Data on in vivo selection of SK-OV-3 Luc ovarian cancer cells and intraperitoneal tumor formation with low inoculation numbers

This data paper contains information about the in vivo model for peritoneal implants used in the paper “Tumor-environment biomimetics delay peritoneal metastasis formation by deceiving and redirecting disseminated cancer cells” (De Vlieghere et al., 2015) [1]. A double in vivo selection of SK-OV-3 Luc human ovarian cancer cell line was used to create SK-OV-3 Luc IP1 and SK-OV-3 Luc IP2 cell lines. This data paper shows functional activities of the three cell lines in vitro and in vivo. Phase-contrast images show the morphology of these cells, metabolic and luciferase activity has been determined. Survival data of mice peritoneally injected with SK-OV-3 Luc or SK-OV-3 Luc IP2 is available with H&E histology of the peritoneal implants. Tumor growth curves and bioluminescent images of mice inoculated with a different number of SK-OV-3 Luc IP2 cells are also included.


a b s t r a c t
This data paper contains information about the in vivo model for peritoneal implants used in the paper "Tumor-environment biomimetics delay peritoneal metastasis formation by deceiving and redirecting disseminated cancer cells" (De Vlieghere et al., 2015) [1]. A double in vivo selection of SK-OV-3 Luc human ovarian cancer cell line was used to create SK-OV-3 Luc IP1 and SK-OV-3 Luc IP2 cell lines. This data paper shows functional activities of the three cell lines in vitro and in vivo. Phase-contrast images show the morphology of these cells, metabolic and luciferase activity has been determined. Survival data of mice peritoneally injected with SK-OV-3 Luc or SK-OV-3 Luc IP2 is available with H&E histology of the peritoneal implants. Tumor growth curves and bioluminescent images of mice inoculated with a different number of SK-OV- 3

Data accessibility
The data is available with this article

Value of the data
This data shows intraperitoneal tumor formation with low cell inoculation after in vivo selection of This method can be applied to other cancer cell lines to increase metastasis take rate even with lower inoculation numbers.
These data provides growth curves, survival data and histology about the SK-OV-3 Luc (IP2) in vivo model for peritoneal implants, providing researchers with a references for their in vivo studies.

Data
Intraperitoneal injection (IP) of SK-OV-3 (Luc) cells is an established in vivo model for the development of peritoneal ovarian tumor implants. Usually inoculation numbers of 1-2 Â 10 6 SK-OV-3 (Luc) are used [2][3][4]. The IP injection of 1 Â 10 6 SK-OV-3 Luc cells gives a 100% tumor take with an average survival time of over 2 months (Fig. 3B) [3]. To better mimic the patient situation where an initial low number of aggressive disseminated cells can form extensive peritoneal metastasis a xenograft mouse model with inoculation of low numbers of cancer cells is needed. in vivo selection has been successfully used to increase the metastatic potential of MDA-MB-231 [5]. These data describe the successive in vivo selection of the SK-OV-3 Luc cell line. Tumor implants of SK-OV-3 Luc bearing mice are re-cultured in vitro to increase in vivo peritoneal implant formation. After successive in vivo selection, IP inoculation of 10-to-20X lower number (1 Â 10 5 ) of SK-OV-3 Luc IP2 is sufficient to form peritoneal implants this model has been applied successfully [1]. (DMEM) supplemented with 10% fetal bovine serum (FBS) and antibiotics (penicillin/streptomycin), and incubated at 37°C with 10% CO 2 in air.

in vivo selection
Animal experiments were conducted accordance with the local ethics committee (Ghent University Hospital). 1 Â 10 6 SK-OV-3-Luc cells were inoculated intraperitoneally in immunodeficient female Swiss/nu mice (Charles River, Chatillon-sur-Chalaronne, France) to isolate populations that form peritoneal implants. Tumor implants were collected in saline. The implants were cut into small pieces (1 mm) and dissociated by de gentleMACS Dissociator (Miltenyi Biotec, Teterow, Germany) in the presences of 1 mg/ml collagenase from Clostridium histolyticum (Sigma-Aldrich) in PBSD þ . The mixture was cleared through a cell strainer (70 mm) and the homogenized single cell suspension was expanded in culture by seeding in DMEM 10% FBS. After 24 h, non-adhered cells were removed and the medium was refreshed; the resulting culture was maintained as the parental cell line. Each subsequent intraperitoneal metastatic generation is designated IP1, IP2. Fig. 1 shows a schematic with the different stages of the in vivo selection. Fig. 2A shows phase-contrast images of the three cell lines cultured on plastic

in vitro bioluminescence
A single cell suspension of SK-OV-3 Luc, SK-OV-3 Luc IP1 and SK-OV-3-Luc-IP2 cells were seeded in a 96-well plate in different cell numbers (125, 250, 500, 1000 and 2000 cells per well). Cells were allowed to adhere for 2 h, just before luciferase activity was measured with IVIS (PerkinElmer), 150 mg/ml D-Luciferin, firefly (Perkin-Elmer) was added. Fig. 2C shows the average bioluminescence value of three replicates.

in vivo survival analysis
Animal experiments were conducted in accordance with the local ethics committee (Ghent University Hospital). Immune deficient female Swiss/nu mice were inoculated intraperitoneally with 1 Â 10 6 SK-OV-3-Luc or SK-OV-3-Luc-IP2 cells. Mice were monitored and from the first visual signs of advanced carcinomatosis (decrease in weight or increase in abdominal circumference) the mice had reached their end-point and were sacrificed. Peritoneal organs were embedded in paraffin before standard hematoxylin and eosin (H&E) staining was conducted.