Ovarian cancer is an unmet medical need and particularly lethal because it is often detected only when disease is quite advanced. In 2017, approximately 22,440 women will be diagnosed with ovarian cancer in the United States, and approximately 14,080 deaths will occur. Combination platinum and anti-mitotic taxane based chemotherapy is the standard of care in the U.S., but while these treatment options are often initially efficacious, relapse and progression usually occur. There is a need for novel therapeutic approaches to treat ovarian cancer.
Based on the recent successes of harnessing the immune system to treat other cancers, drug discovery scientists have explored immunotherapy approaches in ovarian cancer. There are currently upwards of 50 clinical trials testing immunotherapy approaches and combinations in ovarian cancer; however, there are a limited number of syngeneic mouse ovarian cancer models available to enable preclinical pharmacology. Labcorp has developed the ID8 syngeneic mouse cell line model for testing standard therapeutics as well as for immuno-oncology applications. ID8 was derived from C57BL/6 mouse ovarian surface epithelial cells that were transformed by serial passage in vitro.1 Luciferase was expressed in the ID8 cells (ID8-Luc-mCherry-Puro) to enable monitoring of orthotopic (intraperitoneal) tumor growth by bioluminescence imaging (BLI).
The mean tumor growth kinetics (Figure 1A) and individual growth kinetics (Figure 1B) of ID8-Luc-mCh-Puro as monitored by BLI are illustrated. The implantation of 1.0×107 cells per mouse yielded more consistent tumor growth than 5.0×106 cells per mouse in C57BL/6 albino mice. As expected, the signal (photons/sec) is higher in the C57BL/6 albino mice (green line, Figure 1B, group 2) than wild type C57BL/6 mice (red line, Figure 1B) due to a lack of melanin pigment in their skin which absorbs light output from the tumor cells. Representative BLI images of ID8-Luc-mCh-Puro orthotopic disease progression are shown in Figure 1C.