly deadly. Three-dimensional (3D) cancer cell cultures, known as spheroids, better mimic tumor microenvironment (TME) than standard 2D cultures. Cancer-associated fibroblasts (CAF), a major cellular component of TME, promote or restrain cancer cell proliferation, invasion and resistance to drugs. We established spheroids from two human GC cell lines mixed with human primary CAF. Spheroid organization, analyzed by two-photon microscopy, showed CAF in AGS/CAF spheroids clustered in the center, but dispersed throughout in HGT-1/CAF spheroids. Such differences may reflect clonal specificities of GC cell lines and point to the fact that GC should be considered as a highly personalized disease.